I have a 97 pontiac bonneville. when i start the engine up the oil pressure's fine util it gets warmed up then the needle drops. It doesnt go all the way into the red it just fluctuates right over it at idle. Would replacing the pcv valve and putting a thicker grade oil do anygood? Or could it be the oil pressure switch malfunctioning?
2007-10-18 12:49:20 · 4 answers · asked by Anonymous in Cars & Transportation ➔ Maintenance & Repairs
And yes i checked the oil level its completley FULL!
2007-10-18 12:59:10 · update #1
High mileage cars usually have engine wear which produces lower oil pressure when warmed up. You could have the pressure checked at a shop with a good mechanical gauge tapped into the oil switch port to make sure it's not a bad sending unit or dash gauge---they did have problems with those units. Could just be the engine bearings wearing out or the pump. I recommend switching to a heavier grade of oil like 10W-40, 15W-40 or maybe 20W-40 or 50---you may have to play around a bit to get the right grade oil to bring the pressure up--- and I also recommend you add a product every oil change of 3000 miles called Engine Oil Supplement or EOS which can be found at most GM dealers parts dept's---it's a much better product than most aftermarket oil additives and was developed by GM engineers for superior lubrication. Don't forget that adding thicker oil will cause your gas mileage to drop a bit and may be very hard to start the engine in colder weather.
2007-10-18 14:04:00 · answer #1 · answered by paul h 7 · 0⤊ 0⤋
Sorry, the engine is warring out.
As the engine warms up, the oil gets thinner and flows away from the internal components faster, loosing oil pressure.
The basic problem lies with the connecting rod and main bearings.
The good news is you can use heavier oil like 20/50 or straight 30w. You can also try Rislone Engine restore or other brands to improve the oil pressure, Just follow the directions.
If it helps, then your on the right track.
ps it's not impossible that the oil pressure sending unit is bad, but it would more than likely be leaking oil out the top or sides.
jan_elgaard@yahoo.com
2007-10-18 13:12:52 · answer #2 · answered by Doc 2 · 0⤊ 0⤋
Um....did you check your oil levels?
This happened on my caprice when I was running out of oil (it leaked).
2007-10-18 12:56:54 · answer #3 · answered by Anonymous · 0⤊ 0⤋
may only be a bad sending unit
2016-05-23 12:24:52 · answer #4 · answered by ? 3 · 0⤊ 0⤋