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View Full Version : JK CRD Auto Rattles/Vibrations



Paul-JK
02-11-13, 08:26 AM
Yeh, yeh, I know it's a JK & a CRD so what do I expect. Surprised it hasn't rattled itself apart by now. :smile-new:

I have recently noticed 2 more specific rattles though which I'd like to try to diagnose before something falls off or stops working.

Noise #1
This seemed to be transmission related. I have noticed a small vibration/rattle lately when stopped in D, R, 1 or 2. It is still there in N but much less so. It seems to start a second or so after I stop, as if it's related to the transmission in some way and only rattles when the load is taken off. It doesn't happen as much when in N when presumably the transmission is essentially not connected (my mechanically inept brain's reasoning). It also seems worse when the JK warms up.

It's difficult to pin point where it's coming from as the noise is easier to hear from inside the cab. Once I get out and under the JK there are so many other noises from the CRD that it's harder to hear the specific rattle I'm chasing. It seems to be coming from the front of the JK though, which isn't a great surprise as that's where all the noisy bits are!

It's has also since been masked by another rattle that's developed more recently.

Noise #2
This is a far louder rattle coming from the front of the JK that again only seems to happen when stopped, as if whatever system it's part of is having the load released when I stop allowing it to rattle. It's is much much worse when I use the air con (as opposed to just having the fan running), but even when using the air con, it still seems to go once I pull away.

I had the JK serviced last week (not a Jeep dealer/specialist but a good mechanic) and he thought it was the air con clutch. Would that make sense? He also said that with it doing just over 90000km now that I might as well get a new belt/pulley tensioner etc as well as replace them all at the same time while it's getting done.

Being mechanically inept I have no real idea what these parts are, what they do, or where they are really. I'd be great if I could get some advice as to whether this makes sense and what parts would I need/be advised to change while I'm in there.


I think these are 2 different issues as they sound very different. #1 is gentler rattle that seems to be coming from lower down in the JK whereas #2 is much harsher and seems to come from the front of the JK.

Can anyone suggest who might be good to use to look at these and potentially do any work needed? Preferably northern Sydney. The mechanic I use for servicing is a good mechanic and is more than capable of doing the standard servicing but they won't have done any detailed work on the JK CRD motor before so once it starts getting a little more technical (which this feels like it is), I'd rather speak to someone who knows the JK's quirks. I could take it to a dealer but that sounds like an expensive (now out of warranty) and probably ultimately futile thing to do.

I'd appreciate any advice people might have. It's an MY10 JK CRD Auto if that helps.

Cheers,

Paul

jbrad
04-11-13, 09:36 PM
Hey Paul.
Sounds very much to me like the belt tensioner. I had a similar noise issue and changed all belt pullys (about $60), then my serpentine belt started to peel apart (so replaced that- I think another $65), finally I ordered the belt tensioner through Jeep. By the way they ordered me the wrong one initially - was for a Cherokee prior to getting the right part. The correct part No was CH-68027611AB, Description Tensioner Belt, Cost $523.00 From Parramatta Auto Group (Jeep dept) on 06 Nov last year (2012). I pulled the receipt out to check all of this info – no my memory is not that good! When I pulled the old tensioner out it was really obvious that it was shot it was pulling to one side (which was the cause of the Serp belt being damaged and subsequently was also causing the pully to touch the side of the block. After knowing what the good one feels like and how it is sprung, it would have been fairly easy to diagnose on another damaged one. At the time though, when I pulled mine off, it was a good thing that I had the new one to replace it immediately, because the old one pretty much fell apart in my hand once removed and was never going to go back on.

Jas

Paul-JK
05-11-13, 06:47 AM
Hey Jas,

Thanks for that. I think I'll start with replacing the pulley tensioner/pulleys/belt and then see if that sorts it, then look at other things like the air con clutch if the rattle is still there.

Next ....... how easy is this to do, for someone who knows very little, working with basic hand tools in a garage by himself? Or is it better to pay someone to do it so that I don't screw it up?

Cheers,

Paul

glend
05-11-13, 08:14 AM
How old is it? Motor mounts have been known to produce rattles that have no aparent engine source. If it changes or disappears when in D or R, it could be mount related.

Paul-JK
05-11-13, 08:24 AM
It's an MY10. I got it Dec '09, so nearly 4 years.

What is it about the mounts that produces rattles? Is it a failure (so I'd be looking for cracks) or is it less obvious that that?

glend
05-11-13, 11:54 AM
If they are the donut shaped ones they are filled with a fluid that dries out and turns into little rocks that rattle. I know they were used on the KJ CRDs of the same year.

Paul-JK
05-11-13, 12:24 PM
That sounds like a typically Chrysler thing to do......like the self destructing ball joints!

Next barrage of questions:
- How long does it take for them to dry out, give or take? Would you expect it at 4 years old?
- How would I know if that is the case? Is there any easy way of testing?
- How easy are they are to change? Is it something that can be done in your garage with basic hand tools or is it job for a workshop with a hoist?
- Are the replacements readily available (presumably aftermarket) and are there any better options that wouldn't dry out?

Appreciate the help.

glend
05-11-13, 06:16 PM
The turbo side usually goes first due to the heat soak. You need to check the parts fiche to get the part number and to know for sure if you have that particular one. Not saying its the problm, just one possibility.
Try asking on AJOR you should get quick info there.

redrubi
05-11-13, 07:02 PM
Have you checked the ashtray for earrings???? LOL:highly_amused:

Nekked
06-11-13, 08:53 AM
Have you checked the ashtray for earrings???? LOL:highly_amused:


Quote of the year...!

if all else fails and you need some professional help, try ATV automotive five dock, they are very knowledgeable and do top quality work.

Nekked
06-11-13, 09:00 AM
Have you checked the ashtray for earrings???? LOL:highly_amused:


Quote of the year...!

if all else fails and you need some professional help, try ATV automotive five dock, they are very knowledgeable and do top quality work.

i have a jku crd auto 07. I have not had the same issue with mine, however I did notice at 100k that the belt was squeaking a lot, and after further investigation it had totally fallen off, oops. Belt and pulleys were replaced and she hasn't missed a best since.

good luck.

Paul-JK
21-12-13, 07:45 AM
Finally got this sorted.

Took it up to Shents up in Wyong. They had a look and said the fan belt tensioner was definitely shot. So had them replace the belt, tensioner and pulleys, and had them do the timing belt kit while they were at it as it's due at the next service. It's now as quiet as a mouse......for a diesel. The timing belt was also starting to deteriorate when they got a look at it so that might have been contributing to the noise as well.

It's so nice to be able to use the aircon again without worrying that something was going to fall off (using the air con before created some very nasty rattles). It's especially nice while driving around Sydney yesterday in 40˚C+ temps.

It's amazing how noises transpose themselves into other things. I was seemingly getting rattles and noises from all over the place. The alternator was rattling like hell (using a screwdriver as a stethoscope to diagnose), then there was the air con rattling and I also had a noise/rattle that seemed to be coming from the transmission. All have gone once the dodgy fan belt tensioner was fixed.

Next job is to get rid of the slight steering shimmy......there's always a next job!