240 93 Crankshaft seal still leaks after 2 replacements

240Dad · Post by **240Dad** » 11 Nov 2012, 18:14

My 93 240 has 200,000 miles on it. I had quite a large oil leak at the front of the engine that covered the entire underneath of the car back past the transmission. I cleaned it off and, with the engine running, watched thr oil seep in a steady stream from under the harmonic balancer (crankshaft pulley). I removed the required parts to get to the crankshaft seal and inspected the camshaft, intermediate shaft and crankshaft seal. The cam and intermediate seals were dry and the crankshaft seal was wet. I replaced it and it still leaked so I figured I hadn't put it in far enough. I took it all apart and replaced it again. Honestly there is the same amount of oil leaking from the same place as there was before the first seal replacement.

Is there anything else that could be leaking in the area around the crankshaft pulley?
Thanks,
Bill

Post by **billofdurham** » 12 Nov 2012, 12:20

Two things come to mind:
1. The seals are being damaged if you aren't using the correct press tool.
2. How long is it since the flame trap was cleaned?

The second point is one of the first things to check when any engine oil seal starts to leak.

Bill.

240Dad · Post by **240Dad** » 12 Nov 2012, 15:10

I replaced the flame trap about a year ago. I will inspect, replace it again and see if that helps. Also, would it matter at all if I changed the oil to Valvoline Synthetic 5w40? Seems like the leak started soon after the change from conventional oil. I changed out the rear main seal myself 2 years ago and never had a drip from it.
Thanks,
Bill

Post by **billofdurham** » 12 Nov 2012, 15:20

I wouldn't recommend changing to synthetic oil in a high mileage engine. I have heard of and seen too many that have developed leaks.

Bill.

240Dad · Post by **240Dad** » 12 Nov 2012, 17:49

I hope that changing back to conventional oil will take care of it. That is what I will do and let you know. Can you suggest an additive that might help?

Post by **billofdurham** » 13 Nov 2012, 12:21

I no longer use oil additives as research by independents has shown most of the claims to be overstated. (That's a polite way of saying rubbish!!)

For many years I added a teaspoon of Molybdendum Disulphide powder to every gallon of engine oil. This was on the advice of a chemist employed by ICI, who supplied the powder. The moly does not block the oil-ways as do those which use PTFE. The only modern additive I can think of using the same compound is Molyslip.

Bill.