Overheating problem

[DC12k]

This all started about a week ago as I drove to school in the morning. I noticed that the car was heating up quickly and the guage would not stop at the center like it would normally do. It continued to go up to just before the red. I noticed no steam or anything and I was able to get to school and back with no problem.

My first guess was that the thermostat was stuck so that was replaced. I've replaced the coolant and made sure that there was no air in the system but it still heats up quite quickly.

When I drove the car I noticed that around sharp corners the temperature sensor would wobble around and sometimes it would jump back to the center position and stay there a while before jumping back up or quickly moving back to the red.

The car is a 87' 325is.
Does anyone have an idea what could be causing this to happen?

[Ball325]

on the back of the gauge cluster there is a large plug that kinda runs them all. Mine came loose and made all my gauges go crazy for a while until they stopped working. It might be the same case for you. Is there anything else not working? like the High Beam Light, Right Turn Signal, Tach, MPG meter thing... ? if so try taking it out, its difficult and it seems like it might break but mine didnt so i dont see why your would. and check all the connectors.

[Jordan]

Ground nut on the back of the cluster. The one on your temp guage is loose. Tighten it.

[BS87]

What jordan said. Had the same thing happen to my MPG, it would go bonkers and read 1/4 tank when i put 15$ of gas in it, then bounce back and forth on the ride home.

[James Crivellone]

the other issue that I was told with dc12k's car was the return line from the radiator (bottom of the rad to the thermostat) does not get hot at all, and basically stays cold.

I know on my car this gets very warm, does that make any sense?

[DC12k]

the other issue that I was told with dc12k's car was the return line from the radiator (bottom of the rad to the thermostat) does not get hot at all, and basically stays cold.

I know on my car this gets very warm, does that make any sense?

Yeah, after running the car for a little bit (enough to make the guage hit red) I noticed that the return line is cool while the other two lines are hot.

[Fred]

Sounds like coolant isn't circulating through the radiator properly.

[James Crivellone]

Sounds like coolant isn't circulating through the radiator properly.

that was my concern, anybody know of any good chemicals to flush this thing?

[Fred]

Well, you may want to look into getting another radiator. If it's clogged to the point where coolant pressure can't overcome it, I doubt a $5 bottle of Brand X from the store will do much. I mean it never hurts to try, but unfortunately you should keep that possibility in mind.

[DC12k]

youd think that a clog would develop over time and the temperature would rise steadily as the clog increased in size. This was just one morning the car started overheating.

I'll check the ground wire on the cluster tomorrow when I have time but I doubt thats the whole solution.

Thanks for the help everyone so far. Anyone have any other ideas?

[DSchultz325e]

Ground nut on the back of the cluster. The one on your temp guage is loose. Tighten it.

are you joking WTF?@$ i've been looking to the answer to my retarded temp gauge for like 3 weeks and here you go and throw out an answer no one has even REMOTELY come close to. if this works, i'll buy you a 6-pack.

[Rob]

thats pretty much the common cure for the jumpy temp gauge

[DSchultz325e]

I had never even thought about it jumping a little, but it seems to make sense. When I wack on the dash it jumps, so I'm gonna go check it out.

[DSchultz325e]

the ground is the bolt that attaches to the firewall? or did i just finish put the cluster back on for nothing? edit: nm it's fixed, jordan is official #1 player hater. sam adams is on me.

[DC12k]

Ground nut on the back of the cluster. The one on your temp guage is loose. Tighten it.

I just did that today and now the car holds steady below the mid point. Thanks Jordan.
Ahhh knowing you dont have to buy a new radiator is a good feeling.