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Oil Pressure

03-23-2008, 05:28 PM
Hello all little help here.
I started my 99 Bravada this morning and the motor sounded like it was going to throw a rod.
Checked the oil, full and clean.
Noticed that my oil gauge shot straight up to 40 and stayed there. Started again later in the day, same thing but this time the gauge would jump to 60 when revved.
Iím guessing itís the oil pump.?

03-23-2008, 05:39 PM
hello,sounds like oil pressure is ok!!40 psi @ idle 60 when reving.why are u thinking oil pump

03-23-2008, 06:14 PM
Previously it would drop when idle now it sits at 40.

Chris Stewart
03-23-2008, 10:23 PM
One of the lifters would peck cold in my '97 in the winter until I did the winter oil change, then it would be quiet.

03-24-2008, 02:11 PM
Just did an oil change, made no difference. Spoke to a dealer and a motor shop both said the same thing, oil change.

Any other suggestions?

Also noticed that radiator was low. Filled up ran for awhile and noticed water dripping from the muffler. The oil when I changed it was normal (not brown cloudy).
Leaking head?

03-24-2008, 06:11 PM
have you or can u put a pressure gauge on to see what the pressure is??or do u think dash gauge is correct???

Chris Stewart
03-25-2008, 07:58 AM
Check the coolant level later and see if it's still dropping...the exhaust gasses condense water in cold weather.
Like you mention, watch your oil too.

Have you had any transmission work done lately? A loose converter will bang and knock to beat the band.

03-25-2008, 03:03 PM
...Also noticed that radiator was low. Filled up ran for awhile and noticed water dripping from the muffler.

A byproduct of the catalytic converter is water, perfectly normal to see it drip.

Oil pressure spike could be due to the oil pressure relief valve sticking. The oil filter and the oil filter adapter must be removed to replace it, quick, easy, cheap job.

Coolant in the oil will destroy the oils ability to lubricate causing a knock. Pressure test the cooling system. A very common problem with the 4.3L engine is a leaking lower intake manifold gasket. If it leaks, it can leak coolant into the oil, into a combustion chamber, or leak externally. Hope this helps.

03-25-2008, 08:35 PM
Knocking fixed Ö drained out a quart of oil and added a quart of Lucas, drove for 5 miles and knocking went away.
As for the water Ö itís just not a drip it actually leaves a pretty substantial size puddle.
Am going to flush the radiator this weekend and run a sealant through.

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