Would Tensioner Cause Incorrect Exhaust Cam Alignment??

Sharkie1976

Sharkie1976

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Hi all.
I am going to be taking a look at my timing this Saturday.
My car is an A3 2.0TFSI (BWA engine) 57 plate.

After looking at the timing last weekend I noticed that with the bottom crank pully being lined up on TDC (after several rotations), the top exhaust cam is sitting HALF a tooth retarded (anti-clockwise) of the timing mark on the cover.
Would the tensioner being TO TAUGHT effectively cause this? therefore pulling the exhaust cam round anti-clockwise?
Hope you can help guys.
Best regards.
 
No. The belt won't stretch that much. However it isn't uncommon for there to be a fair bit of innacuracy in the belt train on any belt driven engine due to lack of consistency in production machining.

Dave
 
Thanks for your reply. I think your right that it wouldn't stretch. What I think has happened is when the belt was last fitted. They got the timing marks lined up, then activated the belt tensioner and didn't turn the crank around 720 degrees to let the tension take effect. Therefore the exhaust cam has retarded half a tooth back from tdc. My plan is to set the exhaust cam one tooth clockwise (1/2 tooth advanced), then activate the tensioner and rotate the crank a few times and hopefully the timing marks will line up ok. Does this sound about right my friend?
 
Dvapower said:
No. The belt won't stretch that much. However it isn't uncommon for there to be a fair bit of innacuracy in the belt train on any belt driven engine due to lack of consistency in production machining.

Dave
Click to expand...
 
Yeah it sounds like when the belt was fitted the slack has been on the wrong side of the belt and once tensioned has allowed it to move.
As you say either make sure there's no slack on the non tension side or move it forward enough to compensate for tensioning.
 
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Marshy said:
Yeah it sounds like when the belt was fitted the slack has been on the wrong side of the belt and once tensioned has allowed it to move.
As you say either make sure there's no slack on the non tension side or move it forward enough to compensate for tensioning.
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Thanks Marshy.! That's just what I wanted to hear. Glad that you have confirmed for me.
Looking forward to getting it sorted mate!
Hopefully cure my idle judder once and for all. Cam being retarded is definitely not helping.
Nice one fella.
 
Yeah they idle lumpy and are down on power when running like that.
You'll notice a difference.
 
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Marshy said:
Yeah they idle lumpy and are down on power when running like that.
You'll notice a difference.
Click to expand...
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Just curious Marshy, but the intake cam (not sure what it's called, variable) will adapt itself via the ECU?
 
audi upgrades
The ecu will have adapted to run its best with the timing out. Although the belt only goes round one pulley the cams are timed together on the other side via chain.
So if your cam is retarded at the belt end then both cams are retarded, the variable valve timing will still be working via ecu but you won't feel the benefit since the basic timings out.
 
Marshy said:
The ecu will have adapted to run its best with the timing out. Although the belt only goes round one pulley the cams are timed together on the other side via chain.
So if your cam is retarded at the belt end then both cams are retarded, the variable valve timing will still be working via ecu but you won't feel the benefit since the basic timings out.
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So correcting the exhaust cam will effectively correct the other cam?
Sorry for so many questions. Just trying to get my head around this bit.
 
Yeah if the timings out at the belt end and you correct that then both cams will be timed correctly.
The only way the timing would be out on the other cam is if someone had stripped that side of the engine down.
Something that's not touched during belt replacement.
So mate get your timing sorted at the belt end and it should be smooth as silk, it may take a few miles to fully adapt for you to get the full potential but you'll notice the difference.
 
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Marshy said:
Yeah if the timings out at the belt end and you correct that then both cams will be timed correctly.
The only way the timing would be out on the other cam is if someone had stripped that side of the engine down.
Something that's not touched during belt replacement.
So mate get your timing sorted at the belt end and it should be smooth as silk, it may take a few miles to fully adapt for you to get the full potential but you'll notice the difference.
Click to expand...
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Thank you ever so much Marshy! You are a legend mate, and I really appreciate your help, guidance and your time. Nice S3 by the way mate!! Bet that goes like s**t off a stick!!!!
:racer::racer::racer:
 
You can only be one tooth out, not 1/2 a tooth out, if there was slack on the driven side then the pulley will rotate by one or more teeth to take it up, you cannot be half a tooth out unless the belt train itself has innacuracy.

Dave
 
Marshy said:
Yeah it goes well mate.
Keep us posted how you get on.
Click to expand...
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I bet it does mate. I'd love one myself., but happy with what I have for a while.
Should I expect a better MPG once timing is sorted?
I will of course let you know the outcome.
Cheers chief.!
 
