Cant find a cooling system section in here so excuse me if this is in the wrong place. I suspect the fan clutch on my Buick 455 is not working correctly. The temp cycles from 80C to 120C and back, with no apparent reason. As Im in Australia it may be difficult to source another fan clutch so any info on them will be a bonus. Like are they the same as any other vehicle ? Wheres the best place to buy one from? A mechanic tells me my other option could be to change the fluid in mine? Any thoughts, ideas , suggestions, will be greatly appreciated. Thank You Chris (OZGS455) Its a1971 Stage 1 if that makes any dufference .
Spin the fan with the engine off. If it goes around more than 1 turn, it's shot. https://www.rockauto.com/en/catalog/buick,1971,gs+455,7.5l+455cid+v8,1379774
Thanks Larry! RockAuto hey, yeah the guy I bought the car off mentioned them for parts....much cheaper than I imagined...there looks to be a choice though!...wonder which ones correct for my application? Ill get home and check it out. May have to remove it to match it up? Thanks again. I have a contact through the Victory motorbike forum who lives in Oregon and evidently they get a better deal sales tax wise. Hes offered to get it on my behalf and post it to me. Just gotta work out which one.
Doesnt even go one full turn with engine off. Also get engine to 80-100C on gauge and turn engine off and fan stops immediately... So thats not a problem.. That Rock Auto is the place for parts though, thats for sure. Gonna look deeper into thier stuff. Thanks
The thing with Rock Auto is shipping. Often when you purchase multiple items, they come from multiple warehouses. They tag ya with shipping from each one and it can be prohibitive. Jim
OZGS455, if you are interested. I have a used fan clutch I will ship to you. It has very few miles on it and is still tight. $35.00+ shipping. Let me know. Thanks Brian
Have you sat and thought what a fan clutch is supposed to do? Temp rises so fan clutch kicks in and pulls air thru the radiator harder/faster cooling the anti freeze. the temp goes down and clutch stops the fan spinning. Like larry says nothing wrong. Al
That clutch can fail in one of two ways... around town, its slipping and not pulling air in the radiator at slow speeds, yet faster driving cools the engine, OR, at highway speeds it doesnt release and takes an additional 10-20 HP to drive the fan. If the latter occurs, youll hear the fan running. The free wheeling test usually proves the fault but you need to do it with the engine cold and then hot. I guess thats a positive failure or a negative failure? Kinda like a a false positive... ws
Mine just failed. Found oil on fan blades, gave her a spin and round and round she goes.... Explains the temp creep at idle, and crawling along in bumper to bumper. Went thru the stash and gtg now. Will take her out this weekend and she how temps are....Jim
Hi, perhaps you should continue to diagnose the problem before we go any further. I would much rather you get your problem fixed than sell you something you don’t need. Brian
Yes Brian I agree, thanks mate. Another mechanic suggested the problem could be electrical, a bad earth from engine to chassis causing temp gauge to manfunction. Another suggested changing the thermostat...
If the temperature is cycling between 176*F and 248*F, my first thought is a sticking thermostat, not the fan clutch.
And that would be easy to diagnose with the above mention IR temp gun. Or pop the thermostat housing, pull the thermostat out and put eyes on the shaft . You are looking for chafing, clean spots created by it hanging up when attempting to open. Cost ya a gasket and 15-20 minutes to verify one way or another. Jim
Ok..thanks fellas! You blokes are a great help, didnt realise temp guns were so cheap! My original thought on the trip home from buying the Buick a 600 mile + trip was the thermostat. But the engine wasnt showing outward signs of heat . So I thought it was a faulty gauge .
