The source of my ticking...

For about the last month or so, occasionally on startup - appx 1/3 of the time - my engine will have a knock that corresponds with the revs. It is pretty audible, and people I pass in my neighborhood will look at me because they hear it too. Sometimes it'll go away after 3 seconds, sometimes 30, sometimes 3 minutes, and a few times, it has continued for 13+ miles. I have 137k on it (2000 XJ), my oil levels are good and fresh.

It may only be a coincidence, but if it goes on for more than a minute, if I pullover and shut it off, and re-start it, it seems to disappear quickly after re-startup.

It certainly sounds like it is coming from the top-end, perhaps the valves or a valve or a broken tappet spring or something.

I added Lucas oil conditioner to it to try and thicken it up, and that seemed to help slightly. Recently I noticed it was low on coolant, so I topped off on that, and I swear that helped to.

Again, these minor "helps" could only be in my head.

Any solid thoughts anyone?

A broken anything (valve spring, tappet, whatever) is not going to go away. Neither will a rod knock or piston slap. Sometimes both of those moderate as the engine warms up but they never vanish. The Lucas and coolant won't change this. Maybe a gallon of STP would but not a can of Lucas.

I'm betting you have loose torque converter bolts.

Take a length of heater hose and hold to your ear then probe the other end around the engine bay with it running. You will home in on the ticking sound really fast.

I had 1 fan clutch nut loosen up and caused a ticking one time. 2 seconds with the heater hose I found it.

Be careful of any moving parts of course, don't loose any fingers ; p .

ditto

zero the sound first

Next time it happens, run the RPM up to 3700 rpm in idle, and hold it for about 30 seconds. That should get any stuck lifters rotating again, frees them up somehow. It is the only thing I ever found that works well, and long term (over time the noise is less laud and less often at start up) if you do it every time.

The internals of a lifter become stuck as a result of dirt or varnish, not the lifter body which rotates. A lifter that has stopped rotating = dead lifter and cam.

Talyn said:

The internals of a lifter become stuck as a result of dirt or varnish, not the lifter body which rotates. A lifter that has stopped rotating = dead lifter and cam.

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Several of us have proof that it works, so don't knock it (LOL):laugh3: until you have tried it. I find it works on my 87 and 89 renix, and the 87 has 280,000 miles on it now. Mine got stuck due to years of low RPM operation due to a bad TPS that never let the engine get over about 1200 rpm, and it peaked at 2000 rpm at high speeds, so it never got up to the 3700 rpm range.

Forcing it up to about 3700 rpm periodically unsticks them. Everyone that has tried this with sticking lifters, that ticked loadly on cold start up, have reported that it works, works well, after all other efforts (short of replacement) like different oils and additives failed to do much to reduce the noise or free up the sticking parts lifter parts.

Mine ticked like it was about to throw rods for 35,000 miles, and THE FIRST 3-4 years I owned it. It has stopped ticking for about 15,000 miles (now at 280,000) AND RUNS JUST FINE.

I got the idea from 5-90 about 2 years ago in a discussion about valves, rockers, rods, lifters....but he has since forgotten the details. All I know for sure is that it works beautifully on old sticking, knocking, ticking, Jeep 4.0s!!!

I trust empirical evidence. Cruise54 recently tried it and was shocked that it worked, as have others.

The lifter body is not what is sticking and/or not spinning when you you hear the ticking. If that were true you would have bigger problems. Its the internals that are sticking, preventing the lifter from taking up lash. When there is lash you hear the ticking. Where did I say that the rev and hold trick doesn't work? Its your explanation of the problem that was at fault.

Talyn said:

The lifter body is not what is sticking and/or not spinning when you you hear the ticking. If that were true you would have bigger problems. Its the internals that are sticking, preventing the lifter from taking up lash. When there is lash you hear the ticking. Where did I say that the rev and hold trick doesn't work? Its your explanation of the problem that was at fault.