If its 1 crank tooth out then it'll appear as 1/2 tooth out on the cam.
If you line the cam up you'll find the crank is 1 tooth out.
 
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Dvapower said:
You can only be one tooth out, not 1/2 a tooth out, if there was slack on the driven side then the pulley will rotate by one or more teeth to take it up, you cannot be half a tooth out unless the belt train itself has innacuracy.

Dave
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Yes Dave I realise this now. I just looks visually 1/2 a tooth out. It's one tooth retarded, looking forward to getting it sorted.
Cheers for the post.
 
It will still be a tooth out, that may be represented by fewer degrees of rotation as the cam sprocket has twice as many teeth, but It will be a tooth out. If it appears 1/2 a tooth out then there is innacuracy in the system, if you advance the cam by one tooth then it will be half a tooth out in the opposite direction.

Dave
 
Hi guys.
Very long story, so I'm gonna give you just the short version.
Specialist that did timing belt kit a few months back installed the tensioner incorrectly. It wasn't even located it the cutout in the engine block, therefore rattling around against a poece of plastic (very lucky not to have killed my engine). Belt pulled off easily as it wasn't tensioned properly. Belt was already showing wear marks where it had been rubbing on the case and loads of plastic/rubber debris everywhere. The covers had wear marks where belt rubbing was rubbing on them too. NOT AT ALL PLEASED AT THIS POINT!!!

Re-built with new kit, timed up to the proper marks. Runs a treat..!!!
Idle judder is still present, but not as bad.
First start in the morning is still hit and miss.
Any ideas lads......coil packs???
Cheers for your help and shared info.
Rob.
 
Sounds a real bad job mate.
Hopefully that side's sorted now though.
Have you had the car plugged in to see if theres any trouble codes stored?
Pretty common for coils and plugs to give the symptoms you describe.
When did it last have the plugs changed?
You can buy 4 genuine coils and plugs for about £100
 
Ah ha, Marshy me old buddy.! Thanks for helping me out before mate. It's was a b**tard but sorted that side of it, and I was lucky to have found those problems when I did. Phew!!! I was not a happy bunny to find this kind of incompetance from a specialist.:mad:

Yeah, I've had my car plugged in on a Snap On diagnostics machine. The only code that was present and keeps presenting itself is P0441 (which is EVAP related). Not sure if it's the cannister, split hose (although I have checked the best I can and they seem fine), purge valve (although I can hear the solenoid clicking away). Also whilst running live data, I popped up with a mis-fire probably once every couple of minutes, but it doesn't tell you where or what (how annoying).
I changed plugs about a month ago from standard VW/Audi ones to NGK Platinum plugs. They say that the plugs are pre-set to the correct gap, so I fitted them as they were. Although the gaps looked slightly smaller than what they should be.
Do you know if these coil packs are any good http://www.awesomegti.com/car/audi/a38p/genuine-vag-ignition-coil-pack-set-2-0tfsi-es260103 and if they are infact OEM like stated.???

Thank you so much again mate for your time. I do really appreciate your help. :):):)
 
Yeah they're the right coils but most including me get the red R8 coils which are about £10 more expensive.
People say they're uprated but it maybe just that they're red!
It may also worth looking on Samtech performance website.
Thats who I use for all my stuff and I'm friends with the owner Kris
 
Marshy said:
Yeah they're the right coils but most including me get the red R8 coils which are about £10 more expensive.
People say they're uprated but it maybe just that they're red!
It may also worth looking on Samtech performance website.
Thats who I use for all my stuff and I'm friends with the owner Kris
Click to expand...

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Cool. thanks mate. I know my car isn't as big a beast as yours, so I wasn't sure if the R8 ones will be compatible. I'll check it out on Samtech and see what it says about them. It's always good to know someone in the trade mate, can you arrange a discount? LOL.
Speak soon chief!!
 
Marshy said:
Yeah they're the right coils but most including me get the red R8 coils which are about £10 more expensive.
People say they're uprated but it maybe just that they're red!
It may also worth looking on Samtech performance website.
Thats who I use for all my stuff and I'm friends with the owner Kris
Click to expand...
-------
They do the red ones at the other website I sent http://www.awesomegti.com/car/audi/a38p/red-ignition-coil-pack-set-2-0tfsi
The ones you were talking about comes under the S3, and is says they are uprated and ideal for mapped cars (unfortunately mines not mapped). Although it does say any tfsi engine.....so not sure, lol.
 
Hey guys! Changed coil packs this evening and no luck I'm afraid. The judder is still there at idle :(.
Not sure where to go from here tbh. Any suggestions??
Thanks.:keule:
 
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