I have an old 1991 Cavalier 2L OHC SRi that I've owned for 14 years.
Its covered 135,000 miles but still drives well for it's age.

Recently it's developed a problem with the cooling system temperature.

When moving at normal driving speeds the temperature gauge appears
normal - although it does sometimes creep up just slightly and then go
back to normal for no apparent reason.

When I get stuck in slow moving traffic or stop, the temperature rises
much quicker than it used to.
The fan is working ok - it switches on when the gauge reaches 90 (which
it always has done). This brings the temp down to just about normal
running temperature, perhaps just above.

There is a small amount of spitting of coolant around the outside of
the header tank (coming from the cap I think) and I do get a small
amount of greasiness on the inside of the header tank suggesting there
could be a head gasket problem. However, it's been like that for quite
sometime and I've not noticed the temperature problem before. The
coolant level does not drop and I've not found any water in the oil.
The engine does not appear to have lost any power.

The thermostat was replaced a few months ago (it was running too cool
but the new stat fixed that). The radiator, header tank & cap have all
been replaced recently too.

What I should try next?

On Fri, 02 Sep 2005 01:35:29 -0700, brian_mk wrote:


> I have an old 1991 Cavalier 2L OHC SRi that I've owned for 14 years.
> Its covered 135,000 miles but still drives well for it's age.
> 
> Recently it's developed a problem with the cooling system temperature.
> 
> When moving at normal driving speeds the temperature gauge appears
> normal - although it does sometimes creep up just slightly and then go
> back to normal for no apparent reason.
> 
> When I get stuck in slow moving traffic or stop, the temperature rises
> much quicker than it used to.
> The fan is working ok - it switches on when the gauge reaches 90 (which
> it always has done). This brings the temp down to just about normal
> running temperature, perhaps just above.
> 
> There is a small amount of spitting of coolant around the outside of
> the header tank (coming from the cap I think) and I do get a small
> amount of greasiness on the inside of the header tank suggesting there
> could be a head gasket problem. However, it's been like that for quite
> sometime and I've not noticed the temperature problem before. The
> coolant level does not drop and I've not found any water in the oil.
> The engine does not appear to have lost any power.
> 
> The thermostat was replaced a few months ago (it was running too cool
> but the new stat fixed that). The radiator, header tank & cap have all
> been replaced recently too.
> 
> What I should try next?




It sounds like a head gasket problem.

> The thermostat was replaced a few months ago (it was running too cool
> but the new stat fixed that). The radiator, header tank & cap have all
> been replaced recently too.


Flush cooling system with stuff for the job.
But it's most likely head gasket.
DaveK.

Sounds silly, but it couldn't just be the hotter weather could it?

Or maybe the stat has failed?


"brian_mk"  wrote in message 
news:1125650129.449691.146450@z14g2000cwz.googlegroups.com...

>I have an old 1991 Cavalier 2L OHC SRi that I've owned for 14 years.
> Its covered 135,000 miles but still drives well for it's age.
>
> Recently it's developed a problem with the cooling system temperature.
>
> When moving at normal driving speeds the temperature gauge appears
> normal - although it does sometimes creep up just slightly and then go
> back to normal for no apparent reason.
>
> When I get stuck in slow moving traffic or stop, the temperature rises
> much quicker than it used to.
> The fan is working ok - it switches on when the gauge reaches 90 (which
> it always has done). This brings the temp down to just about normal
> running temperature, perhaps just above.
>
> There is a small amount of spitting of coolant around the outside of
> the header tank (coming from the cap I think) and I do get a small
> amount of greasiness on the inside of the header tank suggesting there
> could be a head gasket problem. However, it's been like that for quite
> sometime and I've not noticed the temperature problem before. The
> coolant level does not drop and I've not found any water in the oil.
> The engine does not appear to have lost any power.
>
> The thermostat was replaced a few months ago (it was running too cool
> but the new stat fixed that). The radiator, header tank & cap have all
> been replaced recently too.
>
> What I should try next?
> 

It is possible that the hot weather is making the situation worse -
although I have had the car for 14 years and driven it many times in
hot weather and I've never noticed the temp rise so quickly before.

I've read a couple of articles on the web about head gasket symptoms
and it does seem to fit. If there is a leak between the cylinders and
the cooling system then bubbles of gas can enter the cooling system,
reducing efficiency and causing pressure build up. If the leak is small
then you don't always get water in the oil or a drop in coolant level.
The excessive pressure might explain why the radiator developed a leak
and had to be replaced a few months ago.

I fitted another thermostat the other day (they are relatively cheap
and easy to fit) just to see if that makes a difference. I suspect it
won't help. I haven't used the car enough yet to find out.
Should know one way or the other this week.

In any case I've decided it's time to change the car.
It's been a good car and I will be sorry to see it go but there comes a
time when any car becomes un-economical to maintain.
It still has the original clutch after 135,000 miles (is that a
record?), so that will need replacing soon.
The rust around the welds at the front of the rear wheel arches and
along the top of the windscreen (I had to have a cracked screen
replaced) is getting worse.
The sunroof has been jammed for years and won't slide back.
The MOT due this month and it needs 2 new rear tyres to get through
(£150 for tyres  £40 for MOT).
The trade in value of the car is only £90 !!!
If the head gasket does need replacing as well it just won't be worth
getting it fixed.


