85 Bonneville Boiling Over

[stevenwest13]

Having an issue with my Bonneville always boiling over. The Haynes manual states that this car has a type of pressure system that if the pressure gets to high it is supposed to boil over thing is that it does it even after short trips. I have checked everything I can think to check and have checked the flow in the radiator and it appears to be flowing quite well so that seems to have eliminated the water pump. The thermostat I have already replaced and the fan clutch I will be checking in the morning. I just bought this car and everything about it is great except for the fact that the last oil change and tuneup on it was done back in 2006. Tuneup is complete and Oil change as well. It does not appear to do it when I run the heat but always with the AC running.

Asking you guys for any pointers as to what I can do to stop this boil over as it is getting crazy always seeing smoke coming from under the right side of my hood when I slow down at a stop sign/redlight.

Thanks for any help you guys can give. Let me say this though. Even though I have this slight problem this is the best car I have owned so far. It brings back memories of the old 81 Monte Carlo I used to own.

Thanks guys.

Mark

[00Beast]

Make sure the fins aren't plugged. Have you tested the cooling capability of the coolant? How old is it? Have you flushed it recently?

[spoiledred94]

It does sound like a compromised radiator. Clogged or bent fins. Heat alone causes some water movement. So be sure your pump is indeed working.

[stevenwest13]

Aight. Got under the hood some more today. Found out the fan clutch is offering very little resistance after getting up to normal running temperature. In fact it felt the same resistance it did before I ran it so I am hoping this is my culprit. One other problem I ran into was that my temp light does not come on when I put the key in the on position. I checked the bulb and it was good and I also checked the wire going to the sending unit and it was good so somewhere among this conglomeration of wires I have to have something lose somewhere. I have a light instead of a gauge. I am thinking it would be simpler to go and purchase a cheap SunPro Temp gauge and hook it in instead of tracking down the faulty wire unless you guys have other ideas.

Fan clutch comes in this afternoon and I will let you guys know how it goes.

Thanks again for the ideas.

Mark