C20seh Cambelt slipping off !! - Annoying

[Markd89]

Rebuilt the engine up over the week, just come to put a new waterpump and cambelt on and everytime i turn it over by hand the belt slips off the cam pulley everytime, the more times i turn it over the more it slips off.

does anyone have any ideas ? ive tried the old cambelt and waterpump and it still does the same.
I've tensioned it all different tensions and still the same, i dont understand does anyone have a clue ?

The only thing i have done is spray the cam sprocket silver everything else hasnt been undone or moved

[Lewis.]

something isn't on square mate. most likely the water pump, so you may have the O-ring trapped between the block and the pump, causing the pulley to run out of line. have you had the crank or cam pulleys off too?

[Markd89]

ive had the cam pulley off and the waterpump.
ive fitted and re-fitted the pump a dozen times still the same

[Lewis.]

have you tried the original pump back on? the new one may be faulty?

[Markd89]

yea tried the old pump and old belt

[Novasport]

Not sure if it can be done but have you put the cam pulley on back to front?
Is the bottom alternator belt pulley on, if not does it do it when it is on?

[Lewis.]

and it's still doing it with them? in that case check the cam pulley is on square, it may be sat on the dowel. crank pulley is difficult to get on wrong though. are you turning it over with the V pulley on or just the toothed pulley? you haven't got the washer behind the pulley or anything simple? or the bolt not holding the pulley back fully?

[Markd89]

cam pulley can be on back to front so i tried it both ways and still the same, i lined the cam pulley up and hammered it on as far as it would go on ( sat flush with the dowel ?) and im turning it over by the crank pulleywith a 17mm spanner, the alternator pulley isnt attatched either.

No washers behind the pulley either, i dont understand its such a simple system yet it just slips off

[Lewis.]

the cam pulley isn't bent is it? it might not have liked being hammered

[Markd89]

no seems fine i only tapped it lightly, even had a rag over it just encase

[Lewis.]

hmmm it seems very odd in that case. theres no rusty flakes from the water pump between the block and the pump is there? could have remained there even when swapping the pumps round a few times?

[Markd89]

all nice and cleeean lol, i'll have another go tomorrow and see what happens

[Lee]

Sounds like a tensioner is collapsing, have your replaced them?

[Novasport]

cam pulley can be on back to front so i tried it both ways and still the same, i lined the cam pulley up and hammered it on as far as it would go on ( sat flush with the dowel ?) and im turning it over by the crank pulleywith a 17mm spanner, the alternator pulley isnt attatched either.

No washers behind the pulley either, i dont understand its such a simple system yet it just slips off

Fit the alternator belt bottom pulley and try again. I am sure someone else had a similar problem and it sorted itself out when it was fitted.

[Lewis.]

the 20SEH doesn't have a separate tensioner Lee, it's just the crank, the cam and the waterpump is eccentric to tension it

[mrT]

you should be able to see what isnt inline with your eyes mate, take cam pulley off and check all is well as in its not bent etc, recheck water pump again checking play even though its new, is it the same as old one etc, i'd say its gotta be one of these thats wrong most likely pump as that acts as a guide