Low oil pressure when warm!

[BIGBLAZER]

On my 93 blazer the other night i was out for a drive and started loosing oil pressure got to the point where the check gauges light came on. so i pulled over checked the oil it was right on where it should be so i started it back up and it was good.. drove bout 5 miles and it slowly started loosing it again.. now when i start it up it reads good.. right around 30 which is where its been for the 7 years i owned it.. but then i drive 3-4 miles bout to the point where it gets good and warmed up and i start loosing pressure slowly then by the time ive drove maybe 10-12 miles its down to the red on the gauge.. any ideas? possible sender problem maybe? or something maybe more serious?

 

[ChrisAU]

I'd replace the sender. If it keeps doing it, get a compression test done.

 

[oohunter04oo]

I'd replace the sender. If it keeps doing it, get a compression test done.

X2


But if it is actual low oil pressure, I had a buddy with a 91 that had low pressure and he switch to 20w50 and ran it for a few more yrs like that.

 

[BIGBLAZER]

I'd replace the sender. If it keeps doing it, get a compression test done.

this was kinda my thinking too.. will probably pick one up and give it shot

 

[GMCTRUCKS]

X3 for sure

 

[outalne94z71]

pickup screen getting clogged or failing bypass first comes to mind if its not the sender or even bad filter.

see any metal in the oil?

if it stayed low the whole time hot and only was good cold then i would say you have a bearing/crank journal out of tolerance

 

[BIGBLAZER]

pickup screen getting clogged or failing bypass first comes to mind if its not the sender or even bad filter.

see any metal in the oil?

if it stayed low the whole time hot and only was good cold then i would say you have a bearing/crank journal out of tolerance

Going to change oil and filter tonight.. and check for metal and see if it changes

 

[BIGBLAZER]

changed oil and filter drove it bout 20 miles without a drop in pressure except at idle otherwise held right at about 30 which is right where it always has been.. oil was good no signs of metal or anything else.

 

[DRAGGIN95]

Just keep in mind that the minimum for a SBC is 10 psi per 1k of rpm, so at least 10 at 1k, 20 at 2k and so on, that is the bare minimum.

 

[ChrisAU]

Meh my gauge never reads right. I need to replace the sender.