Cam belt issues

toddao · Post by **toddao** » Tue Jun 23, 2009 5:15 pm

This afternoon I changed the cambelt and waterpump on my n/a 1.9 D. I was careful and methodical and this was my second belt change.
I got the belt on, tensioned it, rotated the engine a few times by hand to check the timing - everything seemed fine.
When I had put it together and tried to start it, it gave off an awful flapping sound. I jacked it up again and tried to rotate the engine by hand - the flapping sound was the belt slipping over the crank pulley ( which was turning)!
Right, I thought belt off again and hopefully can try again but would have to find TDC again on the flywheel.
As I removed the belt from the camshaft pulley I noticed that it was loose. The whole pulley can be moved in and out about half a centimetre each way and rotated left or right 45 degrees though the pulley nut is tight.
What have I done? Is it possible that the cam-shaft broke? ( as the crank turned but the cam shaft didn't?) This is all I can think of.
Any ideas appreciated - my mood is pretty in keeping with the pouring rain that hasn't let up today.

Cheers

toddao · Post by **toddao** » Tue Jun 23, 2009 7:36 pm

Tomorrow I'm going to take the cam cover off and have a look. I just can't understand why the belt slipped off the crank sprocket when, as far as I could see, it was fitted correctly. ( I didn't leave any of the timing screws in!) And also, would the starter motor, engaged for a 2-3 secs have enough power to drive one of the pistons up into the valves and thus break the camshaft?
The irony is, I was doing the belt change as a preventitive measure as it's got no history of a change, but the one I took off looked fine!

RxBX · Post by **RxBX** » Tue Jun 23, 2009 7:52 pm

Hi Todd,
The sign's are not looking good for you

I'm sorry to say, look's like you may have overlooked or not checked something 100% ?
But look thro' this 'Sticky' for how to change your cam-belt it may be of help :-
http://bxclub.co.uk/forum/viewtopic.php?t=2902

Best of luck with your finding's (If the cam-shaft has broke, I have a good cam-shaft and cap's which I've recently removed from my 1992 TXD if you end up needing a replacement), I hope you don't though

toddao · Post by **toddao** » Tue Jun 23, 2009 8:01 pm

Thanks RxBx - I actually read that all last night in preparation but, as I said I did one before with no problem. I don't understand what happened..

I've actually got a brand new Citroen packaged head with cam all valves etc but I liked it more as a paperweight. We're meant to be coming to Uk next week ( and National week after) so I've got to think/work fast.

Jaba · Post by **Jaba** » Tue Jun 23, 2009 9:48 pm

Aaaarrggghhh that looks like a broken camshaft to me.
I have never been that unlucky..........yet.

toddao · Post by **toddao** » Tue Jun 23, 2009 10:04 pm

Hey Jaba! Thanks. Hope to see you at The National - in this car!

I'm seeing it as my apprenticeship as a 'KFZ Meister' ( Kraftfahrzeug - Stong vehicle master - the mechanics qualification here) - it'll only take 20 years or so!

I spoke to my friend Sigmunt who works in the local scrapyard and has just been made redundant. Used car parts is not a good business here right now - ironically the yard is over flowing with €2000 trade-ins against new cars ( to save the economy) - but no one needs parts now for their older cars. Anyway, he's coming to lend a hand once the verdict is in. I'm just drinking a few Fürstenbergs to dull the pain!

Post by **mat_fenwick** » Tue Jun 23, 2009 10:17 pm

I'm sorry to say that I can't see a happier explanation.

The question is: Why? Hope to see you at the National in it Todd, best of luck with it!

toddao · Post by **toddao** » Wed Jun 24, 2009 12:01 pm

Well, I lifted the cam cover this morning and it weren't pretty!
The camshaft was in three pieces with the centre bearing fractured too and the two studs that hold it bent. Oh dear.
Working on the perhaps false assumption that the valves are not bent I decided to fit another camshaft. The one from the new head was not suitable - it didn't have the right fitting for the pump pulley so I took the camshaft from my spare engine and fitted it.

