SPONSORED LINKS

Losing oil quickly, could it be the rear main seal?

Tiny
AZDANNO04
  • MEMBER
  • 2008 CHEVROLET COBALT
  • 2.2L
  • 4 CYL
  • 2WD
  • MANUAL
  • 130,123 MILES
Just changed my oil less than a week ago. I had to replace the oil pressure sensor. I noticed a lot of oil underneath the engine but only a few drops on the driveway. So, I know i’m losing more oil while driving the car. Does that sound like the rear main seal? I don’t have any oil residue on top or around the car, just mainly underneath the vehicle.
SPONSORED LINKS
Friday, August 5th, 2022 AT 9:08 PM

40 Replies

Tiny
JACOBANDNICKOLAS
  • MECHANIC
  • 109,885 POSTS
Hi,

If this started since the oil changed, confirm the drain plug is tight and check around the oil filter to make sure it isn't leaking from there.

If it has been an ongoing issue and it is dry from the top, yes, it could be the rear or front main seal, or the oil pan itself.

Also, if I recall, the pan is aluminum, so check for cracks. The dipstick tube and level sensor can leak as well, so check that too.

Let me know what you find.

Take care,

Joe

See pic below.
Image (Click to make bigger)
Thumb
SPONSORED LINKS
Was this
answer
helpful?
Yes
No
+1
Friday, August 5th, 2022 AT 11:02 PM
Tiny
AZDANNO04
  • MEMBER
  • 285 POSTS
I've been losing oil prior to the oil change and when I noticed I have forgotten what notified me that the oil pressure sensor needed to be replaced. Wasn't an OBDII reader. It was ether oil residue around the area. Because I had no warning for oil pressure on the instrument panel. Also, when I changed the oil, I replaced the gasket for the oil drain plug. When I check the dip stick and wipe it clean to have a clear reading and place to dip stick back to have a reading level. When it came back clean still. I had thought my entire oil had leaked. But after placing some oil in the engine. It read halfway mark. So, the dipstick reads if it's a quart low of the nearly 4 quarts it takes. Still, I am going to place the front portion of the vehicle on jack stands and wipe it down underneath then run the engine and see where I can find the leak source.
Was this
answer
helpful?
Yes
No
Saturday, August 6th, 2022 AT 5:17 PM
Tiny
JACOBANDNICKOLAS
  • MECHANIC
  • 109,885 POSTS
Hi,

I think that is an excellent idea. Use something like brake cleaner to remove the oil and dirt. It dries really fast and will remove oil.

The reason I mentioned the oil filter is that the rubber o-ring where the filter mounts can stick to the engine block and not be noticed. When the new filter is installed, the two together leak.

Regardless, let me know what you find or if there is anything I can do to help.

Take care,

Joe
Was this
answer
helpful?
Yes
No
+1
Saturday, August 6th, 2022 AT 7:47 PM
Tiny
AZDANNO04
  • MEMBER
  • 285 POSTS
Will do, keep you informed.
Was this
answer
helpful?
Yes
No
Sunday, August 7th, 2022 AT 6:38 AM
Tiny
JACOBANDNICKOLAS
  • MECHANIC
  • 109,885 POSTS
Hi,

I haven't heard from you for a couple of days. I was wondering if you had a chance to get things cleaned-off and inspected. I don't mean to be a pain. I'm just interested in knowing.

Hope all is well.

Take care,

Joe
SPONSORED LINKS
Was this
answer
helpful?
Yes
No
+1
Tuesday, August 9th, 2022 AT 12:01 PM
Tiny
AZDANNO04
  • MEMBER
  • 285 POSTS
I have Wednesday and Thursday off. I noticed lately when I accelerate there’s a whistle like noise that I didn’t hear before. Didn’t know if you can send me the vacuum lines diagram for the 2008 Cobalt 2.2 LS manual coupe has over 130,000 miles on it. I will be able to remove the starter and look where the oil pressure sensor is and make sure it's on hand tighten snugged. I changed the oil about two weeks ago. I’ve been checking the oil and only had to add oil to it a couple of days ago. I checked around the engine for no buildup of the engine oil but I haven’t checked underneath the vehicle where the control arms underneath the crossmember bar. Hopefully if its leaking from the seam between the engine and oil pan right by the oil pressure sensor. Will see Wednesday.
Was this
answer
helpful?
Yes
No
Sunday, August 14th, 2022 AT 9:05 PM
Tiny
JACOBANDNICKOLAS
  • MECHANIC
  • 109,885 POSTS
Hi,

I attached what I have for vacuum schematics. I hope they help. As far as the oil leak, has it gotten better?

Let me know.

Joe

See pics below.
Images (Click to make bigger)
Thumb
Thumb
Was this
answer
helpful?
Yes
No
+2
Monday, August 15th, 2022 AT 6:44 PM
Tiny
AZDANNO04
  • MEMBER
  • 285 POSTS
So far, the oil isn’t losing as much as when I checked it last two days ago. Today is the day I will be removing the starter out of the way to clean and check for oil leaks as well making sure the oil pressure sensor is snug.
Was this
answer
helpful?
Yes
No
Wednesday, August 17th, 2022 AT 7:31 AM
Tiny
JACOBANDNICKOLAS
  • MECHANIC
  • 109,885 POSTS
Hi,

Thank you for the update. Let me know what you find. I'm interested in knowing.

