Oil leak

[BGPick]

It's the 6.2 Diesel - I'm slowly fixing stuff since I just bought the truck.
Noticed an oil leak on the driveway but cant quite figure out
where its coming from. Any ideas?

Oil pan is wet also, but gasket seam appears to be "OK" but maybe a bit wet on rear seam portion.
Sort of looks like one of those two lines near the filter could be leaking, no?
It is definitely a higher up leak, running down.

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[436'd skylark]

With a 6.2 you'll have to learn to love oil leaks.

Power wash/ steam clean and then watch for where it starts to leak. You'll likely find you have multiple leaks.

 

[BGPick]

Is there a way to confirm if it is or is NOT the rear main seal?

 

[PrairieDrifter]

Pull off the transmission dust cover and like said above power wash and degrease everything really good then run it and see where it’s coming from. Rear main is a good possibility, the cam plug was weeping slightly on my 350 so that’s an option as well. There are also three oil gallery plugs on the back of the block that could be leaking but those are most likely fine.

Check the oil pressure sending unit as well.

 

[436'd skylark]

Oil won't ride up the block only down. So start from the top

 

[1987 GMC Jimmy]

Autozone has a leak dye you can put in your oil, and I’ve used it before. You just need a UV light to hunt for the leak, and like someone else mentioned, clean it up really well. Also, Fram is not a filter I or many others would use. I didn’t know this till a couple years ago, but people have had some serious problems from them breaking apart and plugging things up. I’d use anything else really. I’ve used Delco, Wix, NAPA Gold, and STP filters, and they’re all good ones.

 

[BGPick]

Alright folks, I did a bit of searching today and found a few spots that are leaking.
Maybe yall can elaborate on what may be the causes of each particular leak?

Leak #1 - Drivers side rear corner of intake manifold has oil around it.

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Leak #2 -There is a decent amount of oil all around the base of the filler neck and such.
This area appears to be the most oil leaking.

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Also found that inside the air cleaner housing, was all greasy/oily and the air filter has wicked up
some of the oil. What would cause this to happen? There is some oily/greasy/wetness inside the
mouth of the intake manifold as well just below the filter.

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[Frankenchevy]

Maybe crankcase pressure among other things? Is the pcv system intact and functioning?

Edit: it’s called a cdr on your engine

 

[Frankenchevy]

Not that this is necessarily related, but your intake manifold looks like it has a crack...

 

[BGPick]

Maybe crankcase pressure among other things. Is the pcv system intact and functioning?

How do I go about checking the PCV system? Not too familiar with diesels at all.

 

[BGPick]

Not that this is necessarily related, but your intake manifold looks like it has a crack...

Yeah I just noticed that. Cleaned it though and no crack, just a line in the casting!

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[Frankenchevy]

Google 6.2 cdr. It should be changed every few years like a pcv in a gasser.

It’s probably more important on the 6.2, as they’re around 20:1 compression...

 

[BGPick]

Thanks, I guess it can’t hurt to replace for the $20 it costs.

 

[Frankenchevy]

Thanks, I guess it can’t hurt to replace for the $20 it costs.

Read this post about cheap CDRs and how people tend to have bad luck with them.

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https://www.steelsoldiers.com/showt...A-questions-and-other-tune-up-questions/page8

 

[BGPick]

Thanks, by “cheap” I meant I found one on eBay which is supposedly NOS ACDelco for $19 and change. Can’t go wrong there!