Low oil pressure at hot idle
#1
Launching!
Thread Starter
iTrader: (1)
Join Date: Jul 2009
Posts: 270
Likes: 0
Received 0 Likes
on
0 Posts
Low oil pressure at hot idle
When i start my car from a cold start then it reads above 50 psi or so. But as it gets warmer it slowly drops to less than 20 psi... It kind of pulses too, i can watch the gauge move u p and down as it idles... Any ideas?
#2
how old is the oil ?how many miles ? it could be bearing tolerances opened up and ready for a freshen up or sending unit messed up basically put a manual gauge on it and see what it really does if its still low pull it and build it
#3
Launching!
Thread Starter
iTrader: (1)
Join Date: Jul 2009
Posts: 270
Likes: 0
Received 0 Likes
on
0 Posts
The oil is like 2k miles old... ANd its Mobil 5000 mile oil... The motor only has 70k on it... I think the switch might be out or going out but im not sure... Where would it be located at because i heard it was a pain in the *** to get to?
#4
TECH Junkie
iTrader: (2)
Join Date: May 2006
Location: somewhere that doesn't get snow
Posts: 3,455
Likes: 0
Received 2 Likes
on
2 Posts
what year is your car? if its a 95+ it's behind the intake manifold on the drivers side of it. if its a 93-94 its down by the oil filter. mine has been doing the same thing for quite some time. just yesterday i had to switch back to 5w30 from 10w30 since the oil change place didn't stock 10w30. it didn't seem to drop my idle oil pressure any more but i generally am around 10-15psi at hot idle when i used to be at 20. a shop broke my original oil sender when my trans was rebuilt in the fall of 07 and the new one they put in has always read low. i changed it with an autozone one that actually would throw the check gauges light every time i came to a stop with the oil pressure on 0 so i returned it and put the other one back in. i've seen the CG light a couple times at hot idle especially in reverse backing into the garage but it's been over a year and a half since i first ever saw a CG light. other than one time in indianapolis last september when it was really hot out and i was in traffic and saw the CG light almost every time i stopped i don't see it much anymore. i'm 99.9% sure its the gauge/sending unit since if it really had oil pressure that low i would have fried the motor in indy last summer and that was about 4k miles ago.
#5
Launching!
Thread Starter
iTrader: (1)
Join Date: Jul 2009
Posts: 270
Likes: 0
Received 0 Likes
on
0 Posts
Okay so now i gotta climb up in my engine bay and find the dang thing and make sure its still there and the wires arent fried before i just go buy another one... Its a 95 California Spec. Idk if that makes a difference but on some stuff it does... Im just glad im not the only one with this problem... Its not like my motor is running any different or anything, if i go WOT then it will hit almost 80 psi. But i havent seen any lights yet... When those come on it will see some shop time lol. Thanks for letting me know im not alone though!
#7
TECH Junkie
iTrader: (2)
Join Date: May 2006
Location: somewhere that doesn't get snow
Posts: 3,455
Likes: 0
Received 2 Likes
on
2 Posts
Okay so now i gotta climb up in my engine bay and find the dang thing and make sure its still there and the wires arent fried before i just go buy another one... Its a 95 California Spec. Idk if that makes a difference but on some stuff it does... Im just glad im not the only one with this problem... Its not like my motor is running any different or anything, if i go WOT then it will hit almost 80 psi. But i havent seen any lights yet... When those come on it will see some shop time lol. Thanks for letting me know im not alone though!
Trending Topics
#9
#12
#14
#16
On The Tree
iTrader: (1)
Join Date: Aug 2009
Location: SNJ
Posts: 100
Likes: 0
Received 0 Likes
on
0 Posts
my low pressure light comes on after about a half hour of driving, already replaced the sensor. Haven't hooked up a mechanical gauge yet but haven't had any problems running and stays topped off.
#17
Village Troll
iTrader: (2)
Rule of thumb is 10psi per 1000rpm. Sounds like you are good. Those LT1's that have 40psi hot at idle either have a high pressure pump or faulty/inaccurate sending unit/gauge or are using oil of the same viscosity as road tar.
#18
My car (95 Z) at hot idle sits at about 20psi. I know the car had the oil pump replaced during the rebuild, dont know the specs on it. Is that high? if so does it mean the car may have a high volume pump?