Engine Oil Leak -- Rear Main Seal? - Dodge Cummins Diesel Forum
3rd Gen. Powertrain Discussion of components that are directly involved in the power production and all that is needed to get and keep the truck moving . Engine , Transmission Ect...NO ADVERTISING

Reply
 
LinkBack Thread Tools Display Modes
post #1 of 24 (permalink) Old 06-16-2019, 03:40 PM Thread Starter
Cummins Enthusiast
 
Join Date: Mar 2014
Posts: 278
Thanks: 81
Thanked 34 Times in 24 Posts
iTrader Score: 0 reviews
Engine Oil Leak -- Rear Main Seal?

Normally there are no fluid spots under the truck in the garage, but today I noticed a patch of oil under the truck, pretty much right at the back of the engine. But it's not a puddle, looks more like possibly it was sprayed there in a fine spray. There is also a fine coating of oil on most of the oil pan plus the transmission. See pic below. I checked the engine oil level and it's down a bit from full.

So from the symptoms, what am I likely looking at here -- a leaking rear main seal? If yes, this is not something I would choose to tackle, so what kind of cost should I expect a (non-dealer) shop to charge to replace the seal?

Are there other possibilities besides the rear main seal? If yes, what might be the source of the oil leak?




04.5 QCSB 4x4, 156K, 2nd Owner, Pacbrake, Airbags with onboard compressor, CTS Insight gauge w/Backup Camera, Smarty Jr tuner
Dudeonthenet is offline  
Sponsored Links
Advertisement
 
post #2 of 24 (permalink) Old 06-16-2019, 04:06 PM
Diesel Head
 
the man in black's Avatar
 
Join Date: Nov 2014
Location: Blowhio
Posts: 3,665
Thanks: 3,910
Thanked 3,441 Times in 2,514 Posts
iTrader Score: 0 reviews
Rear main or pan gasket. Could also possibly be the valve cover leaking down the back of the block.

Scooty Puff Sr - 2016 3500 CCLB
Truckasaurus - 2010 2500 CCSB -sold
the man in black is offline  
post #3 of 24 (permalink) Old 06-16-2019, 05:05 PM Thread Starter
Cummins Enthusiast
 
Join Date: Mar 2014
Posts: 278
Thanks: 81
Thanked 34 Times in 24 Posts
iTrader Score: 0 reviews
Quote:
Originally Posted by the man in black View Post
Rear main or pan gasket. Could also possibly be the valve cover leaking down the back of the block.
Thank you. There is no evidence of oil leaking down from the valve cover, so must either be the rear main or the pan gasket.

04.5 QCSB 4x4, 156K, 2nd Owner, Pacbrake, Airbags with onboard compressor, CTS Insight gauge w/Backup Camera, Smarty Jr tuner
Dudeonthenet is offline  
Sponsored Links
Advertisement
 
post #4 of 24 (permalink) Old 06-16-2019, 07:01 PM
Diesel Head
 
Gator1's Avatar
 
Join Date: Feb 2015
Posts: 4,469
Thanks: 108
Thanked 291 Times in 276 Posts
Garage
iTrader Score: 0 reviews
one spot that is pretty typical to leak, and really hard to see if you don't know where to look is the spacer under the valve cover in the back. Take your hand or a clean rag and wipe back there and see if it's soaked and then it will run down the oil pan, or trans case.

03 Dodge SHO QCLB Dually w/Custom side exit exhaust-Banks intercooler-4" side draft intake-Thuren 3.0 Argon filled Shocks-radius arms-SRW 4 link Conversion-17"methods-42" Squishy's- 4.56's-Griffin Radiator-elec fans & water pump=25.263 mpg legit.
Gator1 is online now  
post #5 of 24 (permalink) Old 06-16-2019, 08:00 PM Thread Starter
Cummins Enthusiast
 
Join Date: Mar 2014
Posts: 278
Thanks: 81
Thanked 34 Times in 24 Posts
iTrader Score: 0 reviews
Quote:
Originally Posted by Gator1 View Post
one spot that is pretty typical to leak, and really hard to see if you don't know where to look is the spacer under the valve cover in the back. Take your hand or a clean rag and wipe back there and see if it's soaked and then it will run down the oil pan, or trans case.
Thanks for the tip! I did that, and it's completely dry back there.

