In reading about various 2000+'* with a ticking noise in this thread: http://www.bonnevilleclub.com/forum/...ic.php?t=70748
I got to wondering...what causes a lifter tick? Well...besides a "bad lifter"...I guess the correct question is what causes a lifter to "go bad"? I have this same noise...always have (bought in Dec 04 with 31k miles).

Do leaky LIM/UIM gaskets damage the lifters somehow? I question that because I replaced mine at 53k miles... and according to the date on the UIM that I took off (2002), it was the 2nd replacement of the UIM. Searching for other posts, it seems that a LIM/UIM failure is present when folks have this noise.

http://www.bonnevilleclub.com/forum/...ht=lifter+tick
http://www.bonnevilleclub.com/forum/...ht=lifter+tick
http://www.bonnevilleclub.com/forum/...hlight=ticking


So...if this is a lifter tick is this something that I should have looked at or replaced? Can it do further damage? Note...it is a very subtle ticking and other members who've seen/heard my car don't seem to notice it... but I do. And it hasn't gotten worse, but it never got better after my gaskets were replaced.

There are a lot of things that can tick under the hood, like the injectors, and the evap solenoid. Are you fairly certain that it'* the lifters? They generally aren't real subtle with their noise.

I am curious as to why you think its a lifter vs a rocker or the many other things that tick.

I mean rockers that aren't torqued to spec can make a lot of ticking noises too.

Definitely. A ton of things can tick. Lifters are DEFINITELY not subtle. But one way to narrow things down is if the noise goes away when the oil gets up to the lifter valley. On one like mine, thats the case. A ticking lifter would probably scare you so much that you would start a whole new thread in all CAPS. They're LOUD, and believe me, you wouldn't be the only one hearing them.

But getting back to diagnosing, if you can, try to determine EXACTLY where this sound is coming from, does it go away with oil pressure, and does it get louder with rpms?

No, I'm not sure what the tick is coming from... yes it is subtle, yes it is the same speed as the engine (both ideling and reving), yes I hear it both when engine is cold and warm... I called it a lifter tick only because that'* the closest description I have (going from memory years ago hearing one) and because it'* been mentioned in so many other threads here. it seemed wierd that others here have heard a similar sound and all have the UIM/LIM failure. Didn't know if there was a connection.

Many members have heard my engine idle with the hood up... no one'* mentioned it... perhaps I'm being overly protective (as all mom'* are ) If nothing else, I can have "the boys" check it out with the stethascope at NEBF and pinpoint it for me...

There'* nothing wrong with being overly protective, Tracy, it'* alright. I'm thinking fuel injector tick. : )

That'* the same noise i heard when my LIM failed. If you get the oil changed and that ticking noise goes away, then you had coolant in the oil causing your motor to not be lubricated properly, aka the ticking noise. You should get the oil changed ASAP and try not to drive the car if it is the LIM or UIM.

First, lifters don't "tick"...the ticking noise is caused by slack in the valve train for some reason..the lifters can't follow the cam lobes and you hear the slack comming out of the valve train every time a valve gets lifted off it'* seat. (frequencey of one bad lifter/valvetrain is 1/2 engine rpm) So the real question becomes "Where did the slack in the valvetrain come from ?"

A coolant leak into the oil can cause it. Take a look at the rebuild thread I've been doing. That milkshake lookin Latte colored sludge found in the oil passages was the engine oil mixed with DexCool. It was so thick that it glued parts together. The lifters themselves were so full of it that they couldn't pump oil and collapsed. To get them apart, I had to soak them in solvent, then pump the sludge out by repeatedly pumping them in the jaws of a vise till they would come apart. It actually didn't harm them, but I don't know how long this motor suffered before being sold to me.

Without a coolant leak, the other things that can cause a ticking noise in the valve train are:

1.) Excessive wear inside the lifter (The lifter has a piston in it that pumps oil, if it wears out, oil gets squeezed past the piston instead of being pumped up inside the pushrod.) This is likely a defective lifter from the get-go. The parts inside the lifter are hard chromed and wicked tough surfaces. Without something metallic getting inside the lifter, it would be rare for one to fail mechanically.

2.) Busted piston return spring inside the lifter (has the same effect as #1)

3.) Bent pushrod...but that raises the question of what happened to cause the pushrod to bend. It can happen. The pushrod is nothing but a steel tube with a hard chromed steel ball at each end. They should have been perfectly straight from the factory, but sometimes aren't. If they have even a slight bend to them, they will flex or bow with every cycle. Sooner or later, they get softer from fatigue and stop springing back to shape.

4.) Excessive wear between the lifter bores and the lifters. (not enough oil is going inside the hole in the lifter body, it'* all going around the outside of the lifter. You would also have abnormally low oil pressure on this one.)

5.) Busted Valve Spring. A busted valve spring is the real dangerous failure because the valve is no longer being forced back into the seat. Should it drop low enough to get hit by the crown of the piston it'* toast.. That will usually drive the retainers out and allow the valve to drop down into the cylinder. In other words: kiss the piston, cylinder bore, and head good-bye.

6.) Worn out cam lobe. This gets ugly fast cause once you are through the hardened surface of the cam, the softer metal inside will wear really fast until the cam lobe isn't a "lobe" any more...and the missing metal is down in the oil pan.

7.) Loose rocker nut. It wasn't tighted up enough to start with, the stud has stretched, or in the case of older motors, the stud has been pulled out of the head.

8.) No or Low oil pressure from the pump...root cause of most engine problems.

Hope that helps explain where the "ticking" noise comes from

Tracy, I assume that you've done all the usual visual and odor checks? Losing coolant, coolant or other sludge around the lower intake manifold, milky looking oil, sweet smelling exhaust...things like that?

Curt ... there'* certainly a lot of feasible options.... thank you for such a great explanation of the various issues. You'll make a gearhead out of me yet!

Archon & BonZ
I'm sorry, I must not have been clear when I posted (3am could have something to do with it) I am not concerned with a "current" coolant contamination: LIM/UIM gaskets were replaced 8,000 miles ago. I found a leak before there were any visibile signs of contamination in the oil. The oil has been changed twice since then - I use Mobil One.

My concern is what may have happened with the previous owner. The upper intake manifold had a stamped date of Dec 16, 2002 on it....and my car was manufactored in June of 2000. Therefore, I have very good reason to believe there was a previous failure. Who knows how bad the previous owner let the leak go.

I can only assume the worse...so that'* where my wondering kicked in. I have this ticking noise....others have had it.... could it be a result of a previous gasket failure..... what else should I be concerned about if there was a total contamination with the previous owner....