silly question

[T25DUB]

are the tappets on a 1.9 DG engine adjustable or are they factory set.
reason I ask is I have had a new engine fitted and after 500 miles It says to adjust tappets and a few other things. but I was always thinking that the tappets are factory set and not adjustable

can some one clear this up I'm confused.

Rob

[T25DUB]

I'm thinking the guarantee is just a printout covering all t25 engines to cover all there bases

[ajsimmo]

Don't worry, there are no silly questions, only silly answers!

The tappets on a DG are hydraulic (or at least they should be if it's built right).
They are adjustable, as in you must set the preload on the hydrulic lifter. I agree it would be best practice to check them 500 miles after a rebuild.

Are you thinking of doing them yourself? If not, stop here and book it in for 500 mile service. If yes, read on!

Tappets are adjust by setting engine to TDC on No.1 (top of firing stroke, rotor arm pointing at No1 notch on dizzy), Slacken lock nuts on both rocker arms on No1, back off screws until you have free play (clearance) and turn screws back in until lightly touching. Then screw in the recommended amount** and tighten locknuts. Turn engine anti-clockwise 180deg (rotor arm 90deg) for each cylinder and repeat for cylinders 2,3 and 4.

**This is variously quoted as anything from "just touching" (absolutely wrong) to VW's own instruction of "just touching then turn in another two full turns". The consensus now from most of those in the know (and my own preferred setting) is touching plus 1.5 turns in. This is because it sets the internal piston in the follower to the centre of it's travel allowing the hydraulic system to work optimally. Some people set them to just half a turn in, but this isn't enough as it will not let the tappet self-bleed properly, and can let the tappet piston "top out" inside the follower when it effectively becomes a solid lifter with no cushioning effect, possibly causing incorrect valve travel, more rattle and increased wear.

[T25DUB]

that's for the great reply puts me at ease. I'm going to book it into my local vw specialist just didn't want to sound like a total tool when booking it in asking for something that couldn't be done

Thanks again

Rob