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You first reply was not clear then. Fair enough.

The theory behind why it works was, is not mine. It was 5-90's, but he has since forgotten the discussion, and partly retracted the "why it works" theory (as I recall it) the last time we discussed it. I am not a lifter expert, nor am I a mechanical engineer, so I will not try to defend the theory. All I know is it worked, and works, and the non rotating, sticking and ticking, and thus not rotating lifter, was the reason I was told it worked when I was told to try it.

That said, the sticking lifter condition was and has been for most of us, an only on cold start ups, first start after a long period of non use, and goes away once the engine warmed up issue (usually, 2-5, maybe 10 minutes at most), so it never was a permanent stuck (non rotating, sticking, or what ever you want to call it) lifter, just ones that were late to the party.

How do you know that lifter rotation, is not temporarily part of the issue? As I recall I was told that lifters can stop rotating if the engine rpm is too low for too long, and that they start to stick (meaning not rotate) at cold start up due to history of the low rpm (and carbon fouling) operation , and I guess that causes, or adds to the internal cleanliness issues you are talking about inside the lifters.

Isn't the internal operation of lifter tied to the rotation in some way?

A lifter that stopped rotating wouldn't make a ticking noise until it is to late when the cam and/or lifter face has been damaged enough to permit lash. As far as RPMs being to low they would have to be very low, well under the idle RPM of a 4.0L. Lifters don't get carbon fouled either. That takes place in the combustion chamber. What happens is that they either get a piece of dirt logged in them or build up varnish from oil and dirt in the oil. The internal operation of a lifter is not tied to lifter rotation. Internal operation is tied to oil flow and oil pressure. A lifter that has stopped rotating will not limit oil flow to the lifter internals either as there is an oil band 360* around the lifter.

Now, the ticking after a period of long sitting for about a minute at cold start isn't necessarily a stuck lifter. It may just be a lifter that has bled down under open spring pressure and isn't any thing to worry about. If it happens for longer than it may be stuck.

Why the sustained RPM works happens for a number of reasons. 1) Hot oil flowing through the lifter, 2) sustained higher pressure oil flowing through he lifter, 3) higher RPM will move the lifter internals more, and 4) just the hammering of the push rod against a stuck lifter all contribute to freeing a lifter by removing dirt/varnish/whatever.

XJpax said:

For about the last month or so, occasionally on startup - appx 1/3 of the time - my engine will have a knock that corresponds with the revs. It is pretty audible, and people I pass in my neighborhood will look at me because they hear it too. Sometimes it'll go away after 3 seconds, sometimes 30, sometimes 3 minutes, and a few times, it has continued for 13+ miles. I have 137k on it (2000 XJ), my oil levels are good and fresh.

It may only be a coincidence, but if it goes on for more than a minute, if I pullover and shut it off, and re-start it, it seems to disappear quickly after re-startup.

It certainly sounds like it is coming from the top-end, perhaps the valves or a valve or a broken tappet spring or something.

I added Lucas oil conditioner to it to try and thicken it up, and that seemed to help slightly. Recently I noticed it was low on coolant, so I topped off on that, and I swear that helped to.

Again, these minor "helps" could only be in my head.

Any solid thoughts anyone?

Click to expand...

Since you were low on coolant, make sure you don't have a cracked head and the coolant mixing with the oil isn't slowly eating your bearings, causing a bit of a knock. The only reason I say this is I have a 2000 that had a cracked head when i bought it so I didn't know how long it was driven like that. I replaced the head and although my oil pressure is not spectacular, it's ok from everything I have read. When hot it's at 12 and at 1500 RPMs its 25-27.

The reason I bring this up is I have the knock you describe at cold startup. Sometimes it sounds like it sounds like it's coming from the top end, sometimes it sounds like it's coming from the oil pan. I guess sounds really bounce around under the hood as everything is connected in some way or another. As others have said, pinpoint the source to be sure and keep an eye on that coolant.