Oil leaks...joy. Pics
10-19-2016, 04:03 PM
#16
There are other places that can be leaking which make their way down to the oil pan. One is the rear cam tower (cork gasket). It is a bit of a magic trick to tighten it, for whoever last did the work. The other sneaky places are the AOS and balance shaft near it (upper?). Both can pool oil on the block where you absolutely cannot see it with the intake in place, and work their way down the back of the block.
Of course the oil pan gasket is always difficult and the world's biggest PITA to get to.
Of course the oil pan gasket is always difficult and the world's biggest PITA to get to.
10-19-2016, 04:25 PM
#17
However, if your car is like mine, the area of the dipstick is where the AOS plugs into the block and there are rubber rings which seal it. You can leak a lot of oil from this area (on the 951 at least).
10-19-2016, 05:00 PM
#18
Oh I know it. I replaced them with factory seals just a few months ago and there still was oil leaking in that general area. This is going to be a DE car for next year so I have time to sort it at least.
10-19-2016, 09:08 PM
#19
Checked tonight. Not so bad so not sure why it smells of burnt oil slightly.
Looks like I really should reseal the balance shafts. The oil around the dipstick actually seems to be coming from the j-tube. I can see the stream coming down so I suspect it's cracked near where the hose from the AOS is and is condensing on the outside instead of the inside.
Looks like I really should reseal the balance shafts. The oil around the dipstick actually seems to be coming from the j-tube. I can see the stream coming down so I suspect it's cracked near where the hose from the AOS is and is condensing on the outside instead of the inside.
10-20-2016, 04:49 PM
#20
I took this pic at work so I apologize for the lack of detail.
The oil is clearly coming out from somewhere above the dipstick. What's odd is that it seemed dry up by the balance shaft last time I was in there (last month).
The AOS seals are new. Maybe this is coming from the rear of the balance shaft or further up as I'm still trying to figure out why there is oil condensation on the plastic J tube.
I need to take this side apart again.
The oil is clearly coming out from somewhere above the dipstick. What's odd is that it seemed dry up by the balance shaft last time I was in there (last month).
The AOS seals are new. Maybe this is coming from the rear of the balance shaft or further up as I'm still trying to figure out why there is oil condensation on the plastic J tube.
I need to take this side apart again.
10-21-2016, 11:03 AM
#21
More mystery. I grabbed another photo to share where you can see oil pooling in a weird spot. This isn't coming from the valve cover as it is dry.
I also looked around the balance shaft cover and it is dry too unless it is being very deceiving about leaking...plus this pooling isn't near it.
Is this all coming from the AOS? It's just so weird as some things near oil covered parts are dry.
I also looked around the balance shaft cover and it is dry too unless it is being very deceiving about leaking...plus this pooling isn't near it.
Is this all coming from the AOS? It's just so weird as some things near oil covered parts are dry.
10-21-2016, 07:25 PM
#23
Drifting
I recommend buying a fluorescent dye tracer kit (cheap) from the autoparts store. Put some in the oil, run the engine for a hundred miles or so, then, using the "magic" glasses and UV flashlight start going over the same areas again. It's a real time saver.
10-30-2016, 10:56 AM
#24
Found the rubber connecting boot torn badly so that was getting oil everywhere. I do have a lot of oil possibly caused by blow by. One thing I just changed was the oil cap O ring...never even thought about that.
Ive ordered parts and should also change the rear balance shaft seal while I'm in there.
10-31-2016, 08:00 AM
#26
Hi Van,
They probably are and head work is on the agenda when I get to needing to do the belts again. I'm doing them at a 20k interval so it won't be too long now.
However, how do worn exhaust valve guides cause too much oil in the intake?
They probably are and head work is on the agenda when I get to needing to do the belts again. I'm doing them at a 20k interval so it won't be too long now.
However, how do worn exhaust valve guides cause too much oil in the intake?
10-31-2016, 11:02 AM
#27
Rennlist Member
Good point - it's probably the intake valve stem seals that are letting the oil get into the intake. When some valves are closed, another is open and the engine is drawing in air, causing a little bit of a vacuum in the intake manifold. This suction will pull oil down along the valve stem and into the manifold. Then there's enough turbulence to make it get past the throttle body into the intake plumbing.
10-31-2016, 11:12 AM
#28
Ah okay. I did replace all the seals last time but this makes some sense especially seeing as the breather tube from the AOS to the intake is not full of oil as I expected.
10-31-2016, 12:54 PM
#29
Rennlist Member
There was a TSB in 89/90 regarding updated valve guides on the early 16V 944s and 32V 928s. The symptom was excessive oil consumption, specifically at high RPM. I can't recall the TSB number but the "cure" was to install updated valve guides or use a specific two part glue on the valve guide and seal. As a side note, the updated guides were factory installed starting in 1989 on the M44/41 motors.