Hello! I've had my 240 for about 4 years, I've done all the work on it myself, from oil changes to replacing the gas tank.

Current issue:

I commute about 60 miles a day, and when leaving work I noticed a little bit of oil under the car, popped the hood and oil had been sprayed here and there, the leak appears to be coming from the bottom of the timing belt case, I think oil was hitting the V belts and getting splattered around from there.

What is the cause of the leak? I figured it'd be the camshaft and/or crankshaft seal. Is this a correct diagnosis? Any special precautions? I ordered a new timing belt and tensioner as well, figured I'd replace it while I'm at it.

Thanks!

 

the cam seal isn't too hard, the crank seal requires removing the main pulley which can be a real pain. you also can get leaks from the intermediate shaft (which drive engine side distributors, and the oil pump)

pop the cover off the top front of the timing belt housing, and peek inside with a flashlight, probably be able to see whats going on...

if you haven't replaced the water pump in 120k miles (2 timing belt intervals), its probably a good time to do that, too, they rarely last much longer.

USE ALL REAL VOLVO BRAND RUBBER SEALS. the after market seals mostly fail.

 

my car is doing the same thing. my t-belt cover is cracked. I changed the Valve cover gasket to see if that was the problem , when removing v-cover I noticed the head was dirty full of particles. so I cleaned with a rag. now I need to degrease the engine and see if the oil leak still persists.

 

Thanks Pierce. Pulled the cover off, it looks like the leak is coming from the camshaft, I'll replace the seal and hopefully that will clear things up.

Woc2, the case is broken on mine too, on the left side where the bolt is. It looks like the case comes in three parts: upper, lower, and inner. I ordered all three plus seals. Hopefully it locks things in.

 

So, here's an update:

I took the entire thing apart yesterday. Replaced the camshaft seal, crankshaft seal, auxiliary shaft seal, valve cover gasket, timing belt and tensioner, and timing belt covers (upper, outer, and lower). The odd thing is, that while oil was pooling up on the bottom of the timing belt cover, there wasn't much oil on the inside. I have no idea where else the leak could have originated from.

My only other hunch is that perhaps the PVC valve has failed and is forcing oil out in several points? Another hunch I have is that all these issues are stemming from the fact that I put synthetic oil in my car, which I've read can clean the inside of the engine, exposing cracks on seals that have been plugged by buildup over the years.

The car is cranking but isn't turning over. Pretty sure I put the t-belt on wrong. No oil appears to be leaking out from cranking the engine.

 

these 'red brick' motors don't have a PVC valve. they have an oil separator box on the intake side of the engine block (under the intake manifold), this has a 'flame trap' in it, which is just a dime sized ceramic disk that has holes in it, these are connected to the intake path. Yes, this box and the trap inside can flug up with tarry combustion byproducts, then once its completely clogged up, the engine will tend to blow its seals (usually the camshaft seals go first)

synthetic oil does not cause seal failures, thats a old wifes tale.

 

I changed the flame trap, It is interesting that when I removed the hose and the flame trap case, there was nothing there! I guess the PO removed it, or it got so bad that it deteriorated on its own. Now I have a new kit in there. But still I have a leak somewhere.

 

fixing the flame trap will stop it from blowing /new/ leaks, but it won't cure an existing one.

 

So I've replaced cam crank and aux seals, valve cover seal, and the leak persists. It looks like I have multiple leaks. Would the water pump gasket cause an oil leak? I'm thinking it's either that or the head gasket needs to be replaced. Although, the oil is only coming from the front (which makes me doubt head gasket), and the water pump appears to have oil around it. I also noticed what looks like engine oil, in the coolant. Thoughts?

 

water pumps strictly leak water.

 

Hey thanks a ton for all the pointers! I discovered that I had set the crank seal too far back. I had set it pretty much as far back as it could go, when it only needed to be set just past flush. So oil was blowing right past the seal.

There was also a timing cover gasket that had failed, so I had to remove the timing cover around the crank case in order to gain access.

What I discovered is that while each failed seal was not leaking much, it was the collective failure of three seals and a gasket that caused a leak as extensive as that one.

While I know that it is a wives tale that synthetic oil can cause engine leaks, this situation has swayed me. I've never had an engine leak, in fact, the oil pan is rusting be causes there is no oil leaking over it to protect it from corrosion. Then I do a oil change, and two days later, I'm leaking a quart every ten miles.

Thanks again for the pointers!