Cambelt Tensioner - It's gone again!

Si_GTi · Post by **Si_GTi** » Wed Oct 20, 2004 1:41 pm

ttaw2 wrote:"If only everything in life was as reliable as a volkswagen"... Ironic!

Yup, you might have noticed they've changed the official tag to something like "aus leibe zum automobiles" or something like that. Wonder why?

Post by **Josh_PoloGTi** » Wed Oct 20, 2004 6:10 pm

Hmmm, if the cam belt has slipped then that would make sense, the timing would be well out.

When my tensioner went, it just sounded REALLY "tappety" under 3k rpm...

Above that was fine, as the speed of the cam belt was tightening itself up... But above that it was pretty slack.

Luckilly there was no damage, so I replaced both timing belts (the big one, and the little one that goes between the 2 cams) both tensioners (even though only one had broken) and the water pump (just for good measure).

Like I said, keep us up to date with how it's going.

ttaw2 · Post by **ttaw2** » Thu Oct 21, 2004 8:54 am

Josh_PoloGTi wrote:Let us know how you get on mate...

The bloke who bought my GTi sent me an email last night telling me that his won't rev over 5k and it takes ages to get there... He said it feels like there's no power...

Sounds like a similar problem doesn't it...

He mentioned that it feels like there's something limiting it revving over 5k... Dunno about missfiring though.

Anyway, let me know so I can pass on the details to him.

Just had a thought, if it's doing it when it's cold, don't all the gti's do this after startup untill the engine temperature reaches a certain point.. I noticed this on mine (when it was working properly) really early in the morning sometimes when it was cold outside...

Sorry if I'm telling you things you already know

ttaw2 · Post by **ttaw2** » Thu Oct 21, 2004 9:53 am

A prize for those who diagnosed cambelt pre-tensiorer.. 100% correct.

Just spoke to the garage and it's definately that.. Â£411 to replace that, and to replace the water pump, which was leaking apparantly, which they're going to do for parts.. At the end of the day, if i'd taken it to VW, they'd have charged me for the 3 days of diagnostic work that it's taken to find the problem, and these guys aren't charging for the diagnostic at all so I don't think they're trying to rip me off...

Does the price sound okay (Bearing in mind they've had to take the engine out to find the problem)

If this is all it is then I'm not too annoyed, i've just got a nervous wait till monday to see if the internals are okay... fingers crossed

I'm almost tempted to drop a 1.8 in the hole...

bstardchild · Post by **bstardchild** » Thu Oct 21, 2004 10:11 am

ttaw2 wrote:A prize for those who diagnosed cambelt pre-tensiorer.. 100% correct.

Just spoke to the garage and it's definately that.. Â£411 to replace that, and to replace the water pump, which was leaking apparantly, which they're going to do for parts.. At the end of the day, if i'd taken it to VW, they'd have charged me for the 3 days of diagnostic work that it's taken to find the problem, and these guys aren't charging for the diagnostic at all so I don't think they're trying to rip me off...

Does the price sound okay (Bearing in mind they've had to take the engine out to find the problem)

If this is all it is then I'm not too annoyed, i've just got a nervous wait till monday to see if the internals are okay... fingers crossed

I'm almost tempted to drop a 1.8 in the hole...

i've got my fingers crossed for you too...... Lucky escape if nothing is bent or broken

ttaw2 · Post by **ttaw2** » Mon Oct 25, 2004 4:24 pm

Update - Car is now fixed, water pump replaced, as is pre-tensioner and cambelt, service finished... Â£600 all in, which isn't too bad

All that it's waiting for is a new set of HT leads, one of which had started to melt?!? Something to do with an extra high load on it due to the timing being out... Sounds wierd?

Picking her up at the end of the week after they've given it a tune for me!

morrismen · Post by **morrismen** » Tue Oct 26, 2004 8:13 pm

Leads don't melt like that unless they have a huge amount of amps going through them. Remember V=IR (Volts = Amps x Resistance) and V/I= R and V/R = I. This means the resistance would have to have been minimal! If volts was steady at 13 ish, then the fuse would have blown before this happened. I would suggest the lead melted because they melted it.

Post by **Josh_PoloGTi** » Wed Oct 27, 2004 7:40 am

IIRC the HT Leads carry huge voltages, not 13v...

