low oil pressure

[Guest davidmullins]

hi I have a 89 reatta that after reaching operating temp. ,the oil pressure drops from 50psi to 12psi.replaced oil pump,no change.engine runs perfect except for this.car has 154000 miles and has been pampered.also replaced oil presuure sensor.engine makes a little noise after warm up,that goes away after reveing engine.

[Ronnie]

Do you only have 12 psi highway speeds? Do you hear a rod knocking?

Try this with the engine warmed up: Hold the throttle at a steady speed (about 1500 RPM). Then just change the engine speed up and down by slightly by moving throttle. If you hear a deep knocking or rattling sound as the engine changes speed you may have a rod bearing bad. If you hear a knocking sound at idle when the engine is hot you could have a bad main bearing (providing the harmonic balancer is good). Bad rod or main bearings will cause a drop in oil pressure.

[D-a-n-i-e-l]

might be time to do a rod bearing job. Cheap fix if yo do it befor it becomes a much more expensive job.

[Guest davidmullins]

did what ronnie sugested and came to the conclusion of main bearings.now what?

[Ronnie]

did what ronnie sugested and came to the conclusion of main bearings.now what?

If you suspect a bad bearing do not drive the car or run the engine for any length of time other than for testing. You can quickly do a lot of damage to the crankshaft (if it hasn't already occurred). How did you determine the problem is the main bearings?

I have heard of cam bearings falling out of these 3800 engines causing a severe drop in oil pressure. I've not had that to happen myself but it might be worth investigating.

Your next move will depend on your level of mechanical skills, access to proper tools and a suitable place to work.

If you feel you are capable of removing the oil pan yourself, (an easy job on the Reatta) and removing the rod and main bearing caps then that is what needs to be done so you can inspect the crankshaft and bearings. If the crankshaft is scored badly or damaged in some way the engine will need to come out for more extensive repairs.

Otherwise you should take the car (don't drive) it to a reliable mechanic to give you his opinion on what needs to be done.

[Guest Corvanti]

where are you in NC?

several folks on the forum are here in Wilmington, Raleigh, Charlotte and more, might be able to help with the problem or guide you to a reliable reatta mechanic.

also check out Ronnie's website: Reatta Owners Journal - The Buick Reatta Community

for loads of reatta info!

[NCReatta]

I can suggest a good mechanic in the Raleigh area if you're interested.

Or I also have a completely overhauled engine and brand new crate transmission for sale if you wanted to go overboard.

[padgett]

First thing the GM manual recommends is check with a mechanical guage. The electrical sender goes bad so often that (1) there was a TSB issued just on the sender and (2) they fail so often I keep a spare around (~$20 FLAPS).

That said I have heard (and had one) of a few '90s dropping the cam bearings with results in oil light on at hot idle and 19 psi on the road but not an '88 or '89. Happened in Indiana, dealer said it was the gauge, drove to Florida at 70 no change. Got home and found two of the mangled cam bearings in pan. Ran fine and never made a sound. Just replaced the engine.

That is strange, it just lost the end of my post.

OK, if you hear noises deep inside then the next thing is to drop the pan and look at a few bearings but if no noise, just low pressure hot then one other possibility is a stuck relief valve in the oil filter housing (four bolts and it is off)

Edited September 10, 2012 by padgett (see edit history)

[Guest davidmullins]

Ncreatta how much for both.where in nc are you.will replace both if i pull engine.i think its worn out like me.

[NCReatta]

Ncreatta how much for both.where in nc are you.will replace both if i pull engine.i think its worn out like me.

Sent you a Private Message. I'm in Raleigh.

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[Guest davidmullins]

Pulled oil filter housing and the button with spring was stuck.cleaned up to assure free movement and reinstalled .seems to have curred issue.now have great oil pressure.

!

[Guest davidmullins]

Well kept hearing noise from engine.looked at oil dipstick.did not look right.pulled oil pan.bad news.metal in the bottom.like flakes.well time for another motor.ncreatta dod you still have the motor/trans. For sale.what is the least you will take.send me details and info about the motor.maybe some pics.am very interested.thanks for the help.

[NCReatta]

Well kept hearing noise from engine.looked at oil dipstick.did not look right.pulled oil pan.bad news.metal in the bottom.like flakes.well time for another motor.ncreatta dod you still have the motor/trans. For sale.what is the least you will take.send me details and info about the motor.maybe some pics.am very interested.thanks for the help.

Shoot me an email at marck@eastcoastreattaparts.com and j can send you pictures.

Make me an offer on it. The worst I can say is no

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