car still overheating

[james]

Well ive still had no luck with this darm car. Ive just spent alot of
money on a new radiator and its still overheating badly. I also had it
tested for combustion gasses in the coolant and it was given the all
clear, although it was done differently than using those bottles with
the fluid in it that detetcs the gasses. he used one of those big
machines with probes that are supposed to detect any gasses, lots of
different types by the looks of it. Would that still be as accurate
as the old fluid tests?
So ive got a new radiator, thermostat, radiator cap. And new head
gaskets as i thought id change them incase i had stuffed them up.
heads were flat, i couldnt get them crack tested or anything because i
dont have a car to take them anywhere so i put them back on.
Ive also checked the fuel mix, and played around with the timing
incase that was casing it. Ive tried 2 different engine fans, old
mechanical type and my newer clutch fan, no diference. Fan shroud is
on. Im running out of ideas now.

To describe exactly what its doing now, at idle the temp will rise,
it gets to 90 and drops a bit and goes back up and cycles, but often
it will hit 90 and then like a rocket will shoot up to 100 or a tad
over and go back down. occasically it wont stop at 100 though and
thats when i panick. if i dont turn the car off it often just blows
out of the overflow. That all happens at idle and aslo at cruising,
around 1500rpm is the worse. If i floor the car the temp will raise
up high to about 90 but then the moment i stop accelerating hard the
temp will just take off.

Lookint at the coolant with the cap off and idling what i see is the
coolant level will drop a bit, and then errupt and just keeps doing
that while the thermostat is open. When closed its still, but as soon
as it opens its rasies and falls shooting around 1litre of coolant all
over the engine bay. Ive tried bleeding the systems amny times,
water pump is new. So is this looking like a head problem that just
wasnt found when it was tested for combustion gasses?

Another idea ive been given is oil problems, can a problem with the
oil system be causing the symptons ive describes? The oil is actually
doing weird things. The pressure is alot lower than it always used to
be, and the weird bit is that the pressure tends to go down with revs
rather than going up higher like it always used to. Its a tad below
specs at 2000rpm now. So im about to go check the pickup screen and
oil pump which is a pain of a job, but could this be a possible cause
for overheating? If not then i may pull the heads off while i pulling
things apart so i can get the checked properly.

Sorry for writing so much! any help greatly appreciated.

[atec]

james wrote:
> Well ive still had no luck with this darm car. Ive just spent alot of
> money on a new radiator and its still overheating badly. I also had it
> tested for combustion gasses in the coolant and it was given the all
> clear, although it was done differently than using those bottles with
> the fluid in it that detetcs the gasses. he used one of those big
> machines with probes that are supposed to detect any gasses, lots of
> different types by the looks of it. Would that still be as accurate
> as the old fluid tests?
> So ive got a new radiator, thermostat, radiator cap. And new head
> gaskets as i thought id change them incase i had stuffed them up.
> heads were flat, i couldnt get them crack tested or anything because i
> dont have a car to take them anywhere so i put them back on.
> Ive also checked the fuel mix, and played around with the timing
> incase that was casing it. Ive tried 2 different engine fans, old
> mechanical type and my newer clutch fan, no diference. Fan shroud is
> on. Im running out of ideas now.
>
> To describe exactly what its doing now, at idle the temp will rise,
> it gets to 90 and drops a bit and goes back up and cycles, but often
> it will hit 90 and then like a rocket will shoot up to 100 or a tad
> over and go back down. occasically it wont stop at 100 though and
> thats when i panick. if i dont turn the car off it often just blows
> out of the overflow. That all happens at idle and aslo at cruising,
> around 1500rpm is the worse. If i floor the car the temp will raise
> up high to about 90 but then the moment i stop accelerating hard the
> temp will just take off.
>
> Lookint at the coolant with the cap off and idling what i see is the
> coolant level will drop a bit, and then errupt and just keeps doing
> that while the thermostat is open. When closed its still, but as soon
> as it opens its rasies and falls shooting around 1litre of coolant all
> over the engine bay. Ive tried bleeding the systems amny times,
> water pump is new. So is this looking like a head problem that just
> wasnt found when it was tested for combustion gasses?
>
> Another idea ive been given is oil problems, can a problem with the
> oil system be causing the symptons ive describes? The oil is actually
> doing weird things. The pressure is alot lower than it always used to
> be, and the weird bit is that the pressure tends to go down with revs
> rather than going up higher like it always used to. Its a tad below
> specs at 2000rpm now. So im about to go check the pickup screen and
> oil pump which is a pain of a job, but could this be a possible cause
> for overheating? If not then i may pull the heads off while i pulling
> things apart so i can get the checked properly.
>
> Sorry for writing so much! any help greatly appreciated.
are you sure the water pump is good ?
sounds rather odd.

