strange noise from FJ40

Joined
May 18, 2002
Messages
25
Mabey some of you guys can tell me what is causing a stange noise in my FJ4O. It sounds like a coffee purculator , and it only happens when I'm decelerating. other than the noise it runs fine. I have a chevy 305 and a th350 automatic tranny in it.
 
Joined
Jul 13, 2003
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57
Location
Medford, OR
whereabouts does it sound like it is coming from? Might be differential gears. Does it make any noise when accelerating?
 
Joined
May 18, 2002
Messages
25
strange noise

It sounds like its coming from the front half of vehicle, mabey the tranny, transfer case, motor, or someplace else. It almost sounds like a gurgling sound that a coffee perculator makes, but only on deceleration, not when its idling or when I'm accelerating...weird.
 
Joined
Mar 13, 2005
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276
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Colorado
Could be the fan rubbing ever so slightly on the radiator or fan shroud, mine does this, been thinking about a solution.
 
Joined
Apr 30, 2005
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Blenheim, New Zealand
Check your spring U-Bolts - especially if you've changed springs recently. Mine had settled & allowed a bit of slop, letting the axle twist so the pinion to driveshaft alignment changed - better alignment under acceleration, worse under deceleration - causing the universal to complain. Also accompanied by a noticeable "CLUNK" when going on or off the throttle.
 
Joined
May 18, 2002
Messages
25
I will check those things

I'll check those things you guys mentioned,exhaust leaks, coolant, one thing I've never tghought of is minor backfiring. Its a hard noise to track down because the only time it does it is when I'm driving and decelerating. I thought it might be the chain in the transfer case, but I'm not sure. Thanks for the replies
 
Joined
Apr 15, 2005
Messages
281
Location
NY
bushwacker said:
I'll check those things you guys mentioned,exhaust leaks, coolant, one thing I've never tghought of is minor backfiring. Its a hard noise to track down because the only time it does it is when I'm driving and decelerating. I thought it might be the chain in the transfer case, but I'm not sure. Thanks for the replies
Please let us know if you find the problem , I have a similar noise
sounds almost like a belt noise while running (but it isn't)
then when the engine stops with the key off
it sound like a tea kettle for a few secons :) almost like it buids steam and releses it when stopped
 
Joined
Jan 6, 2005
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414
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EAST COAST
Are you sure its not exhaust back pressure?
My 2 cents would agree with exhaust leak or coolant system, but when i decelerate I love the gurgling noise my exhaust makes.
 
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Apr 10, 2004
Messages
2,285
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denver
bushwacker said:
I'll check those things you guys mentioned,exhaust leaks, coolant, one thing I've never tghought of is minor backfiring. Its a hard noise to track down because the only time it does it is when I'm driving and decelerating. I thought it might be the chain in the transfer case, but I'm not sure. Thanks for the replies

There is no chain in your transfer case
 

Pin_Head

 
 
 
Joined
Feb 6, 2002
Messages
14,797
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OC, CA
It is detonation of air/unburned fuel in the hot exhaust manifold. This is one of the things that the "smog control" system controls and eliminates.
 
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