Fixing for a friend

Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.

Toyotaguy

TYF Newbie
Joined
Apr 20, 2024
Posts
4
Reaction score
5
My Gf asked me to help a coworker of hers with some vehicle issues she’s having. She doesn’t have a lot of money so she’s had random people making more of a mess than fixing. Example- one of her friends replaced a brake rotor on her Grand Am and forgot to put in one of the bolts that holds the caliper to the hub.

That brings us to the Yukon. She has a 2007 Yukon Denali with 6.2 and 250k. She just bought it and had the transmission fail. I think the same guy who did the incomplete brake job on the Grand Am put a new solenoid in the transmission and now it’s drives but has a massive oil leak.
A steady stream of oil is coming down and draining onto the transmission cooler lines right behind the bell housing.
I’ve only ever seen an oil leak this bad on an engine with a cracked block. It was starting to get dark so I couldn’t really see much. Valve covers definately have some issues on both sides. Filter and cooler lines look good but they are on the other side anyway.

I’ve owned a few chevys in the past. 327, 350, 454, 6.0 so I am familiar with the constant rear main drip. This is different. Can a rear main leak that bad?

I am going to go back over there tomorrow with the bolts to fix her Grand Am and get a better look at her Denali after refreshing myself with GM.

If any of you guys can help me track this leak down I’d appreciate it.
 

89Suburban

Bull in the china shop
Supporting Member
Joined
Jan 10, 2013
Posts
13,237
Reaction score
36,382
Location
SE PA
My Gf asked me to help a coworker of hers with some vehicle issues she’s having. She doesn’t have a lot of money so she’s had random people making more of a mess than fixing. Example- one of her friends replaced a brake rotor on her Grand Am and forgot to put in one of the bolts that holds the caliper to the hub.

That brings us to the Yukon. She has a 2007 Yukon Denali with 6.2 and 250k. She just bought it and had the transmission fail. I think the same guy who did the incomplete brake job on the Grand Am put a new solenoid in the transmission and now it’s drives but has a massive oil leak.
A steady stream of oil is coming down and draining onto the transmission cooler lines right behind the bell housing.
I’ve only ever seen an oil leak this bad on an engine with a cracked block. It was starting to get dark so I couldn’t really see much. Valve covers definately have some issues on both sides. Filter and cooler lines look good but they are on the other side anyway.

I’ve owned a few chevys in the past. 327, 350, 454, 6.0 so I am familiar with the constant rear main drip. This is different. Can a rear main leak that bad?

I am going to go back over there tomorrow with the bolts to fix her Grand Am and get a better look at her Denali after refreshing myself with GM.

If any of you guys can help me track this leak down I’d appreciate it.

You a good man Charlie Brown. Hope we can help. Got to get in there with your camera phone and a work light and take some good pics and investigate the source.
 

Marky Dissod

Full Access Member
Joined
Mar 3, 2023
Posts
1,222
Reaction score
1,599
Location
(718)-
Blind guess: Thoroughly clean PCV system.
Clogged PCV system causes excess oil pressure, finds weakest leaks.
Don't know if 12572717 PCV thingy applies to you, but I have witnessed it reduce leaks.
 

wjburken

Supporting Member
Joined
Dec 26, 2017
Posts
9,816
Reaction score
26,794
Location
Eastern Iowa
Blind guess: Thoroughly clean PCV system.
Clogged PCV system causes excess oil pressure, finds weakest leaks.
Don't know if 12572717 PCV thingy applies to you, but I have witnessed it reduce leaks.
Not really much to the PCV on this vehicle, it’s simply hose barb nipple formed into the valve cover and a hose that runs between the nipple and the intake manifold. No actual valve.
 

Marky Dissod

Full Access Member
Joined
Mar 3, 2023
Posts
1,222
Reaction score
1,599
Location
(718)-
Not really much to the PCV on this vehicle.
simply a hose barb nipple formed into the valve cover,
and a hose that runs between the nipple and the intake manifold.
No actual valve.
So, the idea behind the 12572717 (which isn't really a valve either) has been permanently molded / cast into the valve cover?
If that's the case, I still wonder if that valve cover couldn't use a thorough cleaning.
 
OP
OP
T

Toyotaguy

TYF Newbie
Joined
Apr 20, 2024
Posts
4
Reaction score
5
Take some pictures and post them.
I’ll bring some lights and try to get up in there as best I can. I have a feeling it is the oil pan but probably not worth fixing since the transmission was already giving her problems and then she had some moron band aid it back together. The trans fluid was a sick looking shade of grey. If the guy just replaced a solenoid I would expect a nice red color. The anti freeze color is a mixture of green/orange and grey too so even if I can diagnose the leak it’s probably not something I’m going to tackle on this poor neglected vehicle. The engine runs strong though and is still quiet.
She also was running 0w-20 full synthetic so I might pick up a bit thicker conventional oil to see if that helps. Won’t be in there long anyway the way it was coming out. Said she loses about 1 qt or so about every 10 -20 miles. But I’ll know more after I’ve had a chance to look closer today. Thanks guys. I’ll try to get some pics.
 

Joseph Garcia

Supporting Member
Joined
Aug 2, 2018
Posts
6,558
Reaction score
8,612
Welcome to the Forum from NH.

Lots of knowledgeable folks here who freely share their knowledge, experiences, and perspectives. Knowledge is power.

I hope that you will become a participating member in the Forum's discussions.

You are already receiving sage advice from the knowledgeable folks on this Forum.
 

Doubeleive

Wes
Supporting Member
Joined
Nov 7, 2017
Posts
23,798
Reaction score
34,813
Location
Stockton, Ca.
I’ll bring some lights and try to get up in there as best I can. I have a feeling it is the oil pan but probably not worth fixing since the transmission was already giving her problems and then she had some moron band aid it back together. The trans fluid was a sick looking shade of grey. If the guy just replaced a solenoid I would expect a nice red color. The anti freeze color is a mixture of green/orange and grey too so even if I can diagnose the leak it’s probably not something I’m going to tackle on this poor neglected vehicle. The engine runs strong though and is still quiet.
She also was running 0w-20 full synthetic so I might pick up a bit thicker conventional oil to see if that helps. Won’t be in there long anyway the way it was coming out. Said she loses about 1 qt or so about every 10 -20 miles. But I’ll know more after I’ve had a chance to look closer today. Thanks guys. I’ll try to get some pics.
that much of a oil leak should be easy to find, but if it is already everywhere then grab some degreaser and spray it everywhere in one of those self car wash with the wand and pressure wash it real good, just don't aim for any electrical connectors don't stick the wand super close just a foot two away works fine spray from the top/sides/bottom. that should help figure out the source of the leak after a short drive afterwards.
 

Forum statistics

Threads
129,350
Posts
1,814,444
Members
92,494
Latest member
Naileddown
Top