[james]

On Thu, 07 Apr 2005 20:23:42 +1000, atec <atec77@XXXhotmail.com>
wrote:

>james wrote:
>> Well ive still had no luck with this darm car. Ive just spent alot of
>> money on a new radiator and its still overheating badly. I also had it
>> tested for combustion gasses in the coolant and it was given the all
>> clear, although it was done differently than using those bottles with
>> the fluid in it that detetcs the gasses. he used one of those big
>> machines with probes that are supposed to detect any gasses, lots of
>> different types by the looks of it. Would that still be as accurate
>> as the old fluid tests?
>> So ive got a new radiator, thermostat, radiator cap. And new head
>> gaskets as i thought id change them incase i had stuffed them up.
>> heads were flat, i couldnt get them crack tested or anything because i
>> dont have a car to take them anywhere so i put them back on.
>> Ive also checked the fuel mix, and played around with the timing
>> incase that was casing it. Ive tried 2 different engine fans, old
>> mechanical type and my newer clutch fan, no diference. Fan shroud is
>> on. Im running out of ideas now.
>>
>> To describe exactly what its doing now, at idle the temp will rise,
>> it gets to 90 and drops a bit and goes back up and cycles, but often
>> it will hit 90 and then like a rocket will shoot up to 100 or a tad
>> over and go back down. occasically it wont stop at 100 though and
>> thats when i panick. if i dont turn the car off it often just blows
>> out of the overflow. That all happens at idle and aslo at cruising,
>> around 1500rpm is the worse. If i floor the car the temp will raise
>> up high to about 90 but then the moment i stop accelerating hard the
>> temp will just take off.
>>
>> Lookint at the coolant with the cap off and idling what i see is the
>> coolant level will drop a bit, and then errupt and just keeps doing
>> that while the thermostat is open. When closed its still, but as soon
>> as it opens its rasies and falls shooting around 1litre of coolant all
>> over the engine bay. Ive tried bleeding the systems amny times,
>> water pump is new. So is this looking like a head problem that just
>> wasnt found when it was tested for combustion gasses?
>>
>> Another idea ive been given is oil problems, can a problem with the
>> oil system be causing the symptons ive describes? The oil is actually
>> doing weird things. The pressure is alot lower than it always used to
>> be, and the weird bit is that the pressure tends to go down with revs
>> rather than going up higher like it always used to. Its a tad below
>> specs at 2000rpm now. So im about to go check the pickup screen and
>> oil pump which is a pain of a job, but could this be a possible cause
>> for overheating? If not then i may pull the heads off while i pulling
>> things apart so i can get the checked properly.
>>
>> Sorry for writing so much! any help greatly appreciated.
>are you sure the water pump is good ?
> sounds rather odd.

Well its only around 3 months old. Theres no leakage at all and no
play in the bearing. Thats the only way i know for checking its
condition though, visually it all looked fine before i put it back on.

