Oil Leak after RMS replacement

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.

lspann3525

Member
Joined
Feb 22, 2023
Posts
58
Reaction score
71
Well guys after replacing the rear main seal on my 2008 tahoe z71 5.3 250,000 miles the oil leak has returned. It's not pouring out oil like before but it is seeping somewhere I just hope not the RMS again. Im not getting any oil spots in my driveway but I did notice a very small amount of oil on the left and right side of the bellhousing where it meets the engine block. Its not a severe leak just a very small drip. On top of that I took a trip from Mississippi to Georgia which was about 1000 miles to and from. And when I made it home and I checked the oil and it was at the bottom of the oil dipstick right where the crosshatch starts. Im currently running 5w30 and plan to go to 10w30 just in case the engine is burning oil with all those miles. With the engine running im not able to see any oil leaks it just overtime. Wile under the truck I removed the access hole cover and it's clean as a whistle inside.

I have recently changed the following parts. Replaced RMS with Dorman Rear Cover with seal, Valve Cover Gasket, Crankshaft Sensor, Oil Pressure Switch/Screen. Even thou my oil read at the bottom of the oil dip stick the alert message stop engine has not appeared. After doing some more google on oil leaks I found a couple of threads saying the valley pan gasket could be leaking and it's a known issue with the trucks that have AFM.... Im having a hard time trying to identify if it's the valley pan anyone have any ideas on checking the valley pan?
 

OR VietVet

Multnomah Falls
Supporting Member
Joined
Oct 8, 2014
Posts
18,022
Reaction score
28,339
Location
Willamette Valley
Doubt if is RMS leak but with Dorman products, you never know. Valley pan or rear of intake or even valve covers. Tuff to see back there.

How does 10w-30 effect the oil burning concern?
 

Foggy

Full Access Member
Joined
Jul 25, 2019
Posts
882
Reaction score
1,018
Location
KS
It's probably "burning" some of that oil.. 250K and 15 yrs old will do that..
Also there are updates for the pcv/baffling system in the valve covers which help this situation.
You may be getting a little bit of leak from the oil cooler lines/block off plate at the
engine. It is above the oil filter.. So if you are getting some oil on the left side rear
I'd suspect this..
And going to a 10-30 oil won't change a darn thing.. It's still 30 weight oil when at
operating temps
 
OP
OP
L

lspann3525

Member
Joined
Feb 22, 2023
Posts
58
Reaction score
71
This truck doesnt have an oil cooler. The block off plate is pretty clean no leaks are coming from it.

Do you have any more info on the valve cover update?
 

Dustin Jackson

Full Access Member
Joined
Aug 9, 2018
Posts
1,240
Reaction score
1,322
Not sure how helpful this is but a month after I did my AFM delete I had a couple drips of oil on my driveway, I could see it dripping down my front diff. I could never find out where it came from but whatever was happening stopped, I haven't had a drop of oil on my driveway for a year now...

Maybe wait and see if it was just leftover leak oil and see if it stops.

To see if the valley cover is leaking you would need to remove your intake manifold to inspect it properly. Also oil being low at the bottom of the dipstick is fine, just top it off. When you see no oil on your dipstick is when you start to get yourself into trouble.
 

j91z28d1

Full Access Member
Joined
Feb 28, 2022
Posts
1,155
Reaction score
1,292
did you do the oil pan gasket?

I'm pretty sure the gaskets like to seep in the corners. my truck hasn't but my car did.

bit of a hassle. if it's just a bit wet, I'd just driver it till it becomes a drip
 

89Suburban

Bull in the china shop
Supporting Member
Joined
Jan 10, 2013
Posts
11,444
Reaction score
30,768
Location
SE PA
I have a very high mileage 5.3 and have been chasing down oil leaks since I got the truck. It seems like when I fix one another one pops up. It has a lot of blowby. The valley cover was loose as a goose and I replaced that. Then the valve covers started leaking replaced those with the updated one. Then the lower end started to leak. Front seal is weeping. Could be a pan gasket? Bolts are all tight. Then I tried a bottle of the "miracle" rear main fix and it worked great for a week not one drop on the ground then all of a sudden it is leaking a quart a week onto the ground so I am pretty sure the rear main seal is sht the bed because of that stupid move. Still kicking myself in the ass for that one.