When the broken camshaft was out, while all the valves were up, I turned the crank til I could lock off the flywheel through that timing hole with a hacksaw ( good tip Adams dad). Then I fitted the camshaft straight into its timed position.

I'm going to fit the cam belt again this afternoon and rotate it by hand. If anyone can see any problems with this dose of what they call in Aus 'bush mechanics' then any comments appreciated.

Time for a cuppa

Post by **mat_fenwick** » Wed Jun 24, 2009 12:25 pm

Bugger. Sorry to be the bearer of more bad news, but the camshaft bearing caps are bored in line with the head, and hence matched. You *may* be able to get away with using one from your spare engine, but I would check very carefully for any step in the bearing surface between it and the head. It would also be a good idea to take the cap off and inspect for any unusual wear after say 1000 miles (perhaps when you're over here?)
If anyone has swapped the bearing cap from a different head they would be in a better position than I am to say whether it's a definite no-no or not...

Fingers crossed mate!

toddao · Post by **toddao** » Wed Jun 24, 2009 12:47 pm

Thanks Mat, I hadn't thought of that. There's always so much to consider. Glad you've got faith enough that I'll make it to the National though!
My mate from the scrapyard is coming this afternoon for technical support so hopefully he'll have some thoughts. I'll report back later

DavidRutherford · Post by **DavidRutherford** » Wed Jun 24, 2009 1:56 pm

toddao wrote:the centre bearing fractured too and the two studs that hold it bent.

Sorry to say it, but that head is now scrap. Once the mounting studs have been bent, there's no way you'll be able to recover it.

And yes, the bearing caps are indeed line bored in the head, so there's really no chance of just fitting any old caps. When you torque them up, they will probably clamp the camshaft solid.

Also, when pistons hit valves, what they tend to do is "mushroom" the stem, meaning that the valve stem is now slightly shorter, and very slightly fatter than it was before. In most cases, this will then mean that the stems will be a tight fit in the guide, or in some cases means that the guides themselves will be split.

toddao · Post by **toddao** » Wed Jun 24, 2009 5:25 pm

What you wrote David was also the prognosis of my mechanic friend Sigmunt. He said : new head.

However, I removed the bent studs which conveniently screw in and fitted two from the spare engine then when Sigmunt came he said : maybe you have the 5% luck.

He removed the camshaft then tried the various bearings and how they fitted together without the camshaft, running his finger round the inside to feel for a smooth transition til he found three that he deemed good. Then we fitted the camshaft, tightened the bearings, dropped the crank 90 degrees and rotated the camshaft several times to check its movement. It moves freely and the bearings are also sitting flush.
He then checked the valve clearances and movement which were good then said : put it back together and I'll come tomorrow and we'll try. Maybe you have luck.

His thoughts on what actually happened was that I had slipped a tooth on the belt because he thought there was too much play in the timing fixtures, especially the junior hacksaw in the flywheel of which he didn't approve. Also the 8mm bolts in the cam pulley and pump pulley had too much play. He wrapped insulation tape around the top of them and now they go tight into the pulleys.
He also suggested that whenever changing the cambelt, mark all the pulley positions with with a marker pen.
I'm keeping my finger crossed..

TB2 · Post by **TB2** » Wed Jun 24, 2009 6:29 pm

Sad to hear what happened, Todd. Wish you luck for tomorrow ^^

So, the 1.9D isn't self-tensioning like the 1.7TD?

toddao · Post by **toddao** » Wed Jun 24, 2009 6:40 pm

Hey Carl. Yes, it's self-tensioning. I don't understand what happened really. It seemed to be perfectly fitted but I obviously made a mistake somewhere. Sigmunt suggested the above. I'm not sure, last one I did works fine. I don't think I've heard of another incident like this either. Often when the belt is out a tooth or two the engine won't start not go into self destruct mode!

DavidRutherford · Post by **DavidRutherford** » Wed Jun 24, 2009 8:05 pm

Depends which way out it is. I can't remember off the top of my head, but if you get the camshaft a tooth out one way the engine will simply run like a bag of poo, but get it out the other way and it will crash.