Timing belt tensioner won't tension (Bx TD)

classic2cv · Post by **classic2cv** » Thu Aug 09, 2007 9:52 pm

I’ve just had a go at doing the cambelt and have come across a problem

when i tried to slacken the timing belt tensioner is was stuck fast and would move

After an hour of poking about I ran out of patience

cut the belt though and guess what happened

Nothing !! It only moves about a half an inch but it can’t be moved back

What now ?

ken newbold · Post by **ken newbold** » Thu Aug 09, 2007 11:27 pm

Have you undone both securing nuts?

classic2cv · Post by **classic2cv** » Thu Aug 09, 2007 11:47 pm

hi ken

yes i found both of them(after lots of groping)

After I removed the belt I found that it would only move a very small amount but only to tighten

But it wont go back in (I think the spring plunger thingy is stuck or seized)

Can it be taken off and cleaned up or freed ?

Post by **docchevron** » Fri Aug 10, 2007 2:39 am

Yeah, they can be removed. Remove the bolt and nut completely, and slide the tensioner off. The haynes says you need a special tool to hold the spring in, but you really dont. I've never used a special tool.

I've never seen one seized though..

Oscar · Post by **Oscar** » Fri Aug 10, 2007 8:54 am

How are you trying to move it back? Fingers won't do it - you do need to get a drive in there and get a lot of leverage on it.

Fogrgive me if you've done this - I'm not saying you're a mechanical idiot, just that I've come across plenty of instances when something was "seized" only for it to move with a bit more grunt.

My dad used to accuse me of using "brute force and ignorance" too often - as a result I never use enough force now.

AlanS · Post by **AlanS** » Fri Aug 10, 2007 9:20 am

What kind of engine/tensioner does it have?
If it's an 8 valve petrol or has the same tensioner, you need a 1/4" square key or a spanner that will fit it around the back to roll the cam on the tensioner over to release the tension.
I usually get so frustrated, I take the bloody tensioner off altogether, then free it all up and set it up before I commence fitting the new belt.

Alan S

RichardW · Post by **RichardW** » Fri Aug 10, 2007 9:58 am

Had this trouble on a mates Xantia. The spring piston was seized in the housing meaning you couldn't move the tensioner back. We used a long drift and hammer from underneath to drive the piston back into the housing (there is a flat spot on the tensioner that looks designed for the purpose...!), then set the belt tension manually using the 1/4 turn method. The proper solution of course will be to remove the tensioner and mount and get the spring piston out (some heat should do it - just make sure you are not stood in the way in case the spring fires the piston out

), then clean it up to make sure it doesn't happen again.

classic2cv · Post by **classic2cv** » Fri Aug 10, 2007 7:43 pm

i managed to remove the tensioner and mount and the plunger was very stuck

so i took RichardW advice:

RichardW wrote: The (some heat should do it - just make sure you are not stood in the way in case the spring fires the piston out )

with a little heat (boiling water from a kettle) it shot out with a bang

good advice richard

the plunger was very grotty

this is what it looked like after a little wire brushing

i'll get it cleaned up tonight and refit with a bit of copper grease

that should sort it

RichardW · Post by **RichardW** » Fri Aug 10, 2007 7:47 pm

Hmmm, with all the rusty stains around that - are you in for a head gasket job before too long????? Where did the water come from?

classic2cv · Post by **classic2cv** » Fri Aug 10, 2007 7:59 pm

it's ok

i had a leaking waterpump

and the cambelt needed to be done too

the stains are just the plain water that i used to top up the system

it was a good thing that i went as the belt didn't seem to be that well tensioned

tom · Post by **tom** » Fri Aug 10, 2007 8:21 pm

Now on that tensioner there are a couple of cast bosses. If you drill one and tap it M6, fitting a little allen headed bolt, you can lock the tensioner in place while fitting it and release it when you have the belt on.
I'll bet it runs much better for a new belt!

AndersDK · Post by **AndersDK** » Fri Aug 10, 2007 8:22 pm

There is no mention of or reference to a diesel engine in this thread - or in your signature.

Please always be very specific on precise model and engine designation, as there are as many detail variants as there are engine types.

It would have helped on a much faster & precise answer to this thread - if we all knew you talked a about a diesel engine - and which version - and which year

classic2cv · Post by **classic2cv** » Fri Aug 10, 2007 10:13 pm

Good point Anders

I’ve just amended the header so anyone so people with diesels who have the same problems might

Be able to sort it without pulling out their hair out

Tom

Tapping the casting and fitting a little allen headed bolt is a good way of holding the plunger in place

and safer too

AndersDK · Post by **AndersDK** » Fri Aug 10, 2007 10:35 pm

Haynes mentions a special Citroen tool (bracket) to lock the tensioner in retracted position. This is very easy to make up as DIY using a rigid piece of steel with 2 8mm bolts placed exactly 100mm apart.
I've used a lenght of angled steel profile 30x30mm which do the job nicely.

classic2cv · Post by **classic2cv** » Fri Aug 10, 2007 11:27 pm

do you have a picture of this tool ?