Notices
The Lounge For casual talk about things unrelated to Blazers (ie. Off-Topic).

98 blazer oil pressure

  #1  
Old 06-04-2014, 09:54 AM
New Member
Thread Starter
Join Date: Jan 2014
Posts: 9
98blazermatt is on a distinguished road
Default 98 blazer oil pressure

hi I have I 98 blazer 4 door 4.3 and over about a years time my oil pressure has went from about 40 at idle, 80 while driving after heated up, to 20 at idle and 40 while driving. my pan gasket leaks very slightly and my intake gasket is a bit oily so maybe that could affect pressure. I was also told that it may be a rear main seal. I would imagine that if any gasket in the engine is leaking that there would be somewhat of a drop in oil pressure. seems like common sense. if you have had this problem, I would greatly appreciate any good advice. thanks!
 
  #2  
Old 06-05-2014, 01:12 PM
abig84's Avatar
BF Veteran
Join Date: Aug 2009
Location: munster indiana
Posts: 3,426
abig84 will become famous soon enoughabig84 will become famous soon enough
Default

the oil in the pan isnt pressurized. that would suck cause any kinda pan leak and stuff would be splattering all over the place.

20idle and 40 running really isnt horrible. thats about what most my trucks are at. could just be a faulty gauge or sending unit bouncing around.
 
  #3  
Old 06-06-2014, 09:26 PM
ohsofly's Avatar
Super Member
Join Date: Jan 2010
Location: Camrose AB... Canada
Posts: 1,536
ohsofly will become famous soon enoughohsofly will become famous soon enough
Default

Oil pressure is made by the clearance in the main berrings... Oil pump just moves volume, it doesnt make pressure.

The only way to know for sure is to remove the oil sending unit and plug in a manual gauge to see what the reading is. As said above 20/40 aint bad, but is definately a sign of an engine thats getting tired.

There is no pressure in the crankcase, thats why an engine has a PCV valve (Pressure control valve) to releive the pressure made by pistons going up and down... If there was pressure inside and engine you would blow the pan gaskets out.

When oil pressure is low, its cause the engine is on its way out. The only fix is new main berrings - which are part of a rebuild.

The oil pump is kind of like a running hose. If you stick your finger on the end, you still get the same amount of volume, but you get pressure too. Its the small space that the oil is being pumped through that makes the pressure. When that small space wears out and gets bigger your pressure drops off.
 

Last edited by ohsofly; 06-06-2014 at 09:29 PM.
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
LWegner
Engine & Transmission
1
05-08-2011 08:25 AM
Spectreblazer
Full Size K5 (1969-1991) GMT415 (1992-1994) Tech
3
03-15-2010 11:16 PM
davidsv8mustang
2nd Gen S-series (1995-2005) Tech
1
02-18-2010 02:29 PM
zippy199
Engine & Transmission
4
10-22-2009 06:36 PM
Ak95Blazer
2nd Gen S-series (1995-2005) Tech
5
01-07-2009 06:56 AM


Thread Tools
Search this Thread
Quick Reply: 98 blazer oil pressure


Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service

© 2019 MH Sub I, LLC dba Internet Brands

We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.