tnaratil

Hello,

I have a $1500 craigslist 1997 Chevy Express 1500 5.7L 4l60E 130,000mi with low PSI issue. It is within spec of "GM says 10 psi per 1000x RPM" but idling in gear at a stop sign gives me the creeps seeing such low PSI. Oil PSI goes up during anything above idle and at highway speed. I have ran a mechanical gauge to be sure it was not sending unit. Many mechanics have told not to worry about it. I am running 5w30 Mobil 1 High Mileage. I just noticed a slight knock when it is really hot out 90'+. I would like to replace the oil pickup O ring, oil pump and check screen if I can easily remove the pan. If i I need to pull the motor I will just put heavier oil in it.

Can I remove the oil pan without jacking the motor or pulling it. Mechanic friends say I need to cherry pick the motor in vans and it's a nightmare. Upon inspection it does not appear this way. Not much in forums on this year and I have searched and searched! I am hoping because it's so easy to do there is no need for a post. I am just scared to drop pan in my backyard and be stuck. See attached pictures.



Thanks for your experience and information.

Twscarp

Hi, according to Autozone's Repair Guide, the job is done with the engine in place.

NOTE: The pictures look to be of a 4 wheel drive van, you can see the front driveshaft, not sure if this will affect the job, probably not.

tnaratil

Thank you so much for taking the time to post a detailed response. Your awesome.

it's a express. I will attempt a oil pressure fix when we get home. Knock at idle in gear around 500ish rpm is there. Not sure if I want to put too much cash in it if it needs rebuild. Runs great beyond that if i can get 30k out of it with oil fix I'd be happy and deal with knock. Hope it goes away if i get enough psi.

canucklehead

Not a 4 wd van. All wheel drive or quigley conversios have torsion bars, coils springs wold be in the way of the front axle shafts.

Twscarp

Hi, can you explain what we're looking at?

Rednucleus

Try a heavier oil before doing the work. My 93 Suburban has about 350k miles; with 5/30 oil it barely makes 5psi at idle when warmed up. With 20/50 it gets 10 at idle and 30psi on the highway. No noises and only eats a qt every 2000 miles.

tnaratil

Everyone. Thanks for taking time out of your busy days to help me out.

The pictures attached are of the oil pan in the van.

I think I may just run a heavier weight oil and leave it be. I tend to over engineer and negate the KISS principles for better or worse sometimes. I have had many experienced GM people tell me no to worry about it just run a heavier weight. I would hate to do a tear down and replace everything and has zero results.

What is everyone else's oil PSI at idle at operating temps in 100k + 350 SBs?

canucklehead

Try high mileage oil before higher viscocity. i noticed higher psi at idle in my 2002 express. Heavy oil will starve your valvetrain at startup...

tnaratil

Thanks for the info. I am running 5w30 Mobil 1 High Mileage now. I add a half quart of Lucas Oil Stabilizer and it brought up the PSI a bit.

canucklehead

Try a semi synthetic high mileage oil like valvoline max life. Do you have leaks with the full synthetic on your older engine?