AgentEran

My car usually runs about 193.. 200 - 205 on a hot day and im driving heavy.. Last night i hear the fans cut on and think to myself.. its 65 deg outside theres no reason the fans should be cutting on.. flip to coolant temp and were running at 228 deg 0.o

So when i got home i checked all the hoses and coolant level. Everything is fine and air tight, no coolant missing.

So today when I go to drive of course im 228 deg and climbing! I got all the way up to 233 deg I know people will say this is normal but this isnt my first c4 and this car specifically has run at 190 deg on the highway in 100 deg weather no problems, so its unusual for it to be running 40 deg hotter than normal in cool weather, something is amiss.

Not only this, but the temp climbs under load and at idle.. it only seems to stabilize when under abt 10% load at 1800 rpms in 6th.. pretty much anything else = 233 deg +

So today when I got home, tear down!

Theres nothing blocking the radiator no debris or anything to obstruct air flow, no white smoke or coolant missing.. Thermostat is fine. However, when I pulled the water pump I noticed that its pretty hard to turn the impeller.. but other than that the impeller moves and theres no obvious sign of trouble.

Ive ordered a water pump and some other doodads and will be installing when they arrive.

Should the impeller be hard to turn? What else could tell me the water pump is bad?

Could there be another issue im missing?

twichy2011

Maybe water pump is the problem. Just thinking out loud, have you checked to see if there is a code that may have set? Since the water pump is driven by the cam, its still going to spin at the same speed regardless of whether its difficult to spin. (Unless it causes a bunch of heat because of the drag and ruins a seal in the pump.) I had an issue that was similar to yours and turned out to be caused by an O2 sensor causing the car to run so poorly it generated a lot of heat. (First time something like that has ever happened to me)

Goodluck!

Connor

AgentEran

Thanks Dude!

I just replaced the o2 sensors about 2 yrs ago so hopefully its not that.

I guess Ill have to do the water pump and flush and see what happens.

On another note, the radiator drain plug is plastic?? O.o

Does anyone know of a replacement thats not plastic??

FASTAZU

Could just be a bad or sticking thermostat. How did you check it? A hard to turn impeller I would think is bad water pump bearings.

Tom400CFI

If you had the WP pulley on the pump shaft still, and you whipped the pulley/shaft around as fast/hard as you could, I'd expect it to "coast" at least 2 turns before stopping due to friction imparted by the seal.

If it won't do that, something is binding.

As for your high temps, I agree that's not normal. When it's getting hot, how is your radiator? Is it HOT too? If not, you're not circulating water.

Tom400CFI

It's plastic...as is the entire side tanks.

AgentEran

Radiator was def cooler

Tom400CFI

That's great that you paid attention to that detail. So, with that, you've narrowed it down to a stuck closed T-stat, or the wp not pumping.

AgentEran

So yea.. the bearing is prob bad.. I tried spinning the impeller and it wont spin without considerable force.. and absolutely would not spin past me spinning it manually with a bunch of thumb and finger force