Take care,

Joe
Was this
answer
helpful?
Yes
No
+1
Wednesday, August 17th, 2022 AT 7:50 PM
Tiny
AZDANNO04
  • MEMBER
  • 285 POSTS
Well, I checked my oil levels lately and not losing anything but what else could I be having liquid dripping from? I bought some transmission fluid and how can I check if my transmission fluid is low? Since I don’t have a tranny fluid dipstick.
Was this
answer
helpful?
Yes
No
Wednesday, September 14th, 2022 AT 9:03 PM
Tiny
JACOBANDNICKOLAS
  • MECHANIC
  • 109,885 POSTS
Hi,

To check the fluid level, you need to remove the left front tire to access the fill plug. Do this with the engine cold and the vehicle has to be level.

I attached the directions below. Note: There are two plugs with arrows pointing to them. The upper plug is the fill and check. When you remove the plug, the fluid should be level with the lower part of the plug opening. If you want to drain the transmission, the lower plug is the drain.

Let me know if this helps or if you have questions.

Take care,

Joe

See pics below.
Images (Click to make bigger)
Thumb
Thumb
Thumb
Was this
answer
helpful?
Yes
No
Thursday, September 15th, 2022 AT 5:56 PM
Tiny
AZDANNO04
  • MEMBER
  • 285 POSTS
I noticed spots on the driver's side underneath the vehicle that it didn’t look like oil but more like brake fluid perhaps. As I was pulling it in the garage I gave it high RPMs as I was going the garage and I noticed the spots underneath but that was when I had highly accelerated. Now that I have the car jacked up and on jack stands going to see where exactly its coming from. Also, will be checking the brake fluid to see if it needs to be topped off.
Image (Click to make bigger)
Thumb
SPONSORED LINKS
Was this
answer
helpful?
Yes
No
Friday, September 16th, 2022 AT 3:28 PM
Tiny
AZDANNO04
  • MEMBER
  • 285 POSTS
When I had pushed the acceleration pedal a bit much when going in the garage. As they say, things happen for a reason, that was how I was able to see the drips.
Image (Click to make bigger)
Thumb
Was this
answer
helpful?
Yes
No
Friday, September 16th, 2022 AT 3:30 PM
Tiny
AZDANNO04
  • MEMBER
  • 285 POSTS
Yes, it smells like transmission fluid.
Video (Click to make bigger)
Thumb
Was this
answer
helpful?
Yes
No
Friday, September 16th, 2022 AT 3:36 PM
Tiny
JACOBANDNICKOLAS
  • MECHANIC
  • 109,885 POSTS
Is the leak from the transmission pan or is a plug leaking?

For some reason, I can't get the video to play so you may have already answered the aforementioned question.

Update, I got it to play. The dripping appears to be below where the axles are located. Check to see if there is fluid coming from the axle seals and running down.

Let me know.

Joe
Was this
answer
helpful?
Yes
No
+1
Friday, September 16th, 2022 AT 8:33 PM
Tiny
AZDANNO04
  • MEMBER
  • 285 POSTS
I believe it is. What do I need to do to replace the seals?
Was this
answer
helpful?
Yes
No
Monday, September 19th, 2022 AT 10:36 PM
Tiny
AZDANNO04
  • MEMBER
  • 285 POSTS
Don’t know how long that’s been missing but explains the loss of fluid I placed in the top for the transmission fluid. What’s plug size replacement?
Image (Click to make bigger)
Thumb
Was this
answer
helpful?
Yes
No
Tuesday, September 20th, 2022 AT 11:46 AM
Tiny
JACOBANDNICKOLAS
  • MECHANIC
  • 109,885 POSTS
Hi,

Is that the drain plug that is missing? As far as the part, I believe the OEM part number is 24233099. The specifications are listed below.

Let me know if this helps.

Joe

See pic below.
Image (Click to make bigger)
Thumb
Was this
answer
helpful?
Yes
No
+1
Tuesday, September 20th, 2022 AT 6:50 PM
Tiny
AZDANNO04
  • MEMBER
  • 285 POSTS
Thank you very much!
Was this
answer
helpful?
Yes
No
Wednesday, September 21st, 2022 AT 1:33 AM
Tiny
AZDANNO04
  • MEMBER
  • 285 POSTS
Luckily the check engine light never came on nor did the transmission seize up. Thankful that I only work less than 1.4 miles away from home but I still did the driving around to here and there that was also in a five mile radius.
Was this
answer
helpful?
Yes
No
Wednesday, September 21st, 2022 AT 1:36 AM

Please login or register to post a reply.

Related Crankshaft Rear Crankshaft Seal Replace/Remove Content

Crankshaft Seal Replacement - Rear
GUIDE
Crankshaft Seal Replacement - Rear
Your car's engine rear main crankshaft seal is designed to give the engine oil leak protection from between the crankshaft output flange and the engine block. This seal is...
VIEW MORE

Sponsored links