no oil pressure at start up...sometimes?

**Smithd24** · 06-20-2007, 05:10 AM

hello everyone. I recently pruchased a 2002 trailblazer LT. Lately I have been experiencing a scary situation with this vehicle. Approximately 1 out of every 5 times that I start this vehicle up, the oil pressure guage reads "0" and my dashboard displays "Turn engine off." This does not make any sense to me. I turn the engine off and when I start it up again, the guage reads normal. I dont understand...please help. Is it possible that the guage could be malfunctioning? Why else would the guage read "0"...every now and then?

**tbplus10** · 06-20-2007, 11:24 AM

Chances are good its a gauge issue. To be sure you should hook a mechanical gauge to the engine and try to reproduce the fault.
To install a mechanical guage you'll need an adaptor to install in the sensor port, preferably an adaptor that allows the sensor to be installed at the same time. Dealerships have an adaptor designed to do this test, maybe a local garage will have one and you can borrow theirs or get them to test the system.

**unplugged** · 06-21-2007, 12:55 AM

Couple of things to look at: Faulty sensor, faulty gauge, or something as simple as a faulty oil filter. First check for the obvious, like a loose wire on the oil pressure sensor. Try the recommended test to check the sensor/gauge, and don't forget that the oil filter it should have a functioning ADBV. See the Wix filter site for more info. Wix.com

From: http://www.drivewire.com/replacement...oilfilter.html
The oil filter is used to clean the oil as it is being pumped thru the engine. Most cars have an external oil filter to help keep the engine oil clean between oil changes. For vehicles with external oil filters, there are two types used. The first and most common on domestic and Japanese cars is the spin-on oil filter. This is where the entire oil filter is self contained and can be removed and properly disposed of when you do an oil change. These spin-on oil filters are usually made of metal with a paper-filtering medium inside that traps metallic shavings and dirt that end up in engine oil. Some spin-on filters will have an internal check valve to keep oil inside the oil filter when the engine is off. This helps the engine get oil faster when it is just started up.

Chevy Parts

**Smithd24** · 06-21-2007, 01:20 AM

thanks for the imput... come to think of it, the vehicle just started doing this after my last (and first since ive owned the vehicle) oil change. so...chances are, my engine is fine???

**Smithd24** · 06-21-2007, 04:24 AM

Is it possible that the people who changed my oil could have put the wrong oil filter on...? causing this problem.

**84fiero123** · 06-21-2007, 07:15 AM

Originally Posted by Smithd24

Is it possible that the people who changed my oil could have put the wrong oil filter on...? causing this problem.

Sure is, did you have it done at one of those quicky lube places?

They hire kids most of the time, that’s why the oil changes are so cheap.

**unplugged** · 06-21-2007, 08:04 AM

Yikes! I forgot to mention did you check the oil level? And stay away from quicky lube joints, the money you save up front will cost you in the end. Just do a search on any of the quicky lube names in any auto forum for the horror stories.

**Smithd24** · 06-22-2007, 01:42 AM

the oil level is full. i had the oil changed at valvoline express care. the charged me 34.00 to change the oil. do you think i should take the vehicle back to them, advise them of my problem, and ask them to check to make sure that they put the proper oil filter on?

**Smithd24** · 06-22-2007, 01:47 AM

the vehicle is a 2002 trailblazer LT. I believe it has a 4.6 liter vortec in it. does anyone know the proper oil and filter that is recommended for this vehicle. thanks a ton!!!!!