help! strange thudding noise from rear end when accelerating

[Oolop]

Oh! One more thing... my tachometer isn't working. The previous owner told me that when it's cold outside, sometimes it works, and it did the other day... but then stopped like a minute later lol

Any ideas? Much appreciation

[dkbmxer002]

thanks!

[Fidhle007]

where is the oil sensor for the check panel? i wasn't sure if it was tied into the same sensor for the computer/gauge. thanks!

On the top of the oil pan, on the drivers side. Big mofo...

[Oolop]

U guys rock! Thanks for the help guys!

[Fidhle007]

Ok sweet! Thanks for tellin me which one it is, it's been bugging me for so long lol

But if a thermostat would stay open from the beginning, wouldn't it just mean that it'd take longer for the motor to heat up? I mean it'd get to the optimum temp it'd just take longer right?

Possibly but it might never get there. Culprits for low coolant temp could be either thermostat stuck open or opening too soon.

[dkbmxer002]

Check panel oil and coolant lights are both level-dependent so level sensors in both cases are most likely the culprit. For oil I'd check the sensor plug and wires first because the sensor itself can be pricey and a bitch to change. Coolant sensor is fucking easy... :-)

where is the oil sensor for the check panel? i wasn't sure if it was tied into the same sensor for the computer/gauge. thanks!

[dkbmxer002]

one prong is for the gauge and two prong is for the computer, i believe the oil sensor might be brown and two prong? i could be wrong so someone can correct me.

[Fidhle007]

Check panel oil and coolant lights are both level-dependent so level sensors in both cases are most likely the culprit. For oil I'd check the sensor plug and wires first because the sensor itself can be pricey and a bitch to change. Coolant sensor is fucking easy... :-)

[Oolop]

About that brown sensor for the cluster, on my motor, I have two brown ones, the one furthest forward on the motor has two prongs I guess u call them and the other brown one is further back and that one has just one prong. Which one is it exactly?

[dkbmxer002]

I'd look more at your thermostat then the sensors... Coolant level sensor is in the tank, easy fix and a common issue on cars of this age.

on that note, what should be looked for with the check panel coolant gauge that is in the reservoir? same with the oil light? my buddies 325i will show those lights but the level and pressure will be fine.

[Oolop]

Ok sweet! Thanks for tellin me which one it is, it's been bugging me for so long lol

But if a thermostat would stay open from the beginning, wouldn't it just mean that it'd take longer for the motor to heat up? I mean it'd get to the optimum temp it'd just take longer right?

[Fidhle007]

A lot of t-stats seem to be running cold right out of the box, I've seen it in several cars we've done at my shop but it never hurts to check the sensor. The brown one is the one for the cluster.

[Oolop]

Ah that's what forgot to mention, I did change the thermostat and it didn't change anything

[Fidhle007]

I'd look more at your thermostat then the sensors... Coolant level sensor is in the tank, easy fix and a common issue on cars of this age.

[Oolop]

Yes! U guys were right! It's the CSB, the drive shaft is totally just hangiing there so I'll be ordering the part tomorrow.

Now for my next problem lol, my temp gauge won't go past 1/4. Of the way, and the coolant light goes on. My coolant level is fine, although dirty coolant which I plan to flush out soon. I think it's one of my coolant temp sensors but there are like four of them and I don't know which one it is. I know there's two, one for emissions the other for cold starts and the rest idk...