[Clockmeister]

"james" <kaufman_j@hotmail.com> wrote in message
news:ip2a51d77obfukejae699tldrqeh64m1n5@4ax.com...
> On Thu, 07 Apr 2005 20:23:42 +1000, atec <atec77@XXXhotmail.com>
> wrote:
>
> >james wrote:
> >> Well ive still had no luck with this darm car. Ive just spent alot of
> >> money on a new radiator and its still overheating badly. I also had it
> >> tested for combustion gasses in the coolant and it was given the all
> >> clear, although it was done differently than using those bottles with
> >> the fluid in it that detetcs the gasses. he used one of those big
> >> machines with probes that are supposed to detect any gasses, lots of
> >> different types by the looks of it. Would that still be as accurate
> >> as the old fluid tests?
> >> So ive got a new radiator, thermostat, radiator cap. And new head
> >> gaskets as i thought id change them incase i had stuffed them up.
> >> heads were flat, i couldnt get them crack tested or anything because i
> >> dont have a car to take them anywhere so i put them back on.
> >> Ive also checked the fuel mix, and played around with the timing
> >> incase that was casing it. Ive tried 2 different engine fans, old
> >> mechanical type and my newer clutch fan, no diference. Fan shroud is
> >> on. Im running out of ideas now.
> >>
> >> To describe exactly what its doing now, at idle the temp will rise,
> >> it gets to 90 and drops a bit and goes back up and cycles, but often
> >> it will hit 90 and then like a rocket will shoot up to 100 or a tad
> >> over and go back down. occasically it wont stop at 100 though and
> >> thats when i panick. if i dont turn the car off it often just blows
> >> out of the overflow. That all happens at idle and aslo at cruising,
> >> around 1500rpm is the worse. If i floor the car the temp will raise
> >> up high to about 90 but then the moment i stop accelerating hard the
> >> temp will just take off.
> >>
> >> Lookint at the coolant with the cap off and idling what i see is the
> >> coolant level will drop a bit, and then errupt and just keeps doing
> >> that while the thermostat is open. When closed its still, but as soon
> >> as it opens its rasies and falls shooting around 1litre of coolant all
> >> over the engine bay. Ive tried bleeding the systems amny times,
> >> water pump is new. So is this looking like a head problem that just
> >> wasnt found when it was tested for combustion gasses?
> >>
> >> Another idea ive been given is oil problems, can a problem with the
> >> oil system be causing the symptons ive describes? The oil is actually
> >> doing weird things. The pressure is alot lower than it always used to
> >> be, and the weird bit is that the pressure tends to go down with revs
> >> rather than going up higher like it always used to. Its a tad below
> >> specs at 2000rpm now. So im about to go check the pickup screen and
> >> oil pump which is a pain of a job, but could this be a possible cause
> >> for overheating? If not then i may pull the heads off while i pulling
> >> things apart so i can get the checked properly.
> >>
> >> Sorry for writing so much! any help greatly appreciated.
> >are you sure the water pump is good ?
> > sounds rather odd.
>
> Well its only around 3 months old. Theres no leakage at all and no
> play in the bearing. Thats the only way i know for checking its
> condition though, visually it all looked fine before i put it back on.

And the thermostat?

Try this...

Get engine up to operating temp and get a mate to rev the engine (make sure
the rad cap is on and system has built up a bit of pressure by squeezing the
top hose). Check to see if the top and bottom radiator hoses are collapsing
and flattening out due to the suction when you rev the engine. If so,
replace the hose.

Otherwise remove the thermostat and see if the engine runs cold like it
should.

Regards,

Clockmeister.

[John_H]

james wrote:
>
>water pump is new.

Is it circulating coolant?... You'll probably need to run it without
the thermostat to tell for sure.

It's in the realm of a long shot, but I once spent an inordinate
amount of time tracking down an overheating problem (in a different
make of engine) which turned out to be caused by excessive clearance
between the water pump body and impeller. Pressing the impeller
further onto the shaft cured the problem.

In that instance the correct clearance was given in the manual which
may not be the case for yours.

--
John H

[Gonz]

Are you sure the head gasket was the right one and all the holes lined up
ok?

Used to happen with early holden reds.

