Gti6 Cam Timing

[2052006 10]

I have had my gti6 engine running, however, there is a slight whine when giving it some throttle. I presume this is because the cambelt is slightly too tight and needs the tension slackened off a bit. I have first slackened off the aux belt to check it's not that - made no difference. I have fitted a new cambelt, waterpump, tensioner and roller by the way.

 

On checking the timing holes match up, I have a slight concern:

 

How precisely do the timing holes have match? ie. I believe the crank pulley is meant to have an 8mm pin and the cam pulleys 6mm. However, I can only get them locked if I use a slightly smaller one namely 7mm and 5mm, as the holes are a tiny bit "out", meaning th proper sizes don't slip in properly. How exact do they need to be? I need to sort this first, before sorting the tension.

 

Pete

[Tom Fenton 1,542]

That is the purpose of the 2 piece pulleys- to allow the cams themselves to be locked in place, whilst the pulley outer rings can move with the belt, to allow the belt to be tensioned without affecting the cam timing. The Mi engines for example use 2 tensioners as an alternative method which allows solid pulleys. Get the timing holes lined up as accurately as you can.

 

Also make sure that the crank pulley is accurate, if you have one use an 8v pulley for the timing hole.

[2052006 10]

OK, so if I remove the belt again and use an 8v crank pulley just to be sure, can I then just move the cams individually (obviously not very much) so that they match up excactly?

[Tom Fenton 1,542]

The belt can stay on.

[gti-si 0]

Which cam pulleys do you have? Are they the free moving ones or the earlier type which have three bolts?

 

You pin up the 3 holes as said, then rotate the cam pulleys fully CLOCKWISE, to do this if you have the earlier type slacken off the 3 bolts on each pulley. Then when you tension the belt, as said, the pulleys will move slightly setting the correct tension between the pulleys but will not move the cams so they remain in perfect time.

 

Don't move the pulleys individually, if you hit the top of a cam lobe, they'll spin fast down the duration and you could end up hitting valves together.

[2052006 10]

Cheers Tom. I have just removed my old 8v pulley to use that (wish I had used this to check in the first place). How will the cam sprockets move with the belt still on though? Is it the case, that with the tension off, the cams will be able to move individually?

[2052006 10]

OK, I understand about the tensioning using the two piece cam pulleys, but I just want to make sure of the timing first of all. If they are slightly out, how do I set it correctly, without moving them individually (albeit only a mm or two).

[welshpug 1,657]

put the pins in

[Pob 1]

put the pins in

 

I replace the cambelt on my 406 last week and I over tightened the belt to begin with. I just simply stuck a 8mm allen key in the cam pulley, Some M8 bolts in the timing holes loosened the tensioner bolt slightly and slackened the tensioner off. Don't worry about the cams and crank to be locked solid, As long as the pins/bolts stay straight you shouldn't have any problems. The timing holes would be totally off if you got it a tooth out, once you've nipped the tensioner back up give it two rotations and pop the bolts/pins back in to check timing.

 

Dan

[BuD 0]

I have also done what pob says on a gti6 engine and it worked well, i only needed to loosen it a fraction tho.

Edited July 19, 2009 by BuD

[Paul_13 212 1 Cars]

Sorry to but in, but i read something Anthony posted a while back about checking the belt tension: It should turn 90degreed with light finger tension.

Is this still correct with the GTI6 engine?

 

I am having problems with a whining 6 belt myself (136t)

Edited July 19, 2009 by paul_xiii

[fast_eddie 0]

My Mi has always whined like a bitch and caused me great concern, but I checked and re checked everything and it made no difference at all. New seals pump, bearings everything--still the same 'just not quite right noise' that you know sounds strange...Anyway, it made great power, never went wrong(yet) and didnt chew belts....

Would love it to purr but it whines a little instead lol!!--Infact, its not really a whine its more like a whirrr if that makes sense? but its not a sound that sounds right?--Ok ill stop now !!