R. Murphy wrote:

> Sounds silly, but it couldn't just be the hotter weather could it?
>
> Or maybe the stat has failed?
>
>
> "brian_mk"  wrote in message
> news:1125650129.449691.146450@z14g2000cwz.googlegroups.com...
> >I have an old 1991 Cavalier 2L OHC SRi that I've owned for 14 years.
> > Its covered 135,000 miles but still drives well for it's age.
> >
> > Recently it's developed a problem with the cooling system temperature.
> >
> > When moving at normal driving speeds the temperature gauge appears
> > normal - although it does sometimes creep up just slightly and then go
> > back to normal for no apparent reason.
> >
> > When I get stuck in slow moving traffic or stop, the temperature rises
> > much quicker than it used to.
> > The fan is working ok - it switches on when the gauge reaches 90 (which
> > it always has done). This brings the temp down to just about normal
> > running temperature, perhaps just above.
> >
> > There is a small amount of spitting of coolant around the outside of
> > the header tank (coming from the cap I think) and I do get a small
> > amount of greasiness on the inside of the header tank suggesting there
> > could be a head gasket problem. However, it's been like that for quite
> > sometime and I've not noticed the temperature problem before. The
> > coolant level does not drop and I've not found any water in the oil.
> > The engine does not appear to have lost any power.
> >
> > The thermostat was replaced a few months ago (it was running too cool
> > but the new stat fixed that). The radiator, header tank & cap have all
> > been replaced recently too.
> >
> > What I should try next?
> >

<<It is possible that the hot weather is making the situation worse -
although I have had the car for 14 years and driven it many times in
hot weather and I've never noticed the temp rise so quickly before.>>

<<I've read a couple of articles on the web about head gasket symptoms
and it does seem to fit. If there is a leak between the cylinders and
the cooling system then bubbles of gas can enter the cooling system,
reducing efficiency and causing pressure build up. If the leak is small
then you don't always get water in the oil or a drop in coolant level.
The excessive pressure might explain why the radiator developed a leak
and had to be replaced a few months ago.>>

Find a friendly local garage and get them to do a compression test on it. 
That should tell you whether the head gasket's a problem or not.

<<I fitted another thermostat the other day (they are relatively cheap
and easy to fit) just to see if that makes a difference. I suspect it
won't help. I haven't used the car enough yet to find out.
Should know one way or the other this week.>>

<<In any case I've decided it's time to change the car.
It's been a good car and I will be sorry to see it go but there comes a
time when any car becomes un-economical to maintain.>>

<<It still has the original clutch after 135,000 miles (is that a
record?), so that will need replacing soon.>>

That's no record, and it won't neccessary need replacing any time soon 
unless it's knackered.  I'm not sure, but your Cavalier *might* still be one 
of the 15-minute clutch change designs, so that's a very easy job, and cheap 
for a garage to do - around 100 I'd have said.  Clutches can last for ages 
if treated right - on the motorway there's no wear happening, so if you do 
loads of motorway miles, there's no reason in the world why a clutch 
shouldn't last 300-400k.

<<The rust around the welds at the front of the rear wheel arches and
along the top of the windscreen (I had to have a cracked screen
replaced) is getting worse.
The sunroof has been jammed for years and won't slide back.>>

<<The MOT due this month and it needs 2 new rear tyres to get through
(150 for tyres + 40 for MOT).
The trade in value of the car is only 90 !!!
If the head gasket does need replacing as well it just won't be worth
getting it fixed.>>

Sunroof's a minor thing, but if the head gasket has gone and the rusty 
arches need sorting for the MOT, then yes, it's worth getting rid.

If it's just tyres though, it's immaterial that the tyres might cost more 
than the car's worth - all cars wear out tyres, and you'll be spending the 
same amount on a 5000 car to replace the tyres (roughly speaking) than on 
an old Cavalier.

If I were you I'd get a compression test done, and if that confirms the head 
gasket's on its way out, make a decision.  Vauxhall HG's aren't known to be 
problematic, and if you get it done, it should last for years longer without 
problems (unlike many Rover designs!).  Also, take it to a local friendly 
MOT centre when they're quiet, and politely ask them to have a close look 
and if they reckon they'd fail it on the rust around the arches and 
windscreen (wouldn't have thought so for the windscreen, mind), if they say 
almost certainly not, then it should see at least another year, maybe 2 or 
3.

Regarding the cooling problem - could it be that whoever fitted the new 
radiator didn't bleed the system properly, and left an air lock somewhere? 
That would *definitely* cause things to heat up quicker than usual.  Or 
maybe you may have done this when fitting the new thermostat (I can't 
honestly remember whether than involves disrupting the flow of coolant, 
though).  Get the coolant drained and properly refilled, paying attention to 
not leaving an air lock in there, and it should be fine.

-- 
Peter

"You're not a real UKRCMer until you've had your big end bearings go."