Crackership

I've been (very) slowly trying to figure out what's leaking on my car... but I just can't seem to figure it out. I know my cam tower gasket is leaking, but I don't want to place an order for a new one until I can figure out where the other leak is coming from.

So, here's whats going on:

It's leaking from somewhere on the left (driver's) side of the engine.

It seems to only leak under load as I've run it and laid under it and don't see any leaking.

When it does leak, it leaks a lot... as is about a quart in 20 or so miles.

I've replaced the dipstick o-rings (thanks Matt!) as they appeared to be the source... it did not stop the leak, although, the dipstick was very difficult to install with the new o-rings (perhaps I did it wrong?)

All of the oil that explodes out of the engine appears to be below the oil pan gasket... leading me to think it's either the dipstick tube or the turbo drain.

I recently had the engine out and replaced nearly every seal, except the front seals, as those were done at the last t-belt change.

When I had the engine out (and the pan off), I replaced the crush washers for the turbo drain. I had two sets of crush washers that were the same size, both sets were the appropriate size for the turbo drain banjo bolt... neither package had a part number on it, and the only (noticeable) difference was that one was copper and the other appears to be aluminum. I used the copper ones... should I have used the aluminum-looking ones?


I know a mystery leak is very difficult to diagnose online, I just figured I'd ask if anyone had any ideas... especially about complications with the dipstick tube o-rings or the turbo drain. I'm beyond baffled.

TIA

86 951 Driver

Have you tried to add dye to the oil to see where exactly its coming from?

gpr8er

Under load,boost? Make sure that you didn't reverse the AOS breather hose and the ICV hose. If so you are pressurizing the crankcase under boost. It's easy mistake to make since both hoses are the same size and are right next to each other.

minho78

Balance shaft seal O-ring. Try to look in between the Intake manifold and AOS.

mtnman82

+1 on checking the AOS breather and ICV hoses, especially if you mean it only leaks (orleaks a bunch more) on boost. Easy to accidentally swap them. Ask me how I know...

Crackership

Just picked up some dye today. Hopefully I'll have some time tomorrow to throw it in, drive it a bit and get under it for a look... Do you know how long the dye continues to work after I put it in? Just in case I don't get to it right away...

Just checked those to be sure, but they're in the right place... AOS to the J-pipe, ICV to the hard pipe... I've gotten them backwards before, so I'm usually super extra careful to make sure they're in the right place, but good call, they are easy to swap and could easily have been the problem.

I replaced them when I had the engine out, but I checked there anyway... it's totally dry up there.

Any other ideas? Anyone know which of the turbo drain crush washers I should have used?

NZ951

Did you steam clean the engine before you went looking for the leak? If not, there would be no easy way to find the source.

Crackership

I very thoroughly cleaned the engine with brake cleaner and gasoline when I had it out... There's less than 100 miles on it since putting it back in, so, aside from the small leak I have from the cam tower on the other side of the engine, all of the oil in the engine bay should be from whatever is leaking...

Out of curiosity, and for future reference... how does one go about steam cleaning their engine?

NZ951

I go to the local car wash, put in some $2 coins and away I go!

It might be worth getting a video camera and light and use that to get into the spots you cant check by looking? It might be just as easy to whip the intake manifold off and check the AOS and turbo etc then work down the motor.

Crackership

Ahhh... I was thinking something far more complicated when you said "steam clean"

I'll toss the dye in and see if I can find it from the bottom first, but, if that doesn't show me anything, I'll pop the intake off and start working downward.

Is there a trick I don't know to removing the fuel rail without spraying fuel everywhere? I've done it dozens of times, and tried everything I can think of, and it just vomits fuel everywhere every time....

NZ951

Ah yeah, steam cleaning as in the high pressure hot water at the car wash

I just put a rag under the rail when I take it off...

Crackership

I put a rag under it too... I was just wondering if there was some magical way to prevent the spilling..

NZ951

No magic solution Im aware of, though its better if its not recently been running or primed so there is not so much pressure in the line. In the mornings for example there is almost zero gas coming out.

951Saga

With the ignition off pull the fuel pump fuse then crank the engine a few seconds. There will be fuel in the rail, but not at high pressure.

I’m sure you know this… the ignition must always be off or battery disconnected before removing/ replacing relays and fuses. My friends 951 had evidence of arcing on the DME and fuel pump fuse contacts which contributed to the fuel pump not working.

Doyle623

I'm having a similar issue around the cam tower, but can't seem to find the source. I'm going to check the vacuum lines as suggested. What type of dye are you using? I've heard of using dye for A/C systems, but not oil leaks. Will you need a UV light to detect the leak after adding the dye?