Low oil pressure

[Nick Panda Man Foster]

I have a 96 lesabre with a 3800 and im gettting low oil pressure after 15-20 minutes or the car running, ive already replaced the sending unit and the rod bearings any ideas?
should i just replace the main bearing and the oil pump?

thanks for the help

 

[HotZ28]

Welcome to the forums! You did not mention anything about what the "low oil pressure" is reading? What is the PSI? All aftermarket oil pressure sensors will have different readings on the gauge! I have tried them all, and get wide variations between them. Do you have any engine knocking, or other symptoms of starving for oil? Do you have any coolant in the oil? A lot of unknowns here?

 

[Nick Panda Man Foster]

Welcome to the forums! You did not mention anything about what the "low oil pressure" is reading? What is the PIS? All aftermarket oil pressure sensors will have different readings on the gauge! I have tried them all, and get wide variations between them. Do you have any engine knocking, or other symptoms of starving for oil? Do you have any coolant in the oil? A lot of unknowns here?

i dont remember the brand name of the oil pressure switch i got im sorry but when im driving the pressure reads about 30 psi and at idle im at about 7 psi and the needle is in the red and the light is on, and the temp climbs when im at idle. there is no knocking, i did have an issue with my egr pipe that caused my engine to hydrolock. drained the oil immediately put the replacement egr pipe on and a new intake manifold, new oil and filter.

 

[HotZ28]

After an engine hydro-locks & the UIM/EGR replacement complete, it is recommended to change the oil/filter along with that repair & again after 500 miles. Cheap oil can be used on the first oil change, then graduate to better quality next. Did you replace the oil sending unit before, or after the hydro-lock? Do you remember where you purchased the OP sensor?

 

[Nick Panda Man Foster]

op sensor was replaced after the hydrolock and i got it from oreillys auto parts store.

 

[HotZ28]

op sensor was replaced after the hydro-lock and i got it from oreillys auto parts store.

Those sensors are manufactured either south of the border, or in some other foreign Mid-West country and are not the same quality as the original. 🙁 I tried several of those BWD sensors that were reading low/erratic pressure & most of them failed, gushing oil out the sensor head within two weeks after installation. It is hard to find an original quality OPS!! I hope you caught the internal coolant leak before any major damage to the main bearings, but that could also be a possibility of low oil pressure. If you have no internal noise from the engine, I would suspect the OPS as not reading accurate PSI. Have you thought about installing a manual pressure gauge in tandem, or independent of the original electrical gauge?? It's a very simple installation and will provide you with the info you need to pursue this further.

 

[Nick Panda Man Foster]

i have considered it but i dont have the tool to do so sadly its not something that my roommate has in his tool box here at home.
i will say though that the rod bearings were pitted but the journals had no deep damage that couldnt be buffed out.

i was considering also using a 40 weight oil to help hold the pressure if i do in fact have an oil pressure issue.

 

[HotZ28]

i will say though that the rod bearings were pitted but the journals had no deep damage that couldnt be buffed out.

You can not "BUFF OUT" the crank main & rod journals, it needs to be turned & polished to restore to proper dimensions, either to .010, or .020 oversized with the correct bearing inserts for that application. You can get oversize bearings for the crank @ most any NAPA part stores. I hope that the bearings are not the problem, but if the rod journals had scoring, you will probably need a lower end rebuild (crank grinding & oversize bearings)!

 

[Nick Panda Man Foster]

well the scoring was able to be polished out i checked the gaps after and everything was still within spec

 

[HotZ28]

Did you check the clearance with a micrometer, or plasti-guage inserts and were they within specs? If you can detect any grinding feel on the journal with your fingernail from side-to-side, the journals need to be properly polished, not buffed. How did you "buff" them?

 

[Nick Panda Man Foster]

I did measure the gaps and they were within spec still. And i used a very very fine emery paper 2000 grit and 3000 grit. Mind you i dont have the money to send my car to be pulled apart machined and everything fixed.

Which is why i did the repairs and replacements myself.

I also check the gaps afterwards as well. Still within spec.

 

[Nick Panda Man Foster]

i did indeed check the clearances before and after with micrometer and everything was within spec. and i used a very very fine grit emery paper(2000 and 3000 grit)

 

[HotZ28]

If you were able to polish the rod journals with fine emery cloth, it appears that you did not have any major scoring of the rod journals and the rod bearings and the clearance should be fine. If I were you, I would still be concerned if the OPS as reading correctly.

 

[Nick Panda Man Foster]

im about due for an oil change so what i will do is check to make sure that 1 the unit works or bring it back and claim that it doesnt work (lifetime warranty) 2 make sure that it is correctly installed again

 

[Nick Panda Man Foster]

well it wasnt the ops just replaced it and im still getting the same issue when the oil get hot. pump or main bearings?

 

[HotZ28]

well it wasnt the ops just replaced it and im still getting the same issue when the oil get hot.

If you do not install a manual OPS in place/tandem with the aftermarkest electronic sensor, you may never know what the REAL oil pressure is! You may have a main bearing problem, but that needs to be verified with a manual gauge! I don't think the oil pump would be the issue!

 

[Nick Panda Man Foster]

i looked for a pressure kit but oreillys didnt have one all they had where the oil pressure gauges you put in your car for aftermarket use