Where Do You Think The Oil Is Coming From?

coollx · 01-10-2008, 04:15 PM

I'm just getting organized to perform my first valve adjustment and oil change. The car is a 1985 Targa that is off the road so the engine is not being started but yet I have an oil leak under the engine on the driver's side.

The oil is accumulating on the bottom edge of the lower valve cover then dripping on the floor. Since this 911 is totally new to me I thought I'd ask the experienced members here what the likely places the oil is coming from keeping in mind the oil level is full and the engine is not being run. It probably leaks a half dollar size amount of oil each day.

Could it be from the upper valve cover on the driver's side?

Or something higher on that side of the engine that pools oil so it can leak past a bad seal or gasket?

Any suggestions or thoughts are appreciated.

Dom

coollx · 01-10-2008, 04:18 PM

Sorry for the double post.

tcar · 01-10-2008, 04:22 PM

So, 3-4 drops maybe, even though the car is never started?

coollx · 01-10-2008, 04:33 PM

tcar, I think it amounts to a bit more than 3 or 4 drops.

The formation on the concrete floor where the oil drips is a very wet spot, not like something leaking that just looks bigger because its absorbed and spreads over a wider area.

DUK · 01-10-2008, 05:02 PM

"oil level is full and the engine is not being run"

You're going to want to check this also before starting the engine. It should not be full on a cold engine.

The leak could be coming from various things. Start by cleaning everything and see where it starts from and travels to.

sig_a · 01-10-2008, 05:50 PM

Good advice to clean all evidence of oil from every area under the engine. Then drive the car until oil temp is normal. Park overnight where engine is over a piece of clean cardboard or something similar. Check the next morning to get an idea of how bad the leak is. First check the oil return tubes. It is very common for the seals to leak from above the valve cover and drip down to the lower cover seam. Extensive info on DIY r&r of oil return tubes at pelican search engine. I removed the complete exhaust/heat exchanger system for "easier" replacement of Weltmeister expandable oil return tubes. Fixed the problem and saved +/-$500.

tonythetarga · 01-10-2008, 06:32 PM

Quote:

Originally Posted by Duke Zink

"oil level is full and the engine is not being run"

You're going to want to check this also before starting the engine. It should not be full on a cold engine.

Agree. How do you know the oil level is full if you have not run the car and let it warm right up? The only way to check the oil is when it IS running and FULLY warmed up. If your dipdtick is showing full and the car is not running, you've got way too much oil in the car.

coollx · 01-11-2008, 03:49 AM

Let me clarify that the oil level is not at the full mark now.

It was just below the full mark as it should be when the engine was at normal operating temperature after driving the car a good long time before I put the car up for the winter.

In addition, I wiped off everything I could see and reach from underneath the car to try and determine where the leak might be. One thing I did notice and don't know if it normal is that one of the oil return tubes on the drivers side can be rotated easily with my fingers. Is this normal?

OldTee · 04:35 AM

Get a leak detector kit and put an oz or two in the oil. Clean throughly. Drive until really hot. Check with the light that comes in the kit. Leak will be dark green. Light green is blow around oil. Google oil leak detector. http://www.autobarn.net/fluorleakdet1.html better yet http://www.amazon.com/Tracer-Products-TP1121-Leak-Finder/dp/B0002NYBF0

sig_a · 01-11-2008, 05:42 AM

"One thing I did notice and don't know if it normal is that one of the oil return tubes on the drivers side can be rotated easily with my fingers. Is this normal?"[/QUOTE]

No, that's not normal and indicates worn seals at both ends of the tubes. Good to keep in mind if the tubes are your problem -- replace all four.

I went thru the same process with my 87 targa. First I adjusted the valves thinking the leaks might be eliminated with new valve cover gaskets. When that didn't work, I looked close to find the return tubes were the problem. I pulled the exhaust/heat exchanger system for easier access to R/R the tubes and to clean the oil from the topside of the exchangers. No more burned oil stink. No more leak.

You may also want to invest $100 in a Bentley Manual, if you've not done so.

3.2 CAB · 01-11-2008, 07:12 AM

+1 on what sig_a stated. The oil return tubes should not be really easily turned or rotated. That would indicate loose, torn, cracked, or some type of damage to the o-rings on the return tubes. Are all of your return tubes the same? Or do you have a mix of factory one piece types and replacement two piece types? The reason I ask, if you already have the two piece style, you should be fine if you just replace the o-ring seals, they don't cost much, if they are the factory one piece type, it sounds like it is time to install the two piece type, and if you can, go ahead and replace all four of them, while you are doing the repairs. I think that the CAT, will sometime cause the tubes on the drivers side to prematurely leak before the right side due to the higher temps the drivers side tubes are exposed to. I might be wrong with this, but it seems to me, that I have seen more drivers side tubes leak, before the right side tubes leak on a 3.2. Ditto, on the Bentley Manual! Good luck!!

coollx · 01-11-2008, 07:58 AM

The oil return tubes are all the original ones. The Bentley manual will be one of my next purchases.

As I stated earlier in this thread, the engine is not being started which means the oil has to be coming from a location on the engine where oil resides and the gravity of it is leaking past a seal or gasket.

Over the weekend I'll try to take a closer look at where the oil is coming from paying particular attention to the oil return tubes on the drivers side.

Thanks for all the input.

Dom

sig_a · 01-11-2008, 01:00 PM

"As I stated earlier in this thread, the engine is not being started which means the oil has to be coming from a location on the engine where oil resides and the gravity of it is leaking past a seal or gasket."

All the more reason to suspect the oil return tube seals. You are on the right trail.