tranny buzz

[rdwoodwright]

Bought a 04 GC Loredo in Jan. and just noticed a small buzzing noise coming from the tranny when engaging gears from park. not sure if it's normal or are we in for a repair 3 days after the warrantee is over. the best description is it's not loud and sounds like a small motor is doing something for about a second when shifting. it happens when engaging any gear from park. could be it's been doing it all along and I just noticed it because I had the windows open at the coffee drive thru. I'm a little paranoid because we just had to have a head and rod replaced due to carbon build up and am hoping we'aren't stuck with a lemon.Any insight is greatly appreciated!

[Bob D.]

It makes a small buzzing noise for one second? Consider yourself lucky - Jeep transmissions can be a little noisy.
I seriously doubt there is a problem.

A head and rod replaced due to carbon build up?

How many miles and what motor does that '04 have? I've seen them go over 200k mi without any carbon related problems.

[rdwoodwright]

50k miles 4.7 v8

[rdwoodwright]

dealer took 3 times to diagnosea misfire on #5. 1st was a plug change. 2nd was what they called a "carbon soak".Which they claim should be performed every 30k on all models....go figure?doesn't say that in the manual. After 2 weeks the light was back on so back to the stealership she went. 3rd attempt they opened it up and found a bent rod and mushroomed head. They claim as a result of the carbon the head wasn't rotating which caused it to overheat and caused the rod to bend and head to mushroom...not sure I'm buying that? They think the vehicle must have been driven only in the city and never was blown out on the highway...go figure. Did I mention I'm no longer trusting them and I'm hoping we're not the ones who actually get "soaked"!
As for the tranny noise ,we bought the vehicle because we needed a tow vehicle for our camper and we've had such good luck w/ our 96 cherokee we had faith in a GC. So a week after her maiden tow voyage I hear the tranny noise and as a result of the other fiasco I got nervous! Hope your right about nothing to worry about! Any further input on either is still greatly appreciated!

[Bob D.]

Of course their are exceptions, but 50k mi is nothing for the motor, and the transmission should also be solid at that mileage.
If you're new to Jeeps, you should be aware that correct fluids are very important.
Just make sure you have a honest and competent mechanic.

[Bob D.]

Originally Posted by rdwoodwright

dealer took 3 times to diagnosea misfire on #5. 1st was a plug change. 2nd was what they called a "carbon soak".Which they claim should be performed every 30k on all models....go figure?doesn't say that in the manual. After 2 weeks the light was back on so back to the stealership she went. 3rd attempt they opened it up and found a bent rod and mushroomed head. They claim as a result of the carbon the head wasn't rotating which caused it to overheat and caused the rod to bend and head to mushroom...not sure I'm buying that? They think the vehicle must have been driven only in the city and never was blown out on the highway...go figure. Did I mention I'm no longer trusting them and I'm hoping we're not the ones who actually get "soaked"!

Somehow I missed the above post...

Anyway, the first lesson learned is - STAY AWAY FROM DEALERSHIPS!
Sorry, but the incompetent and disreputable way they operate really steams my clam.

No way it should take three tries to diagnose a misfire.

1. Carbon soak.
First off, I've never heard that terminology before but...they have no way of determining the amount of carbon build up INSIDE the motor, or even suspect it at 50k.

2. The "A Carbon soak should be performed every 30k on all models" statement is pure BS. Some people choose to do it on high mileage engines, sometimes the valves may get too carboned up to rotate, but not often.
There is no routine maintenance that calls for decarbonization at ANY mileage, much less 50k.
There are decarbonizers that can be added to the fuel tank -- every 5 or 10k miles--as a preventive.

3. Quote: "They claim as a result of the carbon the head wasn't rotating which caused it to overheat and caused the rod to bend and head to mushroom..."

That's nonsensical, heads don't rotate. Maybe the reference was to the valves not rotating, but that's a performance problem, not a destructive one.

4. Some decarbonizing methods call for the product to be introduced into the motor via the manifold or throttle body. This essentially floods the motor and causes it to stop or at least stutter. The decarbonizing product is a liquid and not compressible, so if it was done improperly it could have caused a hydrostatic lock, and the result is just as you described - a bent rod. The "mushroomed head" is a new one for me, they probably meant a warped head...if it even happened.
It could have had a warped head to begin with.

There are a number of possible scenarios that could have caused the motor problems you had, but I would just chalk it up to experience for now.

My advise is to stay as far away from the dealership as possible, and find a reputable independent mechanic - now before you need one.

[hulkmn069]

wow this site never ceases to amaze me with some of the crap that the stealerships try to feed folks

[wafrederick]

The 4.7 must be junk,I put in 2 of them in a row due to an overdue oil in one that resulted in heavy sludge build up and the cam broke in the othe other.It probally has that new style transmission,a Dodge Caravan transmission converted to Rear wheel drive