How to check for Headgasket Failure?

[easty-5]

My cooling woes continue. Car is a rev 3 turbo and it drinks a bit of water (About 250ml a week, but only if the car is used for longish journeys 30-40 miles).

I have changed/checked everything I can think of. Heater pipes seem fine. Rad cap has been changed. Bought a sniff test device and it came back saying it was okay but I'm not sure how reliable it is.

The car hasn't overheated in a few months now but I haven't driven the car on a long journey 100+ miles. Everytime I put my foot down the temp gauge comes down to about 1/4, sometimes less and then slowly rises again. Thermostat has been changed and no joy. Bled the system more times than I can remember.

The only thing I can think of now is the HG is gone. Are there any ways to check without taking the head off. There is no mayo under the cap.

[mr2turbo99]

Have a look at the expansion tank overflow hose after a journey (Passenger side wheel well). When my HG popped it was over pressurising the coolant system and pushing coolant out of this hose.

Sniffer test AFAIK are pretty reliable. Its simply detecting Hydrocarbons in the coolant using chemicals. The other steps you could do is get it leak down test done and a compression test.

Mine was recently using coolant and i immediately thought "here we go again" but it turns out the o-ring on the radiator bleed valve had perisehd. Maybe worth a look at.

As for the fluctuating temp needle id say possible air lock? I know you've bleed the system countless times but are you doing it correctly? Theres a great guide on the MR2oc in the know your 2 section. Sometimes people forget to bleed with the heat set to hot e.t.c

Worth a look.

[2barGee]

This might help mate

Drive your car for 30 mins no boast at all then park it for 30mins and keep an eye on your temp gauge. If it over heats its your head gasket.

If its ok after that. Then take the car out again and totally give it the beans as much as you can then pull over straight away, again leave it ticking over for about 30 mins and keep an eye on the temps. If it overheats this time you've got a cracked block.

You might have a split pipe somewhere which over time could cause an air lock. You could try some rad/pipe mix that you pour into your coolant but try the above above first.

Fingers crossed youve not cracked your block dude.

[easty-5]

This might help mate

Drive your car for 30 mins no boast at all then park it for 30mins and keep an eye on your temp gauge. If it over heats its your head gasket.

If its ok after that. Then take the car out again and totally give it the beans as much as you can then pull over straight away, again leave it ticking over for about 30 mins and keep an eye on the temps. If it overheats this time you've got a cracked block.

You might have a split pipe somewhere which over time could cause an air lock. You could try some rad/pipe mix that you pour into your coolant but try the above above first.

Fingers crossed youve not cracked your block dude.

Something I have never tried. I will give it a bash at the weekend. Cheers

[mr2turbo99]

This might help mate

Drive your car for 30 mins no boast at all then park it for 30mins and keep an eye on your temp gauge. If it over heats its your head gasket.

If its ok after that. Then take the car out again and totally give it the beans as much as you can then pull over straight away, again leave it ticking over for about 30 mins and keep an eye on the temps. If it overheats this time you've got a cracked block.

You might have a split pipe somewhere which over time could cause an air lock. You could try some rad/pipe mix that you pour into your coolant but try the above above first.

Fingers crossed youve not cracked your block dude.

Hmm might work. Id still go down the comp and leak down test route myself to determine exactly what the problem is.

Good luck anyway. Fingers crossed its nothing to serious!

[easty-5]

Hmm might work. Id still go down the comp and leak down test route myself to determine exactly what the problem is.

Good luck anyway. Fingers crossed its nothing to serious!

Sorry, never hit the reply button for the reply I had to your post

I will see about getting a leak test done. It will either highlight the issue or I will be able to rule out a leak.

It's either a leak somewhere, of HG failure IMO.

Thanks

[mr2turbo99]

Hmm might work. Id still go down the comp and leak down test route myself to determine exactly what the problem is.

Good luck anyway. Fingers crossed its nothing to serious!

Sorry, never hit the reply button for the reply I had to your post

I will see about getting a leak test done. It will either highlight the issue or I will be able to rule out a leak.

It's either a leak somewhere, of HG failure IMO.

Thanks

Thats ok, get a compression test done too

[Lewis Jay]

Its very unlikely that the headgasket has gone, its a Rev 3.

You either have/had a leak, now a warped head due to overheating on long run/boosting or the thing which is every Rev 3 owners nightmare, a cracked block.

[easty-5]

Its very unlikely that the headgasket has gone, its a Rev 3.

You either have/had a leak, now a warped head due to overheating on long run/boosting or the thing which is every Rev 3 owners nightmare, a cracked block.

Yea that is what I am thinking.

Will a comp test or leak test show up a cracked block?

[Lewis Jay]

Its very unlikely that the headgasket has gone, its a Rev 3.

You either have/had a leak, now a warped head due to overheating on long run/boosting or the thing which is every Rev 3 owners nightmare, a cracked block.

Yea that is what I am thinking.

Will a comp test or leak test show up a cracked block?

Yes a leak down test done with the t/belt taken off so the valves are closed and the piston is at BDC should show a leak.

Have a read here.

http://www.imoc.co.uk/forums/viewtopic.php?t=117048

[willfinch36]

hmm im having something like this, the car isnt overheating or anything.... but appears to be using/ kicking out coolant, also a missfire if the ecu hasnt been reset for a about 10 miles or so.

going to do a compression test tonight.

[willfinch36]

compression test done, all cylinders seem ok..... Think im gonna get a new 1.3 bar RAD cap.

[LimeyMk1]

Everytime I put my foot down the temp gauge comes down to about 1/4, sometimes less and then slowly rises again. Thermostat has been changed and no joy. Bled the system more times than I can remember.

Always thought this was a sign of the thermostat being stuck open. Where did you get your stat from?

[willfinch36]

Got a new HKS rad cap... but still it appears to be going into the overflow tank and under the car?? :S