My Jeep is ticking under the hood. We originally thought it was a lifter but after a mechanic replaced the lifters, the injector o-rings, the gaskets and the plugs....the tick is still there. It is a shallow tick that isn't there when idling but when the gas is pressed. It is quite loud when it does tick. The first time I went through this, the ticking was consistently occurring when I was accelerating then a second tick kicked in which was much louder and was ticking all of the time. Now, after replacing the parts noted above I am back to the original tick. Please help me. I waited 4 months to have enough money to pay a mechanic and now the problem is still there but I'm broke.
:frown:

McGyver, welcome to AF.

What engine do you have, and how many miles?

And if your mechanic charged you an arm and a leg, replaced your injectors to remove a tick, you should probably get a new mechanic.

An exhaust manifold leak (on one cylinder only) are notorious for sounding more like a mechanical 'tick' than anything else.

1988 Jeep Cherokee 4.0 straight six. I thought of the exhaust manifold leak but checked the compression and is fine. Also, the tick is very shallow almost like something is hitting the valve cover but we know it isn't because we've had it off while the vehicle was running and saw nothing that would indicate that.

McGyver, welcome to AF.

What engine do you have, and how many miles?

And if your mechanic charged you an arm and a leg, replaced your injectors to remove a tick, you should probably get a new mechanic.

4.0 straight six with about 148,000 miles on it. The mechanic replaced the lifters and told me that my injectors were leaking so he replaced the o-rings on the bottom only. We replaced the top rings last night after he told me that my injectors were bad. Now, only one is leaking and think it might be the internal ring that comes in the kit.

OK I can see that the lifters needed some maintenance, but they're not causing the tick.

MagicRat's right, the exhaust leak would cause a tick....AND....an exhaust leak would not affect the compression.

Trying to locate the noise more specifically will help a lot;, as will describing it more exactly. Is it a quiet tic-tic-tic? Or a longer sound with some grinding to it? Does it get louder with engine speed?

For the exhaust, you can hold your hand near the exhaust manifold (with the usual warning that it may be uncomfortably warm :) ) to try to feel any escaping exhaust. Some I know use a piece of paper, but that might not fit where you need it to.

Sometimes the 4.0 does make a little tick, called piston slap, and that doesn't hurt anything (you can do a search for piston slap, there are numerous posts on it)

Hopefully that all helps, sorry if it doesn't but diagnosing a noise via the internet isn't the easiest! In any case, try to locate the noise more closely.

OK I can see that the lifters needed some maintenance, but they're not causing the tick.

MagicRat's right, the exhaust leak would cause a tick....AND....an exhaust leak would not affect the compression.

Trying to locate the noise more specifically will help a lot;, as will describing it more exactly. Is it a quiet tic-tic-tic? Or a longer sound with some grinding to it? Does it get louder with engine speed?

For the exhaust, you can hold your hand near the exhaust manifold (with the usual warning that it may be uncomfortably warm :) ) to try to feel any escaping exhaust. Some I know use a piece of paper, but that might not fit where you need it to.

Sometimes the 4.0 does make a little tick, called piston slap, and that doesn't hurt anything (you can do a search for piston slap, there are numerous posts on it)

Hopefully that all helps, sorry if it doesn't but diagnosing a noise via the internet isn't the easiest! In any case, try to locate the noise more closely.

The location of the noise was primarily in the front/middle of the valve cover. It isn't a tick like you would expect to hear from an engine running seriously low on oil. It is more like someone knocking on the inside of the valve cover trying to get out. Once the engine is warmed up, It isn't occurring during idle only with acceleration. Wouldn't the mechanic have fixed and exhaust leak after tearing everything down and replacing the gaskets? I saw the head and it looked good. I didn't take a straight edge to it but there was no indication of oil in the water or water in the oil before or after.

Since it sounds like something hitting the inside of the valve cover, I'd consider taking off the valve cover and having a look at the underside...there should be a scratch or bright spot where/if something is hitting it.

Also, since the mechanic replaced the lifters according to your earlier post, check them to make sure they're all the same type and size.

I've known good mechanics that fixed exhaust leaks while putting things back together, and others that didn't care and only did what was required. I guess I'm saying don't simply assume that any exhaust leak has been repaired.

Since it sounds like something hitting the inside of the valve cover, I'd consider taking off the valve cover and having a look at the underside...there should be a scratch or bright spot where/if something is hitting it.

Also, since the mechanic replaced the lifters according to your earlier post, check them to make sure they're all the same type and size.

I've known good mechanics that fixed exhaust leaks while putting things back together, and others that didn't care and only did what was required. I guess I'm saying don't simply assume that any exhaust leak has been repaired.

Good point. I shouldn't assume that he did a good job just because I would have. I will check the inside of the valve cover. I bought all the parts for the job and checked the lifters myself. They are the right type and size (compared against old ones and book specs). I did notice, however, that I bought a full engine gasket set and he used less than 1/3 of the gaskets in the kit. Normally, I could understand not using all of them based on how far the engine was torn down but less than 1/3? I was wondering about that. Normally, I would do the work myself but I've had shoulder surgery and my hands just don't have the strength to get down and dirty with an engine anymore.

In my experience, the more gaskets in a kit, the more are left over. :D Some are duplicates, as the kits are usually for several years, and slightly different shapes/parts were used.

I, too, hate relying on a shop to do my work, but sometimes you just gotta do it.

Yesterday, I pulled the oil pan to see what was up. Everything looked as it should. I popped the valve covers and there wasn't any indications that lifter was in wrong or not replaced. The ticking that started all of this was shallow and towards the firewall under the valve cover indicating bad lifter. The noise that remains is exactly the same in exactly the same location. Is it possible that there could be one lifter that isn't getting oil to it?
:confused:

Possible I guess. When you had the oil pan back on and before the valve cover was back on, did you run the engine?

Possible I guess. When you had the oil pan back on and before the valve cover was back on, did you run the engine?

No. It wasn't cranked up until after it was back together.

It sounds like your describing either "piston slap" or a collapsed lifter. Usually a collapsed lifter will leave the push rod loose, causing your noise. When the push rods were out, did he make sure that the oil passage threw the rod was clear? I would remove the valve cover and cylinder#4,5,&6 valve rockers. Remove and inspect each push rod, making sure the passage is clear. If so and there is evidence of oil on both ends, you should be fine. Does the noise lessen after its really warmed up. Mine has the Piston slap, and once warmed up is barely noticed.