Cam belt help please

[chicken man]

Hello,

 

When driving back from the Wilts South meet on Monday evening there was a loud bang from the underneath of the car and the red light came on the dash. When I looked under the car I was shocked to see the front pulley and belt missing .

I retreived them from the road and called Dave Andrews for advice (thank you again), Dave said that a loose cambelt can cause the front pulley to loosen and eventually fall off.

I refitted them to the Seven yesterday and changed the cam belt and bottom pulley (not the tensioner) at the same time. My car is an SV 1.8VVC for reference.

It started up fine this morning, I was quite pleased with myself.

This morning we had a good blat and drift in my chicken shed, but all was not well with the car. Below 4000rpm it is low on power and a bit hesitant, difficult to drive at slow speed too.

Our best guess is that the cam belt timing is one tooth out on the bottom pulley? I didn't have a cam locking tool, but made sure the marks were both lined up. However, it may be that the bottom pulley has moved a fraction? I didn't think the engine had moved, but didn't look at the dots again.

Just about to get to work on the car, do you think it is as simple as moving the belt one tooth? Any suggestions welcome.

 

Thanks, Philip

[Mankee]

I really would get a camshaft locking tool to be on the safe side, especially with the VVC mechanisms. It's easy for one of the inlet cams to move around without you knowing and causing havoc with the cam timing. Whoever did the belts on my VVC head previously messed it up a bit as a couple of the inlet valves had been bent.

[Fishy Dave]

I will see if I can lend Philip the cambelt locking tool. Can anyone else help with this please (advice, not the locking tool)?

[charlie_pank]

If your cambelt disappeared while you were driving, how can you be sure that the valves aren't bent?

[SLR No.77]

Philip, before doing anything else it would be worth doing a compression test .... then you'll know if you've bent any valves.

 

Stu.

[Mankee]

From Philip's description, it sounds like the alternator belt and crank pulley had fallen off, rather than the cam belt. Hopefully nothing is bent though.

[Fishy Dave]

Yes, the cambelt was still in place, just the alternator belt and pulley fell off.

[charlie_pank]

Ah, ok, my misunderstanding - the crank pulley and the alternator pulley must be separate.

 

If the car's running rough after a cambelt change, I'd be doing the alignment again for sure!

 

 

C

[myothercarsa2cv]

The alternator pulley is held on by a big ol' bolt through the crank pulley in to the crank. When you changed the cambelt, did you check that the crank pulley was seated correctly?

 

I don't know if it's possible to move the crank relative to the cams, but would have thought so, which could be a consideration. Also, how did you fit the belt? Did you make sure that the non-tensioned side was tight when fitting so that only the tensioned side was tensioned? Does that make sense?