clanking sound that driving me nuts.

Hi all,

I have a 1995 Jeep Grand Cherokee from hell.

I recently had the transmisson rebuilt. (It was not engaging). I also had the radiator replaced. Because the engine was reving and the transmission was not engaging, it blew the radiator.

Now:

I can drive on the highway all day and nothing bad will happen but once I get into stop and go traffic, like today, on a hot day, I would start to hear some clanking, then it would get louder, like something spinning and hitting something else. If I press on the gas pedal to go faster, the clanking sound would be faster, more frequent so I am thinking it has something to do with something spinning while I press on the gas pedal (yeah, really car smart there, lol), if I put it Park, the sound goes away but if I put it in drive to start driving, it would make the clanking sound, hard to explain the sound, like a fan is running and you stick a pencil into it...I think. Now, the thing is, if I pull the car over, pop the hood, wait like 10 mins, snap the hood, and start driving, the sound is gone. When I popped the hood, the engine was really hot but like I said, today was like 90 outside. So to sum up..

  1. Drive on highway -- Fine.
  2. Stop and go traffic on hot day --- start to hear clicking sound follows by clanking sound.
  3. Put car in Park the sound goes away.
  4. Pop the hood, let the engine cool for a few minutes, the sound goes away.
  5. Recently had the Tranmission rebuilt, radiator replaced.

The thing is, it is hard to troubleshoot, if I take it to the repair shop, I would have to have it making the sound but when it happens, I'm afraid to keep on driving so I'd pull over and pop the hood to let it cool now. I don't want to ruin whatever that is making that clanking sound. Also, the car has a strong hum sound, like ummmmmmmmmmm sound, could be from the exhaust system, not sure if it's related.

Any suggestion help , idea is really apreciated.

-J.

Reply to
lilgrasshopper
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Could the exhaust be banging on something? I think that way because putting in Park takes the torque off the drive train, and lets everything settle into its natural alignment. Could the transmission people have left out a bolt or two? Or a bracket? Motor mounts loose?

"Clanking" makes me think of the flex plate, but those usually don't come and go. Or a u-joint, but those are not usually temperature related.

If you can get under the vehicle, check all over for loose stuff, leaking fluid (any kind) or obvious missing bolts.

Earle

Reply to
Earle Horton

Hi Earle:

All I can think of is:

  1. Hot day.
  2. If I put the gear in anything but Park, it makes that clanking sound.
  3. Faster I go, the faster the clanking.
  4. This is in slow stop and go traffic.

So, in term of the engine, what spins when it's in Park and what spins when it's in Drive. ? because something made it stop clanking when I'm in park.

Guess I can take it back to the transmission people to have them take a look.

Thanks,

-J. Earle Hort> Could the exhaust be banging on something? I think that way because putting

Reply to
lilgrasshopper

Reply to
L.W.(Bill) Hughes III

Does it make the noise just when you are moving or if you put it in Park and rev the engine a bit will you hear it then too?

Jeff DeWitt

Reply to
Jeff DeWitt

I hope I'm wrong, but that sounds like a bad rear mains bearing. They usually make a bad clank/grind noise when the engine is under load (like pulling a trailer) but eventually will make that noise even when taking off.

Get yourself a big flat screwdriver or small pry bar. From under the engine see how far the harmonic balancer will pry forward from the engine and go back into the engine. It shouldn't move more than about

1/8" max. If it moves 1/4 like mine did way back when, then it's time for a shortblock. Do not pry hard.. and pry against the inner ring on the balancer. If it's going to move it will move easily.
Reply to
DougW

Hi Jeff:

I have not put it in Park and Rev the engine, worth a try. I know when I put it in drive, it would start to make the noise, even when stopped.

Jeff DeWitt wrote:

Reply to
lilgrasshopper

Hi guys:

What's a good book for cars? I know when it gets complicated like this, take it to the shop, turn around and bend down but I'd like to read and see how things work. (I work as a network Admin at my corp. inc). Shilman? Shulman?

Thanks,

John,

Roosevelt, NJ

DougW wrote:

Reply to
lilgrasshopper

If you have a mechanical belt driven fan in that, I would suspect the clutch on it has gone bad.

'Blew the rad' because it revved too much? That is ummm... BS.

If I can't run my Jeeps at full power (high revs) in low gears off road, they are broken.

I also would be suspecting maybe they forgot to tighten down the tranny mount or something, so when it goes in gear, it could be shifting over or they left a bolt loose in the torque converter or the clank it the bad fan clutch.

Mike

86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail >
Reply to
Mike Romain

Reply to
lilgrasshopper

If you have a bad fan clutch, it will overheat in slow traffic because all that is cooling the rad is wind pressure from how fast you are going.

Typically, even the secondary electric fan only comes on in slow traffic or with the AC too. Once you are at highway speed or the rad is cool enough, the electric fan shuts off. Maybe it has a bad bearing?

Mike

snipped-for-privacy@gmail.com wrote:

Reply to
Mike Romain

This is a stretch but maybe the motor mounts get soft when it gets real hot, or the exhaust pipe gets a millimeter or so longer, and starts hitting something. For books, the Chilton's or Haynes manual for your model and year, available from most auto parts stores, will tell you probably all you need to know.

Earle

Reply to
Earle Horton

I think you answered my question, if it was say the exhaust system hitting a U joint you would only hear the noise when the Jeep was actually moving.

Something else you might try, have someone rev the engine while you watch it. What you would be looking for is the engine shifting around more than it should because of broken motor or transmission mounts. The effect will be a lot more pronounced if you have it in gear, but of course BE SURE to set the hand brake, have your assistant step on the brake AND chock the wheels before trying that... and DON'T stand in front!

Jeff DeWitt

Reply to
Jeff DeWitt

If you pretty much know cars, the factory service manual is the best, in that it explains how each of the systems works, plus how to perform simple and complex checks. You can usually guesstimate the pita factor from the FSM.

snipped-for-privacy@gmail.com proclaimed:

Reply to
Lon

Taking it to Cottman Trans tomorrow, I will let you guys know if they found anything.

pita factor?

L> If you pretty much know cars, the factory service manual is the best, in

Reply to
lilgrasshopper

On 25 Jul 2006 06:31:22 -0700, the following appeared in rec.autos.makers.jeep+willys, posted by snipped-for-privacy@gmail.com:

"Pain In The...Anatomy"

Reply to
Bob Casanova

went to cottman. they said everything related to trans is working fine. they could not replicate the problem, have a nice day.

L> If you pretty much know cars, the factory service manual is the best, in

Reply to
lilgrasshopper

Did you go with them on the test drive?

Reply to
billy ray

Hi Billy Ray!

I did not but I know if I did, the same result would happen: NOTHING.

They said they checked everything and as far as trans is concerned, they are in the clear, goodbye, have a nice day. Maybe the guy that changed your radiator left a wrench in there. (he was joking?? )

I drove there and everything was fine. I would have to do an hour plus drive on highway, then get stuck in stop and go traffic.

Maybe the coolant line to the tranny (I'm getting the lingo down now!) is blocked? I might do a flush this weekend. comments?

-John

billy ray wrote:

Reply to
lilgrasshopper

Reply to
lilgrasshopper

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