Oil light on at idle, I have a oil pressure gauge , need some help! - SRT Forums

Lav · 11-19-2012, 07:12 PM

Hi! okay so ive been searhcing for the past few hours on tons of similar topics , however every topic i found the person didnt have an oil pressure gauge installed , I do so i wanted to ask and see what i can narrow it down to before I take it to a shop.

I have an oil press gauge installed at the head, at idle it reads 0 , as I step on the gas ( i also drove it around the block and back to the house ) it mantained pressure , but as soon as its idle it goes back to 0 .

I opened the hood and I noticed one of the cables that goes to the pressure gauge was missing the cap , so it was barely hanging on... but still making contact, so now i dont even know if those readings were correct.

Assuming the contact the wire was making to the gauge was good enough to give accurate signal , and the oil pressure was indeed dropped at idle which would make the oil light come on , would it still be a faulty sending unit ?

greenneonsrt · 11-19-2012, 07:16 PM

wow so your gauge reads 0 and your pressure light is on?

is your engine noisy?

SRT4FL · 11-19-2012, 07:18 PM

I wonder if your sending unit is bad, and I have heard doing the oil gauge from the head will give you false readings.

Lav · 11-19-2012, 07:25 PM

That's the thing the engine sounds normal like it usually does , I have enough oil in it , no weird knocking or anything of the sort .

All of the 50+ topics ive seen point to the oil sending unit, but they also said to test the pressure first , which i have the ability to do , but now im conflicted as to wether that info is accurate in my gauge since its missing one of the caps needed to keep contact ( i had to hold it in place manually ) .

**underSRTarmor** · 11-19-2012, 07:26 PM

Mine is in the head and reads pretty good.

greenneonsrt · 11-19-2012, 07:32 PM

there's a restrictor in the head so it won't read the same pressure as the bottom end, but it's still a good reference since it's the last part of the engine to get oil so if you have pressure there everything else is good.

I would at the very least thread out the sensor and check it with a mechanical gauge

Lav · 11-20-2012, 01:55 PM

Well im going to replace the sending unit today and ill let you guys know if that fixes it .

UbIlln · 11-20-2012, 02:34 PM

Quote: Originally Posted by underSRTarmor

Mine is in the head and reads pretty good.

curiously what does it read there?

SRT4FL · 11-20-2012, 03:04 PM

Quote: Originally Posted by greenneonsrt

there's a restrictor in the head so it won't read the same pressure as the bottom end, but it's still a good reference since it's the last part of the engine to get oil so if you have pressure there everything else is good.

I would at the very least thread out the sensor and check it with a mechanical gauge

That's a good point, I have had all my oil gauges sent from the bottom end because vise versa, if there is no pressure at the bottom there will be none at the top end. And it's less effort to push the oil from the bottom through the line to the gauge, kind of like a reaction time, but that's my logic lol.

Lav · 11-21-2012, 01:16 PM

Well , I replaced the oil pressure sending unit , and the valve cover gasket . Took it for a run and it seemed fine. Oil pressure was fine at idle , drove around for a few minutes and then as soon as i came to a stop the pressure light came back on.

Seems to only come on at idle , or anything below 1.5k rpm

any ideas?

greenneonsrt · 11-21-2012, 02:52 PM

1. check oil pressure with a known good gauge

2. take your oil filter off and cut it open and see what you find

badboydneon · 11-21-2012, 05:57 PM

Quote: Originally Posted by underSRTarmor

Mine is in the head and reads pretty good.

Yea same here.

Lav · 11-23-2012, 02:28 PM

Quote: Originally Posted by greenneonsrt

1. check oil pressure with a known good gauge

2. take your oil filter off and cut it open and see what you find

Do i take out the pressure gauge currently mounted at the head first? does it come out easily? I had it installed by someone else.

and also what am I looking for when i take out the filter and cut it open?