[james]

On Thu, 07 Apr 2005 21:04:47 +1000, John_H <john4271@hotmail.com>
wrote:

>james wrote:
>>
>>water pump is new.
>
>Is it circulating coolant?... You'll probably need to run it without
>the thermostat to tell for sure.
>
>It's in the realm of a long shot, but I once spent an inordinate
>amount of time tracking down an overheating problem (in a different
>make of engine) which turned out to be caused by excessive clearance
>between the water pump body and impeller. Pressing the impeller
>further onto the shaft cured the problem.
>
>In that instance the correct clearance was given in the manual which
>may not be the case for yours.

Will check that out, thanks. A question regarding this, im wondering
if the clearance between the water pump and the timing cover where it
attatches is important? Looking at the the gasket in there looks alot
thicker than the old one.

[james]

On Thu, 7 Apr 2005 21:12:17 +1000, "Gonz" <abuse@abuse.com> wrote:

>Are you sure the head gasket was the right one and all the holes lined up
>ok?
>
>Used to happen with early holden reds.
>

Sorry forgot to mention i have a holden 308 motor, and when i changed
the head gaskets again i made tripple sure every gasket was on right.

[Chris]

mate 90 to 100 isnt overheating the thermos in a commodore dont even come on
till 104 degrees. the reason for raditor caps is to pressurize the cooling
system so it can go hotter than 100 degrees with out boiling. it will boil
with out cap on ealier. also what car is it. you could put a pressure test
it and run the car and see wht pressure it gets up to at temp
"james" <kaufman_j@hotmail.com> wrote in message
news:sjv951tslsughhqmp2puep059nsqtpd2sn@4ax.com...
> Well ive still had no luck with this darm car. Ive just spent alot of
> money on a new radiator and its still overheating badly. I also had it
> tested for combustion gasses in the coolant and it was given the all
> clear, although it was done differently than using those bottles with
> the fluid in it that detetcs the gasses. he used one of those big
> machines with probes that are supposed to detect any gasses, lots of
> different types by the looks of it. Would that still be as accurate
> as the old fluid tests?
> So ive got a new radiator, thermostat, radiator cap. And new head
> gaskets as i thought id change them incase i had stuffed them up.
> heads were flat, i couldnt get them crack tested or anything because i
> dont have a car to take them anywhere so i put them back on.
> Ive also checked the fuel mix, and played around with the timing
> incase that was casing it. Ive tried 2 different engine fans, old
> mechanical type and my newer clutch fan, no diference. Fan shroud is
> on. Im running out of ideas now.
>
> To describe exactly what its doing now, at idle the temp will rise,
> it gets to 90 and drops a bit and goes back up and cycles, but often
> it will hit 90 and then like a rocket will shoot up to 100 or a tad
> over and go back down. occasically it wont stop at 100 though and
> thats when i panick. if i dont turn the car off it often just blows
> out of the overflow. That all happens at idle and aslo at cruising,
> around 1500rpm is the worse. If i floor the car the temp will raise
> up high to about 90 but then the moment i stop accelerating hard the
> temp will just take off.
>
> Lookint at the coolant with the cap off and idling what i see is the
> coolant level will drop a bit, and then errupt and just keeps doing
> that while the thermostat is open. When closed its still, but as soon
> as it opens its rasies and falls shooting around 1litre of coolant all
> over the engine bay. Ive tried bleeding the systems amny times,
> water pump is new. So is this looking like a head problem that just
> wasnt found when it was tested for combustion gasses?
>
> Another idea ive been given is oil problems, can a problem with the
> oil system be causing the symptons ive describes? The oil is actually
> doing weird things. The pressure is alot lower than it always used to
> be, and the weird bit is that the pressure tends to go down with revs
> rather than going up higher like it always used to. Its a tad below
> specs at 2000rpm now. So im about to go check the pickup screen and
> oil pump which is a pain of a job, but could this be a possible cause
> for overheating? If not then i may pull the heads off while i pulling
> things apart so i can get the checked properly.
>
> Sorry for writing so much! any help greatly appreciated.

