SPONSORED LINKS

1999 GMC Suburban oil pressure drops as engine gets warmed

Tiny
DAVECINCY
  • MEMBER
  • 1999 GMC SUBURBAN
  • V8
  • 4WD
  • AUTOMATIC
  • 113,000 MILES
Recently on long trip I noticed my oil pressure was dropping on the guage lower than normal. I normal ran at a reading on the guage of 40. On the trip it was droppin down to ~ 25-30. This seems like a large percentage drop.

Prior to this trip I had the lower intake gaskets replaced and the oll changed. When I check the oil it was over full.

I don't seem to be losing oil or coolant. But have only driven about 3000 miles.
SPONSORED LINKS
Thursday, March 12th, 2009 AT 7:16 PM

7 Replies

Tiny
RASMATAZ
  • MECHANIC
  • 75,992 POSTS
Do you hear any type of knocking noises inside the engine? If not-try checking the oil pressure with a mechanical gauge if normal reading-replace the oil pressure sending unit abnormal could be the oil pump or the engine bearings-
SPONSORED LINKS
Was this
answer
helpful?
Yes
No
-1
Thursday, March 12th, 2009 AT 7:25 PM
Tiny
DAVECINCY
  • MEMBER
  • 13 POSTS
I will check sending unit. I am getting some what sounds like exhasut manifold noise during accelleration. Not realy knocking. I was thinking oil pump. Why do you think it could be engine bearings?
Was this
answer
helpful?
Yes
No
Thursday, March 12th, 2009 AT 7:57 PM
Tiny
RASMATAZ
  • MECHANIC
  • 75,992 POSTS
Check the oil pressure with a mechanical gauge and get back with the reading for evaluation
Was this
answer
helpful?
Yes
No
Thursday, March 12th, 2009 AT 10:49 PM
Tiny
DAVECINCY
  • MEMBER
  • 13 POSTS
Where is the oil pressure sensor located? The manual I have says it is above the oil filter. I see nothing there. It looks like it is on the right side of the engien looking forward jsut above the oil pan? Is that right.
Was this
answer
helpful?
Yes
No
Friday, March 13th, 2009 AT 7:35 PM
Tiny
RASMATAZ
  • MECHANIC
  • 75,992 POSTS
What CID engine is this-305/350/454?
SPONSORED LINKS
Was this
answer
helpful?
Yes
No
Friday, March 13th, 2009 AT 9:35 PM
Tiny
DAVECINCY
  • MEMBER
  • 13 POSTS
Here is what I know. In my owners manual it is describes as Vortex 5700 V8.

On some oil change reciepts they ID it as a 8 cyl. 5.7L 350 FI (R)

So I am guessing 350 CID.

The VIN is 3GKFK16R7XG539211

Thank you for the help
Was this
answer
helpful?
Yes
No
Saturday, March 14th, 2009 AT 7:39 AM
Tiny
RASMATAZ
  • MECHANIC
  • 75,992 POSTS
Sir-The oi pressure switch is located on top left of engine near the distributor.

Thank you for the donation and for using 2carpros
Was this
answer
helpful?
Yes
No
Saturday, March 14th, 2009 AT 5:02 PM

Please login or register to post a reply.

Related Oil Low Pressure Content

Oil Pressure Low
GUIDE
Oil Pressure Low
Engine oil is used to cool and lubricate bearing and machined surfaces. Without oil pressure an engine will experience extreme internal engine damage due to heat caused by...
VIEW MORE

Sponsored links