Never ending oil leak

[Dutch Rutter]

Looking for some help to end this craziness. Trying to rid my 350 from oil leaks. So far I have replaced Oil pan gasket with 1 piece type, new Oil Pan, new, valve cover gaskets, new cast aluminum valve covers, new valve cover breather grommets, new intake manifold gasket set. And I still have a damn leak.

I checked around the back intake manifold front and back completely dry. Valve covers are dry. Oil Pan is dry. While tuning my carb I noticed a bit of oil burning smoke from the drivers, rear of the exhaust manifold. Figured it was some left over gunk and moved on. This was 2-3 weeks ago. Now I've been noticing a faint burning oil smell after the truck is warm. Usually after highway driving then sitting at a stop light.

I have not gotten under the truck with a light and looked to see if I can pin point it yet. I plan on doing that this weekend. I do hope it is not my head gaskets. Are there any other usual problem areas to check over?

Thanks all

 

[DoubleDingo]

Possible rear main seal? Timing cover gaskets and front seal? Snugging-up-not-over-tightening the valve covers? I had a leak like that, but mine was worn out valve cover gaskets. Had the heads of so I replaced everything but the rear main seal, didn't have time because I had to take the truck cross-country, but it fixed the problem, and then a little snug-check on the valve covers after a few run cycles. No more leaks. Did you add a dab of black rtv where the corners of the oil pan gasket meets the timing cover and rear main. Just a dab at those four spots. And did you make sure all the gasket surfaces were absolutely clean and free of residual oil, etc?

 

[4WDKC]

rear main seal leak.. that is the only gasket I didnt replace when i swapped my vortec heads and the damn thing is leaking

 

[Dutch Rutter]

rear main seal leak.. that is the only gasket I didnt replace when i swapped my vortec heads and the damn thing is leaking

Oops, this is on me. When I did the oil pan gasket I also replaced the rear main seal as well as the oil pump, and oil pump rod with a full metal one (no plastic sleeve) Figured why not since I was in there.

^Completely forgot to add this in the first post. I did not however use a staggered rear main as the crank surface was smooth and not notched in anyway.

 

[Honky Kong jr]

Time to get some dye and a UV light.

 

[DoubleDingo]

Oil pressure sending unit fitting?

 

[Dutch Rutter]

Time to get some dye and a UV light.

That is a great idea.

Oil pressure sending unit fitting?

Also a good one. I felt behind there on the block and didn't notice any fresh oil just grime. But I guess it could follow the cylinder head line then drop on the exhaust manifold. I'll pull it this weekend and add some ultra black to the threads just to make sure it isn't seeping.

 

[Paladin]

You might check the hydroboost unit if you have that, I had a similar problem , checked and rechecked, then rechecked everything and finally discovered a very very small leak from hydroboost unit which when it finally dripped fell exactly on the drivers side exhaust. Good luck!

 

[Rusty Nail]

I had an lil leak from where the sender screwed into the block next to the distributor.
I unscrewed it, painted the threads in Permatex brush on gasket sealer and put it back together.

One time I had a lil leak from the connection midstream in the mechanical gauge line.

 

[Dutch Rutter]

You might check the hydroboost unit if you have that, I had a similar problem , checked and rechecked, then rechecked everything and finally discovered a very very small leak from hydroboost unit which when it finally dripped fell exactly on the drivers side exhaust. Good luck!

No hydroboost on this truck but My master cylinder does leak/seep a little.

I had an lil leak from where the sender screwed into the block next to the distributor.
I unscrewed it, painted the threads in Permatex brush on gasket sealer and put it back together.

One time I had a lil leak from the connection midstream in the mechanical gauge line.

This is exactly what I'm thinking. It would make sense to me as it only happens once the truck is warm and its just the smallest little bit. I'll get this done, and check things over a bit closer.

Thanks everyone for the help.

 

[Honky Kong jr]

No hydroboost on this truck but My master cylinder does leak/seep a little.



This is exactly what I'm thinking. It would make sense to me as it only happens once the truck is warm and its just the smallest little bit. I'll get this done, and check things over a bit closer.

Thanks everyone for the help.

Brake fluid burns man. Like it’s flammable.

 

[GMFORLIFE]

Oil pressure switch leaking?

 

[Dutch Rutter]

Brake fluid burns man. Like it’s flammable.

See I knew there was something like that. I'll add replacing my master cylinder again to my to do list don't want any fires.

 

[Dutch Rutter]

Took out the sender unit and little angled piece. I didn't notice any fresh oil leaking but I put some ultra black on both piece's threads. Put everything back in.

Then took it for a 45 minute drive for some fishing. Several 5 hours and 6 trout later got back home and haven't noticed any more burning oil smell, and the oil level is the same as when I left. I'll be keeping an eye on everything but I think we got it all sorted out. Thanks again everyone

 

[Rusty Nail]

Soooooo....are we gonna have to change the name of this thread then?