[John_H]

james wrote:
>
>im wondering
>if the clearance between the water pump and the timing cover where it
>attatches is important? Looking at the the gasket in there looks alot
>thicker than the old one.

Clearance on the business side where the fins are isn't particularly
critical but the plain side can be. Typical clearance is around 25 -
30 thou.

--
John H

[james]

On Thu, 7 Apr 2005 22:01:18 +1000, "Chris" <ruggers@iprimus.com.au>
wrote:

>mate 90 to 100 isnt overheating the thermos in a commodore dont even come on
>till 104 degrees. the reason for raditor caps is to pressurize the cooling
>system so it can go hotter than 100 degrees with out boiling. it will boil
>with out cap on ealier. also what car is it. you could put a pressure test
>it and run the car and see wht pressure it gets up to at temp
>"james" <kaufman_j@hotmail.com> wrote in message
>news:sjv951tslsughhqmp2puep059nsqtpd2sn@4ax.com...
>
Thing is it always sat dead on around 80deg before i changed the heads
after getting them reconditioned. it wouldnt be so much of a problem
if all it did was go up to 100 and back down, but often it keeps
going, so far ive had a radiatotor hose blow off and another split
right open, other times its just empties out shitloads of coolant
through the overflow with an all mighty bang.

[D Walford]

james wrote:
>
> On Thu, 7 Apr 2005 21:12:17 +1000, "Gonz" <abuse@abuse.com> wrote:
>
> >Are you sure the head gasket was the right one and all the holes lined up
> >ok?
> >
> >Used to happen with early holden reds.
> >
>
> Sorry forgot to mention i have a holden 308 motor, and when i changed
> the head gaskets again i made tripple sure every gasket was on right.

Sounds like an air lock in the cooling system.
Does turning the heater on make any difference?
Are the heater hoses fitted correctly?
I owned a V8(307) HK and the heater tap failed, instead of buying a new
Holden part I "found" a heater tap from a tractor at work and adapted it
to fit. This caused severe engine overheating when the heater was turned
off.
Apparently the original heater tap didn't completely shut off the flow
because the heater was part of the by pass system to allow flow to the
back of the thermostat, by fitting a different tap I stopped the by pass
and the thermostat wouldn't open.
Same problem on a Camira if you fit the 2 heater hoses to the head the
wrong way, it stops by pass so you get severe overheating.



Daryl


Daryl

[Toby Ponsenby]

On Thu, 07 Apr 2005 12:36:16 GMT, james wrote:

> On Thu, 7 Apr 2005 22:01:18 +1000, "Chris" <ruggers@iprimus.com.au>
> wrote:
>
>>mate 90 to 100 isnt overheating the thermos in a commodore dont even come on
>>till 104 degrees. the reason for raditor caps is to pressurize the cooling
>>system so it can go hotter than 100 degrees with out boiling. it will boil
>>with out cap on ealier. also what car is it. you could put a pressure test
>>it and run the car and see wht pressure it gets up to at temp
>>"james" <kaufman_j@hotmail.com> wrote in message
>>news:sjv951tslsughhqmp2puep059nsqtpd2sn@4ax.com...
>>
> Thing is it always sat dead on around 80deg before i changed the heads
> after getting them reconditioned. it wouldnt be so much of a problem
> if all it did was go up to 100 and back down, but often it keeps
> going, so far ive had a radiatotor hose blow off and another split
> right open, other times its just empties out shitloads of coolant
> through the overflow with an all mighty bang.

