couple weeks in ..

ando · **Posted:** Sat Apr 28, 2012 6:41 am

Hi Guys

Couple weeks into my KJ ownership, and slowly ticking off the list of things I want to do to it, usual stuff, changed oil/filter's etc, had the leaky rear pinion seal replaced yesterday, and its booked in for a cam belt next week.

One thing is concerning/puzzling me though

... from cold, on start up the motor sounds about as good as a cold diesel can

, but after a short trip (few miles), it sounds completely differant .. like "tappy" .. like an old london taxi cab

(UK members will prob understand that :lol:

) ... could it be the timing is out do you think ? .. it dosent smoke, or use oil, and as I said, the cam belt is being replaced next Thursday so I guess that will eliminate timing right ?

Andy.

msilbernagel · **Posted:** Sat Apr 28, 2012 5:27 pm

ando, how many miles on the rig?

I suppose it could be lifters (regular oil changes with recommended oil?)

But, other things could be making the noise..

Pop the hood and watch the accessory/serpentine belt near the alternator... any jumping? The decoupler (in the alternator pulley/hub) can go out and cause the belt to become jerky, taking out idler pulleys, etc.

Also, you can use a log steel tool (big long screwdriver), touch one end to whatever you want to listen to (careful!) and the other end to your ear; sometimes you can figure out which item is making noise. Could be a bearing going out in the alternator (top, driver's side), A/C compressor, viscous heater (passenger side, top). If you look down at the passenger-side lower engine you may be able to see the accessory tensioner - if it's dancing/vibrating, that's another hint that the decoupler on the alternator is going.

See if you can identify the source of the noise.. and/or observe anything unusual while it's running, especially warmed up.

Mark

laplaya · **Posted:** Sun Apr 29, 2012 12:04 am

Is the noise while traveling or while stopped or?? When warm is the idle smooth? Any surging at idle according to your tach? Have you pulled the plastic engine cover and listened to it then?
Have you cleaned your map sensor yet? I am sure with time and patience you will sort it out.
Good luck
Al

ando · **Posted:** Sun Apr 29, 2012 6:55 am

Thanks for the replies fella's :wink:

Mark - its done 83k miles, and though I think it hasnt been particularly "loved" by previous owners .. just used

, I'm sure the motor is basically sound. "If" it stops raining here today I'll see if I can checkout a few of the things mentioned above :wink:

Al - I'm no expert, but it does sound "cammy" to me, it's only when warm, gets quicker with the revs, and can be heard both on idle and whilst driving. Idle is pretty stable, and there isnt any hunting on idle ... just "tap tap tap tap"

Andy.

ando · **Posted:** Mon Apr 30, 2012 2:14 pm

Ok, got a little time to myself at work today, so I popped the MAP sensor out ... :shock:

(I wont post another pic of a lump of sooty black horrible stuff, you've all seen it before :wink:

).

Went for a quick drive to warm the motor up, and left it running when I got back without the engine cover on, and the "tappy" noise dosent actually sound like its coming from the engine bay at all !!! .... but as you move around to the side of the truck, you hear it a lot ????

, looked underneath and the things that are visable in that area are obviously the gearbox, tranny case, and cat/exhaust centre section ???

I was wondering if the cat was breaking up inside, but that wouldnt really rise and fall with the revs would it ??

Any idea's guys, now at the rear of the motor ?

papaindigo · **Posted:** Mon Apr 30, 2012 2:46 pm

Loose heat shields, loose bolts on cross members, and bad engine mounts can make strange sounds that appear to come from odd locations.

ChesterCRD · **Posted:** Mon Apr 30, 2012 3:37 pm

Sounds a lot like mounts. Does it change under load? Usually mine will quiet down when the engine is under load. (they are just starting to go again)

ando · **Posted:** Mon Apr 30, 2012 4:02 pm

Not under load, stays the same ... tho it seems to quiet down when holding a cruising speed (ie: not accelerating) ?

Are CRD's known for the mounts going then ?

ando · **Posted:** Thu May 03, 2012 3:51 pm

Update: appreciate the replies, so thought I'd just say .. got the KJ back from the garage today after having the cam belt done, and I asked them have a good look to see if they could locate the source of the tapping noise I mentioned above ..... and basically, they found nothing !!

... they confirmed it wasnt a sticky follower in their oppinion (which is what it sounds like to me, but at the back of the motor), but nothing actually "jumped out" at them when it was up on the ramps

so I'm no better off really ... I think I'll see if I can find anything when the weather picks up, and failing that, I might have a day out in the nearest city that has a Jeep dealer and ask them to take a look !!!

If I ever find out the culprit, I'll post back incase it helps someone else in the future :wink:

papaindigo · **Posted:** Thu May 03, 2012 4:52 pm

Back of motor as in toward the tranny. Makes me wonder about a loose torque converter bolt which has been known to happen and make noise as there is not much clearance in there. I cannot speak from experience (I had SunCoast do my torque convertor install simply because I did not want to mess with the job) but I understand there is a hole with a rubber plug in it that you can use to check those bolts. I'm sure others can provide guidance.

I hope that's not it but if you find this is the problem the fix is to drop the tranny and tighten things up with loctite on the bolts. If you have to do that I'd strongly recommend you consider adding the extra bucks to put in a beefed up torque convertor since you or the shop will already be there. The Euro is a good option, the SunCoast is the best but not cheap, and there has been some recent chat about a west coast company on the forum.

EDIT - Ok I get it, manual tranny so never mind

ando · **Posted:** Thu May 03, 2012 5:07 pm

Cheer's bud, but being a noob to the KJ, what is a torque converter exactly, I seem to see that pop up quite often on here ?

