Temperature Problem
 

Actually , I don't think for a minute it's anything to do with temp guage, the car engine DOES overheat ..
Car
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Subaru Imprezza 2.0 Turbo
Symptoms (recent & now)
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#Recent Symptoms
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Drove fine, but temp guage would seem to act a bit funny.
- If driven lightly, it would stay on `mid`
- If driven relatively hard, would climb steadily to `Max`
- When on `Max` I would stop and let it cool down , however .. I discovered, if it was climbing nearly up to `Max` , I could drop a gear, HOOF it, and the temp would go DOWN (!)

Current Symptoms
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- drives fine, but temp guage stays on `cold` for a few minutes, then suddenly , goes up to `mid` point (takes about 6 seconds for the needle to go from cold to mid point.
- follwoing that, needle climbs over period of a few mins (& depending on driving), to MAX.
- AT NO POINT is there ANY HOT AIR in the car, even when I`ve got the heater blower on. (It is COLD in the car .. not even slightly warm)
- (when I stop , I can hear the expansion tank burbling like mad, so the car i sdefinatley overheating).
Question
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Could this be the thermostat ? - it reminds me of thermostat problems on other cars. However, the manual says that when thermostat is closed, water still allowed into cars internal passenger heating system.

Taking the thermostat out is NOT a 5 minute job on these things, so I wouldn`t mind some advice / thoughts first.

(Background info - I suspected it might be `head gasket` but did a block check with the chemical tester and it was inconclusive (went from blue to ever so slightly greener blue .. rather than blue to yellow like it says in block tester manual).

Also - had engine rebuild before I bought car (but - high mielage, and seems to have an old-ish radiator in ).

I've never heard of those symptoms b4 but the first thing I would check is the water temperature sensor as that can play havoc with the ecu's ability to read engine temperature when it's knackered.

MAFFA :)

Could it be the RAD ?
 

Thanks mate. Thing is , the engine IS overheating. I pulled on the drive last night, turned it off, and the expansion tank was burbling and spluttering like me mams hot-pot at a family do.

But seriously - someone mentioned blocked radiator. Could it be that ? How would I check ?

Cheers - Mark

I've owned 2 wrx's in the past 9 months and have had overheating problems with both, my current scoob, a my97wrx imported from singapore had a crack in the radiator which i managed to sort out by removing the plastic tanks on the side and having steel ones fitted. I couldn't spot the leak but saw the temperature gauge shoot up very fast when the car is idling, it would gradually go down again when i was on the move

My other scoob, which i've now sold had a fooked thermostat, initially i was told that it could be the head gasket, thank god it wasn't, it din't take too long to remove the thermostat and ever since then all's been good :) i recall the first time i took the car out for a spin it was boiling like crazy, could hear it inside the car!! anyways hope i've given you a bit on an insight on overheating scoobs as from what i've seen its a common problem, specially here in africa,

cheerz,

suhail

hey .....1st things 1st ...ur right , the removal of the thermostat isnt a five minute job .....its more like 2mins .....its about the easiest job you can do on your engine m8 ........wip the stat out and dunk it in a boiling hot cup of water ....i`d check that b4 i did anything else .

Are you using coolant? Sorry but there is a possibility it is a head gasket. Get a garage to check your coolant. They can tell if there is combustion gas in the coolant.
If that is clear, change the thermostat and ensure you have the system properly bled. Work forward from there.

I had the same this morning!
 

I was just using the search facility to have a look at the symptoms,

I thought my heater was slow to get warm last week, but as the car has lived in my garage since this morning I didnt realise it was wrong.

My own car is not overheating badly? I dont think? (No noise of hot smells under the bonnet)

But my heater keeps going cold (no heat) at the same time as my temperature nedle is rising to the top of the gauge? All of a sudden I get warm air and it drops (very) quickly to midway.

If it was not for the cold air, I would think that I had an overheating problem, but then I woudl expect hot air constantly.

I havent made any changes to the car, but it has been in for a new 5th Gear synchro and I wonder if they may have put an airlock in?

I hope you are lucky but the fact that the needle is going up/high means you do have an overheating problem.

don't know if this is the issue but it rings a bell from a previous car I owned.. Used to overheat on the gauge and then would drop right down again. what was happening was that water was going out into the expansion tank and leaving the galley where the temp sender was without water hence the reading dropping.. It did take some finding as I had no experience with cars at all..

Are you sure it's not just an airlock somewhere?

If the car was overheating, surely the heater would be working? Cold air from the vents = cold water, or no water, in the heater matrix. High coolant temp means either it's not being cooled properly, or the coolant isn't being pumped round the system. If the temp gauge goes very quickly from cold to mid, that suggests to me that the sensor may not even be sitting in water until pressure has built up in the system and the air bubble it's sitting in is getting compressed. The subsequent rise (and/or unusual drop) in temperature is consistent with poor coolant flow.

When the expansion tank starts burbling, can you (carefully!) ease off the cap and actually measure the temperature of the water to see if it's actually boiling or if there's just a lot of air being pumped round?

fan and waterpump?

Got a similar prob with my MY95 WRX, wonder if anyone can shed any light. Only problem i have is i see bubbles in the overflow tank near the battery, the temp gauge does not move at all apart from where it has sat for the past three years (around half way up the gauge) Doesnt seem to be any excess pressure in any of the hoses e.t.c.

One thing i have noticed is there seems to be small leak on the main alloy hose coming off the block under the inlet manifold just in front of the knock sensor could this leak be causing me to get bubbles in the overflow or is this the inevitable head gasket failure..?? Car also drives fine..!! no loss of water e.t.c

Thanks

Dan:D

Well my gauge issue has cleared up. As it was never really getting hot.

The water level was very low. Although the car wasn't overheating.
I have drained the fluids amd stuck in some fresh water antifreeze. Left it running with the cap off to try and heat up, but it just stayed around half way. Took it for a drive and still half way on the gauge, nice and warm inside (oil temp just uner 90deg) but engine not overheating.

Its been suggested I either had low water for a while or my rad end caps may be weeping slightly. Ill just have to keep an eye on it as its always been serviced and Ive never had to remove the cap myself in 2.5 years..

Greeprodrive, have you found out what your problem is yet?

Yep I had same problem on my scoob sportwagon, Rad blocked partially,
New Rad fitted, problem gone. Local garage found it no probs'
Cheap as chips. I hope this all that's wrong with your Motor.
MACH1.

were abouts is the thermostat in a wrx engine (93), my mate needs to find it can anybody help

its at the end of the bottom rad hose near the water pump... You will see the housing for it.

Dan:D

I would tend to agree with these possibilities:

a; Dodgy thermostat (easy check as stated)

b; Air lock (although the system should be self purging!)

c; Blocked gallery from rebuild crud

Also if gauge is moving rapidly could be electrical (guage or sender).

Sort of narrows it down a bit! ;)

i know what it is
 

Hi,
I read your message on the scoobynet forums.


I also have a green pro drive which i have to got back from repair with the same problem.

I had the same problem, i posted loads of links on the forums everywhere, and no-one had ever heard of the fault.

In the end it turned out to be both head kaskets.
the thermostate was fine.

I found it really weird that the temp gauge went normal aain too, in the space of 5 secs of putting your foot down,
then the temp needle would shoot back up again when you slowed down.

Anyway, after having the kaskets changed, the car has done 500+ miles and seems to be running fine.


I find it really weird that noone has ever heard of this fault, yet we both own the same car and in the same colour. also with pro-drive kits.
maybe its something pro-drive have done with the upgrades.



Hope this helps.

Paul.