Please Diagnose My Jeep

I have a 1994 Jeep Grand Cherokee Laredo.

Start the engine, sounds fine. Then, after a few moments, there's a terrible rattle. No performance problems, just bothersome. You can hear the sound fairly well on the video:

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What's causing this knocking/rattling noise? Any ideas? How much will it cost to repair?

Thanks!

Reply to
Brettster
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From where you are pointing the camera I am guessing that the water pump or viscous coupling is going bad allowing the cooling fan to rub against the radiator shroud. For further diagnostic with the engine turned off grasp one of the cooling fan blades and check for play.

Cheers,

Earle

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Reply to
Earle Horton

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Reply to
L.W.(ßill)Hughes III

Sounds and looks like the bearing on the viscous fan or the water pump is toast.

Turn the engine off, grab fan blade and see if it wobbles. If it wobbles, see if the finned center section of the fan is tight to the fan and the wobble is at the water pump.

I'm bett> I have a 1994 Jeep Grand Cherokee Laredo.

Reply to
RoyJ

Thanks for everybody's help!

I think the video is showing a little optical illusion. The fan seems fine. There is no wobble or play whatsoever.

Reply to
Brettster

Gonna have to agree with RoyJ. Sounds like the fan hitting the shroud caused by a failing bearing, bent blade, or viscous fan coupling. Examine the fan shroud edges for wear spots and check the radiator for any bent fins. The fan sits very close to the radiator and if the coupling starts to go the fan can eat the radiator.

Reply to
DougW

Could be a loose or tweaked motor mount too.

Earle

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Reply to
Earle Horton

Still sounds like a water pump!

Things to try:

take the belt off, check to see if the adjuster seems to sp> Thanks for everybody's help!

Reply to
RoyJ

Sometimes, but I'd expect a full out grinding if one let go, not sounds that come on after a while of running.

I do know my I6 will compla>> RoyJ wrote:

Reply to
DougW

hat come on after a while of running.

grinding) when the mounts go.

Doug,

How can motor mounts cause grinding sounds? My YJ sometimes makes a sort of grinding sound on downhills, maybe it is something similar.

Thanks

Reply to
nrs

that come on after a while of running.

grinding) when the mounts go.

I6.http://revbeergoggles.com/motormount/> Parts change a bit, but otherwise it's the same.>

Doug,

How can motor mounts cause grinding sounds? My YJ sometimes makes a sort of grinding sound on downhills, maybe it is something similar.

Thanks

Reply to
Superman Hughes TrollKiller of scum 24bit & squarewheel

I thought about sending you here but decided that the signal:noise ratio was too wide.

Did you inspect the fan shroud all the way around?

Reply to
Lee Ayrton

They can make the fan hit the shroud too. There isn't much room for error there.

Grinding sound on downhills could be the exhaust hitting the frame, a result of misaligned exhaust or again bad motor mounts.

Earle

Reply to
Earle Horton

that come on after a while of running.

of grinding) when the mounts go.

tp://revbeergoggles.com/motormount/

Thanks for the ideas. I'll resume my search for the grinding sound.

Reply to
nrs

FYI,

I took the Jeep to a local shop (Chuck's Auto in L.A.). They diagnosed it as a bad water pump. Cost to replace: $400+.

Brett

Reply to
Brettster

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