SRT4FL · 11-23-2012, 03:01 PM

Anything abnormal such as metal chunks or things of that nature.

greenneonsrt · 11-23-2012, 04:57 PM

It's not easiest to get to but the factory sensor on the back of the block would be best for getting a reading

use something like this Oil Pressure Tester | AutoZone.com

11-19-2012, 07:12 PM	#1 (permalink)
Lav SRTforums Member Join Date: Jun 2010 Member Number: 79804 Location: Houston Posts: 267	Oil light on at idle, I have a oil pressure gauge , need some help! Hi! okay so ive been searhcing for the past few hours on tons of similar topics , however every topic i found the person didnt have an oil pressure gauge installed , I do so i wanted to ask and see what i can narrow it down to before I take it to a shop. I have an oil press gauge installed at the head, at idle it reads 0 , as I step on the gas ( i also drove it around the block and back to the house ) it mantained pressure , but as soon as its idle it goes back to 0 . I opened the hood and I noticed one of the cables that goes to the pressure gauge was missing the cap , so it was barely hanging on... but still making contact, so now i dont even know if those readings were correct. Assuming the contact the wire was making to the gauge was good enough to give accurate signal , and the oil pressure was indeed dropped at idle which would make the oil light come on , would it still be a faulty sending unit ?

11-19-2012, 07:16 PM	#2 (permalink)
greenneonsrt SRTforums Member Join Date: Dec 2010 Member Number: 82185 Location: Bowmanville, On Posts: 973	wow so your gauge reads 0 and your pressure light is on? is your engine noisy? __________________ 280whp 303wtq 16g bws, injen short ram, meth injection. Stock intercooler, manifolds, o2 housing, wastegate, and motor. Best et: 13.4 Best trap: 107

11-19-2012, 07:18 PM	#3 (permalink)
SRT4FL Premium Member Join Date: Jul 2011 Member Number: 85452 Location: Cape Coral FL Posts: 752	I wonder if your sending unit is bad, and I have heard doing the oil gauge from the head will give you false readings. __________________ 2003 SRT-4 SOLD 2011 TOYOTA TACOMA DC 4x4 acquired RIP 40ROLL

11-19-2012, 07:26 PM	#5 (permalink)
underSRTarmor Premium Member (Lifetime) SRT of the Month Join Date: Aug 2005 Member Number: 32888 Location: N. La/ E. Tx Posts: 7,724	Mine is in the head and reads pretty good. __________________ • MyBuild Thread • Duster360 Track Times List • PTE 5831 info • MAP Sensor info TUNED by DUSTER360 PTE 5831 11.19 @125.65 1.64 60ft 27 psi ^^^all clickable

11-19-2012, 07:32 PM	#6 (permalink)
greenneonsrt SRTforums Member Join Date: Dec 2010 Member Number: 82185 Location: Bowmanville, On Posts: 973	there's a restrictor in the head so it won't read the same pressure as the bottom end, but it's still a good reference since it's the last part of the engine to get oil so if you have pressure there everything else is good. I would at the very least thread out the sensor and check it with a mechanical gauge __________________ 280whp 303wtq 16g bws, injen short ram, meth injection. Stock intercooler, manifolds, o2 housing, wastegate, and motor. Best et: 13.4 Best trap: 107

11-19-2012, 07:25 PM	#4 (permalink)
Lav SRTforums Member Join Date: Jun 2010 Member Number: 79804 Location: Houston Posts: 267	That's the thing the engine sounds normal like it usually does , I have enough oil in it , no weird knocking or anything of the sort . All of the 50+ topics ive seen point to the oil sending unit, but they also said to test the pressure first , which i have the ability to do , but now im conflicted as to wether that info is accurate in my gauge since its missing one of the caps needed to keep contact ( i had to hold it in place manually ) .

11-20-2012, 01:55 PM	#7 (permalink)
Lav SRTforums Member Join Date: Jun 2010 Member Number: 79804 Location: Houston Posts: 267	Well im going to replace the sending unit today and ill let you guys know if that fixes it .