Obvious question, is the thermostat in there back-arsewards?
--
Toby.
quidquid latine dictum
sit, altum viditur

[james]

On Thu, 7 Apr 2005 23:05:09 +1000, Toby Ponsenby <toby@privacy.net>
wrote:

>On Thu, 07 Apr 2005 12:36:16 GMT, james wrote:
>
>> On Thu, 7 Apr 2005 22:01:18 +1000, "Chris" <ruggers@iprimus.com.au>
>> wrote:
>>
>>>mate 90 to 100 isnt overheating the thermos in a commodore dont even come on
>>>till 104 degrees. the reason for raditor caps is to pressurize the cooling
>>>system so it can go hotter than 100 degrees with out boiling. it will boil
>>>with out cap on ealier. also what car is it. you could put a pressure test
>>>it and run the car and see wht pressure it gets up to at temp
>>>"james" <kaufman_j@hotmail.com> wrote in message
>>>news:sjv951tslsughhqmp2puep059nsqtpd2sn@4ax.com...
>>>
>> Thing is it always sat dead on around 80deg before i changed the heads
>> after getting them reconditioned. it wouldnt be so much of a problem
>> if all it did was go up to 100 and back down, but often it keeps
>> going, so far ive had a radiatotor hose blow off and another split
>> right open, other times its just empties out shitloads of coolant
>> through the overflow with an all mighty bang.
>
>Obvious question, is the thermostat in there back-arsewards?

Thermostat is in there correctly. Not even i could stuff that one up
:)

[Toby Ponsenby]

On Thu, 07 Apr 2005 13:13:16 GMT, james wrote:

> On Thu, 7 Apr 2005 23:05:09 +1000, Toby Ponsenby <toby@privacy.net>
> wrote:
>
>>On Thu, 07 Apr 2005 12:36:16 GMT, james wrote:
>>
>>> On Thu, 7 Apr 2005 22:01:18 +1000, "Chris" <ruggers@iprimus.com.au>
>>> wrote:
>>>
>>>>mate 90 to 100 isnt overheating the thermos in a commodore dont even come on
>>>>till 104 degrees. the reason for raditor caps is to pressurize the cooling
>>>>system so it can go hotter than 100 degrees with out boiling. it will boil
>>>>with out cap on ealier. also what car is it. you could put a pressure test
>>>>it and run the car and see wht pressure it gets up to at temp
>>>>"james" <kaufman_j@hotmail.com> wrote in message
>>>>news:sjv951tslsughhqmp2puep059nsqtpd2sn@4ax.com...
>>>>
>>> Thing is it always sat dead on around 80deg before i changed the heads
>>> after getting them reconditioned. it wouldnt be so much of a problem
>>> if all it did was go up to 100 and back down, but often it keeps
>>> going, so far ive had a radiatotor hose blow off and another split
>>> right open, other times its just empties out shitloads of coolant
>>> through the overflow with an all mighty bang.
>>
>>Obvious question, is the thermostat in there back-arsewards?
>
> Thermostat is in there correctly. Not even i could stuff that one up
> :)

Sorry - had to ask.
No manufacturer worthy of the name misses the opportunity to allow
those devices to fit either way round:-)
--
Toby.
quidquid latine dictum
sit, altum viditur

[james]

On Thu, 07 Apr 2005 22:33:41 +1000, John_H <john4271@hotmail.com>
wrote:

>james wrote:
>>
>>im wondering
>>if the clearance between the water pump and the timing cover where it
>>attatches is important? Looking at the the gasket in there looks alot
>>thicker than the old one.
>
>Clearance on the business side where the fins are isn't particularly
>critical but the plain side can be. Typical clearance is around 25 -
>30 thou.

If i could just pick your braing a bit more, a few things im wondering
about. Just wondering if these things could be causing heat problems.
Firstly would colder spark plugs cause more heat to go into the
cooling system? Just thinking of things i changed. I dont know how
they work, just thinking with a colder heat range it may work that
they just transfer more heat out into the heads.
Also with the valve seats. They looked like they were cut alot
narrower than before, although it may have just looked that way
because they are now a 3 angle cut rather than single but i do
remember thinking they were extremely narrow and checked against the
specs in my manual and they barely made the minimum requierment .889mm
intake. i forgot to measure the exhaust seats though but i dont
remember them being any wider and min spec on them is 1.28mm. Could
this be causing cooling system problems?

