- This topic has 4 replies, 3 voices, and was last updated 8 years, 10 months ago by
.
-
Topic
-
Hey everyone.. first post for me.
I have a 2004 Yukon with the 6.0L. I have an oil leak that I can not find.
It is leaking on the starter side (starter bolts are wet). I have replaced the valve cover gaskets, Oil cooler gasket, and Oil pan gasket. As best i can tell it is NOT coming from the oil sending unit.
after the replacing the oil pan gasket, the leak did not change (better or worse). It will leave a spot about the size of a silver dollar after 20 minutes of driving.
the truck has 98,000 miles on it and is GREAT shape, so I’d like to fix it.
When I did the pan gasket I did not see any visual indication that the main seal is leaking, however it is very hard to see. I did put some dye in the oil and verified the valve covers don’t appear to be leaking, and the leak doesn’t appear to be coming from “above”
any thoughts or past experience where this leak might be occurring? Rear seal? Rear Seal cover gasket? ????
Now you might be thinking “if he did a pan gasket, why not do a main seal?” Honestly wrestling that front diff out was at the end of my rope for “heavy mechanics” especially on a cold floor here in MN.. so the thought of doing a transfer case and transmission R&R makes me cringe!
I appreciate your input in advance.
Mike
PS: it is an iron block motor, aluminum heads.
-
Replies
-
Did you install the bolts to the trans bell housing before or after you torqued all the pan bolts?
Also was the truck ever in the rust belt? If so check the dipstick tube at the block.
Did you check the back of the motor where the intake bolts into the valley?
The pan bolts were put in, hand tight. Then I installed the bell housing bolts, very lightly tightened, to make sure the pan was seated against the bell housing, then torqued the pan bolts, finally tightened the bell housing bolts. and I used Permatex Black in all 4 corners, allowed it to setup for 15 minutes or so. Put the rest of the truck back together and left it over night before adding oil or running the engine. I did have a space heater that made the garage about 40 degrees and left that on overnight as well, hoping the RTV would harden before running with oil.
The truck is from Texas. I bought it there last summer and drove it back to Minnesota.. hence why it is a “nice truck” for those of us that live in the rust belt.
I did not check the intake valley.. is there oil passages in the intake? I will though.. have you seen them leak there?
thanks!
Mike
I’ve heard of the intake oil leaks, I’ve never seen one. Now that I think about it, I’ve seen oil cooler lines leak that can run down the back of the engine.
I would clean those lines and around the intake manifold and look for leaks while its running. Remember that any leak in the valley will drip down the back of the motor because of the engine cant.
Sounds like you did the oil pan correctly. If you tighten the trans bellhousing bolts first it can cause the pan to leak.
In my experience taken the trans off and replacing it is easier than putting that front diff back in. Those front diffs are a huge pain unless you remove the steering drag link. And even then its only marginally easier.
On the back of the engine is an rear engine cover. You can’t see it without removing the transmission and tourque plate. That, or the rear seal could be leaking. Search google for 5.3l, 6.0l gm rear engine cover. You should see pictures of it, that is a common leak source. There is also a porosity issue with the rear engine cover on some years.
Sent from my iPad using Tapatalk
- You must be logged in to reply to this topic.