Help me diagnose my oil leak

[BRAIDusa]

Looking for advice/suggestions/experience on where my oil might be leaking from on my 84 3.2 engine in my rally car.

It always had a dry stain on the bottom of the cyclinder #6 but now it's very wet, covers the underside of the block and drips on the floor a bit too much. There is also a similar amount of oil on the other bank mostly in the vicinity of cyclinder #3. On the right side the oil seems to be coming from somewhere higher than the oil tubes but on the left it may be from lower than the oil tubes. It also seems to continue to leak while parked, even for weeks at a time.

I've only looked from underneath so far and have not pulled anything off. Some images:

Untitled by Team Illuminata Motorsport, on Flickr

Untitled by Team Illuminata Motorsport, on Flickr

Untitled by Team Illuminata Motorsport, on Flickr

Untitled by Team Illuminata Motorsport, on Flickr

[Zuffenwerker]

Hi Paul, cylinder 6 is very wet near the base gasket area of the cylinder. That doesn’t necessarily mean it’s coming from the base gasket but certainly could. If it’s not coming from the base gasket look up. Possible leaks above cylinder 6 are: case through bolt o rings, “triangle of death”, or oil cooler seals.
It would be wise to clean everything real dry and give the suspected areas you can get to a coat of white powder…dry shampoo or foot powder. Watch carefully for leaks while the engine runs.

You may find leaky rockers to be part of your leak on the other side. It’s pretty cheap and easy to pull off all 4 valve covers and inspect the ends of the rocker bores for oil. It would also be a good time to ensure cylinders #6 head nuts are good and tight.

[David Inc.]

For sure the triangle of death has issues but maybe more. Eliminate that first because it's a heck of a lot easier than the base cylinder gasket! #3 might be rockers like Zuffenwerker suggests.

[PeteKz]

I had similar leaking from somewhere near the head/cylinder area on my engine. I figured it was the rocker shafts, so I took off the valve covers. Yep, oil from the ends of the rocker shafts. SO now I'm in the laborious and awkward process of removing each rocker and shaft and putting the rubber o-rings in the grooves to stop the leaks. What a PITA working in those tight spots bent over for several hours. Wish I had installed them when I rebuilt that engine a year and a half ago.

[BRAIDusa]

Thans for all the input. The car has been on the hoist for about a week now and not run since but oilcontinues to leak from around #6 cylinder. It runs down the block, accumalates on one of the bolt bosses then drips onto the floor. Does this after drying and spraying with brake cleaner. The left side seems to be coming from the oil line near #3. I peared over the engine and the top of the block over #3 and #6 appears dry. The oil cooler seals were replaced a few years ago and the area appears to be dry.

If that leaves the only candidates as rocker shafts or base gasket I'm wondering how bad it would be to use the car one more season before taking the engine out and going over everything? if I did this at light duty (car shows) or race duty would it be ok for another season? I could really use having this car available till next winter when the Quattro rally car should come online.

Untitled by Team Illuminata Motorsport, on Flickr

[PeteKz]

If it were my car and I was racing it, I'd fix any leaks in the TOD without dropping the engine, or do a partial drop to get better access (depends on what your engine bay looks like--do you have the stock Motronic system installed?). I would pull off the rocker covers and check for leakage around the rocker shafts, and install the O-rings on those if leaking. If it's the cylinder bases, or oil cooler, I'd just live with it until the winter.

[fallingat120mph]

Letting you know I just did the "triangle of death" -engine in - and could not believe where oil was getting from those leaks. Didn't solve everything, probably as in your case, but it has made diagnosing other leaks so much easier.

Agree with PeteKz...

[BRAIDusa]

So I pulled all the valve covers the other day and checked the head studs. The good news is NO BROKEN HEAD STUDS YAY!!!!!

I then checked all the rocker shafts for leaking. I couldn't say with any confidence that any of them are actually leaking. More YAY.

