Oil pressure?

[Deanfe]

Hello, my first thread/post here except for an introduction. I bought a 97 4runner Limited Dec 2013 with 184,000 miles. The vehicle looks pretty good considering it's age and mileage, it is destined to live at a beach house on the Gulf coast. I changed the oil and filter immediately after getting the vehicle, it appeared pretty clean actually, within 3-4 weeks I noticed the coolant level was down, and after research and doing a coolant/block test found there to be exhaust in the coolant. With the help of this forum and a PDF manual I found online. I tore into it, found a blown head gasket and cracked head, so I went ahead and did both head gaskets and installed a rebuilt head. Installed a new timing belt, idlers, knock sensor harness, and water pump. It fired right up and has been running great with no issues until now. Which has been about 2 weeks/150 miles after doing the head gaskets.

I am getting the low oil pressure light at idle, I do have a manual pressure gauge on order to verify the operating and idle pressure, should be here tomorrow. I did pull the pressure switch to checks its operation and it closes at about 2 1/2-3 psi. I am seeing reference to the bearing clearances being worn/too large to maintain good oil pressure, if too large of clearance would I be getting some noise? I am just curious if I should drop the pan to check the pickup and if it is clear, would you suspect the oil pump?

Sorry for drawing that out.

Thanks for any help!

Dean

 

[agloukhoff]

Once your manual pressure gauge arrives, check your oil pressure higher RPMs. The service manual has the ranges.

My oil pressure light also goes on at 700rpm - but is perfectly fine at all other ranges.

 

[Deanfe]

Thanks, that is where mine is coming on, while at operating temperature. Did you also check your pressure at higher RPMs and find it to be good? How long has yours been doing that?

Dean

 

[agloukhoff]

Thanks, that is where mine is coming on, while at operating temperature. Did you also check your pressure at higher RPMs and find it to be good? How long has yours been doing that?

Dean

It's been doing that ever since I replaced the engine. The replacement engine is fairly newish looking with great compression - so I doubt it's the culprit. Anyway its' been about 2 years at this point. I figure I messed up the oil pickup one way or another when I had to swap it out. (Probably just not tight enough)

My reading with the mechanical gauge were:

3000RPM = 70 PSI
2000RPM = 45 PSI
1000RPM = 15 PSI
800RPM = 6 PSI
700RPM = 3 PSI

I did nothing about it, it's not really been an issue. I don't spend a great deal of time idling and with the AC on the RPMs stay too high for the low pressure to hit.

In short, if your reading are like mine, I'd not worry about it.

 

[Singtoe]

How did you clean you head surface when you replaced HG?

Theory : A piece of debris(sand,hard carbon) or wire brush bristle fell into the oil pan and the oil pumped picked it up and wiped it out.

Cut open up the the oil filter and check it for metal shavings, chips and grit.

 

[Deanfe]

Thanks for the info Agloukhoff, I had seen that information posted previously, but couldn't find it again. I will post up my findings this weekend.

I used gasket scrappers and blades, I will check my filter.

 

[Ol'Blue]

It sounds like you have a handle on this pretty much. One thing to remember always.

If you take the intake off an engine rather to do head work, gaskets what ever, ALWAYS do an oil change with it. We had this argument with a Tech at my shop years back because he thought that was BS because he knew it all. Well his tuned changed after he bought a customer a new engine after a job he did because coolant got into the oil pan after doing a intake gasket job.

As said above check the filters and see what you have.


Blue