mitch14

Hey guys, I'm pretty new here and have a question.
My car is an 04 allroad 4.2
My low oil pressure indicator is coming on only after about 15 minutes or more of driving, and then goes back off.
I checked the oil level the first time and it was low, so I added about 1.5 liters.
It seems to be full now but the light came on again, same thing, only after driving about 20 mins or so, so I shut it off, waited a bit, started it again and drove it to work for the remaining 5 mins with no lights coming on again in that time.
I'm going to be taking it into the dealer soon for an oil change hoping that might help a bit.
But was wondering if there is some sort of known problem causing this, or a fix for it.
Any help would be greatly appreciated

SHOaddict

How long does the light stay on before shutting off by itself? How many miles? It may just be as simple as a faulty sensor.

mitch14

It used to just come on and flash the three times or whatever and go off. But now its been staying on, and when I shut off the car and wait a bit it takes a few minutes and comes back on.
The light usually comes on when the oil temp reaches 180-190 degrees fahrenheit. Doesn't come on when the oil is colder than that which leads me to believe that the sensor is not just faulty.
It is going into the dealership next week for a full synthetic oil change so hopefully that will help.
And I have checked the oil level multiple times, and it's reading full, and no other warning lights or weird sounds are present.
I just hope it's not something serious

mitch14

Got an oil change yesterday with full synthetic, and it seems to have fixed the issue. Also the chain rattle on startup is greatly reduced... I should have done this sooner

mishar

If oil change “fixed” your problem be sure it’s not fixed. It will come back as soon as oil breaks down a bit. Now it is just above minimum level detected by sensor. Your best chance is faulty sensor. I would measure oil pressure. Good mechanic can easily find a place to connect pressure gauge. If it is OK change sensor. If it is not it can be oil pump, regulator, some pressure leak within cylinder block or head, even crack somewhere there, or bearings. Neither one simple.

mitch14

Could it be that it was just crappy oil that was in the engine that broke down poorly?
As I bought it from a dealership, and they seemed to have done everything cheaply on the car, so I'm sure they skimped on the oil as well and just threw in whatever they had on hand.
If it comes back before the next oil change is completed I'll get it looked at forsure.
If it was a crack or something like that when I added more oil it should have fixed the issue, so I'm going to rule that one out.
Could a bad oil pump also cause more chain rattle?

Thanks for your input

mishar

Not sure what is regular working pressure on this engine, but it has to be in the neighbourhood of 3-5 bar (45-75 PSI). Minimum (idling engine) is somewhere around 1bar (15 PSI). That’s where the warning light kicks in. If you had warning lite on when driving (that was my understanding) than pressure is way too low. No oil can be that bed. I think you should check oil pressure with pressure gauge ASAP. If your pressure is just above low limit it is bed. If you drive it longer like that it just gets worse.

If there is a crack before pump adding oil may help. It won’t help if it is after oil pump.

I don’t know if chain rattle can be caused by a bed pump, probably not, but bed pump may create some noise itself.

To conclude: if pressure is OK you are OK too. Probably just sensor. If it is low let’s hope that it is pump. Not sure on this engine, but usually it can be changed relatively easy.

Theresa Wagner

I am having the same trouble with low oil pressure. The dealer thinks its the oil level sensor and oil pressure switch. They had the car for over 24 hours and performed all sorts of diagnostics. They said they are 95% sure and that would be the cheapest alternative. It is just recently out of warranty, ugh. Did you ever have that problem again or was it resolved? I wonder if anyone actually blew the engine or if its just some sort of nuisance alarm.

twentysevenlitres

The low oil pressure warning (red) is there to save the engine. They don't put it there for the fun of it. Ignore it at your peril!

Lots of things can cause it, don't just assume it's a faulty switch - worst assumption you can make...
Clogged oil stainer on the pick-up is very common, as is a failing pump. Have a mechanic check it out...

If the warning is yellow, that is low oil level - top it up...

Prospeeder

I have seen on 2.8, 3.0 and Im sure the 4.2 uses the same style oil pump, with metal tubes with rubber orings come from the oil pump to the block up inside the engine. I have seen where the orings get hard or distorted and cause low oil pressure warning randomly or when the engine gets hot enough. Just something to check.