oil leakage

[engatwork]

I seem to have developed an oil leak. Weekend before last I changed the oil and filter and went with 10-40W Castrol. Prior to that I had been running 20-50W. Since the oil change I seem to have a slight leak. I can wipe it down and then after around 100 miles I look in the area of the bellhousing and see drops hanging on some of the bolts on the outside of the bell housing. In addition, I "feel" in the low area of the bell housing closest to the engine and it seems to be wet with motor oil. Could changing to 10-40W have caused this? Is it possible that the rear main seal is bad? I do not see any signs of oil streaking on any of the rotating parts inside the bell housing. Any thoughts/ideas on what is going on here? What is the estimated cost for replacing the rear main seal?
I am considering going back to 20-50W oil this weekend to see if it will stop the dripping.
thanks,
engatwork
'95 E320
'97 Honda CRV

[Benzmac]

I have NEVER seen different oils cause oil leaks.

I would suspect that maybe you dripped some off or the o-ring on the canister did not seat well.

Also, head gaskets are know to leak on these above the passenger's side and will hang right off of the bell housing.

Take it up on a lift to see exactly where it is coming from.

If it is the head gasket, I will do it if needed.

[engatwork]

Thanks Donnie,
I got underneath yesterday evening and I don't see anything coming from underneath the oil filter area but it does seem to be kind of "wet" underneath/behind the starter. I will keep an eye on it over the next few days and see if I can tell anymore about it. Have you ever had to replace a rear main seal. I don't really feel this is where it is coming from because I do not see any oil "streaking" on the rotating parts in the bell housing. What is the estimated time on replacing the head gasket Donnie?
thanks,
engatwork
'95 E320
'97 Honda CRV

[Zoonhollis]

I too would like to know how much a rear main seal replacement costs. I have the exact same oil-leak symptoms on my '84 300D. It leaks about 1/2 ounce every time I park for any length of time, and it seems to come from the bell housing area. I had a main seal replaced on a Volvo 240, and it cost me $400. I would be surprised if that amount would be sufficient for the same job on a Mercedes...

Sometimes oil dripping from the bell housing is from a leaky oil pan seal. It blows back there when driving. Just a thought.

[engatwork]

I went back with the 20-50W yesterday evening and the leak seems to have been substantially reduced. When I look under there with the trusty old maglite I can see a drop hanging on a couple of the bolt heads in the area of the bell housing. One of the bolts is up near the grounding strap on the passenger side of the engine. I do not see any oil coming from the head gasket area on either side of the engine. Maybe it is coming from the rear of the engine. Has anyone ever seen the head gasket leak at the rear of the block? I am going to have to bring my inspection mirror home to look up in this area. As long as it is no more than just drops hanging on the bolt heads I will probably not worry too much about it (if that is possible).
thanks for any comments/advise.
engatwork
'95 E320
'97 Honda CRV