Engine oil pressure reading Zero

rgd · #1 (**permalink**) 04-20-07, 11:39 PM

Went to start the car yesterday and found the oil pressure reading zero. The last time I drove it seemed ok although, I remember the oil pressure took a few seconds to register. At the time I didn't think much of it.

Wondering if anybody else has seen this. I have not had time to dig in yet, just about to head to the garage and check things out. Hopefully it's just a bad pressure sensor but I have my doubts. My car has always run hotter than average. Before I got my oil cooler it would top 300deg during track events and I noticed during my last track event it was doing that again.

It's an 04, I have already had the re-calibration to the computer to fix the heat sensor glitch.

Anyway, if anyone has had a similar issue or has any wisdom to share, I'm all eyes.

Thanks,

rgd

nikon · #2 (**permalink**) 04-20-07, 11:40 PM

bad sensor?? any leaks around the cooler you added?? Thats all I can think off, unless it needs to be re-calibrated again....

rgd · #3 (**permalink**) 04-20-07, 11:55 PM

No leaks I can find.
No water in the oil, thank God!!!

**heavymetals** · #4 (**permalink**) 04-20-07, 11:57 PM

You can check by taking a 4.7k ohm resistor and jumping a pair of the contacts in the plug going to the sensor.

2 to 3 connections or GY to TN/WHwires.

Start the motor and you should get a pressure reading.

Same thing happened to me.

Bad sensor.

rgd · #5 (**permalink**) 04-21-07, 12:07 AM

Cool, thanks Heavy, thats a good place to start.

Now were the heck do I find a wire lead resistor.
They still make those?
Kidding, I sell electronics.
Most are SMT these days.

rgd

Quote:

Originally Posted by heavymetals

You can check by taking a 4.7k ohm resistor and jumping a pair of the contacts in the plug going to the sensor.

B to C connections or GY to TN/BK wires.

Start the motor and you should get a pressure reading.

Same thing happened to me.

Bad sensor.

**heavymetals** · #6 (**permalink**) 04-21-07, 12:16 AM

Just solder a pair of leads to a SMT.

rgd · #7 (**permalink**) 04-21-07, 12:18 AM

I'm not that good, I'd probably smoke it with my solder capabilities. lol
I can find one.

Time to get to work!

Quote:

Originally Posted by heavymetals

Just solder a pair of leads to a SMT.

**heavymetals** · #8 (**permalink**) 04-21-07, 12:52 AM

I corrected those connections.

OOPS.

G-- · #9 (**permalink**) 04-21-07, 08:14 AM

Quote:

Originally Posted by rgd

Went to start the car yesterday and found the oil pressure reading zero. The last time I drove it seemed ok although, I remember the oil pressure took a few seconds to register. At the time I didn't think much of it.

Wondering if anybody else has seen this. I have not had time to dig in yet, just about to head to the garage and check things out. Hopefully it's just a bad pressure sensor but I have my doubts. My car has always run hotter than average. Before I got my oil cooler it would top 300deg during track events and I noticed during my last track event it was doing that again.

It's an 04, I have already had the re-calibration to the computer to fix the heat sensor glitch.

Anyway, if anyone has had a similar issue or has any wisdom to share, I'm all eyes.

Thanks,

rgd

rgd,
Happened to me about 2 months ago at a gas station. Restarted, same message. Called Caddy, had it towed to the dealer. I thought it was the sensor, turns out it was a bad Oil Pump. Replaced under warranty. Hope it's a simplier issue for you. Mine's an 05 w/LS6.
Thanks,
G

rgd · #10 (**permalink**) 04-21-07, 04:45 PM

Right now, so do I.

Can't say for sure but I think I might have a little water in my oil.
Blown head gasket??
I need to look a little closer, it was raining last night. Only saw what looks to be a little water on dipstick, might have ... well who knows.

Time will tell, I'm going to check it out now.
Didn't have time last night.

rgd

Quote:

Originally Posted by G--

rgd,
Happened to me about 2 months ago at a gas station. Restarted, same message. Called Caddy, had it towed to the dealer. I thought it was the sensor, turns out it was a bad Oil Pump. Replaced under warranty. Hope it's a simplier issue for you. Mine's an 05 w/LS6.
Thanks,
G

calicadi · #11 (**permalink**) 04-21-07, 07:53 PM

Slightly off-subject but pertains to oil temp...

Anybody know the relationship between a/c operation and engine cooling? If I turn a/c off the oil temp increases.

At an autocross, thought I'd be a nice guy and not drop condensation water on the grid, so I shut the a/c off. It was a mild day. By the time I made my second run I got the oil temp chime and warning. Does the computer think if you're not on a/c the engine will run too cold and shut the fans down?

rgd · #12 (**permalink**) 04-23-07, 04:49 PM

Ok, looks like there is no water in oil and I have been etting a oil pressure read.
That is a good thing, however during start-up my oil pressure takes a long/long while befor it comes up. Tis is new.
Anybody have a similar situation.
At the track I have been running hot!

Dennisscars · #13 (**permalink**) 04-23-07, 11:17 PM

Quote:

Originally Posted by calicadi

Slightly off-subject but pertains to oil temp...

Anybody know the relationship between a/c operation and engine cooling? If I turn a/c off the oil temp increases.

At an autocross, thought I'd be a nice guy and not drop condensation water on the grid, so I shut the a/c off. It was a mild day. By the time I made my second run I got the oil temp chime and warning. Does the computer think if you're not on a/c the engine will run too cold and shut the fans down?

Fans run if A/C on because A/C condenser needs airflow all the time and off when A/C off. Usually the ram air is sufficient enough to keep engine cool. (normal traffic etc.) I run with A/C on on track, kicks off automatically at certain speed/RPM and back on to help slow down for turn. I guess that's why I don't have "golden" calipers.. It will help to turn A/C on immediatly for cool down lap, both fans run on high.

I had an instructor ask me if I knew that my A/C was on. I told him "It's a Cadillac...it's suppose to be comfortable." plus once he heard the Maggie, he said I guess you don't need the extra couple of HP.

No oil temp problems here, only when I spend too much time over 5k.

rgd, I got the no oil/low pressure on the DIC at start up once, after shatting my pants and shutting it off, checking oil etc started up fine and haven't seen since. Mechanical gauge test is safest bet.

How old is your oil? Maybe it's tired. I used to have trouble with Penzoil thining out in a big block car after a short period. I don't know how M1 holds up to High temp cycles.

calicadi · #14 (**permalink**) 04-24-07, 01:57 AM

Thanks for confirming my suspicions. I'm leaving it on here on out. Maybe even reset the fan thermo to 165 with my Hyperchip. U DA MAN!

PS... never gotten a low OP, real or false positive. Pressure has been pretty constant in the 39 to 45 range.

Glad to hear your non-colloidal, rgd!

CTSVetteMark · #15 (**permalink**) 10-13-09, 01:18 PM

This just happened to my '05 CTS-V, and I'm outta warranty! Anyone know what it costs to replace the oil pump? Also, is this too complex to do in the driveway? Thanks!