Did I ruin my VVT or have I got my cam timing wrong?

[Splab333]

After a crack developed in my head (2001 AMK S3) I found a suitable recently re built AGU head that I was able to get at a good price to use on my car. I swapped all of the S3 components over to it today and put it all back together but I've lost loads of low down power / torque. It now seems to get going at around 4000rpm and is certainly feeling sluggish compared to before.

I have a feeling it's the cam to cam timing, I triple checked the cam belt timing and I'm certain that is spot on but I wonder if I'm getting confused with the 16 rollers count from exhaust to inlet on the chain.

First off though, when I installed the 3366 tensioner compression tool, the curved nylon type runner was flush with the two prongs that the tensioner tool sits between. Pretty much like in this picture, if not even a little higher than this.

After I compressed it and swapped the cams over, the cam notches didn't seem to line up, the ex cam notch was a little towards the back of the head and the inlet notch was a little towards the front of the head. This looked wrong at first but then I realised that the VVT tensioner had only sprung back half way up the prongs so it looked like when it is pressurised, it would rise up and pull the cam notches towards the centre of the head. It seemed to make sense but after a disappointing test drive, I took the valve cover off and the tensioner was still only half way up the prongs.

Could the tensioner be damaged? (I don't think I cranked it too far with the 3366 as I imagine the plastic would have broken on my cheap ebay tool if I tried to wrench it)
Or is the inlet cam a roller out and causing the tensioner to sit lower than before as the incorrect position is causing a cam lobe to be under tension from the valve spring, pulling the chain tighter and pulling the curved part lower?

I'd really appreciate any input as I'm totally lost with this and am dreading the prospect of removing the cams again as taking the tension of the cam belt tensioner on the other side is a nightmare!!

Thanks to any input, sorry for the long post, I should have taken pictures along the way!

 

[Splab333]

I've just found this, a lucky shot that I took earlier without realising it's usefulness! Obviously in the picture the ex cam isn't at TDC but can you see how if at TDC, the inlet cam notch would be passed the arrow but If the tensioner was all the way up, the inlet cam would pull in to the centre? Maybe at full height the difference is tiny though so it is actually a roller out? The VVT tensioner does fully extend when I turn the cams over by hand but at TDC with this possibly incorrect timing, it pulls the chain tight, pulling the tensioner down.

 

[Stuart B]

Whilst I was doing mine I was informed a fault would occur when the cam to cam timing was out, do you have any fault codes.

 

[Splab333]

I read this too this afternoon as I hoped it would bring up an engine light, but nothing showed up on the dash. I haven't scanned for codes as I didn't have my laptop but I will asap, someone on another forum said it may not bring up a code all the time but I imagine 1000s of unexpected hall sensor reading a minute would flag up surely. I may have to go and prise the laptop away from my wife and check now. Thanks for your input

 

[Splab333]

Oops, the image I was referring to in my OP was this one and it's about the same, not any higher like I mentioned (different pic originally)

 

[Stuart B]

this is the image from ross-tech - it looks wonky and confusing to me.. as not the teeth either side or between the marks.

essentially if the mark is on a tooth and the roller is counted on the outside of the tooth if the mark is on a gap the roller is counted on the mark.

 

[Splab333]

Awesome, thank you for your help and input, I think it's cam cover off time to check again.

 

[superkarl]

From when I timed mine up wrong

Sent from my iPhone using Tapatalk

 

[Stuart B]

where is this bit of your engine?

 

[myth]

I find confusing counting the teeth, but in this picture it is clearly out of sync.The exhaust cam is one tooth jumped.
You can take out the intake cam out(including the hall sensor), jump a tooth on the exhaust cam, then reinstall. This was, you don't need to touch the timing belt.

 

[badger5]

After a crack developed in my head (2001 AMK S3) I found a suitable recently re built AGU head that I was able to get at a good price to use on my car. I swapped all of the S3 components over to it today and put it all back together but I've lost loads of low down power / torque. It now seems to get going at around 4000rpm and is certainly feeling sluggish compared to before.

I have a feeling it's the cam to cam timing, I triple checked the cam belt timing and I'm certain that is spot on but I wonder if I'm getting confused with the 16 rollers count from exhaust to inlet on the chain.

First off though, when I installed the 3366 tensioner compression tool, the curved nylon type runner was flush with the two prongs that the tensioner tool sits between. Pretty much like in this picture, if not even a little higher than this.

After I compressed it and swapped the cams over, the cam notches didn't seem to line up, the ex cam notch was a little towards the back of the head and the inlet notch was a little towards the front of the head. This looked wrong at first but then I realised that the VVT tensioner had only sprung back half way up the prongs so it looked like when it is pressurised, it would rise up and pull the cam notches towards the centre of the head. It seemed to make sense but after a disappointing test drive, I took the valve cover off and the tensioner was still only half way up the prongs.

