88 300E oil leak getting serious - PeachParts Mercedes-Benz Forum

cmcdonnell · #1 03-10-2007, 04:25 PM

I bought this car last month and noticed a few drops of oil on the driveway. Now it is a rather large rectangular puddle right under the front of the tranny. I bought some ramps today (Rhino plastic, pretty cool) and got under the car for the first time. It appears that the oil is coming from the oil filter housing area and dripping down behind the starter and blowing back. It was very hard to see anything. I can tell that it is not coming from the head gasket, it is dry up there.
Question: Is this a common leak and how do I go about repairing it, from under the car or from the top? Any help is appreciated.
Chris

softconsult · #2 03-10-2007, 04:53 PM

I don't get it. The oil filter is on the left side of the engine , if you are facing forward. The starter is on the right side. A leak from the timing chain cover is very common and blowing backward in the air stream is too. Don't think I've ever seen a post about a leaking oil filter housing.

Steve

psfred · #3 03-10-2007, 06:15 PM

Starter is on the left on the M103.

Replace your valve cover gasket and make sure the drain hole is good if there are any signs of oil leakage there.

I'd replace the oil filter, it's a spin-on and there is no reason to suspect that the gasket isn't bad. Worst case there are two there, but usually you dump out the entire crankcase full pretty fast as they won't stay in. I've never heard of the housing leaking, but I can easily imagine a spin-on filter leaking. In fact, the oil change place we use at work has had an entire truck load of bad filters appear -- replaced every single one due to leaking filter seams.

By a Wix filter, Hengst, Mann, or Bosch. If the Bosch is made in India, get one from a different maker.

Peter

cmcdonnell · #4 03-10-2007, 10:52 PM

Valve cover gasket and filler cap replaced last weekend. I wiped off the oil under the gasket to check for any leaks and so far, it is dry. What drain hole are you referring to, the one on the right side of the crankcase? I don't have a manual yet and am new to the M103. I was afraid to take off the filter today because I didn't have a spare, but will do it tomorrow. I guess I will be able to see alot more with it off. Thanks!

softconsult · #5 03-11-2007, 08:13 AM

I was definitely wrong, starter is on the left side as psfred said. I do recall that one time I did an oil and filter change on my M103 and experienced a massive leak. Really more like a dam breaking. I fired it up and drove off only to see the oil pressure guage descend to zero. I pulled over and shut it off.

Had it towed home. Turned out that the rubber seal on the filter had warped and didn't seal. Put on a new filter and all was well.

Steve

S-Class Guru · #6 03-11-2007, 07:11 PM

The oil pressure guage sender is right under the filter. I guess it could maybe spring a leak? Generally the valve cover gasket drips on the passenger side when it hardens and cracks cause it leans that way.

Good luck, hope it's a filter.

DG

cmcdonnell · #7 03-18-2007, 12:19 AM

Here are the pics David requested, however it is difficult to see much.

joel · #8 03-18-2007, 03:02 AM

this maybe a long shot, but it happened to me on my Jeep GC.

are you sure you took out the old rubber gasket from your last oil filter?

what happened to me is i left the old rubber gasket and place the new filter on top of it. oil all over.

cc260E · #9 03-18-2007, 08:16 AM

I would suggest to monitor also the oil level? Is it really motor oil?

Have a look to the steering damper, it may leak.

May be you did it already, have you removed the bottom protector to try to see from bottom where the oil is dropping from.

Good luck

cmcdonnell · #10 03-18-2007, 11:26 AM

I did check the steering and it is dry and all buttoned up. At first I thought that was the problem but luckily it is not. When under the car, I traced the stream of oil and it was apparently coming from the area of the oil filter. Changed the filter properly, changed the oil pressure sending unit properly, and it still leaks just as much as before. I am going to order a new oil filter stand gasket and replace it. There is old oil in places coming from the timing cover, but nothing fresh. It looks like someone dealt with that in the past, because there is gasket sealant on both sides of the cover. Question: Can the oil filter stand be removed without removing other assemblies?
Thanks for the ongoing support!
Chris

cc260E · #11 03-18-2007, 02:26 PM

just a recommendation.

If I were you I would try to clean every single zone where there is oil, and then try to identify more precisely where oil is coming out before bying any further part.

If you remove the oil filter have a look to the contact surface on the engine crankcase where the gasket is applied in case that surface has been damaged.

cmcdonnell · #12 03-18-2007, 03:20 PM

OK let's use our noggins here. M103 engine with oil leak on left rear. Oil cap replaced and dry. Valve cover gasket replaced and dry. Timing cover inspected and dry. Head gasket inspected and dry. Oil filter replaced properly. Oil sending unit replaced properly. As with any oil leak, area was cleaned (with Brakleen) and wiped down. Cannot determine source of leek because I cannot see behind the starter motor or under the intake manifold.
I asked the question earlier in this thread: Does anyone know where I can get the dye additive for the oil to determine the leak source?????
Also asked: Does anyone know the procedure for disassembling the oil filter stand from the engine???????
I appreciate all of the suggestions, but I feel we are covering the same ground. Where else COULD it be leaking from? I just want to be able to go show off my car without leaving a streak mark behind!

Thanks,
Chris

John Plut · #13 12-01-2007, 12:29 PM

You definitely need to apply the sealant to the ends of the strip gasket and the vertical face of the cover (that has no gasket). I used a thin film of sealant on the surface that mates with the strip gasket because you have to slide the upper cover in place (due to the cam seal and guide pins). The thin film helps keep the strip gasket from rolling out of its groove.

richard28 · #14 01-09-2008, 12:15 PM

Chris,
Yesterday I pulled the oil pressure sender and discovered there was no sealing ring, or what I would call a "washer". Got one from the dealer ($1.80) and installed it, noting the oil level; after this weekend of driving, I should know if the leak is gone.