[Jason James]

"james" <kaufman_j@hotmail.com> wrote in message
news:ip2a51d77obfukejae699tldrqeh64m1n5@4ax.com...
> On Thu, 07 Apr 2005 20:23:42 +1000, atec <atec77@XXXhotmail.com>
> wrote:
>
> >james wrote:
> >> Well ive still had no luck with this darm car. Ive just spent alot of
> >> money on a new radiator and its still overheating badly. I also had it
> >> tested for combustion gasses in the coolant and it was given the all
> >> clear, although it was done differently than using those bottles with
> >> the fluid in it that detetcs the gasses. he used one of those big
> >> machines with probes that are supposed to detect any gasses, lots of
> >> different types by the looks of it. Would that still be as accurate
> >> as the old fluid tests?

Lets hope so,...but if it hasn't picked up a compression leak there are
other symptoms which vary in intensity consistant with how bad the leak is.

First there is the old test of noting any bubbles which maybe constantly
forming and popping out the radiator cap-hole. This test is done by ensuring
the system is full first. If the water keeps dropping away a lot (its normal
for the water to drop away slightly as the engine is revved and the coolant
is cooled thus losing some of its volume), it means that not only is gas
being pushed into the water-jacket, but water is being sucked into one or
more chambers, then it is shoved out the exhaust. If the leak is small, the
exhaust will vapourise the water before it gets to the outlet,...but lots of
steam is a bad sign or lots of condensed water *after* the exhaust has
heated up.

There are more obscure problems such as a split bore, a free-wheeling
impellor on the w/pump, a collapsing lower hose. Have the heads been
crack-tested?

Is there sufficient air flow thru the radiator. If you are using a viscous
cuopling,..it shouls start the fan roaring as the temp rises toward 100c.




> >> So ive got a new radiator, thermostat, radiator cap. And new head
> >> gaskets as i thought id change them incase i had stuffed them up.
> >> heads were flat, i couldnt get them crack tested or anything because i
> >> dont have a car to take them anywhere so i put them back on.
> >> Ive also checked the fuel mix, and played around with the timing
> >> incase that was casing it. Ive tried 2 different engine fans, old
> >> mechanical type and my newer clutch fan, no diference. Fan shroud is
> >> on. Im running out of ideas now.
> >>
> >> To describe exactly what its doing now, at idle the temp will rise,
> >> it gets to 90 and drops a bit and goes back up and cycles, but often
> >> it will hit 90 and then like a rocket will shoot up to 100 or a tad
> >> over and go back down. occasically it wont stop at 100 though and
> >> thats when i panick. if i dont turn the car off it often just blows
> >> out of the overflow. That all happens at idle and aslo at cruising,
> >> around 1500rpm is the worse. If i floor the car the temp will raise
> >> up high to about 90 but then the moment i stop accelerating hard the
> >> temp will just take off.
> >>
> >> Lookint at the coolant with the cap off and idling what i see is the
> >> coolant level will drop a bit, and then errupt and just keeps doing
> >> that while the thermostat is open. When closed its still, but as soon
> >> as it opens its rasies and falls shooting around 1litre of coolant all
> >> over the engine bay. Ive tried bleeding the systems amny times,
> >> water pump is new. So is this looking like a head problem that just
> >> wasnt found when it was tested for combustion gasses?
> >>
> >> Another idea ive been given is oil problems, can a problem with the
> >> oil system be causing the symptons ive describes?

No. Its not related.


The oil is actually
> >> doing weird things. The pressure is alot lower than it always used to
> >> be, and the weird bit is that the pressure tends to go down with revs
> >> rather than going up higher like it always used to.

That is weird.


Its a tad below
> >> specs at 2000rpm now. So im about to go check the pickup screen and
> >> oil pump which is a pain of a job, but could this be a possible cause
> >> for overheating?

No,..not related. Personally I wouldnt be checking the screen at this stage.
Other engine parameters dont have a significant effect on coolant temp IME.


