hello people, just wondering if anyone could giv me some advice. I stupidly decided to remove the rocker gasket on my girlfriends vw polo 1.4 16v, w reg. oil was covering the spark plugs and causing the car to misfire etc. so i removed it only to find that it wasnt just a cover as am sure u will know. so i quickly pasted it with quick gasket and refitted it. but on removal, i slipped the cambelt off the cog. everythings back in place apart from that. I cant get it back on as it is tight. if i can force it back on will the timing be affected? Sorry i sound a bit daft but i am in a real dilemma here!!!

I'm not sure how the cambelt is tentioned on a mk4 ( just assume thats what it is) but insteads of forcing it on, why not just slacken off the tentioner whatever it is (on the mk3 its the waterpump) and gently put the cambelt back on. If you force it there is a chance of damagin it and you dont want the belt snapping and your gf blaming you for a knackered engine. Aslong as you haven't moved the crank or the camshaft then it wont be out of timing. Have you moved anything since the belt has been off?

Edited 8 July, 200917 yr by goosyganger

how did you manage to knock the belt off by taking off the rocker cover?

there should be a tensioner which would need loosening off.

i'd want to check the timing to make sure nothing has moved before you turn it over aswell

Good luck

I'm not sure how the cambelt is tentioned on a mk4 ( just assume thats what it is) but insteads of forcing it on, why not just slacken off the tentioner whatever it is (on the mk3 its the waterpump) and gently put the cambelt back on. If you force it there is a chance of damagin it and you dont want the belt snapping and your gf blaming you for a knackered engine. Aslong as you haven't moved the crank or the camshaft then it wont be out of timing. Have you moved anything since the belt has been off?

no, literally just lifted the cover off, put the quick gasket on and fixed it back together. nothing has turned or anything. i will get a mechanic to look at it tomorrow and sort it out. i was just worried that i had caused a major problem by removing the belt!! atleat i will sleep easier now! thank you for your help, its much appreciated!!

how did you manage to knock the belt off by taking off the rocker cover?

there should be a tensioner which would need loosening off.

i'd want to check the timing to make sure nothing has moved before you turn it over aswell

Good luck

there was no method to how i did it!! i just slid it off!! i cant really speak with any knowledge here as i am mechanically daft!! i am electrically minded! i certainly wont be messing with engines again after this!

lol its no biggy if you haven't moved any pulleys. So I woundlt worry much. If you slacken off the tensioner and put the belt back on and tighten it back up so that you can turn the belt 90degrees or something then it should be ok. But if for your peice of mind you want it checked then it wont hurt.

Good luck anyway I'm sure itll be fine

Yeah i wouldn't worry too much pal you should be fine then.

Good luck with this and just think of it as a learning curve :)

WHOOOOA THERE!!

The cams are in the cam cover on that engine,as are the pulleys,which is why its impossible to remove the cover without slipping the belt off - so its almost certain the main cam pulley has moved the cams because you've taken the cams out of the head and they'll have been moved by the resistance against the lobes by the valve springs because there is always one pair of valves slightly open at any one time (Both cams will still be in sync with eachother though,as they're still joined by the second/tiny belt,so forget the second/small cam pulley).

But the large cam pulley and the crank pulley must both be turned to their marked positions before putting the belt on. If you dont do this,you'll almost inevitably do huge damage when you start the engine.

And given that the belt was loose enough to slide off with ease,you'll want to check the age of it,and consider using a new belt anyway - unless its quite new (its not supposed to be 'tight' but shouldn't just push off that easily unless you'd lifted the other end of the cover before sliding it off).

If you need to change it,then change both belts,both tensioners and both guides - you'll get them all in the belt kit (seventy-odd quid for one made by 'Continental' from eurocarparts - other retailers,such as GSF and VW's TPS are available).

If you dont want to do it,but hand it to your mechanic,show him this post - which to him/her means its just a belt change.

WHOOOOA THERE!!

The cams are in the cam cover on that engine,as are the pulleys,which is why its impossible to remove the cover without slipping the belt off - so its almost certain the main cam pulley has moved the cams because you've taken the cams out of the head and they'll have been moved by the resistance against the lobes by the valve springs because there is always one pair of valves slightly open at any one time (Both cams will still be in sync with eachother though,as they're still joined by the second/tiny belt,so forget the second/small cam pulley).

But the large cam pulley and the crank pulley must both be turned to their marked positions before putting the belt on. If you dont do this,you'll almost inevitably do huge damage when you start the engine.

And given that the belt was loose enough to slide off with ease,you'll want to check the age of it,and consider using a new belt anyway - unless its quite new (its not supposed to be 'tight' but shouldn't just push off that easily unless you'd lifted the other end of the cover before sliding it off).

If you need to change it,then change both belts,both tensioners and both guides - you'll get them all in the belt kit (seventy-odd quid for one made by 'Continental' from eurocarparts - other retailers,such as GSF and VW's TPS are available).

If you dont want to do it,but hand it to your mechanic,show him this post - which to him/her means its just a belt change.

if the car turns over but doesn't start does that mean that it hasnt one any damage?

Not necessarily,because it may have just caught them a fraction,but its looking good.

Even still,with the belt on and engine turning over,line up the crank pulley and then see how close the cam pulley is to its mark. If its halfway round,turn the crank once more and then it'll meet.

If the mark is spot-on,sweet. If its a notch or two out one way or other,this will need sorting or it wont run properly.

If you've not yet turned the engine without checking the marks - dont! Not even by hand,because the valves are so fragile when pushed by the piston (they'll be struck diagonally) you can bend them just turning the pulley by hand.

If its out by like a quarter turn,you may have damage,i dont know,it'll need a compression test by a mechanic/engineer if it wont run.

Not necessarily,because it may have just caught them a fraction,but its looking good.

Even still,with the belt on and engine turning over,line up the crank pulley and then see how close the cam pulley is to its mark. If its halfway round,turn the crank once more and then it'll meet.

If the mark is spot-on,sweet. If its a notch or two out one way or other,this will need sorting or it wont run properly.

If you've not yet turned the engine without checking the marks - dont! Not even by hand,because the valves are so fragile when pushed by the piston (they'll be struck diagonally) you can bend them just turning the pulley by hand.

If its out by like a quarter turn,you may have damage,i dont know,it'll need a compression test by a mechanic/engineer if it wont run.

by the marks, are you referring to the mark on the belt? as i cant see any other marks

CONCLUSION:- I turned it over and it didnt start. The mechanic had a look, and i hadnt aligned it correctly!! four damaged valves = £100 parts and labour!! lucky escape i'd say. I wont be tinkering with the polo in future!! But thanks to all those who advised, it was much appreciated!