Hey my engine just recently started overheateing fequently, its full of coolant & there are no leaks in the hoses. My buddy has an 06 & told me he was having the same issue & he had to replace the water pump. Should I go ahead & replace it or does it sound like something else?

 

Based on what you described, I am not thinking it's the water pump. From my experience a water pump that fails also will leak (you can sometimes see coolant spraying and sometimes hear bearing noise). Slide the belt off, grab the water pump pulley and wiggle it, if you have play in it, you may just have a bad pump.

If you have no leaks, I would consider flushing the coolant (to get rid of any sludge in the system that may cause a blockage, a lot of people don't flush/change coolant on a regular basis and they should). While messing with coolant, change the T-stat. You may have a T-stat that is failing and sticking closed.

BTW - Does the temp run hot and eventually come down, or is it constantly running hot?? Also, what engine is in your car?

 

It's funny the other day it was constantly overheating & then coming back down to normal then overheating again. But since then it's been fine. I know I have a T-Stat prob cause my heat wasn't working properly during the winter & I was told my T-stat was stuck. But I never had this prob during the winter either just recently when the weather began to get warm again

 

oh & it's a 3.5 Flex Fuel engine

 

It's full of coolant, but is it fresh coolant?

 

I have a 04 Monte Carlo, after some vandelism (trash in the radiator) I had to relace the radiator and termostat, flushed and bled the system. After about 2 months the heater quits working and you hear bubbling noise in the heater coil. Bleed the system again and it is fine. But after 2 more months the same thing again. No visable leaks, no water in the oil or steam out of the pipes. I had a mechanic look at it, he pressure tested the system and it checked out fine. What could be the problem???

 

Hi there-
It's very possible that you having problems with the upper and lower intake manifold gaskets. It may be leaking just enough to where any coolant that gets into the engine is burned off, hence why it's not showing up in the oil. Both the 3.4L and the 3.8L engines in the 2000-2005 GM W-Body (which the Monte Carlo is part of) are notorious for having gasket failures. The Dex-Cool that's in there will eat away at the gasket over time, causing small leaks. There are aftermarket gaskets that are made of another material that replaces the factory gaskets, that can stand Dex-Cool.

 

It might be worth starting your own thread on this. But I'll add my 2 cents.
First, do you know what was entered into the cooling system during this vandalism?
Also, you should reach a point where you can't bleed anymore air out of the system. When you have this bubbling noise, have you checked the overflow bottle to see if the coolant level is overly high?
Last time I have a car with a problem of consistant air pockets was my '94 Grand Am with a 3100 (same basic design as the 3400). My issue with a couple of other observations was a result of a blown head gasket. Most people are used to a blown head gasket allowing coolant and oil to mix, mine was not doing that enough to really show a sign. I was getting compression gases into the cooling system (which is what was causing my air pockets). During times my heater would quite blowing warm/hot air, my temp guage would climb and then as soon as I began getting some warmth, my temp guage would rocket back to normal. Towards the end of this saga trying to figure this mess out, the final tell-tale sign was when I first started the car, I'd get huge clouds of white smoke with a slight rough idle (went away fast, but the smoke was REALLY noticable). Changed the headgaskets at 180K, now at 207K and NO problems.

 

My car runs great at speed 170-180, and I have a 180* thermostat... if you sit for a while, it starts approaching 205-210... been wondering if one of my fans is bad.

 

Keep in mind, the reading on your guage is not always 100% accurate (but should be close) to the actual temp. Best way to know for sure is plug into the computer and see directly what the computer is reading.