tapping ticking noise from engine

Hey all...
My 96 passat TDI now has a tapping ticking noise coming from the engine. It increses with RPM. It is now changed with synthetic 5w50. The noise remains unchanged. I traced the sound to the first lifter nearest the timing belt area. I suspect it is not getting oil due to crud blockage. I poured in some wynns oil treatment/cleaner this morning and there is no change. Does it work over time??
Any ideas what else i can try before spending the $$$ for diagnosis?
Can I continue to drive without causing damage?
Thanks all

[ September 18, 2002, 12:21: Message edited by: ROBSTAFF ]

How "overdue" was the service?

It's possible the lifter is dead. Before you go further, order some Amsoil Motor Flush. Use it according to the directions, then drain it and put in fresh oil. A high quality Group IV/V blend like Series 3000 will help, since the Group V stuff is a pretty efficient "detergent" by itself.

-mickey

ticking hydraulic lifters are nothing to be concerned about. My car has 19k miles and ticks on occasion, usually when cold.

5w50 synthetic eh? What brand?

Previous cars with well over 100k miles have had noisy lifters that come and go over time. Unless the tick really bugs you I wouldn't sweat it until the lifter collapses (the valve stops opening), which probably won't happen any time soon.

On the contrary, if it's a collapsed hydraulic lifter I'd suggest getting that fixed. If you run the engine with excessive valve clearance, the cam is slamming into the valve stem on every revolution and the valve is slamming into the seat on every revolution. Doing that for long enough is asking for valve/valve seat damage. If the valve stem snaps, look out ...

Given that this involves camshaft removal, it's probably worth trying an engine flush to see if it makes a difference, but if it doesn't, get it fixed.

Camshaft removal is not that hard on this vehicle and it's an excuse to change the timing belt. Do all the things you normally do to get at the timing belt, but then disassemble a little bit more to get the camshaft out of there. Exchange the lifter, re-assemble, there you go. Hard part is figuring out which lifter is bad before disassembling. I'd consider changing all of them.

Castrol Syntec makes 5w50 don't they?

If the lifter collapses, will this kill the motor instantly?

A collapsed lifter would mean that the valve wouldn't open...or wouldn't open fully. That wouldn't hurt the piston. It would just make a ticking noise, and the engine would run poorly.

A "sticky" lifter is a less severe version. There is too much gap between the cam and the lifter. In a hydraulic system, there should be zero clearance, and thus zero tappet noises.

The only way you could get a catastrophic failure from a bad lifter would be if the lifter jams in the "down" position, forcing the valve to stay open. I've never heard of that happening, but it probably has happened now and then. It's just not normally the way lifters fail.

If motor flush and fresh oil doesn't solve the problem after a few weeks, you'll have to decide between living with the noise and replacing the lifter. There is always the possibility that it could eventually "freeze" a valve open and tweak the head, but that's unlikely. Plenty of old Chevys have been clattering around with gummy lifters for decades.

-mickey

Castrol Syntec is, indeed, available in 5w50. It's a bad idea in general, and it's counterproductive in this specific case. A 5w50 Group III oil is lousy with Viscosity Index Improver...the polymer chemical that allows it to span that "heat range". VI Improver has no lubricating properties.

Besides that, what you want when you're trying to revive a recalcitrant lifter is THINNER oil.

Flush it, and put in Series 3000! I predict after a couple of weeks, if not sooner, the lifter will quiet down.

-mickey

Thanks for your responses all...
It seems it is unlikely that damage can occur in its current state - so I will be patient and see if the oil additive fixes the problem. If not I will try the engine flush and replace oil with 3000 as recommended. I was using castrol syntech 5w50.
I'll let you all know how it goes.
Thanks

Well friends - the ticking problem is a collapsed lifter afterall. Had it diagnosed yesterday - thought it was the injector but was wrong.
Anyway - lifters need to be replaced.
Question is... is it that difficult? Maybe it is time to get the bentley manual and go for it. I was warned I would need to set the valve timing afterwards - other than that it should be simple.(!?)

Stay away from the Series 3000 the oil is the wrong viscocity and too thin causing high wear rates on the cam lobes. Use some Petro Canada 5w40 or Delvac 1 5w40 or just stick with the 5w50.

Replacing the lifters is not a big deal to do. If you wanted to take a drive down to my place the total cost plus parts would be $100.00 (USD)

Or get a hold of Gofaster I think he could get this done for you no problem.

DB

Robstaff ...

How much mileage on the timing belt in your engine? Camshaft needs to come out to fix this problem and if you're in there doing that, might as well change the timing belt.

Is the problem isolated to one known lifter, or are you planning to get them all changed?