[SOLVED] Need help identifying oil leak when the car is on

[thefrey]

Finished my DOD delete. Truck runs great. 70psi cold start makes me happy

In the process of upgrading many things, I have unintentionally upgraded to the self-lubing chassis.

I am happy that it isn’t burning oil because I thought that was what was happening at first. I am getting smoke as the oil hits my exhaust. I especially notice if I am giving it the beans going up a hill when I’m putting some stress on the engine.

I drove 4 hours today and went through 5 quarts. It seems like the leak happens when underway.

Since I just basically took off any oil gasket surface, I am curious where to start or places to look. Not sure if anyone else has had this issue. My first thing thinks oil cooler lines since they have pressure on them?

Thanks in advance

 

[Marky Dissod]

Valvecover gaskets?

 

[thefrey]

Valvecover gaskets?

New gaskets. Checked them recently and they don’t seem to be leaking at all.

 

[SpareParts]

You have a few threads. Kinda hard keeping track with different threads covering the same job.
Did you replace the front crank seal, timing cover gasket and oil pan gasket?.
If you replaced any one of them, i would look there. Could also be the oil pressure sensor.

 

[thefrey]

You have a few threads. Kinda hard keeping track with different threads covering the same job.
Did you replace the front crank seal, timing cover gasket and oil pan gasket?.
If you replaced any one of them, i would look there. Could also be the oil pressure sensor.

Sorry, lol. Figured it would be better to start a new thread since it’s done already and is somewhat unrelated to the DOD delete itself.

Replaced all of the above. I don’t think it’s the oil pressure sensor from what I’ve seen. I am just confused at how much oil there is coming out but I haven’t had a chance to inspect anything yet.

 

[strutaeng]

The rear main seal (RMS) leaks are almost impossible to find because the oil is flung out.

I would clean/degrease as much as possible, add dye and go for a drive. Check with a UV light.

That's how i found the RMS leak on my 06 LQ4, but even then, it was hard to see. Only made it out looking through the flexplate holes, right under the RMS round gasket at the crank flange.

 

[thefrey]

I have a slight feeling it may be my front cover crank seal

 

[West 1]

That job involves removing the entire front of the engine. The timing cover seal could have certainly been damaged, even if the seal is new was the harmonic balancer cleaned prior to re install. Minor scratches and make large leaks.

You mentioned great cold oil pressure, I suspect that means you had the oil pan off as part of this repair? Installing these oil pans is a process and the bolt sequence has to be adhered to or you will have leaks if not a broken/ cracked oil pan.

If the pan was off it should have been fully cleaned before install so spotting a leak should be pretty easy?

There are two types of gaskets for the oil cooler cover or oil cooler lines above the oil filter on the oil pan. Install the wrong gasket and that cover will leak. Trucks with the oil cooler and lines running above the oil pan use the gasket that has two holes. The trucks with no oil cooler use the gasket that has only one large oval hole. On the large hole gaskets I like to use two gaskets as those covers tend to leak.

5 quarts leaking in one day is a very serious leak. Keep us posted what is found.

 

[thefrey]

If the pan was off it should have been fully cleaned before install so spotting a leak should be pretty easy?

Everything at this point is oily and dirty, so I can’t really tell what the source is.

I can say it looks like the front of my diff is oily. I think that it is something front timing cover related.

I am wondering if there’s a way to fix it while keeping everything on. I just took apart the front timing cover, oil pan, etc and put it back together so taking it apart is the last thing I wanna do.

Perhaps my harmonic balancer isn’t fully seated onto the crank? I am not sure if there’s a way to check but I am googling now

 

[thefrey]

Here’s what I can get a pic of.

Looks like my seal might have gotten messed up. Seems like the lip of the seal may have rolled somehow?

Not super familiar with how these work (or how it would’ve happened, or how to truly fix) so anything is welcome. Seems like my only option is to install a new one. I don’t know how it happened or how to avoid it for next time…

 

[Dustin Jackson]

@thefrey I also have a front seal leak from doing my AFM delete so you aren't the only one

 

[rdezs]

Remove front cover......replace seal. Use front cover alignment tool. Dab of rtv in lower corners. Seal and harmonic balancer go on dry, no oil, grease, etc on either.

Most likely, cover wasn't aligned.

 

[SpareParts]

Is that seal new? Whether it is or not you will need a new one.
If it is the front seal leaking there is a good chance the front cover is misaligned if you had the front cover off.
I'm thinking you could have it fixed in a couple of hours depending on skill level.

 

[thefrey]

The seal is new. I put the front cover on hand tight before I installed the harmonic balancer to align it. I installed it dry and didn’t put any kind of grease on anything. Installed the harmonic balancer and then tightened the front timing cover. I didn’t use a tool because I didn’t have one, and many people online said the harmonic balancer works as well to align the cover.

In theory it should be aligned no issues. Maybe my issue is that I turned the harmonic balancer to help align it and that messed up the seal? It seems like these seals are picky from install from what google says.

I don’t know if a new seal will fix the issue or if I need to go all the way and take everything off again.

 

[donjetman]

I replaced the tc seal, pulley/balancer, etc 5k miles and 1.5 yrs ago. I didn't use an alignment tool. I DID put lube on new seal. No Leaks.
https://www.tahoeyukonforum.com/threads/valley-cover-crank-pulley-etc.149036/

 

[SpareParts]

Could be a hundred reasons why it went bad during install.
When i did mine both front and rear looked like a regular seal to me and there was nothing in the package saying to install dry. I coated mine with a film of engine oil. Been a few months and no leaks.
I used the Fel-Pro gasket/seal set for front and rear main.
I did use an alignment tool on the front.

 

[thefrey]

Now the question is do I pull the timing cover off or try to install a new seal and see what happens.

I am traveling for the holidays so I might have just enough tools to do what I need to do.

 

[SpareParts]

The only way to know for sure if the cover is misaligned would be with the tool. You could also try measuring around the crank to timing cover. Either way the pulley needs to come off.
I would give it a 50/50 chance that just putting a new seal on will fix it. Maybe a parts store has the alignment tool to rent?
In any case you're only out a little time and a few $ to put a new seal on it and who knows, it very well could fix that problem.
Are you sure that is where the leak is coming from?

 

[thefrey]

The only way to know for sure if the cover is misaligned would be with the tool. You could also try measuring around the crank to timing cover. Either way the pulley needs to come off.
I would give it a 50/50 chance that just putting a new seal on will fix it. Maybe a parts store has the alignment tool to rent?
In any case you're only out a little time and a few $ to put a new seal on it and who knows, it very well could fix that problem.
Are you sure that is where the leak is coming from?

I am not 100% yet that it is where it’s coming from. But from the 5 mins of me looking it seems that is where it’s coming from. There’s oil on the harmonic balancer so that definitely points to something IMO. Going to wash underside later and look in detail to figure out the source.

I used a flywheel holding tool to stop the crank from moving. Is there a good way of easily holding it now since I don’t have the starter off / don’t have access to the tool?

 

[solli5pack]

If you didn't use the alingment tool on the front or rear seal then most likely that's your problem. Some people get lucky without the tool and no leaks and some don't. I've used the tool on both to be sure its correct and no leaks for me. Losing 5 quarts in a day is insane!