Superfans

Does anyone know whether it is expensive to fix the hydraulic tappets of the Variocam plus mechanism (by an authorised dealer)?

Any adverse effect if you let the car run with a faulty tappet? Is it safe to do so?

HAMMER502

I'M NOT SURE ABOUT THE PRICE AT THE DEALER,BUT I THINK THE LABOR IS AROUND 12-14 HOURS BOOK TIME(IIRC).I WOULD NOT RECOMMEND DRIVING THE CAR WITH A BAD TAPPET.

StanSoph

What is your basis for diagnosis?

TT Surgeon

yes, very.

Superfans

Guys, one more question. What will happen if the tappet gets sticky? Will it affect the A/F ratio and cause the vehicle to backfire. The reason I ask is that my 2002 996 will somtimes backfire during moderate acceleration. Thanks in advance.

P-Car fanatic

I had an issue on the variocam on my boxster recently - causing misfire and CEL to come on

1200 GBP to fix at the OPC - thats $2000 usd

NOT CHEAP

djantlive

Can you get a bent valve from sticky tappet? I haven't heard of this issue on 996. I assume your 02 is out of warranty. Maybe you can get PCNA to pay for partial cost if your warranty just ended and you have low mileage. Make sure the diagnosis is done properly - ie spend the money to have it properly checked. I'd do it at a reputable dealer if you think you have a chance to get any money from PCNA.

Superfans

Aren't those hydraulic tappets suppose to be maintanence free? Do you know how they can worn out or get stuck?

1999Porsche911

Try to clean up the top of the engine by sucking ATF into the intake with the engine running. Remove a small vacuum line and insert it into a container of ATF. Let the engine idle while the fluid is sucked in. Turn off the engine after sucking in about 1/2 quart. (there is no danger if more or less fuid is used) Let the car sit for 30 minutes.

Wait until dark, and then take the car for a spin to blow out the ATF. The car will smoke like hell as the fluid is burned and will be less embarassing in the dark to drive down your street.

This procedure quite often will rejuivinate the valves and lifters.

Darren

This is just bad advice. This works great on 1967 Chevy Pickups, but on a 996 with multiple cats, do so at your own risk. Besides, he was complaining about a lifter problem, what could that possibly have to do with combustion chamber carbon deposits?

My 996 has a few sticky lifters, they clack to the point that my car sounds like an older 911. I'm fighting with the dealership who said its "normal". I don't think you risk doing valve damage because if anything, the collapsed lifter will result in less valve lift rather than more.

Lifter problems are not unheard of with 996's. The dealerships stock a product that you can add to your oil to possibly free up sticky lifters. It hasn't worked for me, but it may work for you. Give them a call and find out what they use, if that doesn't work you may need to have the lifters replaced.

1999Porsche911

All it takes is a little grit stuck on a valver to get it stuck. Running ATF through the intake can help remove this grit. It is also a great preventative of valve train problems and I do it in all my cars, new and old once a year. I have no idea why you mention the CATS, the use of ATF in this manner does not damage them.

A more extreme methed is to use water which will create a steam and also soften and remove carbon from the upper engine. This does a great job but can clog the cats if large pieces of carbon are dislodged. In this case, cats should be removed prior to treatment.

I suggest that YOU try this procedure and maybe you won't have your sticky valve problem, as it IS NOT normal or common in the 996 unless you are running 0W-40 in hot climates.

Darren

My car is under warrranty

But your reply shows a basic misunderstanding. When you put ATF into the intake system of your car, it will NEVER come in contact with a lifter.

1999Porsche911

Sorry for the confusing explaination, but I am watching the White Sox win again which for a Chicago sports fan is confusing in itself. Yes, the ATF will not get to the lifter, but it will get behind the valves and into the guides if grit is present. Often the ticking is caused by the valve guide or the back of the valve getting grit on it and does not allow the valve to bottom out against the lifter (leaving the valve slighly open). The cam then pushes the lifter up and it taps the valve shaft as it makes solid contact. The use of the ATF (or any light weight oil based product) ease of flow under cylinder compression, can help lossen this grit and pass it out through the exhaust or into the crankcase where the oil filter will trap it. To a lesser degree than water, the ATF creates a steam in the cylinder and safely steam cleans everything it can get too.