RPM150

Overheating STI

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Hi,

It's my Daughters car I would like some help with. She has an Impreza WRX STI PPP 2006 that has done 85000 miles.

The car over heated, due to a leak in the Radiator. She drove about another 2 miles once cooled down, then the AA transported her home.

Rad changed, but the engine overheats when driven. Ok when ticking over. Temperature gauge rock steady in the middle. No sign of Water in oil, on dip stick in rad or water out of exhaust.

As you can tell my knowledge of engines is limited. Is there any way we can tell if it is the head gasket or could it hopefully be the thermostat?

I have now stepped in to try and help. The car has know been standing for about 3 months and it's such a shame to see it like that.

If you can suggest any way I can test if it is a head gasket blown.

Your advise would be greatly appreciated so we can get this great car flying again.

Thanks again

RPM150

 

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From the little I know it can be tricky to diagnose.

As you have had the rad changed recently I would like to think it is an air lock, which is easy to do on these motors. I would drain the coolant and refill with the front end pointing in the air. Fill from the filler tank near the turbo, fill slowly. Burp system and see if it still overheats. I refilled mine recently and it got an air lock which would allow the engine temps to rise. The temp gauge in the car is too slow, I used a cheap bluetooth dongle and my android phone to keep an eye on temps. I burped it and all is good now.

If the above does not work then I would start suspecting the HG. I hear that an exhaust gas analyser sniffing the air in the overflow tank could be the best bet. Sniff tests have prooved to be not reliable based on other threads.

GOOD LUCK

Just a thought does the heater blow hot air, if not may be a sign of airlock.

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"could it hopefully be the thermostat?"

Does the rad fan kick in? It should kick in approx 97 cool water to high 80s and turn off fan. It will just repeat this cycle if normal.

The temp gauge is useless, try not to overheat it as you will blow gaskets or warp head/block.

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Same boat that i was in, no oil in water/water in oil, no bad smoke out of exhaust ect, had it hydrocarbon tested then boom, exhaust gases found in the coolant, was the headgaskset.

So i would get it hydrocarbon tested before wasting any more time.

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10 hours ago, anorexic_sti said:

Same boat that i was in, no oil in water/water in oil, no bad smoke out of exhaust ect, had it hydrocarbon tested then boom, exhaust gases found in the coolant, was the headgaskset.

So i would get it hydrocarbon tested before wasting any more time.

Yes I have seen many stories like yours. No symptoms but was the HG. What hydrocarbon test do you use, same as the MOT tests or the liquid sniff test? 

@RPM150 i have my fingers crossed for you.

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5 hours ago, Siluro said:

Yes I have seen many stories like yours. No symptoms but was the HG. What hydrocarbon test do you use, same as the MOT tests or the liquid sniff test? 

@RPM150 i have my fingers crossed for you.

sniff test?, that color changing liquid.

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1 hour ago, anorexic_sti said:

sniff test?, that color changing liquid.

Thanks.

I am sort of going through this. I get bubbling noise in my heater matrix it seems. Not always and seems to be related to how hard i drive it. My car however does not overheat. I use bluetooth dongle to see actual temps and the car does what is supposed to. This only started when i had a blonde moment and opened the rad cap. I gave it to Subaru but they !Removed! it up, caught on dashcam and that is whole other story.

I decided to replace the coolant myself. I took rad out, flushed it and replaced nearly all coolant lines with a Samco kit. Replaced rad caps too. Car runs great, no oil lose, no sign of water mixing or loss of coolant. Hawkeye with map 270bhp fly.  Only mods are performance panel filter and uprated brakes. Only done 46000 miles 2007 WRX. now used as daily driver.

As i said previously I have read so many stories like your but the one thing they have in common is overheating. I hoping it is something else like all the others.

Do you have a link to the test you bought?

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6 hours ago, Siluro said:

Thanks.

I am sort of going through this. I get bubbling noise in my heater matrix it seems. Not always and seems to be related to how hard i drive it. My car however does not overheat. I use bluetooth dongle to see actual temps and the car does what is supposed to. This only started when i had a blonde moment and opened the rad cap. I gave it to Subaru but they !Removed! it up, caught on dashcam and that is whole other story.

I decided to replace the coolant myself. I took rad out, flushed it and replaced nearly all coolant lines with a Samco kit. Replaced rad caps too. Car runs great, no oil lose, no sign of water mixing or loss of coolant. Hawkeye with map 270bhp fly.  Only mods are performance panel filter and uprated brakes. Only done 46000 miles 2007 WRX. now used as daily driver.

As i said previously I have read so many stories like your but the one thing they have in common is overheating. I hoping it is something else like all the others.

Do you have a link to the test you bought?

didnt buy it as it's like a £40 kit just to tell you your HG is !Removed!, just took it to my mechanic, insta pic and video here for reference.

 

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Thanks Lads,

Sorry not replied till now, sent a reply but never went anywhere, wondered why no one answered me.

I did buy a sniff test kit on ebay blue liquid but not conclusive Also bought one of those Funnel kits for refilling the Rad fits in place of the Rad cap  so air can escape while engine running.

I did notice when running the engine with the Funnel in place there was  showing  in the Funnel at a regular rate..

..Did I see  MOT garage should be able to tell if Hydrocarbons are present with their test equipment.

If any one knows of a good garage in kent I would love to have their details.

Many Thanks for your input.

RPM150

 

 

,

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It would be tricky I believe to measure hydrocarbons without there being load on the engine (on boost). Ticking over may not produce enough if any hydrocarbons to change the fluid. How about pumping/sucking the air out of the overflow tank into your sniff tester while the car is using boost. You could run a pipe from top of tank (sealed somehow) into passenger side and get a friend to pump/suck the air up through the sniff tester. Overflow tank is next to the radiator.

You could also see if the pipe that goes into the overflow tank pushes fluid out when on boost. Extend this pipe into the car and catch it into a tank. If there is a large rush of coolant under boost and the HG has gone then you could catch hydrocarbons then. I am not sure but if the gushes out coolant then there is a problem with the HG or air getting drawn in somewhere (unlikely). The water pump seal could allow air in I suppose under high rpm but be fine with normal driving conditions.

If the heads air lifting under boost only for example a ticking over sniff test would probably not see it.

I have seen your story over and over again. Sniff test do not always catch a bad HG. Most of these cases I am afraid all turn out to be HG with one common symptom, overheating without reason. Now that you have bought one then it maybe best to try the tester when the engine is under load.

Best of luck

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RPM150 How did you get on? I would love to hear a nice ending.

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