: Low Oil Pressure???

02-13-05, 09:47 PM
Hello All, I am a new member and have been very impressed by the knowledge depth of the members here. I do need some help. I have a 97 STS that runs fantastic except for the fact that once it gets to temperature the oil light on the rpm gauge will start to flicker (one time the low pressure indicator did display and stated to shutdown the engine). This only occurs when you are at a stand still (idle) in any gear. The weird thing is that if I push the gas pedal to bring the engine off idle even by a 100 rpms it goes away..

02-13-05, 09:53 PM
I'll bet there are at least a dozen similar posts. Go to the toolbar and do a search on oil pressure. You'll like it.

02-13-05, 09:57 PM
A similar thing happened on the 96 aurora. In the summer on hot days the message showed up. It got worse and worse until I replaced the sensor, problem gone.

I believe the sts uses only a switch (on/off) instead of a sensor (various levels) but it would be worth looking into.

02-13-05, 10:15 PM
What I am gathering from the previous posts that the issue would be solved with a different weight oil?? Does anyone have a verified fix for the low oil pressure at idle issue?

02-13-05, 11:03 PM
The resident Cadillac engineer usually suggests that you replace the oil pressure sending switch with a genuine Cadillac repair part. It is unlikely that you have a genuine low oil pressure problem but instead it is a sensor fault. If the sensor doesn't help then go to heavier oil.

02-14-05, 12:58 AM
Heavier weight oil did not fix the issue on the aurora.

02-14-05, 01:21 AM
The way I have always troubleshot an oil pressure problem is to install a trustworthy gauge in the system and find out what is really going on. Then you know immediately whether you have a sensor/warning switch problem, thin oil, or a worn motor. If you put the gauge in place of the sending unit and the pressure is okay, you're already halfway there replacing the sender.

02-17-05, 10:23 AM
Thank you all.. The heavier weight did not work. I do appreciate the input.

02-17-05, 08:29 PM
You need to replace the low oil pressure switch.....relatively simple to do. It is located on the oil filter adapter just above the oil filter.

05-18-07, 01:01 AM
Can anyone help me??? 1997 Deville

replace my radiator because it was leaking. car sat for like a month. had mechanic replace the main seal on the block (did this by taking the cover off the passenger side, behind the tire). car is done and fixed. he said it was low in oil. I added 3 quarts of 10w30. car runs with what seems all the lifters tapping all at once. "turn engine off""low oil pressure" messages appear on the dash. any suggestions???

05-18-07, 09:16 AM
Did he pull the harmonic balancer? If so did he torque it to spec's? The torque spec's are quite high (300 ft/lb +). It drives the oil pump and if not torqued enough, the pump will slip causing low oil pressure.

05-18-07, 03:35 PM
Supreme, Do Ranger's check....300 ft/lb is a LOT of torque. You can't do it without mechanical multiplier and flywheel lock help. Then, check the dipstick after engine off for 4 minutes. Oil somewhere in the hashmark is OK. Too much oil gets whipped into foam and can cause lifter collapse or malfunction. Too little oil just plain causes loss of oil pressure. A no-no.

05-18-07, 03:55 PM
Ranger and Sub,

thanks for the advise and will look into it this wekeend and fill you in on results. thanks a bunch, this site is plain out great!

05-29-07, 10:01 PM
here's an update...

with torquing the pulley/harmonic balancer. changed the oil, after a few seconds of ticking on the lifters, sound went away. car is running fine. the oil in the car was thin for some reason and was causing the "low oil pressure". been driving the car with the new radiator and runs perfect. thanks caddy lovers. LOL

05-31-07, 08:58 PM
:yup: OK...Great. Glad the ticking has disappeared. With the info from your first 2 posts, sounds as if there was some sort of lubrication problem.....Now that you've changed the oil (& filter ?), run the car for a few hundred more miles, then change the oil and filter, using your Manual recommended viscosity and a good name-brand filter. IF there was any wear associated with the earlier problem, it would show up as metallic deposits in your present filter. Drain it and carefully cut off the tapping plate with a lathe or hacksaw. Gently remove the media pack. Break the media away from the end plates and separate it into 4 or 5 equal sections. Squeeze each section in a vise (paper towels under...) to dry the media. Open the media like an accordion and, disregarding the hacksaw debris at one end, evaluate the remaining material for metallic and gasket content. This procedure, while time consuming, will give you a very good idea of your engine's mechanical condition. Ideally, there should be nothing in the media except dark oil residue.