I finally got my 1986 FJ60 (2F) running. I have noticed a strange engine noise when cruising on the interstate (running about 2500 rpm). It sounds as if the engine speed is increasing (it hums or "whines" louder intermittantly). It will make this sound off and on about every 2 minutes and it lasts 20 o 30 seconds. None of the gauges move (oil pressure, volt meter, tach, heat gauge) and there is no change in speed or engine performance. If I let off on the gas and coast with the clutch disengaged, the sound immedialtely is gone. Could it be the radiator fan running off and on? Or the air flow into the air cleaner being switched from the outside to the manifold?
mystery noise (1 Viewer)
- Thread starter Heartworm
- Start date
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what you've described sounds like the radiator fan. It has a silicone oil clutch that engages the fan at a certain temperature. The increased air flow cools and the fan disengages. And so on. When the fan is engaged, it's speed is the same as the engine. At 3000 rpm it's faster and a lot louder than it is at idle.
I'll bet it is the carb cooling fan, coming on and off.
fan clutch normaly would not lock up on the hiway.
carb cooling fan should only run when you turn off the motor, not when running.
carb cooling fan should only run when you turn off the motor, not when running.
yes I have them all. 13 total.
b56tc said:
You Are My Hero!!!! 
I Don't Think My Wife Would Go For Anything Over 2 Or 3 Cruisers. And I Am Having A Herd Time Convincing Her Of That.
13- You Cruiser Stud!!!!!!!!!
YETIMAM
I Don't Think My Wife Would Go For Anything Over 2 Or 3 Cruisers. And I Am Having A Herd Time Convincing Her Of That.
13- You Cruiser Stud!!!!!!!!!
YETIMAM
yeah yeti I agree.
I have not yet found out how to get more than 2 of the same vehicle without undue marital stress (if you have 2, one is yours, one is hers. Even if she doesn't drive a manual).
What is the rest of your fleet - as if you need anything else?
I'm just enjoying living vicariously through someone in LC heaven.
I have not yet found out how to get more than 2 of the same vehicle without undue marital stress (if you have 2, one is yours, one is hers. Even if she doesn't drive a manual).
What is the rest of your fleet - as if you need anything else?
I'm just enjoying living vicariously through someone in LC heaven.
Ya I Just Narrowed My Fleet Down To My Dd 85 Fj60, I Just Sold A 60 Last Thursday. My Wife Has Baby Feaver. So We Are Thinning Things Out. My Wife Has A Wrx. She Likes A Little Smaller Car For Her Dd. After We Do The Kiddo' Thing We Plan On Adding A 40, And Mybe An Iron Pig. Well Those Are The Two On My List. If The Right Price Came Up I Would Add One Sooner. I Have An Extra 2f So That Helps Me With Adding Another Rig.
Yeti
Yeti
Dr. John
SILVER Star
My rad fan did that for years but I haven't noticed it lately...Hmmm. There was a thread on the old TLCA list years ago about changing out the silicon fluid in the clutch. Lighter weight fluid would make the engagement less abrupt.
87 60
87 60
I would say its also not the fan clutch, as you say it goes away when you coast and put in the clutch.
kinda sounds like its in the clutch or trany.........but that is only lasts 20-30 seconds would make me think its not clutch or trany related.
once warm the air flow to the air cleaner should not change, the little flaper opens at a set tempature.
I am stumped..........but there is something in the back of my mind.........I just can't pull it up
kinda sounds like its in the clutch or trany.........but that is only lasts 20-30 seconds would make me think its not clutch or trany related.
once warm the air flow to the air cleaner should not change, the little flaper opens at a set tempature.
I am stumped..........but there is something in the back of my mind.........I just can't pull it up
Heartworm said:
could it be your transfer case or tranny whining? like does it change with pressure on your pedal?
60wag
SILVER Star
I still think is the fan spinning up and free wheeling. Mine does that on the highway. I think its normal. When the clutch fails, it free wheels all the time doesn't it?
could it be a vaccuum leak? I know I had one on my 40 around the base of my carb....cruiser still ran decent, and ya only heard the noise when you applied the gas pedal. Could be 2 different sounds we are talkin about...lol.
- Thread starter
- #18
Still hoping it is the fan
Landpimp: Dropping the RPMs on the motor from 2500 to 650 would certainly slow the radiator fan considerably and thus the noise I am hearing. The rig idles very smoothly so I am not leaning toward a vacuum leak. There is no shuddering in the driveline when the noise comes on and the RPMs don't change. Incidentally, I tried to choke the motor down by puttin my hand over the plastic air intake tube without success. I had just driven 17 highway miles so the motor was up to temperature. Maybe my HAC is acting weird?
Landpimp: Dropping the RPMs on the motor from 2500 to 650 would certainly slow the radiator fan considerably and thus the noise I am hearing. The rig idles very smoothly so I am not leaning toward a vacuum leak. There is no shuddering in the driveline when the noise comes on and the RPMs don't change. Incidentally, I tried to choke the motor down by puttin my hand over the plastic air intake tube without success. I had just driven 17 highway miles so the motor was up to temperature. Maybe my HAC is acting weird?
it "could" be the fan clutch I suppose......I just have never had any of mine kick on when on the highway or if they did I couldn't hear them kick on.
Heartworm said:
