Hi well I recently re did the HG on my 86.5 supra and after the rebuild i now have a loud fan noise when the car is cold, WHen i start it up it sounds like a school bus and sort of like the fan clutch is locked up, but it isnt, i can free spin the fan clutch most of the time but on rare occasions it wont spin the clutch it will sometimes spin the water pump over with it. I know tthis is an indicator that the fan clutch is probally bad but it also has an other issue. At this point when it has the loud fan noise if the engine is revved over 3000 rpms it seems like the belt is slipping bc it squeals and u can feel peices of debris coming off of the belt. and now that it is getting colder outside this condition last longer bc it wont heat up fast enough. Any ideas?
I had a bhg about a year ago and prior to fixing it I tried to eliminate any easy possibilities which included doing thr fan clutch. Whoa, first start up and it sounded like a dumptruck just revved up. Been that way ever since. The fan disengages after a minute (still spins but doesn't increase much with revving) and the noise is gone. My old fan clutch was actually worn out and although the fan would spin, revving the engine wouldn't make it spin any faster and it never really engaged even on hot days. Basically, my experience is that your fan is working properly.now. as long as it disengages after a minute or I wouldn't worry about it. On my car it always does that after it sat breifly orand even cold starts as well. On those really hot days when the fan is needed, you hear it taking off from every stop sign. Yeah it robs a little power when engaged, but unless it's a hot day, I try to avoid beating on my car immediately after start up anyways. Lol.
As for the belt squeak, make sure it's tight enough. Mine used to loosen up over time and squeak on start up. This eventually wore out the belt and then it really squeaked. The solution? I spent the extra 15 bucks or so on the Dayco poly-rib upgraded one or whatever it is. Put her on, tightened her up and that belt hasn't made a peep. I have been very happy with it actually. Hope this helps.
As for the belt squeak, make sure it's tight enough. Mine used to loosen up over time and squeak on start up. This eventually wore out the belt and then it really squeaked. The solution? I spent the extra 15 bucks or so on the Dayco poly-rib upgraded one or whatever it is. Put her on, tightened her up and that belt hasn't made a peep. I have been very happy with it actually. Hope this helps.
Just re-read your post. I would try replacing the fan clutch and belt. It will probably mimic mine in that it will still blow hard for a few minutes after start up, but I think that's normal. If not I should go get another fan clutch. I don't remember where I got this information and it could be totally wrong but I seem to recall that mechanical fan clutches have fluid in them and it settles from gravity while sitting. When you start the car it takes a little bit to even back out. Probably related to our school bus roar.
thanks, I think im going to remove the fan and run it in the garage to see if the noise goes away bc i beleive the fan clutch is the issue and it does have a newer dayco polyrib belt on it so i dont think the belt is my issue but i will see and im also thinking of going to an electric fan assemby instead of the mechanical fan anyways any feedback on the electric fan conversion cause ive been trying to find info on it.
It's not supposed to do that.
I had a brand new OEM fan clutch, and when first started up, it was really quiet. It only started to approach loud when it was really hot out, AND had been running hard. I could see it MAYBE if you have major heat soak, IE, the radiator is really hot, the air is really hot and you only left it shut down for a shorter period... Naw. Not even then.
I had a brand new OEM fan clutch, and when first started up, it was really quiet. It only started to approach loud when it was really hot out, AND had been running hard. I could see it MAYBE if you have major heat soak, IE, the radiator is really hot, the air is really hot and you only left it shut down for a shorter period... Naw. Not even then.
well the issue is that the colder it gets the longer it lasts i mean somedays its liek it for 5 to 10 minutes but on others it can last the whole duration driving its even happened after like 30 minutes of freeway driving and usually it will go away when it is hot
If its locked to the pulley when the engine is off and you rotate by hand (as I think you described above) then the clutch is not working properly.
^ This. The two halves should never be locked together. There isn't any mechanical device inside that's designed to let that happen even when the thing is working.
From this, I'll operate under the assumption that it wasn't long enough for me to notice between the starter noise and the engine starting while the intake manifold isn't under vacuum.jetjock;1890837 said: