Why is my Buick Rendezvous over heating?

In order fir it to get hot its leaking anti- freeze somewhere. The 3.4 liter has a very common intake gasket problem. It could be a hose, the radiator the intake gasket or a head gasket. I had a head gasket go on a Montana van (same 3.4 engine as yours) a few years ago. Never saw it leak on the ground, it was all internal.

Thanks so much!!! my dad was trying to figure out what could be the problem as to why the anti freeze leaking & he just couldn't understand why.

Go get it checked out by a REPUTABLE mechanic. They will probably do a pressure test on it. Glad I could help.

I have a FWD CXL model Rendezvous with a 3.4 liter, for me, it is a bad water pump. The pump started chirping about three days ago, I was able to locate the problem, and decided to change both the water pump, and the thermostat. This fix was a problem to access, but a quick fix for me. I had heard about the tendency of the 3.4 to develop overheating difficulties, so I checked all of my gaskets, and to my surprise, found the engine had undergone a complete rebuild a month before I bought it in April, with all new gaskets.

I've finally got this car to stop overheating! (for now) I'll do my best to explain what all I had to do to it. First off, it's a lemon. Great interior, crap engine. Let's move on. I replaced (in order) *Radiator *Water pump *Thermostat (twice because the first got stuck) *Antifreeze to green instead of red *Head gasket job These cars run on a pressurized coolant system, and it's a pain. Some tips I have are : *Flush the system until you would drink the water coming out, and fill it up with green antifreeze. The Dexcool eats the intake manifold gaskets, get the Dexcool out of the car ASAP!!! *BLEED. I haven't determined if this car needs routine coolant bleeding on a biweekly or monthly basis, but it's a good idea. There is a bleeder screw on the thermostat housing, and another on the metal line atop the water pump. Run the car, open the bleeder valve, count to 30, close it back, count to 30, open the other bleeder valve, count to 30, close it back, repeat repeat repeat. *If there is no air in the coolant system, the heat will work. If your heat starts going out, you need to bleed it again. I usually check all fluids once a month, and bleed it out at the same time. IF IT'S CONSTANTLY GETTING AIR IN THE SYSTEM, YOU NEED TO FIGURE OUT WHY. It will not run right. This deduction led me to the water pump, and ultimately the head gasket. *I haven't changed the heater core out yet, but screw it, do it too. Good luck. Get it running right, and get rid of it

Ok people these motors are pron to getting air in there systems. Before jumping ing into big money. First things first start with you basics. If the gauge is up and down. First replace the cap. People forget they do go bad even. Even new ones do just like thermostats. Ive seen this problem time and time again. Then replace the thermostat. Oem or better. Never cheaper than oem quality. And of course bleed thermostat housing first until car heats up then on to waterpump. Good luck hope tis works. Oh yes also make make sure your overflow hose is clean and has no cracks air leaks..hole this help and god bless you

I have 2002 Buick Rendezvous it’s running hot wat can be d problem ?