'90 1uzfe turbo, oil in cooling system.

[Mr2turbo]

Hi,

I've been running this 1uzf(t)e in my granvia/hiace for 30000 km and 1.5 year now as my daily driver, http://www.lextreme.com/forums/showthread.php?t=9198, and yesterday I found that there where signs of engine oil in the coolant in the radiator.
It is both oil in the radiator and the overflow tank, and I filled about 0.5 l oil to get to normal level in oil sump.(it has nomally no oil consumption...)

btw. I'm running 9.5 psi or 0.65bar boost (had 344rwhp&531rwnm @ 0.5bar)

First off, I was thinking of a blown headgasket, making oil leaking from an oil passage to the water passage. But I've never heard of that leading to my kind of problem...

Can a crack in the engine block, leading to this symptom? ?

Does anyone have experienced similar problems?

 

[XR8tt]

I would say head gasket !!

 

[Mr2turbo]

thanks, xr8tt, talked to a bmw mechanic yesterday and he had seen several blown head gaskets leading to my kind of symptoms.

But I haven't noticed any other having head gasket problems on their uz??

my engine was stored for a while without coolant, from time it entered the japanese wrecker to i had it up running. I know this is might lead to erosion and blowing of head gaskets on some engines, typical 7mgte.. but would have thought there were others with that experience if this would have been an issue on the UZ....

 

[XR8tt]

thanks, xr8tt, talked to a bmw mechanic yesterday and he had seen several blown head gaskets leading to my kind of symptoms.

But I haven't noticed any other having head gasket problems on their uz??

my engine was stored for a while without coolant, from time it entered the japanese wrecker to i had it up running. I know this is might lead to erosion and blowing of head gaskets on some engines, typical 7mgte.. but would have thought there were others with that experience if this would have been an issue on the UZ....

Do the others have forced induction ??
Heads can lift easy if tune was alittle...?? thin.

 

[gloverman]

I Know of another with the same problem. Head will be off shortly to find out. Cheers

 

[spf_lexus]

were they factory gaskets or aftermarket?

 

[-Nemesis-]

I don't think it's as much a problem with OEM gaskets as it is the fact the gaskets are already 15-20 years old before people boost them. I'm expecting mine to go eventually.

 

[spf_lexus]

totally true, when my originals were under boost for the first time they lasted about a week! Gotta keep the revs within OEM though, it took one 7,000rpm pull by accident to become an oil fountain.

 

[Mr2turbo]

Thanks for your answer, folks..

Gloveman, appreciate to hear about your findings

spf_lexus, they are original gaskets, engine never opened. and guess you and -nemesis- do have a point about the age, including the storing without coolant, as i mentioned earier.

This migt have happend when I pulled a heavy trailer couple weeks ago, had a total weight passing 5 tonnes, when I let the engine pull hard all the way to follow the traffic in the norwgian hills... hehe

well, anyway, I think i might pull the engine this weekeend to invesitgate further. I'll take som pictures and share wat I find with you guys :happysad:

btw, off topic, here's a small launch outside my local tire-shop..
http://www.youtube.com/watch?v=N6V5TAZEXuE

 

[XR8tt]

Tmk its the alloy heads expanding, contracting which weakens head bolts over time.. Hence with boost heads lift and blow head gasket out..
Over time std bolts lose there elasticity...
Newer engines have multi layer metal/ steel [MLS] head gaskets which prevents them blowing out with more durable head bolts..
100 % smooth machining surface is required with these gaskets..

 

[-Nemesis-]

MLS gaskets and ARP studs are the cure for the 1UZ and mild boost yeah?

 

[XR8tt]

Yes and its not that hard to drill and tap to larger 12mm studs...
Re-drill head head bolt holes larger.. If engine is being assembled etc..

 

[Mr2turbo]

ok, maybe I will go for mls gasket/ arp bolts. But guess the standard size bolts will be good enough for a maximum of 600hp??

A friend running www.turbomotor.dk sell kevlar head gasket for the 1UZFE, he has told me that it's better than mls, as long as both block/head ar aluminum.. never heard of that before. anyone?

Do you think I will get a good result with a mls gasket, if i machine both head surfaces and clean and check straightness of the block ?

 

[Mr2turbo]

I removed and disassembled the engine last weekend, and found a small defect on one of the heads. this has lead to a little lack of pressure on the gasket in this area, just around the oil gallery. I guess this has lead to my oil leakage into the cooling water.
picture of the distortion:

There where also signs of oil from the oil gallery on the headgasket:

So I have ordered a pair of the carbon/kevlar 1.6mm headgaskets... I guess they will do the job. I will measure and re-use the original toyota head bolts.

in the meantime when I wait for the parts, I will powdercoat the top-covers and intake manifold...