Water Pump bust > Cooling Overhaul > Running hot?! (help!)

[OnlytheBest]

After spontaneously overheating one night, we replaced the radiator fan switch (which was not working), the fan clutch (not working), and changed the coolant, which we thought would fix the problem. We noticed it was hard to bleed afterwards. It seemed like air was continually getting into the system, but we tried to bleed it as well as we could.

It didn't solve the probelm--and the car wanted to overheat again. So we digged a little deeper and of course, the water pump had disassembled. The shaft had separated and was not doing its job anymore. We replaced the Water Pump and the thermostat while we were at it. Following, of course, we bled the coolant, which bled as it should by now (opening the bleed screw released air bubble-less coolant).

Felt pretty good after all that, but now, the temp gauge needle wants to freak me out by sitting on the right side of the halfway mark. Any of you who've had overheating can I'm surely relate to my anxiety. It hasn't ever went further than a hair past noon, but I wonder what to look at next, if anything. Any advice/wisdom/questions? Thanks in advance.


http://adamwaugh.com/Temp/TempGauge.png

[bmwpower]

Check:

- the bypass line going to the reservoir - if this gets clogged the car will overheat
- the heater core - see if you see bubbles coming out of the outlet going to the reservoir or coolant coming from the weep holes near the tranny. my core was leaky enough to allow air into the system and I could see bubbles flowing up into the reservoir from the heater core outlet.

Once both of these were fixed, my car has been dead center on the gauge ever since.

[mottati]

where did you get the thermostat? Sure it's the right one?

[OnlytheBest]

**Update**

Went to poke around a bit after a drive and saw a very slow drip coming from the end of this hose (pic attached). The clamp is tightened but there may be a crack in the hose? Maybe this is part of my problem.

http://adamwaugh.com/Temp/leakyhose.png

[zubbie]

Isn't the "noon" mark where it should be? Any hair difference is probably just the thermostat setting.

[AlmostEvil]

mine is always at the "noon" position. only once has it gone a hair above and that was my first day of owning it and was having a lot of fun with some friends. went back to normal in a few minutes

[Shuasha]

The stock temp gauge is "buffered". Anything between around 150 and 220 degrees is "in the middle". Pretty much worthless. Don't be worried if it's a hair in either direction, means nothing.

When was the radiator last replaced? If it's unknown or more than 80k miles, the neck could be cracked and will be a much more fun problem in the near future. Replace it ASAP if it's the cause of the leak, they crack and break off frequently. There's usually a label on top that states the build too.

[OnlytheBest]

*** Update 2 ***

Shuasha gets the gold star. The threaded neck of the radiator had completely broke off and was floating in the upper radiator hose. You may even be able to see it from the pic?

So now the question is--do I need an entirely new radiator, or can I just replace the piece with the neck on it? If a new radiator--is this a part with upgrade potential or is it a 'stick with OEM' part.

Thanks guys..

[John Q Public]

The picture of your temp gauge...it's sitting just a hair above where mine always lives...be it 100ºF or -10ºF...I wouldn't worry about where it's sitting in the pic...just if it goes too much higher...


http://adamwaugh.com/Temp/TempGauge.png

[OnlytheBest]

Thanks for the post. Maybe I was just paranoid from already having the car overheat. And hopefully the new radiator going in next weekend will bring my needle back to a perfect 12 o'clock noon. I'll definitely post an update. Any further thoughts from the group, please post. Thanks again.