It ain't a gusher, but I am still leaking oil....

lmwatbullrun · #1 07-20-2010, 04:21 PM

After I checked the valves on the 740 D24T a couple weeks ago, I had to replace the valve cover gasket. (old one was dry and brittle and leaked oil. <mumbling>) At the time, all I had was a cork set. Did that, carefully using the passenger side gasket on the passenger side and making sure the two cam cap rubber pieces were properly placed. Still leaking oil. Seemed to be coming out at the juncture where the cork gasket joins the rubber curved pieces going around the cam bearing and seal at the end, running down between the head/block and the sheet metal, puddling in that little hollow above the crank seal, then flowing into the cam belt space and getting distributed around the inside. (muttering

) Found a place that had the one piece neoprene gasket, and replaced the cork set.

Much improved, no leaks at idle, but still leaking oil when driven at highway speed. ( bad language

) Tightened up the nuts on the valve cover.

Still leaking oil. (much bad language

) Tightened the nuts more, and STILL leaking oil. Clearly, this is not the problem.

Since this area was dry as a bone when I replaced the cam belt, and I don't think I did anything stupid to the cam seal, I cannot figure out why I'm getting this really annoying leak now. It is true that the car was not driven or run much for a couple of years before I replaced the belt, but is it possible that the cam seal is bad? I'm starting to suspect that rascal as the problem; I put a rag in the space between the sheet metal and the block, and there IS oil coming down the front of the block between the block and the sheet metal, so it is not the main seal around the crank. At least it's not JUST the main...

Thoughts/suggestions?

Thoughts?

lmwatbullrun · #2 07-24-2010, 02:50 AM

Well, I am going to replace the cam seal and see if that helps.

lmwatbullrun · #3 07-24-2010, 12:52 PM

Well, it's not the cam seal, and it's not the valve cover gasket, and it is not the leetle bolts on the front. The cam seal was worn, but didn't look fried. I was surprised that there was no bearing insert on the front cam bearing, but I guess that bearing is really only taking one cylinder's worth of load, and it's good and wide.

I ran the beast for a while after I replaced the cam seal, (which was surprisingly painless once I welded up a copy of the Volvo 9995199 wrench out of a large pipe hanger I scrounged from the dumpster; that tool helps.... ) and it appears that oil is still being deposited on the *leading* edge of the timing belt somewhere below the idler and the water pump, being carried around the belt and past the idler pulley. I know this because I ran it for a while with the upper belt cover off, and carefully wiped the belt clean as it came around. The oil came up from the idler pulley on the outboard side of the belt from the block. This is puzzling.

At any rate, I can think of no other oil source except for the front main shaft seal. How big a pain is that to change? I have the books and the only three things I have not done are removing the alternator/fan bracket, which does not look too tough to do, removing the crankshaft pulley (??? hard/easy, what?) and pulling the old shaft seal (again, how hard is this?) Volvo book mentions special tools, but I have managed pretty well without any so far.

Any comments or responses?

Jason · #4 07-24-2010, 02:42 PM

Probably the front main seal. You'll need the counter hold tool to torque that front pulley bolt to the 350ish lbs of torque it takes. (assuming you don't have the special volvo torque multiplier tool). You'll have to re-time the engine so you'll need the dial indicator for the pump, but I think you said you already have that. Pretty much the only tool you'll need is the crank pulley holder tool.

Jason

lmwatbullrun · #5 07-25-2010, 03:25 AM

... and have removed and replaced the crank pulley assy a couple of times with no problems so far. What I meant was the crank gear that the timing belt sits on; my mistake (it was quite hot yesterday; I plead dehydration) That I have never removed.

Also, I really wanted to know how bad removing the crank seal is.

Thanks for the response!

Jason · #6 07-25-2010, 06:35 AM

Thats what I was talking about... the crank timing gear that the pulley is mounted to. It has a 27mm head size bolt that gets torqued to 350ish lbs of torque. The seal isn't anything strange or special. Pry it out with a screw driver and tap a new one in. Pretty much all there is to it besides retiming the engine and all that bs.

Jason

piper109 · #7 07-31-2010, 01:03 AM

Sometimes when you remove the valve cover, the studs that hold the cover down become partially screwed out of the head. Then when you replace the cover and tighten the nuts, they tighten with a space under the cover and the gasket is not being squashed and this results in a leak.
Remove the cover again, screw in the studs all the way then replace in the normal way.

I chased a leak for a while there and even replaced the cam shaft seal before realizing the problem. It always seems to be the studs on the ends of the head that do this.

Steve

lmwatbullrun · #8 07-31-2010, 12:48 PM

will look into that, thanks for the tip.

lmwatbullrun · #9 09-05-2010, 06:09 PM

I have done the following-
Replaced the Valve cover gasket;
Replaced the cam seal;
replaced the front main seal;
checked the VC gasket studs;

And I am STILL getting a trickle of oil on the front timing belt! none at idle, only when driven hard, uphill. Not as bad as it was before I replaced the front main seal, but enough to wet the belt. I am considering removing the belts (fan and alternator) and the timing belt cover, and looking to see where the bloody oil is coming from. THis is starting to really piss me off. ANyone got any ideas?

lmwatbullrun · #10 11-13-2010, 09:52 AM

OK, the oil was coming from the front crank seal that I just replaced. I took everything apart, again, and it looks as though there is a groove on the crankshaft. It would appear that the old seal got some rust around it and wore a little groove in the shaft, which I did not see when I replaced it the first time. I got a shaft repair kit from Rock Auto, and plan to install this later today. HAs anyone done one of these? I really don't want to have to remove the oil pump to get at this shaft......