1999 Buick Lesabre oil pressure

BUICK9874

MEMBER
1999 BUICK LESABRE
6 CYL
FWD
AUTOMATIC
77,000 MILES

After I bought the car, I had the oil changed. Not sure if the Valvoline put in 5w-30 or 10W-30. Over the first 3000 miles during the summer, it lost 1.5 quarts of oil. No sign of a leak. A mechanic suggested I put in 10W-40. Immediately, the oil pressure gauge read about 60 instead of 40-50. The engine sounded louder and louder over the next two weeks. Poor acceleration. Trouble getting up hills. "Crack" sound from under hood one time after I started the car. Since winter was starting, I switched to 5w-30. Engine quieted down. Runs good. No evidence of losing oil for 2000miles. However, oil pressure has gradually gone back up to 60 or more.

3 Replies

BUDDYCRAIGG

MECHANIC
2,262 POSTS

The rule of thumb is 10psi of oil pressure for every 1000rpm.
If you are there or above that level, then no worries.

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Wednesday, December 10th, 2008 AT 11:53 PM

JACOBANDNICKOLAS

MECHANIC
108,192 POSTS

Hi:
Keep an eye on the oil pressure. You really don't want it to exceed 60PSI In the oil pump there is a pressure release valve that is designed to release pressure at 60PSI. If it goes above that, your oil filter could fail or leak. There have been cases where the check ball / spring have stuck or became sluggish allowing pressure to raise. A normal OEM filter can withstand up to 150PSI before they let loose (the gasket blows or the steel filter fails); however, with aftermarket filters I can't be sure. Just keep an eye on the gauge. If you notice it spike, let me know and I'll tell you what to check. Also, I strongly recommend staying with 5w30. With the close bearing tolerances in todays engines, you want oil to them ASAP.

Let me know if you have any questions.

Joe