04.5 QCSB 4x4, 156K, 2nd Owner, Pacbrake, Airbags with onboard compressor, CTS Insight gauge w/Backup Camera, Smarty Jr tuner
Dudeonthenet is offline  
post #6 of 24 (permalink) Old 06-16-2019, 10:00 PM
Diesel Head
 
cerberusiam's Avatar
 
Join Date: Mar 2006
Location: Minco OK
Posts: 14,917
Thanks: 9
Thanked 2,690 Times in 2,256 Posts
iTrader Score: 0 reviews
Either rear main or cam seal. It is almost always one or both of them with any miles on the engine.

05 QC LWB 4x4 Auto 3.73 LSD, IssproEV2's, Performance 48RE Opie TransGo , Smarty Tuned BBI Injected
cerberusiam is offline  
post #7 of 24 (permalink) Old 06-17-2019, 09:19 AM Thread Starter
Cummins Enthusiast
 
Join Date: Mar 2014
Posts: 278
Thanks: 81
Thanked 34 Times in 24 Posts
iTrader Score: 0 reviews
Quote:
Originally Posted by cerberusiam View Post
Either rear main or cam seal. It is almost always one or both of them with any miles on the engine.
Thanks, cerb.

04.5 QCSB 4x4, 156K, 2nd Owner, Pacbrake, Airbags with onboard compressor, CTS Insight gauge w/Backup Camera, Smarty Jr tuner
Dudeonthenet is offline  
post #8 of 24 (permalink) Old 06-17-2019, 09:56 AM
Cummins Fan
 
Kbess's Avatar
 
Join Date: Mar 2019
Posts: 73
Thanks: 5
Thanked 4 Times in 4 Posts
Garage
iTrader Score: 0 reviews
How would you check the cam seal? I have the same symptoms just not yet leaving a mark, I’ve been leaning towards oil pan gasket but don’t know how to narrow it down. Thanks and sorry to hijack

2004.5 Dodge Ram 2500. QCSB, NV5600. Stock
Kbess is offline  
post #9 of 24 (permalink) Old 06-17-2019, 12:17 PM
Diesel Head
 
cerberusiam's Avatar
 
Join Date: Mar 2006
Location: Minco OK
Posts: 14,917
Thanks: 9
Thanked 2,690 Times in 2,256 Posts
iTrader Score: 0 reviews
Have to pull the engine adapter off the block to check the cam seal, it is buried pretty deep in there to see.

05 QC LWB 4x4 Auto 3.73 LSD, IssproEV2's, Performance 48RE Opie TransGo , Smarty Tuned BBI Injected
cerberusiam is offline  
post #10 of 24 (permalink) Old 06-17-2019, 01:02 PM
Cummins Fan
 
Kbess's Avatar
 
Join Date: Mar 2019
Posts: 73
Thanks: 5
Thanked 4 Times in 4 Posts
Garage
iTrader Score: 0 reviews
Quote:
Originally Posted by cerberusiam View Post
Have to pull the engine adapter off the block to check the cam seal, it is buried pretty deep in there to see.
Ahh, so it would be something to do while knocking the RM out. Sounds like a pain, I appreciate the expertise.

2004.5 Dodge Ram 2500. QCSB, NV5600. Stock
Kbess is offline  
post #11 of 24 (permalink) Old 06-18-2019, 03:23 PM Thread Starter
Cummins Enthusiast
 
Join Date: Mar 2014
Posts: 278
Thanks: 81
Thanked 34 Times in 24 Posts
iTrader Score: 0 reviews
I found the source of the oil that has been ending up on the bottom of my oil pan and transmission plus on the garage floor. It's the tube in the photo which comes down the driver's side of the engine, and as you can see, next to the starter. I'm having trouble tracing this tube. It's difficult to see where it goes, though it looks like the tubing turns up higher.

Can someone tell me what this tube is, and why it should suddenly start throwing some oil?

Thanks for any advice!


04.5 QCSB 4x4, 156K, 2nd Owner, Pacbrake, Airbags with onboard compressor, CTS Insight gauge w/Backup Camera, Smarty Jr tuner
Dudeonthenet is offline  
post #12 of 24 (permalink) Old 06-18-2019, 04:04 PM
Diesel Head
 
cerberusiam's Avatar
 
Join Date: Mar 2006
Location: Minco OK
Posts: 14,917
Thanks: 9
Thanked 2,690 Times in 2,256 Posts
iTrader Score: 0 reviews
Crank case breather. You might want to check and see if you have developing blow by.

05 QC LWB 4x4 Auto 3.73 LSD, IssproEV2's, Performance 48RE Opie TransGo , Smarty Tuned BBI Injected
cerberusiam is offline  
Sponsored Links
Advertisement
 
Reply

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the Dodge Cummins Diesel Forum forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in










Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode



Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome