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Tim's Auto Repair
Tim's Auto Repair, mechanic
Category: Chevy
Satisfied Customers: 16035
Experience:  Have owned a repair shop for 25 yrs.
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Very recently my oil pressure has dropped. It was around

Customer Question

Very recently my oil pressure has dropped. It was around 30psi and now is about 18psi at 2200RPM Highway. When I stop/idle it drops to about 5psi. The oil is full and was recently changed (Mobil1 and Filter). I have noticed since I owned it that the pressure
has not been steady- it might go from 30ish to 38/40 very quickly and then back again. I am hearing a 'knock', but it sounds like a lifter (guessing, not enough oil). Other thing I notice is that cruising at 65MPH (pressure at 18psi, RPM 2200), and I suddenly
take my foot off the gas, pressure inches to 20+psi. Let it sit and cool down a bit and start the engine- pressure goes to 28/30psi. What should I check? Would this be the oil pump and is there a pressure valve that might be malfunctioning? If a rod bearing
'went', I would guess there would be other issues and the pressure wouldn't drop this much? The engine seems to still idle and rev fairly smooth. Let me know how to diagnosis this.....thanks!
Submitted: 2 years ago.
Category: Chevy
Expert:  Tim's Auto Repair replied 2 years ago.

Hi, My name is ***** ***** for the delay.

I will do my best to assist you

how many miles is on the suburban?

Expert:  Tim's Auto Repair replied 2 years ago.

is the noise you hear a deep tone knock?or a light ticking sound?

Customer: replied 2 years ago.
hey Tim. Around 105K on miles. It sounds more like a lifter than a rod. I did some research on the internet and there are a lot of different issues with these pumps (it seem)...everything from a damaged seal on the inlet tube (causing air suction) to a stuck relief valve, plugged oil filter, or plugged pickup. I am almost thinking it is a damaged seal, as the pressure has never been more than 30ish once warm and it would jump just in normal driving. It looks like the pumps (well the bolt for the pickup anyway) can be difficult to remove/install with the pan in place, but other than that, the job looks straight forward. Thoughts?
Expert:  Tim's Auto Repair replied 2 years ago.

i would think your problem is the pick-up o-ring or the pressure relief valve on the pump,,sense it does have more pressure when the oil is cold and thick

Expert:  Tim's Auto Repair replied 2 years ago.

if i were you,,,i would replace the complete oil pump here

Expert:  Tim's Auto Repair replied 2 years ago.

is it a 2 or*****

Expert:  Tim's Auto Repair replied 2 years ago.

i will give you directions

Customer: replied 2 years ago.
Hey Tim. That is what I am thinking. It is***** Also, do I need to prime the pump prior to starting the engine once I have the new pump in? If I do, I was thinking about using a starter button on the starter (so I don't have to use the ignition). If I do that, should I pull the spark plugs?
Expert:  Tim's Auto Repair replied 2 years ago.

no need to prime..

Expert:  Tim's Auto Repair replied 2 years ago.

please stand by

Expert:  Tim's Auto Repair replied 2 years ago.

Parts InformationOEM Part #Price

Oil Pump

33 - Oil Pump


Labor InformationSkill LevelMfg. WarrantyStandard



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Customer: replied 2 years ago.
Thanks Tim! One last question. GM makes a high vol pump (17801830). Should I/can I use this one? Says it is for LS engines, so it should be ok with the AFM (Active Fuel MGMT).
Expert:  Tim's Auto Repair replied 2 years ago.

just stay with the stock unit,,no need for a high volume pump..