11-20-2012, 02:34 PM	#8 (permalink)
UbIlln SRTforums Member Join Date: Oct 2005 Member Number: 35070 Location: Arlington, TX Posts: 135	Quote: Originally Posted by underSRTarmor Mine is in the head and reads pretty good. curiously what does it read there? __________________

11-20-2012, 03:04 PM	#9 (permalink)
SRT4FL Premium Member Join Date: Jul 2011 Member Number: 85452 Location: Cape Coral FL Posts: 752	Quote: Originally Posted by greenneonsrt there's a restrictor in the head so it won't read the same pressure as the bottom end, but it's still a good reference since it's the last part of the engine to get oil so if you have pressure there everything else is good. I would at the very least thread out the sensor and check it with a mechanical gauge That's a good point, I have had all my oil gauges sent from the bottom end because vise versa, if there is no pressure at the bottom there will be none at the top end. And it's less effort to push the oil from the bottom through the line to the gauge, kind of like a reaction time, but that's my logic lol. __________________ 2003 SRT-4 SOLD 2011 TOYOTA TACOMA DC 4x4 acquired RIP 40ROLL

11-21-2012, 01:16 PM	#10 (permalink)
Lav SRTforums Member Join Date: Jun 2010 Member Number: 79804 Location: Houston Posts: 267	Well , I replaced the oil pressure sending unit , and the valve cover gasket . Took it for a run and it seemed fine. Oil pressure was fine at idle , drove around for a few minutes and then as soon as i came to a stop the pressure light came back on. Seems to only come on at idle , or anything below 1.5k rpm any ideas?

11-21-2012, 02:52 PM	#11 (permalink)
greenneonsrt SRTforums Member Join Date: Dec 2010 Member Number: 82185 Location: Bowmanville, On Posts: 973	1. check oil pressure with a known good gauge 2. take your oil filter off and cut it open and see what you find __________________ 280whp 303wtq 16g bws, injen short ram, meth injection. Stock intercooler, manifolds, o2 housing, wastegate, and motor. Best et: 13.4 Best trap: 107

11-21-2012, 05:57 PM	#12 (permalink)
badboydneon SRTforums Member Join Date: Apr 2008 Member Number: 63272 Location: Poconos, PA Posts: 707	Quote: Originally Posted by underSRTarmor Mine is in the head and reads pretty good. Yea same here. __________________ 2004 Black SRT-4- Mopar Stage 3 with the works 2003 Silver SRT-4- BW s200sx-rs-56 .63ar 1997 Black 1G, 2.4 built and turboed-project Any1 local in need of PCM flash...hit me up

11-23-2012, 02:28 PM	#13 (permalink)
Lav SRTforums Member Join Date: Jun 2010 Member Number: 79804 Location: Houston Posts: 267	Quote: Originally Posted by greenneonsrt 1. check oil pressure with a known good gauge 2. take your oil filter off and cut it open and see what you find Do i take out the pressure gauge currently mounted at the head first? does it come out easily? I had it installed by someone else. and also what am I looking for when i take out the filter and cut it open?

11-23-2012, 03:01 PM	#14 (permalink)
SRT4FL Premium Member Join Date: Jul 2011 Member Number: 85452 Location: Cape Coral FL Posts: 752	Anything abnormal such as metal chunks or things of that nature. __________________ 2003 SRT-4 SOLD 2011 TOYOTA TACOMA DC 4x4 acquired RIP 40ROLL

11-23-2012, 04:57 PM	#15 (permalink)
greenneonsrt SRTforums Member Join Date: Dec 2010 Member Number: 82185 Location: Bowmanville, On Posts: 973	It's not easiest to get to but the factory sensor on the back of the block would be best for getting a reading use something like this Oil Pressure Tester \| AutoZone.com __________________ 280whp 303wtq 16g bws, injen short ram, meth injection. Stock intercooler, manifolds, o2 housing, wastegate, and motor. Best et: 13.4 Best trap: 107

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