Oil Pump going bad?

**clg82** · 05-10-2007, 03:45 PM

I am in the military and all my life have lived in Illinois I now live in Southern California where they get hotter temp's then illinois. My question is when I lived in illinois my oil pressure gauge would consistently read 40-60. Normal right? Now that I live in southern california it is reading a little above 20 and sometime "Bobbing" between 20-40. I haven't changed the type of oil I use so what could be the problem?....I run penzoil 5w30 by the way. Is my oil pump going bad? Or is it just the heat and should I change oils?

**Y2KPewterSS** · 05-10-2007, 04:49 PM

If you are down around 20 PSI, thats a strong sign your pump is dying and I would stop driving it until you find out exactly what it is and fix it. Otherwise, you are potentially looking at a spun bearing/blown motor pretty soon.

**LETHALxLS1** · 05-10-2007, 05:12 PM

Could it not be the sending unit for your oil pressure gauge? I had one go bad in my old 87 IROC and the oil pressure was really low around 10-15. I put a new sending unit or sensor in for like 10 bucks and the pressure went up to 50psi!!! Might be worth a try.

**clg82** · 05-10-2007, 05:38 PM

Originally Posted by DEADBYDAWN

Could it not be the sending unit for your oil pressure gauge? I had one go bad in my old 87 IROC and the oil pressure was really low around 10-15. I put a new sending unit or sensor in for like 10 bucks and the pressure went up to 50psi!!! Might be worth a try.

where is the sending unit located? I have a 2000 trans am if that helps any.

**clg82** · 05-10-2007, 05:38 PM

Originally Posted by Y2KPewterSS

If you are down around 20 PSI, thats a strong sign your pump is dying and I would stop driving it until you find out exactly what it is and fix it. Otherwise, you are potentially looking at a spun bearing/blown motor pretty soon.

how much does a new one cost and can I replace it myself?

**LETHALxLS1** · 05-10-2007, 05:41 PM

I have to dig out my service manual so it my take a little while but I will find out for ya. I have a z28 but it should be the same as your car.

**LETHALxLS1** · 05-10-2007, 05:43 PM

Go on gmpartsdirect.com and look it up. Yes you can replace it. It basically plugs in-nothing to it.

**clg82** · 05-10-2007, 05:43 PM

cool thanks man, also if this helps any when i start my car in the morning it reads normal but after it get's hot and it's been running awhile around town, that is when it starts to read low.

**Y2KPewterSS** · 05-10-2007, 05:46 PM

The sending unit is behind the intake manifold, its a little bit of work but can be replaced.

I don't know what your mechanical level is, but the pump itself takes some work to access.

**LETHALxLS1** · 05-10-2007, 05:46 PM

Thats because the oil gets hot and thinner which causes the pressure to drop down a bit(normal). I cant gaurantee the oil pressure sending unit is your problem but my old car did the same thing. I actually bought the car really cheap because the guy thought the oil pump was bad but it wasnt-it was just the sending unit.LOL

**LETHALxLS1** · 05-10-2007, 05:48 PM

I would definately buy one and try it before replacing the oil pump

**Y2KPewterSS** · 05-10-2007, 05:50 PM

Originally Posted by DEADBYDAWN

I would definately buy one and try it before replacing the oil pump

I second this idea, its definately worth a try. I would still keep the driving of the car to a bare minimum until the problem is diagnosed and fixed though.

**LETHALxLS1** · 05-10-2007, 05:52 PM

I agree-just in case its not the sending unit.

**clg82** · 05-10-2007, 06:41 PM

Originally Posted by Y2KPewterSS

The sending unit is behind the intake manifold, its a little bit of work but can be replaced.

I don't know what your mechanical level is, but the pump itself takes some work to access.

any pix of where the sending unit is exactly? so i can try that tomorrow and if that doesn't work then i will just take it to a shop so they can try and fix the pump itself

**LETHALxLS1** · 05-10-2007, 09:19 PM

Originally Posted by clg82

any pix of where the sending unit is exactly? so i can try that tomorrow and if that doesn't work then i will just take it to a shop so they can try and fix the pump itself

I would highly advise not jumping the gun and going to a shop and asking them what is wrong. If anything buy the sending unit and take the part to a shop and get it put on (shouldnt be more than $25.00 labor) if you think you cant handle it. See if the local NAPA parts store has the part. After you get that fixed I would change to 10-40 weight oil since its very hot there. I live in Florida and use 10-40. It will help raise the oil pressure a bit as well.

**clg82** · 05-10-2007, 09:56 PM

Ok I will probably do that tomorrow. But I heard that 10w40 is extremly thick for our cars and that it reduces horsepower is that true?

**LETHALxLS1** · 05-10-2007, 10:02 PM

No man 20/50 is kinda thick 10/40 isnt but a tiny bit thicker than what u are using. You wont loose any HP. If anything your engine will last longer. I ran 20/50 in my 86 s-10 truck and got 300,000 miles out of it.And I was 17 years old and drove like a idiot. LOL I wouldnt go with 20/50 in your car its a bit thick but 10/40 is perfect. I think 5/30 is way too thin. Good luck with your car I believe its the oil pressure sending unit. Did you find out the price on it? It should be 10-15 bucks

**LETHALxLS1** · 05-10-2007, 10:04 PM

also-how long are you going between oil changes?? you should change oil every 3,000 miles

**clg82** · 05-11-2007, 07:34 AM

Originally Posted by DEADBYDAWN

also-how long are you going between oil changes?? you should change oil every 3,000 miles

Of course I change it every three thousand miles silly!! I actually am about to go get the sending unit. So I will let you know how everything turns out when I get it done. And I think I am gonna get an oil change with some thicker oil also. I will let you know and thanks for all of your help.

**LETHALxLS1** · 05-11-2007, 07:57 AM

No problem-I sure hope its an easy fix for you. The people here have helped me so many times. I think this site is so awsome. First place I go online every day. Good Luck!!