16v possible damage

[Roger Blassberg 0]

Changed the timing belt and tensioner on the ABF passat today, and thought I'd do the timing chain as well, the one at the other end that goes from the exhaust to the inlet cam. I thought I had got it right, but the inlet was one tooth out on the small sprocket and when I started it there was a horrible clatter and it ran like a bucket of poo. So I stripped it down again, took off the belt and realigned the cams.

 

Then I must have lost my presence of mind completely, because I then turned the cams over by putting a socket on the timing wheel WITHOUT putting the belt back on, so the crank stayed at TDC while I turned the cams. Needless to say there was a coming together of cams and pistons, which pushed the crank away from tdc (emphasise that this was only turning by hand).

 

What do you think? Will this have bent valves? I was concerned about the claterring (see first paragraph) I had taken the cams out - was this due to the tappets pumping up, or was one tooth out on the inlet enough to cause damage? The rough running must have been due to the inlet being out of sync.

 

Comments please and offers of condolence for being terminally careless.... I suppose the safe thing to do is to take off the head and have a good look.

 

The moral of the story is, " stop when you are tired, mistakes are easy to make"

 

Best wishes

 

RB

 

Best wishes

 

RB

[fla 9]

Doesnt sound too bad Roger, you only turned it over by hand and not on the starter, right? If so, you may have just scratched the top of the pistons or the valves, shouldnt be an issue.

[dirtytorque 0]

wouldn't loose sleep mate.

Unless u was turning over with a MASSIVE breaker bar?!!

The fact that the engine moved was good.Help take away some of the force of impact.

[tyler 0]

you started with 1 tooth out? this could of done the damage probbably bent a couple off valves the turning over by hand wouldnt do much unless you could fell things bending. best bet is to put it back together and start it and see what happens :D

[davidwort 0]

highly unlikely you'll bend anything from turning it over by hand unless you're the Hulk or somthing :)

I've seen so many 16v's wrongly set up and running a tooth or two out it's also v unlikely the valves would hit the pistons running like that, you need to get them way out.

Like above, set it up right, run it and see, perhaps do a compression test if you think it's down on power.

[dirtytorque 0]

people dial in a tooth or so of adjustment with vernier pulleys

It's not going to damage your engine.As above needs to be way out.

[Roger Blassberg 0]

Well, a real Hollywood ending to this !!

 

I took the cams out again to make sure all valves were shut, turned the crank back to tdc 1/4, and put it all back together.

 

I turned it over on the starter, plugs in, leads off, and there was a dreadful and unmistakable sound of one cylinder losing compression (slow-slow-slow-fast-slow-slow-slow-fast). So I connected the leads and sure enough the engine ran but only on 3.

 

Thoroughly fed up, and resigned to having to take off the head, I packed my tools away and cleaned myself up with the view of at least having a few hours watching Formula 1 GP, but thought, "I'll move the car to the back of the drive to get it out of the way". I turned the key and, miraculously, it started and ran absolutely perfectly!!

There must have been one or two sticking valves which popped shut after a few minutes to restore compression,

 

God is in His heaven and all is well with the World !! AND our man won again

 

So now we have new valve timing gear and some satisfaction with a job properly jobbed. Just a gearbox transplant to go now ( A Golf GTi 16v CDA with closer ratios than Passat standard is all cleaned up and sitting in the garage).

 

Thanks to all for your interest in a subject non-Corrado which may have general interst for 16V owners; I won't need an ABF cylinder head after all. Final moral is, have faith in your ability but think things through and don't work when tired because that's when you make mistakes.

 

Best wishes,

 

RB

[dirtytorque 0]

well done mate. :)

 

All part of the fun.

[adam16v 0]

sorry to jump in on your thread but since i done my head gasket. also had head polished and ported at the same time it was apart. i have been un able to get it running right when on timing marks i currently hav the cam one tooth past mark on the cam belt end for it too run properly or better than than when on marks anyway. i also have to advance the dizzy a bit as well. so all i can think is that i have the cam to cam timing out a bit.

 

to me the car fills retarded until about 4500rpm it just does not fill like it goes like it should but i brought it as a non runner and am comparing performance on my old 2lt 16v astra so this may just be the way of this engine

 

how do you guys line your cam to cam timing up?

or any other info on what it could be i would be greatful

[davidwort 0]

There are round marks on both cam sprockets that should be level with the cam cover surface of the head when everything is put back.

It's not unknown for 16v's to shear the woodruff key on the exhaust cam timing belt pulley or the crank pulley, putting the crank to cam timing out a tooth, but usually only if a belt has snapped or something.

The flywheel mark wont go anywhere so start with that, open the timing hole on top of the box get the wheel to the 'O' TDC mark, not the 6 deg advance mark, and line it up with the 'V' shape in the box housing.

From there check the crank pulley mark is in the right place, i.e. lines up with the arrow on the cover, and that the dizzy body mark is in line with the rotor arm, you should have the top timing pulley mark in the right place (inside mark level with head surface) and those cam to cam marks should be level and also level with the head surface.

HTH.

there were some pics of all this somewhere, and also on the Club GTI forum

[adam16v 0]

cheers for reply i could not find any marks on my flywheel so i been lining my crank pulley up with mark on cam belt cover. yeah lined circles on cam chain cogs up with edge of the head but to then line up the cam shaft mark for the cam belt i have to turn the cam back a bit to line up mark which then puts the chain cogs out of line slightly.

[davidwort 0]

those flywheel marks are there, it's just the flywheel is so much bigger it moves past the opening v quickly with small movements turning the engine over via the crank pulley bolt

[Roger Blassberg 0]

The difficulty I found with the round cam-cam sprocket marks is that they can appear to line up to each other before the camshaft bearing caps are tightened down, and then move relative to each other as the chain is tensioned during the final torquing of the caps. They must line up AFTER the tightening, so you need to take that into account when aligning them. Those sprockets are small with very few teeth; one tooth represents more than 10 degrees.

 

Mine is now running like a dream, much quieter due to a new chain. And the Golf GTi CDA transmission with its longer 1st 2nd and 3rd gears together with a new, much lighter clutch action, have tranformed the feel of the car.

 

Best wishes

 

RB

[dirtytorque 0]

re did mine today and it sorted a running problem i had.

Aim for this.

[adam16v 0]

cheers for info and pics will try and hav a look at mine again at weekend. so i right in thinking that the dots should be in line and the cam belt pulley on mark at the same time? sorry if simple questions but i new to vw i been with vauxhall past 11yrs but this came up cheap so had to give it a go. 1st job once it was running was heater matrix have to say not the worst i done wasn looking forward to it after reading what everyone said but start to finish took me about 4.5hrs

[dirtytorque 0]

all the above(poor quality I admit) pictures were taken with the engine in the same position i.e TDC.

This will give you straight up factory cam timing in relation to the bottom end.

 

hth.

[bigred 0]

Are the teeth on the cam chain gears worn out?