Sticky tappets

[superfans]

Dear Loren,

Will sticking hydraulic tappets cause the car to misfire or backfire when accelerate?

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

Thanks. :notworthy:

[1999Porsche911]

Yes, it could.

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.

[superfans]

Is it a must that a ticking noise will sound if the tappets are not working right?

[ickle_monster_au]

Stupid question but what product do you mean when you say "ATF"?

PL

[1999Porsche911]

Stupid question but what product do you mean when you say "ATF"?

PL

<{POST_SNAPBACK}>

Automatic transmission fluid.

[superfans]

Is it a must that a ticking noise will sound if the tappets are not working right?

<{POST_SNAPBACK}>

The reason I ask this question is because the engine doesn't make any tapping noise but the dealer believes that the hydraulic tappets are not working properly.