Oil Pressure in a 3.3L V6

[/6 Matt]

Got a 1992 Plymouth Grand Caravan 3.3L 2WD, 186,000 Miles.

The engine was replaced with a reman unit from surefire, please hold your surefire comments, I already read all the "wonderful" reviews unfortunately after my sister had purchased it and I installed it. Engine replacement was at 182,000 miles, the oil pump was rebuilt with the new engine installation, the engine was filled with 5 quarts of castrol 10w-30 and an orange can fram filer (I wasn't there when she bought it:violent1. Oil was replaced again with Castrol 10w-30 with a wix filter at 182,500 miles.

I just did an oil change today with Castrol full synthetic 10w-30 and used a wix filter. Now the oil pressure seems low.

When we first put the engine in, oil pressure was at.

L|__|__||__|H

Oil pressure has eventually worked it's way down to

L|__|__||__|H

It would fluctuate in between the above picture and the first one.

Changed the oil today and the oil went to the first picture and then eventually dropped to here on idle:

L|__|__|__|H

As engine rpm increases it will climb to the second picture, at about 3K rpm its fluctuating between the first and second picture.

Any thoughts as to what the hell is going on? Oil is halfway between add and full. Why is it so low on idle?:dontknow::scratch:

 

[RustyRatRod]

Don't sweat the little things. Drive it till it drops. It's a road toad.

 

[/6 Matt]

LOL ok Rob, it just kinda freaked me the hell out ya know. The van might be a road toad but I love it, it's a very nice van for it's age.

 

[VOETOM]

We change sending units on those often at our shop.
Tom

 

[/6 Matt]

We change sending units on those often at our shop.
Tom

Common failure? It's a $20 part and easy to change so I might see if she wants to go ahead and replace it. All we did was clean it when we put the engine in.

 

[66plyValiant]

you can never go by factory oil pressure gauges or sending units, if your that worried about it put a aftermarket one under the dash and call it a day, anything over 20 PSI at idle is really good

most senders that use lights don't trigger the light until 7 PSI

 

[/6 Matt]

you can never go by factory oil pressure gauges or sending units, if your that worried about it put a aftermarket one under the dash and call it a day, anything over 20 PSI at idle is really good

most senders that use lights don't trigger the light until 7 PSI

If I am not mistaken the sending unit goes to the pcm which controls the gauge. Just sayin.

 

[krazykuda]

Aren't those supposed to take 5w-30?

 

[ramenth]

Aren't those supposed to take 5w-30?

For winter weight, yes. On the engines from the '90's Chrysler usually recommends 5-30 in the winter, with a switch to 10-30 in the summer.

As far as the gauge goes... "L" is low. That's what it means. When it hits the "L" then the oil pressure is low. Sounds obvious, I know. Anything above that is considered normal.

You can always use both the factory gauge and an aftermarket one. The sending unit is pipe thread. It doesn't take much to T one off between the factory unit and the block and run a capillary tube for an aftermarket gauge.

But Tom is right. The sending units on these things like to crap out. After a while they'll develop small holes that will allow oil to seep by making the gauge do all manners of funky things.