Joe Romas · **Posted:** Thu May 03, 2012 7:08 pm

ando wrote:

Cheer's bud, but being a noob to the KJ, what is a torque converter exactly, I seem to see that pop up quite often on here ?

Papa didn't read the fine print :mrgreen:

Since yours is a 6 speed manual transmission you don't have a Torque converter :juggle:

GreenDieselEngineering · **Joined:** Sun Jun 07, 2009 5:10 pm **Posts:** 1111

Does the noise change based on clutch pedal position? Just want to try ruling out the clutch. How about putting it in neutral while cruising, does the noise change?

joelukex4 · **Joined:** Thu Sep 29, 2011 4:54 pm **Posts:** 386

Push the clutch pedal in and tell me if the noise goes away, then let the clutch out and see if it returns. If it does it is the throw out bearing. If the noise is the same or worse the clutch disc springs may be loose.

ando · **Posted:** Fri May 04, 2012 4:25 am

Cheers fella's ... but none of the above

Once warmed up, the tapping only ever changes with revs ... clutch, in gear, outa gear, none of these seem to change the sound in any way, thats why it does sound like a follower, but isnt !!??

ando · **Posted:** Fri May 04, 2012 4:49 am

Joe Romas wrote:

ando wrote:

Cheer's bud, but being a noob to the KJ, what is a torque converter exactly, I seem to see that pop up quite often on here ?

Papa didn't read the fine print :mrgreen:

Since yours is a 6 speed manual transmission you don't have a Torque converter :juggle:

I kinda thought that in the back of my mind but wasnt sure :oops:

, sayin that, it is in the general area of the tranny etc !???

In an effort to narrow down the options, I suppose I could drop the oil out of the T/case, put new in, and see if the noise gets quieter ? then do the same with the gearbox ? (was gonna change them when I 2mins to myself anyhow :wink:

)

Pippobug · **Posted:** Fri May 04, 2012 5:46 am

Andy

The torque convertor is in the gearbox in in Automatic KJ. Having said that changing the oil in the Transfer box & greabox is still a good and useful thing to do, as probably it never has been changed to date since new.

I take it you tapping noise is still there and hasn't quiettend down, have you check there isn't anything loose in the engine bay? there are a lot of parts hidden away under all that Plastic covering....

Fil.

ando · **Posted:** Fri May 04, 2012 5:34 pm

Waitin for a break in all this rain Fil so I can get underneath with a torch for a good poke around :wink:

ando · **Posted:** Tue May 08, 2012 10:46 am

Ok, I feel like I'm gettin closer since the sun's been shining, and I've been under the Jeep with a torch

I deduced that it cant be transmission related since clutch/gear operation makes absolutely no differance to the sound, so that take's me back to the engine, and more specifically, the rear r/h side of the engine .... so, I get under there with said torch and look up !!! what do I see ? .. the underneath of the turbo, part of which is covered in black oily gunge, also a solid pipe that runs from the bottom of the turbo into the crankcase also covered in wet gunge!!

Now, whatever is leaking on or around the turbo in that area, would explain a number of symptoms - increased engine noise (eg. "tapping"), a "wush" sound like a dump valve upon each gear change (manual remember), and what I have always thought of as pretty bad turbo lag at low revs!!

What do you guy's think ? could a leak on or around the turbo cause these things, and if so, presumably if the turbo is ok in itself, a relatively cheap fix if its just a seal issue ?

Andy.

papaindigo · **Posted:** Tue May 08, 2012 11:11 am

I don't know how the turbo sounds or feels on a manual transmission but.
1. on the stock vacuum activated turbo there is noticable turbo lag at low rpms but it shouldn't be more than a fraction of a second to a second. Just enough to feel but not a lot.
2. that pipe you see is the turbo oil drain back to the block. At the turbo end it's secured with 2 small bolts and has a gasket while at the other end it's simply pressed into the block with a rubber seal. This line is not under pressure but it can leak a bit usually at the block seal end although it's possible that the turbo end is a bit loose and/or the gasket is gone. You may be able to, with some extensions, get to those bottom bolts to check. I know when we installed my GDE Stage II turbo you could be then we had dropped the exhaust pipe which might be in the way. If so the exhaust pipe is connected to the stock turbo with a simple marmon clamp that's easy to loosen.
3. however lots of oil in that area makes me suspect that your airbox to turbo hose has torn on the bottom side just in front of the turbo and immediately below where the CCV dumps oil into that hose. This could produce some extra turbo noise and of course is not good for turbo or engine life as it's letting unfiltered air directly into the engine. A replacement hose is a dealer only item that in the US costs about $60. If that's the problem be sure to pull/push the upper end of the hose onto the airbox outlet all the way upto the MAF sensor base before tightening the clamp lest you crush the airbox outlet (I know).

While you are in there check the turbo shaft for play. May have a tiny bit in/out should have none side to side. FYI when turbos fail they do so fairly loadly and quickly so I think your turbo is probably ok.

On that lag is could be your turbo vanes are a bit sticky. Per GDE you can check the vane functionality at idle in park. Underneath the vacuum actuator on the turbo is rod extending downward connected to the vane mechanism. If you pull off the vacuum line at the turbo, the arm should drop about 1/2 inch and then raise back up after reconnecting the vacuum line. It is a bit difficult to see the rod, but this is the easiest method to check for proper VGT vane moevment. If they are sticky an Italian tuneup, several full throttle runs thru the gears, usually takes care of the problem

couple weeks in ..

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