Oil pan woes

[InspectahDEck]

I have been recently replacing various points of suspected oil leaks on my 05 yukon 6.0L, including valve covers, oil pressure sensor, cam sensor, and now recently I did the oil pan gasket and pick up tube O ring.

A couple days after replacing the oil pan gasket and o ring, I received a check oil level warning. I drove it around a for the next week or so and it never dissappeared, and confirmed daily the proper amount of oil was being used. I decided to order a new oil level sensor, and upon removing the old oil level sensor, I found part of the sensor missing. See attached screenshots. Assuming this piece broke off inside the oil pan gasket, is it fine to leave it in there?

And of course another issue popped up. When draining the oil when swapping the new oil level sensor, the oil was a bit milky. I found a piece of plastic underneath my car just 2 days ago, and wasn't sure where it came from. I found where the piece attaches to, and it is the starter opening cover. It appears the top of this piece broke off, likely during oil pan gasket replacement. I just ordered the new piece here, but is it possible that water could of mixed with oil through this now exposed area? Attaching additions screenshots

Also there is still oil leaking from above the starter, for which I will be replacing the crank sensor next.

 

[TollKeeper]

You said you did the oil pan gasket, when you had the oil pan off, did you clean out any debris in the oil pan? Did you clean out the oil pickup screen?

Back to your question, the problem isnt the plastic piece on the end, its the rubber piece in front of that, and the small spring inside of it.

I think I would be looking at dropping the oil pan again, verify the missing parts/pieces, and put it back together.

Did you remember to replace the pickup tube O-Ring? A known failure point for the LS engines. Something to think about while your in there.

 

[InspectahDEck]

Yes I cleaned the oil pan thoroughly and also the pickup screen. Is the reason for taking it back apart is because the small spring could get stuck in the pickup tube?

Also yes I did replace the pickup tube O ring. I had a bad oil pressure sensor, and after replacing that I was able to see I did infact have low oil pressure (~20-25), and replaced the O ring while I was in there.

 

[TollKeeper]

The spring and that rubber end piece.

Edit: By the way, what truck are you working on? Year make and model..

 

[InspectahDEck]

05 yukon, 6.0L

 

[Blackcar]

I would be worried about Milky looking oil is coolant level down.

 

[InspectahDEck]

@Blackcar Just checked yes it is low

 

[InspectahDEck]

I did put in a new Felpro intake manifold gasket while working on other various things, could be the culprit?

 

[Blackcar]

@Blackcar Just checked yes it is low

I sounds like you have head gasket problem, or something is letting water into crankcase,

 

[InspectahDEck]

I just hooked up a pressure tester to the cooling system, will report back if I have a loss of pressure or not. I have drove around 350 miles since and have not noticed any contaminents in the oil yet again.

 

[InspectahDEck]

Loss of pressure confirmed. I bought this block tester and the test came back negative, fluid remained blue. It's odd because the engine does not overheat, it sits around 208 deg. The coolant loss is minimal. I checked the dip stick and the fresh oil I put in has not became milky. There is no visible coolant leak externally I can see, I park in the garage and the floor there makes it easy to see if anything is leaking.

Could replacing the intake manifold gasket somehow cause coolant leaks? Not sure what else would cause this coolant leak to randomly start.

 

[mattbta]

On mine, I had Castech heads that cracked causing slow coolant loss that in the end turned rapid. To be sure (despite the milkshake on my valve covers) I added some dye to the coolant, popped said covers, and then pressurized the cooling system. With a black light I was able to see a small crack with coolant bubbles on one of the heads.

I got reman’d heads and in less than 500 miles one of those cracked. Yay.

Good luck, seems like the coolant leak might be internal.


P.S. our intakes are dry so changing gaskets would not create a coolant leak.

 

[InspectahDEck]

I hoped the heads wouldn't be cracked as I was under the impression the 6.0 did not have the defective castech heads. Bummer, think I will run out and grab some dye and do the same. Thanks for the help

 

[mattbta]

I hoped the heads wouldn't be cracked as I was under the impression the 6.0 did not have the defective castech heads. Bummer, think I will run out and grab some dye and do the same. Thanks for the help

Crap, I missed that detail. Yeah, IIRC the 6.0 hasn’t shown head problems.

But if you’re losing coolant and it isn’t holding pressure and you don’t see anything external lot sure seems internal.


Good luck.

 

[InspectahDEck]

I found the leak, no coolant mixing with oil luckily. It's coming from the top area of the valve cover, looks to be coming from the bolt? Unsure of what to address here if someone can shed some light on the issue... attaching a pic

 

[Blackcar]

Are you talking about rust spots that is valve cover should be any coolant on them. Might look higher at heater lines?

 

[MassHoe04]

Are you talking about rust spots that is valve cover should be any coolant on them. Might look higher at heater lines?

This ^^^
It does seem to line up with the location of hoses at the heater core... Certainly a good place to look. The rust stains could just be the valve cover bolt rusting after having slow leak dripping from above and probably not anything coming from the bolt itself.

 

[InspectahDEck]

Maybe not so coincidentally, 2 days ago I lost spark on this same cylinder, I noticed after driving and the engine started hesitating. P0300 code. Spark is fine from all coil packs except the one where that has the fluid on it. I have checked the hoses several times after driving and they are always dry, mysterious...

 

[Blackcar]

Can you smell anti-freeze.

 

[InspectahDEck]

No