ST165 oil leaks from back of the engine

Mateo

Member
Getting pretty frustrated with my oil leaks... Just did my valve cover, distributor O-ring and oil pan gasket (used a pretty terrible cork gasket and now is just Toyota FIPG) and it still pisses oil through the back of the engine. Does anyone have any ideas where I should check? I replaced all the hoses in the back but its not implausible they are leaking now.
 

alltracman78

Active member
Have you thoroughly cleaned the back of the engine? So you can see where it's coming from?
That's your first order of business. Then you can track it down.
Here are some possibilities.

It could be the head gasket leaking oil to the outside.
Or you didn't clean the sealing surface on the oil pan and bottom of block correctly so the FIPG couldn't correctly attach to the surfaces.
Or the valve cover gasket isn't seated right. I know on the gen II engines the corners over the cam caps need FIPG also. Does the gen I need it?
Can you tell where on the back it's coming from? The timing belt end has the oil pump, it's possible that's leaking.

I don't think there are any hoses carrying oil anywhere on the engine except for the turbo. What about your power steering lines? Or the pump?

Or, your block has a crack in it?
Unlikely, but trying to cover all the bases.
 

Mateo

Member
Yeah I took it to work and used some Gunk engine degreaser and pressure washed it down so now its sparkly clean. Highly doubt its a cracked block or head gasket, I've had the engine out twice and its passed a compression and leakdown test with flying colors, but I did my oil pan with someone who was a certified Toyota/Mitsubishi technician so I highly doubt that's still leaking. But the Gen 1 head does need the FPIG from Toyota (Which I used, but I think it still leaking, but not as bad. I have a twosrus valve cover bolt set coming in for when I redo it.) It's pretty difficult to check at the moment where exactly it is leaking from, but it seems to be above the transmission onto the exhaust and I'm fairly certain my oil cooler O-Rings are leaking so I'm going to redo those and find some new crush washers that fit the oil cooler bolts. This is definitely engine oil though, I can see it on the dipstick and also see oil pressure gradually drop over a few days before realizing I can't even see oil on the dipstick. I also think maybe the reason it seems difficult to track down is maybe the oil cooler is leaking onto the exhaust and just burning instantly so I can't even tell. I did the small distributor O-Ring as well, does the larger internal one tend to leak also?

Thanks for the help
 

Mateo

Member
Update; disassembled the crossmembers and exhaust and went to check my bolts for the oil pan and snapped one... But I found where my oil leaks coming from, the oil cooler is trickling down onto the sump, then onto the crossmembers which made it look like the back of the engine was leaking. Now I have to deal with this oil cooler leak which looks super fun...
 

Mateo

Member
rallygarage":c9lx3pnm said:
Oil seal inside destriburor? Not the o ring on the outside.

Nope, I said I already did the distributor O-Ring, but it's the top bolt for the oil cooler that's just constantly leaking as soon as the engine starts. Does the MR2 use a heat exchanger style oil cooler instead of the ST165s coolant box thing?
 

alltracman78

Active member
No, all the 3SGTEs use the same type. They're not all identical though.

Not the end of the world.

Remove your alternator, remove and carefully hang your ac compressor and use patience. Make sure you replace all the seals and hoses in there while you're at it.

Considering how old the engine is might be time to pull it and reseal everything?
 

Mateo

Member
alltracman78":2a3ix1za said:
No, all the 3SGTEs use the same type. They're not all identical though.

Not the end of the world.

Remove your alternator, remove and carefully hang your ac compressor and use patience. Make sure you replace all the seals and hoses in there while you're at it.

Considering how old the engine is might be time to pull it and reseal everything?


Already pulled it twice for clutch stuff and put all new gaskets on everything, along with most hoses and lines. I pulled the engine again after my slave cylinder ate my throwout bearing and did the valve stems while I was there. Bold of you to assume I still have AC, I was planning on removing the entire turbo assembly by disconnecting the 4 bolts that hold it to the exhaust manifold but I'll give it a shot with just the alternator.
 

Mateo

Member
Alright got new crush washers (original isn't available so I had the guys at Toyota find me simile one's to what I have) and new O rings and I started it aaaand it leaks worse. It looks like it's pouring out of the banjo bolts so I'm hoping if I torque them down maybe because they are different they needed a bit more torque? Massive pain to do in the driveway though
 

simple

Member
It's such a knuckle buster engine. Good luck but maybe try another washer size and definitely use the service manual to get the right torque. They are on there pretty tight. Big bolts.
 

Mateo

Member
simple":2atxi8ea said:
It's such a knuckle buster engine. Good luck but maybe try another washer size and definitely use the service manual to get the right torque. They are on there pretty tight. Big bolts.

It's such a pain. I was just going to go from 38 FT/LBs to maybe 45ish to see if that helps... I don't even know anymore it's just a pain for 2 bolts and o rings
 

Mateo

Member
Well I've torqued down the bolts with no luck and am going to get new washers and o rings... Again. Does anyone have any tips or part numbers for different crush washers? Toyota discontinued the part number for the washers because it's Toyota and if it's 20+ years old it's probably discontinued
 
Maet":c12wv3ik said:
Well I've torqued down the bolts with no luck and am going to get new washers and o rings... Again. Does anyone have any tips or part numbers for different crush washers? Toyota discontinued the part number for the washers because it's Toyota and if it's 20+ years old it's probably discontinued
What is the part number(s) of the crush washers you need (that you said Toyota has discontinued)?
 

Mateo

Member
93celicaconv":3bmq7hl4 said:
Maet":3bmq7hl4 said:
Well I've torqued down the bolts with no luck and am going to get new washers and o rings... Again. Does anyone have any tips or part numbers for different crush washers? Toyota discontinued the part number for the washers because it's Toyota and if it's 20+ years old it's probably discontinued
What is the part number(s) of the crush washers you need (that you said Toyota has discontinued)?


Crush washers for oil cooler(ST165):
15785-88380 (X4)

Not much help now because I just found a crack in my line right next to it which made me think the bolts weren't sealing. Going to try to repair the line first, if I can't do that find one in the US then if I still can't find one then I'll have to order one from GT4 play in the UK.
 
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