If not then i may pull the heads off while i pulling
> >> things apart so i can get the checked properly.

They need to be crack-tested.



Jason

[Noddy]

"Clockmeister" <no-one@nowhere.com> wrote in message
news:425511db$1@duster.adelaide.on.net...

> Try this...
>
> Get engine up to operating temp and get a mate to rev the engine (make
> sure
> the rad cap is on and system has built up a bit of pressure by squeezing
> the
> top hose). Check to see if the top and bottom radiator hoses are
> collapsing
> and flattening out due to the suction when you rev the engine. If so,
> replace the hose.

Good call.

I've seen that problem occur a couple of times now, and it can be a bastard
to locate.

--
Regards,
Noddy.

[Cranky]

james <kaufman_j@hotmail.com> wrote in
news:sjv951tslsughhqmp2puep059nsqtpd2sn@4ax.com:

> Well ive still had no luck with this darm car. Ive just spent alot of
> money on a new radiator and its still overheating badly. I also had it
> tested for combustion gasses in the coolant and it was given the all
> clear, although it was done differently than using those bottles with
> the fluid in it that detetcs the gasses. he used one of those big
> machines with probes that are supposed to detect any gasses, lots of
> different types by the looks of it. Would that still be as accurate
> as the old fluid tests?
> So ive got a new radiator, thermostat, radiator cap. And new head
> gaskets as i thought id change them incase i had stuffed them up.
> heads were flat, i couldnt get them crack tested or anything because i
> dont have a car to take them anywhere so i put them back on.
> Ive also checked the fuel mix, and played around with the timing
> incase that was casing it. Ive tried 2 different engine fans, old
> mechanical type and my newer clutch fan, no diference. Fan shroud is
> on. Im running out of ideas now.
>
> To describe exactly what its doing now, at idle the temp will rise,
> it gets to 90 and drops a bit and goes back up and cycles, but often
> it will hit 90 and then like a rocket will shoot up to 100 or a tad
> over and go back down. occasically it wont stop at 100 though and
> thats when i panick. if i dont turn the car off it often just blows
> out of the overflow. That all happens at idle and aslo at cruising,
> around 1500rpm is the worse. If i floor the car the temp will raise
> up high to about 90 but then the moment i stop accelerating hard the
> temp will just take off.
>
> Lookint at the coolant with the cap off and idling what i see is the
> coolant level will drop a bit, and then errupt and just keeps doing
> that while the thermostat is open. When closed its still, but as soon
> as it opens its rasies and falls shooting around 1litre of coolant all
> over the engine bay. Ive tried bleeding the systems amny times,
> water pump is new. So is this looking like a head problem that just
> wasnt found when it was tested for combustion gasses?
>
> Another idea ive been given is oil problems, can a problem with the
> oil system be causing the symptons ive describes? The oil is actually
> doing weird things. The pressure is alot lower than it always used to
> be, and the weird bit is that the pressure tends to go down with revs
> rather than going up higher like it always used to. Its a tad below
> specs at 2000rpm now. So im about to go check the pickup screen and
> oil pump which is a pain of a job, but could this be a possible cause
> for overheating? If not then i may pull the heads off while i pulling
> things apart so i can get the checked properly.
>
> Sorry for writing so much! any help greatly appreciated.

I had a similar problem with a 302V8 in a ZB Fairlane, changed every
thing, planned the heads, etc.... Problem was a crack in the block and I
sold the bloody thing.

Regards,
Ron

[John_H]

james wrote:

>Firstly would colder spark plugs cause more heat to go into the
>cooling system?

Nope.

>Also with the valve seats. They looked like they were cut alot
>narrower than before, although it may have just looked that way
>because they are now a 3 angle cut rather than single but i do
>remember thinking they were extremely narrow and checked against the
>specs in my manual and they barely made the minimum requierment .889mm
>intake. i forgot to measure the exhaust seats though but i dont
>remember them being any wider and min spec on them is 1.28mm. Could
>this be causing cooling system problems?

Nope.

--
John H