However, a couple of the galleries (right word) between the rockers are stained with tar-like old oil, as I've seen elsewhere on the cyclinder fins. No sign of where this or the fresh, clean oil is coming from. I'm calling that a win for now and plan on buttoning it back up. Good idea? I'll pull the engine next winter and go through it thourougly then. Meanwhile here are some pictures of what I found.

Untitled by Team Illuminata Motorsport, on Flickr

Untitled by Team Illuminata Motorsport, on Flickr

Untitled by Team Illuminata Motorsport, on Flickr

Untitled by Team Illuminata Motorsport, on Flickr

Untitled by Team Illuminata Motorsport, on Flickr

[PeteKz]

I wish my rocker shafts weren't leaking. I'm in the middle of the laborious process of removing each one and adding the RSR O-rings, then reinstalling. A PITA.

If you already plan to pull the engine next winter, I'd button it up and tolerate the leaks until then. The only thing you can re-check without dropping the engine is the ToD area, but I think you already did that. Check again anyway. Otherwise, get another driving season out of it first.

[kevbo]

I’ve been using this for a couple of years to chase down various oil leaks. Get a black light as well

ACDelco 1148963 GM Original Equipment 10-5045 Multi-Purpose Fluorescent Leak Detection Dye - 1 Oz

[David Inc.]

Originally Posted by kevbo

I’ve been using this for a couple of years to chase down various oil leaks. Get a black light as well

ACDelco 1148963 GM Original Equipment 10-5045 Multi-Purpose Fluorescent Leak Detection Dye - 1 Oz

Yes but also no. It's incredible how easy it is to spot this stuff, so it's a great tool, but also you're going to see so much more oil everywhere than you wanted to.

[dannobee]

Engine oil dye and a black light is how we located oil leaks at the stealerships.

Only the oil leaks AFTER the dye has been installed will show up. It works great. After the leaks are found and repaired, clean everything up to your heart's content.

[BRAIDusa]

Thanks chaps. I may try the dye. It sounds intriguing. However, I may just slap it back together and enjoy it for another season. Next year our Audi Quattro project should be ready so this one can have a well earned rest while we flog the Quattro.

[Mark Salvetti]

Guys, doesn't the fact that the main leak continues dripping even after the engine hasn't been run point to the oil return tubes? Although I realize the base of Cyl 6 is higher.

When sitting, would enough oil transfer back to the engine case from the tank to reach the bottom of Cylinder #6? Just seems odd to me that it would keep dripping from there when the engine hasn't been run.

Mark

[PeteKz]

Originally Posted by Mark Salvetti

Guys, doesn't the fact that the main leak continues dripping even after the engine hasn't been run point to the oil return tubes? Although I realize the base of Cyl 6 is higher.

When sitting, would enough oil transfer back to the engine case from the tank to reach the bottom of Cylinder #6? Just seems odd to me that it would keep dripping from there when the engine hasn't been run.

Mark

It's wet above the oil return tubes so it looks like it's coming from above them.

[kevbo]

Here's a pic of how i traced down a leak AFTER i put the engine back in. I had put a nose seal behind the pulley and hadn't put enough sealant. luckily some dow 732 helped until i drop the engine again next winter:

[BRAIDusa]

Oil leak update.

I did just put it back together and it no longer leaks! Weird no? It might not be though. There was a vacuum line off too. It goes from the back of the throttle body to a valve on the side of the oil tank. So i reconnected it. Could it be that this was causing a buildup of pressure in the oil system that precipitated the leak? I drove it about 80 miles, last 40 on the freeway. Parked it overnight over some carboard and not a drop! Same thing again after driving back, all freeway.

Untitled by Team Illuminata Motorsport, on Flickr

Untitled by Team Illuminata Motorsport, on Flickr

[911 SLANT]

Maybe the valve cover gaskets

[PeteKz]

Update on my project to install RSR seals on the rocker shafts: It worked. No more oil leaks coming from above the oil tubes. I still have a slight leak from somewhere on the back of the engine (some dampness, maybe one drop after parking it overnight), but I can live with that for some time.

Damn, that was a long project. It took at least an hour per rocker shaft, plus cleaning and resealing the covers, and changing the oil as long as I had drained it out anyway.