Oil Leak

[hegel]

I was in my shop last night and i decided to install a battery tender lead since the truck wont be driven much... so i put it in neutral and pushed it back a few feet so i could get at the hood. when i got to the front of the truck there was a small oil spot on the ground. so i grabbed my flashlight and crawled under and the oil pan has an oily sheen on it. I'm not too familiar with the 4.3 so i figured i'd post here and see what the most likely culprit is. the truck has 63,xxx miles on it.

[HenryJ]

Got Dex?

Are you very sure it is not the dex-cool coolant? It does look oily and brownish when leaking and blowing across the oil pan. If this is the case it will be leaking from the lower intake gaskets. Usually under the ac where you can't see it, also down the back of the engine dripping from the bellhousing and starter sometimes.

If it is indeed oil, and from the front, you are in need of a new crank seal in the timing cover. While you have it apart, consider replacing the pan gasket and rear main seal. Lots and lots of work. You may just replace the crank seal and call it a day?

[hegel]

so I took the lower belly pan off. I found this



best as I can work out it's dexcool for 1 spot and the 2nd spot is some kind of oil (unsure if it's power steering or motor)

so based on that I think that I may be in for a bit of work. Is the general consensus that when there's a coolant leak 99% of the time its due to the lower intake gasket?

does anyone have a service manual they'd like to sell? or an electronic version that they could email me?

thanks,
Steve

[HenryJ]

There are quoted instructions for the intake gasket replacements around here. The intake gaskets were the issue if you have a leak on the upper engine. The water pump can fail too, but that is usually an easy diagnosis.

Check ebay for the GM service manuals. Helm publishing still has them too. Get ready though it is a three volume set and not cheap. Well worth it for the investment if you keep the truck long term.

[ApproachMedium]

The oil line from the relocator to the engine looks fairly new, but with the oil marks on it looks like maybe the line from the cooler in the radiator to the filter re locator itself is probably leaking. Mine was bad on my truck and I replaced it.