Community Forums

donr103 · 07-19-2022, 03:59 PM

Telephonebil.. wipe it down then use your cellphone with flash on and record around and under the motor.. many times part number is on the bottom where it is most convenient
Good luck and keep us posted

LETMGROW · 07-19-2022, 05:44 PM

Quote:

Originally Posted by LETMGROW

This sounds suspiciously like detonation. If you are running regular gas now, try running your tank low on gas and fill up with premium gas. You may need to boost octane a bit to make up for carbon deposits on the tops of the pistons or in the combustion chambers.
If the noise lessens or goes away you'll know what is causing it.
What temperature are you running on the temperature gauge? Is your "Check Engine" or "Service Engine Soon" light coming on when you are driving?
A lean mixture can also cause detonation. A common problem on 8.1 engines in Motor Homes is a bad or dirty MAF (Mass Air Flow) sensor. These can often be cleaned by removing the sensor and using MAF sensor cleaner to clean it following the directions on the can. Do NOT use anything else. These sensors are delicate. Do NOT try to blow out the sensor or dry it with compressed air. The sensor will be permanently damaged if you do. Yes, air flows past the sensor but not at 125# plus pressure.

This was intended for kernst52

Telephonebil · 07-19-2022, 11:31 PM

Wow thanks guys. But the culprit was the air conditioner fan assembly. The whole where the shaft from motor goes thru had elongated and the e-clip missing making the blades hit the condenser. Oreillys had a replacement. It’s in and installed and I’m out the door in morning. Going fishing.

kernst52 · 07-24-2022, 11:48 AM

Thanks for your reply. The noise is pretty fast frequency - almost like what I would call a buzz that also sounds like metal. It is always occurring suddenly in hot afternoons when I have been climbing a long hill for a while. Always starts when I hear the fan kicking in and moving more air. Then it goes away on the down side of the hill when I have been "coasting" for a while. The noise stops exactly when the fan kicks out. Since the idler, tensioner pulleys or okay and the fan has no damage at all I think it must be the fan clutch. How does a person know if the fan clutch is making the noise. It is doing its cooling but the noise has been getting louder for the past couple of years.

Ken

fayjim2 · 08-22-2022, 07:15 PM

Hello I,m on the road. I heard a loud bang from engine area. .Temp went up so I pulled over, I large portion of a fan blade broke off. Sooooooooo I kinda snapped off some the opposite blade. Engine isn,t acting perfectly but better When the clutch engages its definitely a different sound but it does seem to be coming on late. By noon its 99 to 100 and I ran in low red for majority of day. Minimum cargo and no Toad. How difficult is it to change the clutch fan assembly?. When it gets to red NO A/C is that right? Cruise gets fussy also and its not the brake switch. Oh well enough complaining starting early when its only 80 Jim

Isaac-1 · 08-22-2022, 08:21 PM

Its not too bad, but you will need a couple of special tools (thin open ended wrench looking tool) to hold the fan hub in place while you unscrew things. When I changed mine I did it from the top removing the alternator, tensioner and idler pulley to gain better access (also needed to replace the alternator at the same time, while there I replaced the tensioner and idler also) There is a youtube video showing the process here:

https://www.youtube.com/watch?v=arVkjHR1PSA

MrMark52 · 08-22-2022, 08:31 PM

Make sure the bottom fan shroud hasn’t crept up and interfered with the fan.

When we got our ‘02 coach early last year, I came across a post on IRV2 that mentioned this was a known problem for the 8.1’s. Got under the coach and saw the center bottom of the fan shroud had been worn away by the fan blade scraping the shroud. Fortunately it never “caught” - which I’ve read where if it does, good-bye radiator.

Workhorse put holding clips out at each corner of the radiator (which is already adequately supported in place) but nothing in the middle (which is the weakest place).

All you do is pull the shroud down in the middle and drill a hole in the shroud flange and then into the 16 ga. flange along the bottom of the radiator frame (I used a #10x1/2” self-drilling TEK screw).

Not sure what plastic they used (probably ABS), likely vacuum formed so the plastic is trying to creep back to its original flat shape.

F4Gary · 08-22-2022, 08:34 PM

Quote:

Originally Posted by Telephonebil

sorry for the interruption, but i cant find how to post a question. I too have a fan noise.
I think its the oil cooler fan assembly. the fan is wobbling. its the fan right out in front when you drop the hood. It seems to come on when the AC is on.When it wobbles it hits the cooling fins behind it. I need to find one. Any ideas as to part number ?? 2002 Sunova 8.1 chev thanks in advance.

Go to O'Reilly auto and get a Hayden 3680 and transfer the fan and motor into your Workhorse fan frame.

See post #1:

https://www.irv2.com/forums/f22/wh-8...nt-261542.html