Jeep Enthusiast Forums banner

Knocking or clicking noise

2K views 19 replies 9 participants last post by  wickedsprint 
#1 ·
I get this knocking or clicking noise when the car is idling and gets even loder when it is under a load in low rpm's. It is not the pinging noise that you get from detonation, but sounds like a loose bolt or nut rattling arround. I don't think it is a lookse bolt or a nut because I have looked everywhere and can't find it.
I get this knocking or clicking noise when the car is idling and gets even loder when it is under a load in low rpm's. It is not the pinging noise that you get from detonation, but sounds like a loose bolt or nut rattling arround. I don't think it is a lookse bolt or a nut because I have looked everywhere and can't find it.
:brickwall
I do have a hole in my exhaust near the cat, but the noise that I hear is coming from the negine bay or transmission area. Any ideas on where to go now?

Thanks,
AGT
 
#3 ·
Sounds like either a noisy lifter (most jeeps have them) or a leak in the exhaust manifold either at the head, in itself, or at the joint to the midpipe.
 
#4 ·
AustinGT said:
I get this knocking or clicking noise when the car is idling and gets even loder when it is under a load in low rpm's. It is not the pinging noise that you get from detonation, but sounds like a loose bolt or nut rattling arround. I don't think it is a lookse bolt or a nut because I have looked everywhere and can't find it.
I get this knocking or clicking noise when the car is idling and gets even loder when it is under a load in low rpm's. It is not the pinging noise that you get from detonation, but sounds like a loose bolt or nut rattling arround. I don't think it is a lookse bolt or a nut because I have looked everywhere and can't find it.
:brickwall
I do have a hole in my exhaust near the cat, but the noise that I hear is coming from the negine bay or transmission area. Any ideas on where to go now?

Thanks,
AGT
Is the noise consistant with one cylinder firing or all 6 ?
Is is a tick sound ... like the exhaust blowing from the manifold (at the head) or where the downpipe joins the maniifold ??
Exhaust blowing in the engine bay is fairly easy to suss out .. do it when it's cold and you'll feel it blowing (keep hands out of belts and fans tho).
If it isn't exhaust related then I would suspect big-end bearing (deeper knock) or lifter noise (lighter tick/knock). Check oil pressure .. a knocking bearing will show low pressure .. moreso when hot.
Also check the fan clutch (engine off) .. does it feel loose on the waterpump ??
 
#5 ·
I seriously doubt if it is themain bearing because my oil pressure is great. I took it to an exhaust place and the only leak that they found was from a hole right behind the cat. I can hear the noise better when it is under a load (in gear) at lower rpm's but when the RPMs get past 2500 or 3000 the noise goes away or I don't hear it as well. Is there any one local that wants to help me find the problem. Lunch and beer is on me. :D

BTW...this is a 2.5 L.

If it is a noisly lifter, how do I fix that? Replace it?

AGT
 
#6 ·
AustinGT said:
I seriously doubt if it is themain bearing because my oil pressure is great. I took it to an exhaust place and the only leak that they found was from a hole right behind the cat. I can hear the noise better when it is under a load (in gear) at lower rpm's but when the RPMs get past 2500 or 3000 the noise goes away or I don't hear it as well. Is there any one local that wants to help me find the problem. Lunch and beer is on me. :D

BTW...this is a 2.5 L.

If it is a noisly lifter, how do I fix that? Replace it?

AGT
main bearing don't knock .. they rumble.
Lifters will tick with/without load, small ends will tick/light tap off load .. piston slap has a sweet spot just off load .. big ends knock on load.

So .. try and work out what conditions make this sound worse (hot engine .. cold engine) .. does it do it stood still ??
I can help you (but I ain't local) .. just need some more details.
 
#8 ·
my guess is still on the lifters, try running some penzoil high mileage and some of the lucas semi synthetic oil addative. I swear by the lucas stuff...or atleast I will untill, my engine blows up. I had two cylinders with compression at 80 lbs. Now one of them is up to 140 and the other is up to like 100, and thats only after 2,000 miles. Althe other cylinders got healthier too. I'm gonna change my oil again real soon and put two quarts in this time instead of just one. So, unless it causes my engine to blow up I'd have to say its working pretty well. Oh, and by the way, since running the penzoil, my lifter tick went away.
 
#9 ·
AustinGT said:
It does it hot or cold. It does itlouder just after start-up when the RPM drop down to 700-800. Gets louder under load at lower rpms. When cruising it cannot be heard (or at least I can't her it).

Any other stuff that may help?
is it a tick or a knock .. does it sound mechanical ??
 
#12 ·
I had a noise that sounded like a loose bolt or something in the engine bay. I had everything apart trying to find out what it was. It was driving me nuts. It turned out to be the fan clutch. Try taking the fan off and running it for a few secs reving it up and stuff. If u dont hear it then, then that's probably it. Your description sounds just like what mine sounded like. Good Luck! :thumbsup:
 
#14 ·
88Jeepster said:
.. .. .. Also check the fan clutch (engine off) .. does it feel loose on the waterpump ??
isn't that what I said earlier ??

I actually have a noisy (read loose) fan clutch .. I should replace it. It sounds like a can of nuts being rattled about .. more so when the engine is cold. It doesn't sound like a tick .. it definately rattles .. sort of a deep tinny sound. Very easy to tell where it's coming from cos it's right at the front of the engine in the radiator (duh .. surprise surprise).
All modern engines have them .. unless you've converted to electric.
 
#18 ·
I had the same problom a few times. It was the slave cylinder bearing. there famous for going out. if it is, dont get the cheap $100. get the factory replacement. there closer to $300, but they last alot longer. and dont forget the pilot bearing.
 
#19 ·
Here's an update. I took off the fan, the waterpump pulley and the belt and started it up and the noise was still there. But it deffinately sounded like it was coming from teh timing chain cover or the block, I couldn't isolate the noise to one area. I am going to get some ATF to put in teh oil, but if it is the timing chain...how difficult is it to replace? When I had the fan and belt off it looked like the cover was pretty easy to get to. Am I right?

AGT
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top