Help! Timing belt creeping off cog

[sopranolady]

Hi, apologies if this is the wrong category for the post, I'm looking for urgent advice, having hit a snag with our engine fitting project.

Our 1990 T25 1.6 tdi engine had bore wear and cracked cylinder head so we decided to purchase a 1.9 recon engine from AW engineering and have this fitted by our trusted local mechanic. (He's not a VW specialist but an excellent mechanic who has done engine installs.) The original fuel pump has also been refurbed.

Our mechanic has fitted the engine and all is satisfactory so far, except that within seconds of first running, the timing belt started to creep off one of the cogs, so that it overhangs the edge by about 1/3 of its width. The cogs appear to be out of alignment somehow which means the belt runs at a slight angle. This is something he's never seen before and is rightly not happy to run the engine any more until it's sorted as the consequences could be catastrophic (and expensive!)

In a bid to track down the cause, so far he/we have:
- Checked the cog itself is not mis-shapen or out of true
- Had the fuel pump refurb guy check and verify our mechanic's correct installation of the fuel pump (as this is the only element not supplied with the recon engine but comes from our van)
- Request that AW Engineering send another back plate (the plate the cogs attach to), thinking that the plate might be bent, putting the cogs out of alignment with each other. They sent this plate, sure enough the one originally supplied was slightly bent. HOWEVER on installing the straight plate, the creep is still happening.

Having contacted AW Engineering again, they are now telling our mechanic that this is 'normal', they've seen it before, and if run longer than a few seconds it will naturally 'find a place to sit' on the cog, overhanging slightly. He has advised our mechanic to run it for 20mins and see what happens!

Neither we nor mechanic are happy with this at all, it can't be right. Sitting where it does, it would wear unevenly, not have as much traction, and rub against the cover when this is put on. Not to mention the risk of it slipping off completely.

Please can anyone say if they have had this problem before with a recon engine, what might be the cause (spindles out of alignment in the engine itself??) and what can be done?

AW Engineering guarantee the engine from date of purchase for 1 year, so its within guarantee. Given it's not even successfully running yet, possibly thanks to a build error, I'm guessing if it comes to it we have a right to a refund, or exchange for an engine that's fit for purpose?

Any advice very welcome, please excuse my misuse of technical terms. Thank you very much!

[ELVIS]

Are you using the original pump/pulleys off the 1.9?

Take the plastic cam cover off and with engine running do any pulleys look out of true when looked at individually?

Long straight edge across two pulleys at a time. Crank to cam. Cam to pump. Pump to crank.

Correct cam belt kit - is it the tensioner sitting too far out?

[max and caddy]

I have had this issue in the past...it s the bracket for the pump, solution is remove the pump, loosen the brackets 3 bolts to the block,push up on the rear of the bracket ( turn it anti-clockwise on the block) and re tighten...I know it barely even moves...but it works...I will try and find a link to the VW bulletin as i can imagine your mechanic will struggle to believe this information...as did I...untill I did it!

[max and caddy]

Here you go..don't worry about the first bit about the tensioner...also ensure the block and bracket are clean on the mounts...no paint build up, rust, etc..

http://i13.photobucket.com/albums/a269/ ... ical-1.jpg" onclick="window.open(this.href);return false;

I'm assuming this bracket from a 1.9 is what your using? not a "plate" taken from the JX engine? the correct part is a fairly heavy casting and unlikely to bend...

[sopranolady]

That bulletin page is really helpful thanks! I will share it, and your advice, with our mechanic and see if this fixes things. It's good to hear it might be a relatively simple thing!

I wasnt sure what the word for the 'plate' was, but yes it's the bracket pictured in the bulletin. I agree it seems odd for such a tough thing to be bent - the engine manufacturer didnt believe it either although they were willing to send a replacement. I will see it we can get a photo of the two side by side.

Thanks very much for your quick responses, wish me luck!

[max and caddy]

Good luck...maybe the bracket came off a scrap car...scrapyards tend to remove engines with excavators these days so bent parts are not unknown...hopefully your sorted now.