GMT 800 & Older GM General Discussion 2006 & Older Trucks | General Discussion

Oil leak...but where?

Thread Tools
 
Search this Thread
 
Old Nov 11, 2014 | 06:42 PM
  #1  
robt342003's Avatar
Thread Starter
Staging Lane
iTrader: (1)
 
Joined: May 2007
Posts: 95
Likes: 0
From: San Antonio, Tx
Default Oil leak...but where?

I noticed a few drops of engine oil on the garage flood today. Climbed under the truck and snapped some pics. I can't tell where its coming from. Oil plug is tight, so are the bell housing bolts. It does seem to be around the oil pan/starter area. Any ideas on possible causes? Thanks in advance for the help


Name:  2014-11-11165813_zps1ccd5fe5.jpg
Views: 9864
Size:  50.0 KB

Name:  2014-11-11170032_zps50479347.jpg
Views: 4560
Size:  40.2 KB

Name:  2014-11-11165922_zps2c961750.jpg
Views: 8836
Size:  59.4 KB

Name:  2014-11-11165922_zps2c961750.jpg
Views: 8836
Size:  59.4 KB

Name:  2014-11-11165702_zpsd259f9f5.jpg
Views: 4401
Size:  55.5 KB

Name:  2014-11-11165533_zps0ec1f719.jpg
Views: 5331
Size:  46.4 KB

Name:  2014-11-11165434_zps2907ac97.jpg
Views: 4501
Size:  37.0 KB

Name:  2014-11-11170057_zpsd8b02e52.jpg
Views: 4568
Size:  50.9 KB

Name:  2014-11-11165743_zps9525b9ae.jpg
Views: 4518
Size:  62.2 KB
Attached Images
File Type: jpg
Reply
Old Nov 11, 2014 | 08:04 PM
  #2  
RS/SS 4.8's Avatar
10 Second Truck Club
iTrader: (13)
 
Joined: Jul 2012
Posts: 1,258
Likes: 5
From: San Antonio Tx
Default

On your first pic pull the little cover on the trans. Look behind the flywheel and around the crank area for oil, If theres any then ur rear main seal is leaking. If its coming down from above the bellhousing the check your oil pressure sender.
Reply
Old Nov 11, 2014 | 09:40 PM
  #3  
robt342003's Avatar
Thread Starter
Staging Lane
iTrader: (1)
 
Joined: May 2007
Posts: 95
Likes: 0
From: San Antonio, Tx
Default

alright I'll pull that cover and give it a look. Where about is the oil pressure sender? I have a feeling it may be the rear main.
Reply
Old Nov 11, 2014 | 10:03 PM
  #4  
robt342003's Avatar
Thread Starter
Staging Lane
iTrader: (1)
 
Joined: May 2007
Posts: 95
Likes: 0
From: San Antonio, Tx
Default

Found the oil pressure sender. I'll pull trans cover tomorrow and have a look around.

Last edited by robt342003; Nov 11, 2014 at 10:37 PM.
Reply
Old Nov 12, 2014 | 02:07 AM
  #5  
Suburbazine's Avatar
TECH Fanatic
 
Joined: Feb 2009
Posts: 1,635
Likes: 1
From: Baton Rouge, LA
Default

That mess is going to be from a rear main seal. Pop the cap out of the bellhousing bottom and look for all the oil inside. If it was your pan gasket leaking you'd have a big oil spot reaching around most of the pan.
Reply
Old Nov 12, 2014 | 03:52 AM
  #6  
LQ9Chevy1500's Avatar
Teching In
iTrader: (1)
 
Joined: Jan 2013
Posts: 43
Likes: 0
Default

Try the gasket that's on that adapter by the oil filter. I couldn't figure mine out til I did a swap and saw it
Reply
Old Nov 12, 2014 | 07:54 AM
  #7  
robt342003's Avatar
Thread Starter
Staging Lane
iTrader: (1)
 
Joined: May 2007
Posts: 95
Likes: 0
From: San Antonio, Tx
Default

Originally Posted by Suburbazine
That mess is going to be from a rear main seal. Pop the cap out of the bellhousing bottom and look for all the oil inside. If it was your pan gasket leaking you'd have a big oil spot reaching around most of the pan.
Yea I'll pop the cap today and see if that's it. After doing some research I'm leaning towards the oil sender because just recently the there has been some oil stains collecting under the intake.

Originally Posted by LQ9Chevy1500
Try the gasket that's on that adapter by the oil filter. I couldn't figure mine out til I did a swap and saw it
I'll definitely add that to my list, thanks man.
Reply
Old Nov 12, 2014 | 08:19 AM
  #8  
Atomic's Avatar
I have a gauge for that
15 Year Member
Loved
Liked
Community Favorite
iTrader: (42)
 
Joined: Jan 2006
Posts: 16,282
Likes: 438
From: Huntsville, AL
Default

Oil pressure sensor, rear main seal, valve covers, cam sensor, and oil filter thing are all possibilities...
Reply
Old Nov 12, 2014 | 01:59 PM
  #9  
Gadgetized's Avatar
TECH Junkie
15 Year Member
iTrader: (9)
 
Joined: Jan 2010
Posts: 3,095
Likes: 3
From: Rochester, NY
Default

If the leak is inside the bell housing it is coming from the rear main or the cam sensor. I would feel around on top of the engine near the oil sender to see if there is fresh oil there.
Reply
Old Nov 19, 2014 | 09:35 AM
  #10  
robt342003's Avatar
Thread Starter
Staging Lane
iTrader: (1)
 
Joined: May 2007
Posts: 95
Likes: 0
From: San Antonio, Tx
Default

Originally Posted by Gadgetized
If the leak is inside the bell housing it is coming from the rear main or the cam sensor. I would feel around on top of the engine near the oil sender to see if there is fresh oil there.
I felt around the oil sender and there wasn't any fresh oil but I changed it anyway, 10 year old part it was probably due anyway.

I couldn't get my hand down far enough to feel around the cam sensor. There is alot of caked up oil and dirt under the intake that I was sure was the oil sender but the leak persists.

So, oil sender is good, valve covers are dry, next to try is the oil filter adapter or possibly the oil pan.

I popped the cap on the bellhousing and it was dry except for a small amount of oil residue on the back wall of the motor. I had to touch it just to notice it. Is this area supposed to be completely dry of oil? Right now its very faint.

I'm leaning towards something on top of the motor due to all the oil/dirt under the intake. Posting more pics in a bit..
Reply



All times are GMT -5. The time now is 08:06 AM.