Things oil and electrical

[Asiah119]

I recently took my car up to Ohio to visit family. On the 1k+ mile round trip I had a few things pop up that I wanted to run by my learned peers.

The first occurrence was that my tire pressure sensor went off for no apparent reason. I stopped in at a small mechanic off the highway and asked him to check my tire pressures and he said everything was good. I reset the pressure sensor and it stayed quiet for the rest of the trip. Is this a (fairly) common occurance?

Next was after driving off the highway in 101 heat my DSC and yellow e-brake light popped on. The manual attributed that to a failure of the system that governs them. I'm assuming that the heat just got to it and it switched off to try to prevent damage.

The third thing is that I seem to be having a recurring issue with my yellow oil light popping on. I've recently put about .5 quart of oil in (2 weeks ago or so) and have pulled the air cleaner off and didnt see any oil leaks. Is there somewhere else that I should be looking for leaking oil. I'm not getting any sooty build up on the back of the car so it doesn't seem to me that I'm burning it off.

Edit: Not exactly the correct place for this but I'm rapidly losing the seals for my rear windows (coupe) has anyone changed these out and can give me an idea of the level of difficulty\frustration that I'm likely to encounter?

[kayger12]

#1-- The TPMS is set to trigger at a certain amount of loss. Iirc, it's somewhere around 8psi. Most likely one of your tires is down that much.I'd check all of your pressures so you know where they're at and can monitor for a slow leak.

#2-- Most likely a bad wheel speed sensor, but could be something else. I would look into this one and narrow it down.

#3-- Is the light popping on when you start the car or after shutdown? Light remaining on after startup=bad oil level sensor; after shutdown=low oil. If you're losing oil the two most common places are via the VCG (check the exhaust manifold heat shield at the passenger rear of the motor) or the oil filter housing gasket (pull the air box and check the waffle area of the block for oil). If those are good, could be the CCV or a leak from a solenoid or sensor in the area of the vanos on the front of the motor.

[BCS_ZHP]

Additional to what Keith said on #1. Two of three ZHPs we have or had did this same thing, and tire pressures were perfectly fine, within 2 psi of where we set them. We simply reset the TPMS and it was good to go until it decides to do it again. We experienced it about twice per year on each car.

[Asiah119]

The oil light is most commonly popping on when I park and turn the car off at work (on a level surface) after a ~5mi drive from my house. Infrequently, the light will come on as I go up a hill on my way to work. I'm going to go poking around tomorrow morning for that leak before it gets into the upper 90s.

The DSC + Brake light went away after I stopped to get gas (sorry I wasnt clear about that in the post) so that's why I'm thinking heat.

[llll1l1ll]

Heat can do some crazy things to cars. My old E30 hated the heat. I hate the heat, too.

Anyway, for your oil leak, I would second looking around the valve cover gasket area by the exhaust manifold side of the gasket. That's where mine was leaking. It leaked a lot - to the point where you could smell oil dripping on the exhaust. Pretty common area from what it seems. Other spots of leaking oil would most likely be your oil filter housing gasket. Other places might be front/rear main seals.

If your yellow light is coming on while driving, I'd keep a close eye on the oil level.

[Asiah119]

The yellow light comes on sometimes while driving, so I'm guessing that the oil level is on the verge of being low enough to trip the sensor, but its also only sometimes coming on when I turn the car off. So I'm kind of baffled. But I carry a spare quart of oil in the trunk just in case.

[llll1l1ll]

Usually when the yellow light comes on while driving, that means the oil is really low. Like, "stop the car now and add some" low.

[danewilson77]

Usually when the yellow light comes on while driving, that means the oil is really low. Like, "stop the car now and add some" low.

I think the yelow light means the car is one quart low, though I agree you should not be driving all over the place with the ellow light locked in.

I think of the red light (pressure) as the pull over now light.

[WOLFN8TR]

Usually when the yellow light comes on while driving, that means the oil is really low. Like, "stop the car now and add some" low.

Not necessarily, my Yellow oil light comes on when I'm 1/4 quart low on oil or sometimes not low at all. I do believe my sensor is bad.

I've replaced my rear window seal. It's a real pain but doable. Got a new one from ECSTuning. Will post a link later on a good DIY.


Bayerische-Motoren-Werke

[zhp43867]

Not necessarily, my Yellow oil light comes on when I'm 1/4 quart low on oil. I do believe my sensor is bad.

I've replaced my rear window seal. It's a real pain but doable. Will post a link later on a good DIY.


Bayerische-Motoren-Werke

Your dipstick might be wrong. E46s shipped with all different lengths of dipsticks, it's a mess. My light comes on when I'm ~.5 quarts down on the dipstick, but light on means a quart down- so I add a full quart.

The sensors can go bad- when my sedan's sensor went bad it just stopped reporting low oil.