[Mk2] [Turbo] still STILL overheating :(

[shabz]

Symptoms:

- Overheats after 4 or 5 boosted pulls
- Water boils and spills out of the overflow container (lots of bubbling noises)
- Temperature drops back down after coming off boost
- Coolant turns brown when put through the system (probably old tubes?)
- Headgasket test came back clear

Things I've tried:

- Changed rad cap and the plastic bit that it screws onto...It used to overheat as soon as I came anywhere near 3-4k on boost...Now overheats after 4 or 5 boosted pulls

- Bled and burped the coolant using services hoses the proper way...I've done this twice and a mechanic once with no success

- Changed thermostat for a new unit

I'm really near quitting and breaking for parts (please don't pm me you vultures lol)

What can I try next? Should I check the waterpump? radfans? how can I test these?

[Quigonjay]

head gasket maybe?

[shabz]

Had a sniff test done...came back negative

Plus its rare for a metal rev3 headgasket to go...

Am totally stumped at the moment

[Quigonjay]

would have said thermostat next but you have done that
could be water pump but i wouldnt expect it to take 5 attempts at boosting for it to overheat if it was
could just be a really bad air pocket, i see you have had it done but i still wouldnt rule it out, it takes a few attempts sometimes

[shabz]

how would you go about getting rid of air pockets without bleeding the whole system down? is there a quicker way?

i'm sure i read somewhere running the engine with the radcap off? could that work

[Razor04]

Had a sniff test done...came back negative

Plus its rare for a metal rev3 headgasket to go...

Am totally stumped at the moment

Hi Im battling the same issue at the moment changing the rad cap seems to have stopped the water p1$$ing out the overflow but im not convinced its not still boiling up inside the engine. you are right Rev3 steel head gaskets very rarely fail. I spoke to 3S and they said it would more likely be a cracked block than a blown gasket on a rev3. Im currently waitin for a quote on a recon long block it will be around 2K fitted. I had this test done where they put a tube of blue liquid onto the coolant filler neck and pump it. it is supposed to turn green if there is exhaust gas in the coolant one garage said it turned green HG failure whereas the AA did same test when i broke down and the liquid stayed blue? Rogue say those test rarely work properly on MR2's

[spannerman]

Sorry to say this guys but mine was exactly like what your experiencing.

Replaced all the little things, thermostat / Rad cap etc. Ultimately it turned out to be the head gasket.

[Graeme Shaw]

I have had all the same symptoms twice! And had to replace the head gasket twice. What I think happens is: coolant leak, (rev 1 or 2 usually the coolant pipes that run along the bottom of the car above the fuel tank)

Then not enough coolant to cool the engine, so coolant boils and overflows out of overflow, eventually blows head gasket.

You may be lucky and just have a coolant leak.

Graeme

[shabz]

i can't spot any leaks

i'll try running the car for 5 minutes and check the floor afterwards, if there's a leak the floor should be wet right? how else can i check?

[2barGee]

Symptoms:

- Overheats after 4 or 5 boosted pulls
- Water boils and spills out of the overflow container (lots of bubbling noises)
- Temperature drops back down after coming off boost
- Coolant turns brown when put through the system (probably old tubes?)
- Headgasket test came back clear

Things I've tried:

- Changed rad cap and the plastic bit that it screws onto...It used to overheat as soon as I came anywhere near 3-4k on boost...Now overheats after 4 or 5 boosted pulls

- Bled and burped the coolant using services hoses the proper way...I've done this twice and a mechanic once with no success

- Changed thermostat for a new unit

I'm really near quitting and breaking for parts (please don't pm me you vultures lol)

What can I try next? Should I check the waterpump? radfans? how can I test these?

I had all of the above mate and i am sorry to say it turned out to be a cracked block I got a small crack over the water way, the crack only opened on boost and when the car was really warm.

Good luck finding out the problem mate

[Graeme Shaw]

i can't spot any leaks

i'll try running the car for 5 minutes and check the floor afterwards, if there's a leak the floor should be wet right? how else can i check?

It may be the coolant pipes under the car. Hard to spot, as the coolant drops onto the undertrays. Try removing the undertarys, and see if you can spot anything then.
Graeme

[shabz]

underneath...do you mean the 2 hard metal coolant pipes near the centre of the car?

i suppose any leak would cause the system to lose pressure

[mark239]

had same symptoms myself - block was cracked.

sleeved now though.

[shabz]

what do you mean by sleeved? and how did you find out in the end that it was cracked?

[JJ]

Definitely the head gasket... your problem you have, the head has already warped, so head needs to come off and skimmed.... Steel head gasket is no good if the rest of it looks like a banana !!

All the symptons point to it.... yes.. understandably, you've had a sniffer test done on it... however, this is probably when you've place new coolant in the system and just drove it down the road not on boost....

In a nut shell, you're pressurising the coolant system... air goes into the block.... starts to over heat, creates massive amounts of gass and blows out the expansion tank...

[shabz]

i think you may have solved it as that makes perfect sense!! thanks i think its time for the head to come off!

if i replace the whole head from another rev3/4/5 turbo including its headgasket it should be ok then? i can imagine skimming the head will be expensive...and a new cometic hg will cost £80 anyway

[3sgte]

skimming the head wil be about 40-50 ,also even if you bought another head you would idealy need to get that skimmed aswell to make sure it is 100% true

[shabz]

ahh thats fairly cheap...

just called a local place who said £30 so thats fair enough

the most i've ever done is a thermostat change, oil filter, fuel filter, oil, dump valve so getting the head off will be a challenge i will have time and a spare mr2 turbo so should be ok

[splintermcinnes]

if only i knew sooner! a skimmed head and new HG woulve been cheaper....

i had the same hing, but mine would be fine one day, drove the legth of the country, other days would over heat after five mins! i replaced all sorts, new rad cap, new TRD low temp 'stat, new temperature porbes, tested the fans - low speed wasn't working! sorted that and still happening, i ran the engine with the rad cap off, and ran the garden hose through the system till it ran clear - mine was also very red! bled it off properly with service hoses.

Eventually i got so pi$$ed off, i pulled over to let her cool off fo a few mins, then carryd on up the A19, foot to the floor till she ground to a halt lots of banging, loads of smoke, was bangin like a xxxx house door in high winds, i dipped the clutch to change down to get more revs - was at 2000rpm foot to the floor in fith! but as soon as the clutch pedal was pressed it seized solid!

i then had a V6 put in - problem solved! Mwa hahahaha!

[shabz]

so your car was overheating and banging but you thraped it some more? lol

im hoping mine is headgasket and not something more serious