Oil leak on a 3.4 Merc timing cover

[Seevee]

All,
I believe I have a leak on the timing cover on my 280 Dancer, 4.3 Merc engine.

Looks like it's a bitch to change. Has anyone done this? My mechanic says pull the engine, but looks like it could be changed in place, perhaps with some wiggling. There's a flange on the cover that makes it hard. Any reason this flange can't be cut off?

Seevee
2003 280 Suncancer, 3.4 Merc, A1 drives.

 

[BillK2632]

-How much is it leaking? I have a small leak on mine, started leaking around 100hrs, I chose to leave it and 500hrs later it is no worse and barely noticeable. I just wipe that area down periodically.
-Are you sure it is the timing cover and not the the crank seal?
-Could be the crankshaft position sensor.

Ok, if none of the above, then it's likely the oil pan / timing cover seal.

This is a PIA job, listen to your mechanic, it is just not possible to fix this correctly without removing the engine. You need to replace the timing cover and seal, the timing cover on these engines is composite. The bottom of the timing cover mates up with the front of the oil pan, the seal that leaks is really the oil pan seal where the timing cover mates up. To fix it you need to remove the timing cover and oil pan, clean everything up and put on a new timing cover and seal. And make sure all the oil pan bolts are torqued correctly - oil pan is aluminum and will warp easily. This is why I asked how bad the leak is, I have heard of plenty of people screwing it up worse trying to fix it. This is a common problem with the GM 4.3, boat and car/truck engines. I had a friend with a Chevy S10 that literally dripped oil.

 

[Seevee]

It's leaking about a quart in ~8 hours or so, but don't have an exact handle on that. Yes, pulling the engine is a real PITA and expensive.

 

[BillK2632]

I bet your timing cover is cracked - that's a big leak. Make sure it is not the crankshaft sensor leaking before you start on the timing cover. You can try the fix with the engine in the boat, but the problem is access, you can't drop the oil pan enough to really work in their and clean everything up, get the new gasket in problem and then torque the oil pan bolts again. If you can figure out those things, then you can do it without pulling the engine. You have a big leak, so worst you can do is try, then pull the engine if you can fix it. If you google there are lot's of things on the topic. Like I said, this is a common problem with the 4.3, lucky for me my leak has always been small.

 

[fonkngrooven]

All,
I believe I have a leak on the timing cover on my 280 Dancer, 4.3 Merc engine.

Looks like it's a bitch to change. Has anyone done this? My mechanic says pull the engine, but looks like it could be changed in place, perhaps with some wiggling. There's a flange on the cover that makes it hard. Any reason this flange can't be cut off?

Seevee
2003 280 Suncancer, 3.4 Merc, A1 drives.

You signature is incorrect I think you own a 4.3 LOL, chat soon. I post about our current issue.

 

[dwna1a]

My neighbor did his while the motor was in the boat, he used a two part cover and it was a complete PITA. He and another boater did it together. It took them about two weeks to get it straight.

BTW, his was not the gasket or the bolts, it was the cover itself. It was pitted bad. When held up to the light you could see thru all the holes.

Good luck with it and let us know how it goes