That's what the coilpack does.

morrismen · Post by **morrismen** » Wed Oct 27, 2004 8:45 am

Right, yes the coil increases the voltage. Even so, it's the amps that would melt the HT lead.

ttaw2 · Post by **ttaw2** » Wed Oct 27, 2004 9:50 am

morrismen wrote:Leads don't melt like that unless they have a huge amount of amps going through them. Remember V=IR (Volts = Amps x Resistance) and V/I= R and V/R = I. This means the resistance would have to have been minimal! If volts was steady at 13 ish, then the fuse would have blown before this happened. I would suggest the lead melted because they melted it.

This I realise, I'm an electronics engineer

- but i couldn't think why it would've drawn so much current

As far as I knew, there isn't a fuse between the coil and the plug, it just goes through the dizzie - hence that not blowing.

Thinking about it, if it has melted (rather than them accidentally ripping the head off one of them which I've done before pulling it out, or them melting it as you said), it's probably been shorted at some point - this melts spanners let alone ht leads.

I don't think i've been scumped because they could've charged me for all the diagnostic work. They thought it might be an intake problem to start with, so they've cleaned my intake fully including the throttle body, they did the the injectors, changed fuel filter, flushed the fuel lines - all for free

At the end of the day I don't really care as long as the car works when I get it back..

Think I might keep the car it if it's all okay, i just need to get my rims sorted now... want to stay with 15s but go a bit wider (probably 7 or 7.5)... anyone got any ideas on what offset i'll need bearing in mind it'll be dropped 40 -50 mm at some point in the future.

bstardchild · Post by **bstardchild** » Wed Oct 27, 2004 11:25 am

ttaw2 wrote:Think I might keep the car it if it's all okay, i just need to get my rims sorted now... want to stay with 15s but go a bit wider (probably 7 or 7.5)... anyone got any ideas on what offset i'll need bearing in mind it'll be dropped 40 -50 mm at some point in the future.

I've posted this link before - it's the best web link I've found for comparing wheels tyres ET's and gives the resultant effect on speedo accuracy and gearing if you complete all the details

http://gs.tolan-hoechst.com/tirecalc.htm

You need to do a few measurements on your car to start with but once you have that it's a very handy tool to make sure whatever you buy fits first time....

Worth bookmarking IMHO

ttaw2 · Post by **ttaw2** » Wed Oct 27, 2004 12:31 pm

bstardchild wrote: I've posted this link before - it's the best web link I've found for comparing wheels tyres ET's and gives the resultant effect on speedo accuracy and gearing if you complete all the details

http://gs.tolan-hoechst.com/tirecalc.htm

You need to do a few measurements on your car to start with but once you have that it's a very handy tool to make sure whatever you buy fits first time....

Worth bookmarking IMHO

Cheers for that Bstardchild. The links not working at the moment - i'll try it at home and have a look.. I'm torn between modding my polo, or getting a mk1 golf and screwing about with that instead..

ttaw2 · Post by **ttaw2** » Mon Nov 01, 2004 9:19 am

It's gone again!

More info to follow once i've spoken to the garage....

ttaw2 · Post by **ttaw2** » Mon Nov 01, 2004 9:56 am

ttaw2 wrote:It's gone again!

More info to follow once i've spoken to the garage....

Right - they're picking it up from work for free, ands they're going to have a look at it...

It's ever so slightly different this time, it's misfiring at about 2k upwards, and it's repeatedly backfiring on the overrun... the only problem is that i can garuntee they're not going to be able to replicate the fault at the garage, as it only started about an hour into my journey!

Swear words!

Lots of them!

JWC · Post by **JWC** » Mon Nov 01, 2004 2:16 pm

From what you said it did sound like the valve timing wasn't correct, either because it has jumped a tooth or because there is a fault with the ECU or some feedback loop. It isn't impossible for the cambelt to jump a tooth but it almost is, they should be able to tellif the cambelt is damaged straight away.

The good news is that if it slipped to a point but the engine still runs, no matter how rough, then you have probably got away with it. But I'd be looking at simpler things first. Presumably the ECU noticed something amiss, like a problem with the crank angle sensor causing the timing to go out. If it gets too advanced, you'll find it does sound like a black smith is hammering your pistons. And it can damage your engine. I would be very supprised if you have had a collision with the valves and the piston, so be hopeful and keep us posted. It isn't an engine out job though, although it could be quicker to do that.

Unfortunatley, it can happen to any car, at anytime, vw or not vw.

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Cambelt Tensioner - It's gone again!

eh?

Ah