Intermittent Heat on 2005 Bonneville SE

[homeboy517]

Sometimes I get Heat and sometimes I do not.

Blower motor runs fine as I can feel strong push of air when the air is warm/hot (working) and when it is cool (not working)

I changed the thermostat and I can't see or smell any signs of leaks.

When the air is hot the temp guage is usally around 200, maybe a little more.

When the air is not hot I notice the temp gauge goes well past the norm of 200......in the 240 range.

There doesn't seem to be a pattern to follow in getting it to not work. Sometimes I'll just be driving with the heat on and working and all of a sudden cool air is coming out.

Any ideas what the problem is?

Thanks, Al

[crash93ssei]

Sounds like low on coolant / air trapped in the system. Make sure the radiator is full as well as the overflow tank. Let the car get up to temp and burp the air out of the system using the bleeder screw on top of the thermostat housing.

[homeboy517]

Thanks for the suggestions. Took little over a gallon of 50/50 to get it filled. Surprised that I wasn't getting a low coolant warning. Anyways, filled up the system and that's when I noticed that there was indeed a leak. Near water pump, but not the weep hole. After a couple days of investigation and research I found that there is a small elbow pipe on the serpentine belt tensioner assembly. I replaced this pipe about a week ago, filled the system again, and all is good.

[Trinity]

Thanks for the suggestions. Took little over a gallon of 50/50 to get it filled. Surprised that I wasn't getting a low coolant warning. Anyways, filled up the system and that's when I noticed that there was indeed a leak. Near water pump, but not the weep hole. After a couple days of investigation and research I found that there is a small elbow pipe on the serpentine belt tensioner assembly. I replaced this pipe about a week ago, filled the system again, and all is good.

Be aware that the coolant had to go somewhere! If it's not leaking on the ground, check oil, if it's not milky you are burning it. If you are burning it it's time to do the LIM gasket or you will spin a bearing or worse.

[crash93ssei]

Good to see you got it fixed up! There is actually two of those coolant elbows, and they are a known issue on our beloved 3800 engines. Dorman now makes both elbows in aluminum so they should last much longer then original or the old replacement plastic elbows that Dorman used to make. I would imagine that you got the plastic set as that is what most pasts stores still carry, if so just keep an eye on them and when they start to leak again replace with the aluminum set and be worry free from there on out