Oil Leak Exhaust Manifold R688Rst E6 350

[kahall82]

Hi all,

Have noticed an oil leak from the exhaust manifold on my 1982 R688RST with a E6 350 engine. The exhaust is a bit smokey but the puff limiter is blocked so we assumed it was from that.

Any thoughts on what it could be? Where would the oil be coming from if it is just a leaking exhaust manifold gasket???

Engine seems to run perfect. Doesn't really get over 70 degrees celcius on the water temp gauge. neither on the oil temp gauge.

Just fixed the exhaust on the weekend and the inside of the exhaust was wet. Black sooty wetness that could be oil or diesel?

Edited June 28, 2011 by kahall82

[Rob]

Hi all,

Have noticed an oil leak from the exhaust manifold on my 1982 R688RST with a E6 350 engine. The exhaust is a bit smokey but the puff limiter is blocked so we assumed it was from that.

Any thoughts on what it could be? Where would the oil be coming from if it is just a leaking exhaust manifold gasket???

Engine seems to run perfect. Doesn't really get over 70 degrees celcius on the water temp gauge. neither on the oil temp gauge.

Just fixed the exhaust on the weekend and the inside of the exhaust was wet. Black sooty wetness that could be oil or diesel?

Sounds like you are not getting the exhaust hot enough to thoroughly burn the fuel and this is called "wet stacking". A common problem if the engine does not work hard or is very easily worked. Try to put some weight on the truck and use hard acceleration for a little bit to clean it up internally.

Rob

[Mike]

Robs correct. I would find a Fairgrounds that has Truck & Tractor Pulls and let the guys hook the sled to it if ya don't have a trailer with enough weight to get that engine up to maximum temps. Or call the mother inlaw and ask her to stand behind the truck and hook her up to it. Tell her it's for her heart and that it will help her releve some of the stress.

mike

[kahall82]

Classic Mike Thanks for your response Rob!!

And the smokey exhaust is only when changing gears or revving. Have had a smokey turbo on a car before and it was totally different so i'm guessing engine oil blow-by would be similar.

Is the wet stacking causing damage? I'm guessing it is because full fuel is getting through due to puff limiter plugged up. When we set up the puff as it should be the truck has zero power. Back to researching

[Rob]

Classic Mike Thanks for your response Rob!!

And the smokey exhaust is only when changing gears or revving. Have had a smokey turbo on a car before and it was totally different so i'm guessing engine oil blow-by would be similar.

Is the wet stacking causing damage? I'm guessing it is because full fuel is getting through due to puff limiter plugged up. When we set up the puff as it should be the truck has zero power. Back to researching

"Wet Stacking" is not really too detrimental that I know of but it can make a mess out of surrounding cars, trucks, trailers, and the like when it blows out of the pipe. The puff limiter is a device to limit the fuel rack travel internal to the injection pump until the boost from the turbocharger rises. It then allows more rack travel and conversly, more fuel and power for/from the engine. Many disconnect them but watch your pyrometer under a pull as the exhaust can get hot.

Typically the puff limiter being disconnected or defunct will not cause the problems you experience. Not getting the engine to a good operating temperature is about the only way I've seen if timing is correct.

Rob