Tap, Tap, Tap

[jay79cj7]

2000 4.0L- Tonight I was looking under the hood with the engine running and heard a tapping or ticking coming from the back of the engine. It varied with the speed of the engine as I moved the throttle. The engine was cold at the time. This made me pretty worried, and after driving 10 min down the road to get gas, it wasn't doing it. What is this tapping, is it normal or not, and do I need to take care of it right away?
Thanks guys.

 

[laneiac]

Good be a sticky lifter. Not really anything you can do about it other than maybe adding some oil treatment your next oil change, that seems to quite mine down for a while.

 

[jugghead23]

I have a similar tap tap tap but happens only at idle and sounds as if it is coming from the serpentine belt. Mine also comes and goes, could go 3-7 days without hearing it.

I thought mind was probably just the belt...perhaps I am wrong? Seems to be affected by temperature outside

 

[graewulf]

most likely a lifter... how's the mileage? they tend to wear as you get up there, could hve a clogged gallery causing the lifter not to pump up fast, which is why it taps till it fills up.

 

[jugghead23]

mine too you think Graewolf?
I've only got 48k miles

 

[graewulf]

if its a lifter - after a short warm up it will stop and not do ti till its cold again.. if it soulds like its coming from the serpentine belt, at 48k i would hope its not lifters.. they should be good for well over 100k (normally). try a stethoscope (or if you don't have one, a wood dowel, your thumb over the end, ear to the thumb... see if you can isolate it to a certain area of the engine.. might help narrow it down. Keep in mind, a quiet tap doesn't necessarily mean you need to run out and buy parts.. i've seen engines with valve knock, piston slap, and lifter knock go 100k without needing replacing.... if it goes away when it warms up, probably not much of a concern.... BTW: where in joisey, jugghead? down south here...

 

[Tug-n-pull]

Not that hard or costly to do a Valve Seal replacement with new pivots and lifters while you are in there. Can be done with out removing the head and this will make the top end sond as quite as can be and remove that start up puff of blue smoke as well. Was the next repair I had lined up on tugly prior to selling her. tug

 

[jeepin916]

it sounds like a sticking or cloged lifter..... i would run some of that engine cleaner stuff in it and change the oil arterwards and see if it cleans out the lifter. other than that theres really nothing you can do unless you want to change the lifters.....

 

[jugghead23]

my 'tap tap tap' usually only starts after the jeep has warmed up.
Graewulf, we've talked before...I was the guy who's also having a 'clunk clunk clunk' down in my driveshaft area LOL...you had told me last weekend you would look at it if I was in the area. Grew up in Toms River, live in Woodbridge area now.

I have 3 noises right now that make me concerned, the tapping at idle sounds like its coming from the belt area, the clunking under the tunnel forward of the shifter at low RPMs and over bumps in neutral (you suggested could be a driveshaft issue), and finally after putting my lift on, a very slight pop that sounds like its coming from the right rear suspension...took it all apart after the lift, all was tight, almost sounds as if the plastic bump stop spacer is loose.

None of the sounds worry me too much. The jeep starts/runs/drives great. By far the one that I'd like to solve first is the clunking...but since someone else brought up tapping, thought I'd jump on the bandwagon LOL..didn't mean to hijack the thread

 

[jay79cj7]

My tapping is definitely coming from the back of the engine, opposite end of the serpentine belt. It started when it was cold, and disappeared when it warmed up. The engine has 73k miles on it right now. I am hoping that it lasts much, much longer. I want to drive this for a LONG time.

 

[laneiac]

Its a lifter. It is not a crucial concern. Follow the mentioned methods and you should almost eliminate any problems.

 

[graewulf]

Jay79CJ7 - definitely sounds like a lifter.. if it goes away when warmed up i personally wouldnt worry about it...

jugghead - duh! i knew that,... offer still stands BTW... actually that goes for anyone who needs a hand.. if you're in south jersey i'd be glad to help.

 

[jay79cj7]

Thanks guys. I am glad its not a major concern, but I will definitely try an engine cleaner. I actually used the CD2 stuff an oil change ago. Any reccommended ones? I have seen some that you pour in and let run for 5 min then drain the oil... Any experience with those?

 

[JP]

Jay, does it change or go away when you depress the clutch? if so, it could be the throw-out bearing. Mine is doing it a little. with the clutch out, it makes a rythmic "tick"

 

[jay79cj7]

It's an auto, so no clutch. Thanks for the try though.

Anybody want to plug an engine cleaner? I have seen these ones that you dump in before a change, let 'er idle for 5 min, and then drain. It says make sure not to drive around with it in there, so I am a little nervous to put something in the engine that driving on it would mess it up. What do you think?

 

[laneiac]

I was wondering the same thing Jay...

 

[doglegdr]

Related question, have a 4 liter with dud lifter on #4 exhaust. Can this be changed with-out pulling off the head? Left arm is only working 50% due to injury and I don't want to start anything I can't finish.

 

[Snitty]

could be a dead lifter, or a shot lobe on the cam... you'll likely have to go in through the block

 

[nkdskls1978]

Could be an EXHAUST LEAK .. my jeep sounds like a lifter is tapping till it warms up ... somehow the last bolt on the manifold got broken off by the previous owner and the manifold is now loose ... Do you have any power loss if you drive before it warms up ? Take it to a jeep dealer b/c i heard the warranty still covers the manifold up to 82K ... got my jeep at 82k so no hope for me

Use Berriman's engine cleaner ... just put it in before you change the oil and let it run ... it comes in a white can w/ blue and red writing ... it is also a gas treatment ... autozone/walmart $3....get some RESTORE too