block or head gasket?

[2revup]

Is there any way to tell if a block is cracked or its just a head gasget, apart from the obvious of pulling the damn thing apart.

Also other symptions is there is no bubling there doesnt seem to be any discolouration in the coolent. the oil seems normal its not runny.

The only thing i could see was that the coolent cap did have some sludge on it (wich is not promising.

[KARNAGE]

whats the engine doing to make you think there is a problem?

[2revup]

the car is overheating, however from what i can see if i drive sensably no boost at all then i could get quite far with out issues, as soon as i give it a boot full then bang it starts to overheat.
The current gasket is a TRD 1.2mm metal. and the funny thing is there is only about 15,000 since the rebuild.

Any help here would be great, what are the tests i can perform if any to find out what is the go?

[benny]

Have the cooling system flushed. I just had mine done and they had to take the radiator out because it was so full of crap and even after 3 flushes there was still crap coming out the block. Head gasket and motor are still in good condition, but the car use to start over heating if the weather was hot enough

Although if you just had a rebuild i would assume the cooling system was checked over then

[love ke70]

when u rebuilt the motor how long did the radiator sit empty for? and did you flush it when removed?

[2revup]

everything was flushed completly before the rebuild, i actully just did this well i didnt flush it properly, i did release the coolent and it did look clean still. I suppose i could try fluching everything.

What do you guys suggest, stuff the hose in the radator cap / opening and flush away?

But the question is what if it is not the radiator, will acompression test show if its a cracked head or blown gasket?

[2revup]

the other question is why, all of a sudden???
the car has been sitting for some time, whilst the car does get a start every now and then, I wouldn't have driven the car for bout 2 - 3 months, could this have any bearing on the issue?

[o_man_ra23]

DId you burp the coolant after you re-installed it?? 3S-GTEs are apparently notorious for getting airlocks in the cooling system.

Compression test should tell you if you have a leak. Also, does your motor use any water?? As it could be sending it out the exhaust.

How does the power feel?? Does it feel doughy or gutless or rough??

[2revup]

the power still feels nice, although there are some boosting it issues from 2second to third, but nothing i am concerned with more of a tuning issue.

No i must adminit i didnt burp it. Which is something i think i need to re-vist anyways. But even with the old coolent it showed the same symptons, so i am not sure this is the issue.

I will do a compression test ASAP.

if it were sending water out the motor wouldnt it normal smoke white?

It could be using the water, but if it is its doing it slowly.

[o_man_ra23]

Check your plugs and make sure your not running lean

[2revup]

o man, i dont understand how a plug can make it run lean, i understand about the gap of the plug, but know nothing on how a plug could make it run lean (unless maybe the plug wasnt firing, but then i would expect it not to idle)

I will test compression and burp the coolent see how this goes.

God help me if its a block.

I was reading something on this actully they say when its cold the block is open (if cracked) and then when it heats up then the crack closes, i suppose this could be true!?!

[allencr]

edited 11/2/8@00:22 for ignorance
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[Joshstix]

A borescope is the way to find out if you have a cracked block without pulling the motor down. It's a scope with an optical fibre through it and a lens on the end to allow you to look at the inside of the cylinders via the spark plug hole. I'd advise taking it to a workshop that has both a bore scope (boroscope) and a cooling system pressure tester.

They can pressurise the cooling system then look at the inside of the bores to see if there is an leakage from cracks.

[2revup]

NO, it is not the block and has almost never been the block in any car, ever, it's just a phrase that people who don't know shit, like to say for some reason.
Is it a race turbo/super charged running fuel(nitro/alcohol) or had ALL its core/welsh/freeze plugs pushed out by ice? If not, then it isn't the block.

thats not entirly true i have seen a few cracked blocks in my time.

I haven't read any symptoms of overheating but you saying it.
It's the gauge IMO.

Not the guage because the EMS ecu is also telling me that the temprateure is rising.

Hey Josh, Do you know if SAS has a borescope?

[Joshstix]

Yeah SAS have a bore scope, I used theres to diagnose my cracked block.

Yes allencr I had a cracked block. It cracked while it was running 10psi and making ~205rwkw. Luckily rather than believeing that I knew everything and people who say they have a cracked block know nothing I checked for myself. There is a definate problem with the 3S and cracking blocks. I guess you knew that already though as you make statements in such a way as to imply all knowledge is yours.

As to air in the system this is a real problem with MR2's as they are extremely difficult to get all of the air out of the cooling system with the radiator being in the front of the car and connected by water lines that run under the body of the car to the engine in the rear. In an ideal world yes once the thermostat has opened and the heater is full and the rad is full then the air should be out of the system. Unfortunately most of us live in a world effected by reality though and ideals aren't necessarily how things work.