I don't want to invest in having the RMS replaced on a 350K motor so I am currently price shopping a replacement motor and saving for one. Just going to run it like it is unit then. But I am certainly am sick of the oil spots and stink.
 

donjetman

Full Access Member
Joined
Oct 22, 2018
Posts
1,147
Reaction score
1,888
Well guys after replacing the rear main seal on my 2008 tahoe z71 5.3 250,000 miles the oil leak has returned. It's not pouring out oil like before but it is seeping somewhere I just hope not the RMS again. Im not getting any oil spots in my driveway but I did notice a very small amount of oil on the left and right side of the bellhousing where it meets the engine block. Its not a severe leak just a very small drip. On top of that I took a trip from Mississippi to Georgia which was about 1000 miles to and from. And when I made it home and I checked the oil and it was at the bottom of the oil dipstick right where the crosshatch starts. Im currently running 5w30 and plan to go to 10w30 just in case the engine is burning oil with all those miles. With the engine running im not able to see any oil leaks it just overtime. Wile under the truck I removed the access hole cover and it's clean as a whistle inside.

I have recently changed the following parts. Replaced RMS with Dorman Rear Cover with seal, Valve Cover Gasket, Crankshaft Sensor, Oil Pressure Switch/Screen. Even thou my oil read at the bottom of the oil dip stick the alert message stop engine has not appeared. After doing some more google on oil leaks I found a couple of threads saying the valley pan gasket could be leaking and it's a known issue with the trucks that have AFM.... Im having a hard time trying to identify if it's the valley pan anyone have any ideas on checking the valley pan?
You must be burning it.

In the fall of 2018 our new to us Yukon was leaking and burning 2oz of oil every 100 miles. Here is what all 8 of the spark plugs looked like at 130k miles.

https://f01.justanswer.com/ebrock63...il+Consumption,+MIL+ON,+Engine+Runs+Rough.pdf

I fixed it. I found out about GM technical service bulletin TSB 10-06-01-008M - So, I installed the new improved valve cover, did a piston/combustion chamber soak (although differently than the way the TSB says to do it) installed deflector on pressure relief valve. It immediately stopped burning and leaking oil.

Now it has 187k miles and is still not consuming any oil.
sparkie2.jpg
relief valve w shield.JPG
https://www.tahoeyukonforum.com/threads/valve-cover-change-cleanup.108604/
and
https://www.tahoeyukonforum.com/thr...tor-oil-consumption-tsb-10-60-10-008m.108493/
and
https://www.tahoeyukonforum.com/threads/rear-main-seal-job-pan-etc-07-yukon-denali-6-2.108334/
and
https://www.tahoeyukonforum.com/threads/engine-oil-pan-gasket-change-6-2-yukon-l92.108487/
and
https://www.tahoeyukonforum.com/threads/get-a-catch-can-before-any-mods.49716/page-52#post-1287883
 

davidavidd

Member
Joined
Oct 29, 2020
Posts
46
Reaction score
62
Location
CO
Well guys after replacing the rear main seal on my 2008 tahoe z71 5.3 250,000 miles the oil leak has returned. It's not pouring out oil like before but it is seeping somewhere I just hope not the RMS again. Im not getting any oil spots in my driveway but I did notice a very small amount of oil on the left and right side of the bellhousing where it meets the engine block. Its not a severe leak just a very small drip. On top of that I took a trip from Mississippi to Georgia which was about 1000 miles to and from. And when I made it home and I checked the oil and it was at the bottom of the oil dipstick right where the crosshatch starts. Im currently running 5w30 and plan to go to 10w30 just in case the engine is burning oil with all those miles. With the engine running im not able to see any oil leaks it just overtime. Wile under the truck I removed the access hole cover and it's clean as a whistle inside.

I have recently changed the following parts. Replaced RMS with Dorman Rear Cover with seal, Valve Cover Gasket, Crankshaft Sensor, Oil Pressure Switch/Screen. Even thou my oil read at the bottom of the oil dip stick the alert message stop engine has not appeared. After doing some more google on oil leaks I found a couple of threads saying the valley pan gasket could be leaking and it's a known issue with the trucks that have AFM.... Im having a hard time trying to identify if it's the valley pan anyone have any ideas on checking the valley pan?
Hey @lspann3525 check my post https://www.tahoeyukonforum.com/threads/serious-engine-oil-leak-tahoe-5-3-2007.126153/ and have the pleasure of knowing the infamous VLOM leak, it looks like a RMS leaking but the reality is different. At the time this made me pull my hair trying to know where so much oil came from.

If is your case:

Part needed: https://www.amazon.com/Fel-Pro-MS-96871-Intake-Manifold/dp/B0033DNA5S/, sometimes you can't remove the VLOM solenoids to change the gasket so you have to cut them and use only the gasket around the cover or replace the entire cover already with a new gasket included.


D
 

Forum statistics

Threads
126,830
Posts
1,772,316
Members
89,036
Latest member
iggy913

Latest posts

Top