Ok I just had my 180 t-stat in and had my coolant flushed. The problem is when I'm moving the temp gauge in the car will stay way below 200 but when I pulled in my drive way and idled for 5-6 min. the temp started going over 200, so I poped the hood and the fans on the radiator weren't moving, so I turned the AC on for a sec. then turned it off to get the fans moving, both of them where moving and the temp started going down, the fans are on a timer for the AC I guess and finally shut off, and the temp would start rising again so I turned the AC back on and the same thing happened. Now whats causing the fans not to come no to keep the temp under control. If I have to I will just use the AC to get them spinning, but shouldn't they come on automaticly? Any segjestions? I'm stumped.


Thanks, for you relplys.

One more thing, it never did this before I got the 180 t-stat in and before I flushed the coolant, hope this helps.

It is my understanding that one of the fans come on when the temp. hits around 200-220, but they both will be running anytime you have the a/c turned on. You may need to let the car idle long enough for the temp to go that high and make sure that the one comes on. At least that is what seems to happen with mine...............Hope this helps

My understanding is the same. One fan come on in the 200-220 range, and the other somewhere right before redline. They both come on with AC on. I couldn't tell you why it may have acted differently before.

Does anybody know if the GP high speed fan switch kit will work on a Bonneville?

Ya but with the 180 t-stat why would it go that high. with the 195 in there it would stay at that temp most of the time, sometimes it would go to 200 or a little over.

Still why would the 180 do that, does anyelse with the 180 go up over 200??? :?:

The 180 opens at 180 and STAYS open. It'll let you climb all the way up at idle. It won't control the temps and hold them at 180 unless you're moving, and even then it won't be that low.

To prevent the 200 spikes, you have to drill the stat, so you don't get the initial 180 heat saturation before opening. Without that intitial saturation, the engine can control it'* temps better.

With my stock stat I was hitting the 240+ range. With the 180 I usually stay below 210. On occasion I will go a bit higher but no where nea as high as it used to. I am sitting at roughly 175-190 with my temps lately and it hs been around 55 outside.

OK thanks for all the answers. I will just have to leave my car idling one day and see what happens.

I've never liked how hot both of my Bonnies run. And according to others, what mine do is "normal". You'd think GM would have set the fan trip temps lower in order to cool the engine better. I remember reading the temp trip values in the shop manual, but I don't remember what they are offhand.

Once I drove my '92 to the mountains on a day when the outside temp was around 70 degrees F, and within 10 minutes or so the temp gage was about 1/8" from the red, so I pulled over and opened the hood, expecting to find leaking coolant, but everything was dry and the coolant level was still full, so I continued the trip with the AC on, and the temp went down to around 200 quickly and stayed there. I told a GM mechanic about this trip, and he said it'* "normal" for these engines to run that hot and there'* nothing to worry about, not even at 240 degrees. I've never owned a vehicle that got so close to the red while operating under "normal" conditions!

I'm soon planning to install 180 tstats on both of mine, but I wouldn't be surprised if they both still run at 220 or higher during extended idling ("normal" here in So. Ca.) or on warm 80 or 90 degree days...that'* what both of mine do now, and I assume they both have stock 195 tstats in them.