Could the tensioner be damaged? (I don't think I cranked it too far with the 3366 as I imagine the plastic would have broken on my cheap ebay tool if I tried to wrench it)
Or is the inlet cam a roller out and causing the tensioner to sit lower than before as the incorrect position is causing a cam lobe to be under tension from the valve spring, pulling the chain tighter and pulling the curved part lower?

I'd really appreciate any input as I'm totally lost with this and am dreading the prospect of removing the cams again as taking the tension of the cam belt tensioner on the other side is a nightmare!!

Thanks to any input, sorry for the long post, I should have taken pictures along the way!

you have indeed lost port velocity going to largeport head which will loose you torque.. Thats why its not the correct size of head.
any fault codes relating to cam position or correlation error?

 

[Splab333]

Ah wow, thanks for all the replies, I thought I'd subscribed to my thread but I didn't get any notifications!
Thanks for everyone's input, it's super helpful as I'm really struggling with this.

There are some developments however, the more profound lack of power was down to the knock sensor plug not being fully pushed on, after a few miles VCDS gave me a code which made me double check the connection and hey presto, about 100bhp more.... That was awesome but now I'm still second guessing the cam timing anyway as it just doesn't seem to pull like it did (with the cracked head).

Although thanks to Bill's post above I wonder if it is the AGU head? I'm not getting any codes for the cam timing, should I expect to definitely have had one now after about 15 miles of driving if the inter- cam timing is wrong?

Is there a big difference in torque with the lost velocity? I'd read up on it before about being not noticeable but having the benefit of allowing better flow in BT applications, it might be a case of hearsay on the internet saying it will be fine, have a made my car a lot slower with the large port? I certainly didn't buy it for 'upgrade' reasons but it was recently reconditioned and at a good price where the other options were junk heads on ebay with questionable history.

When the turbo starts to boost, it kind of feels lacking compared to how much I can hear the turbo. I've had the cam cover off again today and taken some pictures this time, I checked again and again for the 16 rollers and was so sure that it was correct but now I'm doubting it again as the pictures seem to look out because of the angles.

I'd truly appreciate any input from the pictures below as it seems so close that one tooth either way would make it miles out? That said, the height of the tensioner changes when I turn the engine over by hand so it's really hard to tell.

 

[Splab333]

From when I timed mine up wrong

Sent from my iPhone using Tapatalk

Thanks, it shows how close it can be although I can see on yours how much more compressed the tensioner is than normal at TDC

where is this bit of your engine?

This was an image from google, not my head, sorry if it caused confusion, it was just to illustrate the height of the tensioner.

I find confusing counting the teeth, but in this picture it is clearly out of sync.The exhaust cam is one tooth jumped.
You can take out the intake cam out(including the hall sensor), jump a tooth on the exhaust cam, then reinstall. This was, you don't need to touch the timing belt.

Yeah, this image looks miles out yet it hasn't been changed between the times of that picture (head off the car) and the one above (head after 15 miles of use) which looks right (?)
I feel like my head is going to explode! I had a pretty messed up year with Meningitis and Encephalitis and a little bit of brain damage (yay) so this is maybe stressing me out a bit more than it maybe would have before!

Thanks to everyone again for the input.

 

[Stuart B]

Jesus - just watch Netflix or Amazon prime boxsets and leave the car for a bit buddy.

This was mine if it is any help.

didn't Bill suggest your issue is the large port head?
When I was concerned about my timing was informed (by tuffty) strange error is logged if cam to cam timing is out "ground to zero" or similar.

what actual errors do you have from VCDS?

 

[Splab333]

Hopefully this shows it's correct? And hopefully it's clear enough if zoomed in a little...

I've outlined where the valleys in the sprockets are as well as the corresponding rollers and where I think number 1 roller is as like in the workshop manual, and rosstech diagrams, 1 is to the left of the spike on the pulley and 16 is in the centre of the valley.

The red arrows illustrate where which valley is going to be occupied by which roller if the engine was turning anti clockwise.

 

[Splab333]

Thanks again Stuart I haven't had any codes for timing, just the knock sensor one.
So would it bring up a code immediately?
Indeed, Bill's statement left me with a lump in my throat as it seems very possible to be a result of the head, but I'm really surprised at how much torque is lost from the bigger ports, it feels like a totally different car, and not in a good way! I guess I'm just hoping that someone will come along and confirm that the cam timing is wrong and I'll get it sorted and forget about it. Changing the head again wouldn't be so easy

 

[Stuart B]

I think only prawn and tuffty have large port heads in their cars as regular posters.
I don't have any knowledge of this but if your knock sensor thinks its knocking isn't it retarding the timing for protection.
Can you log the car? With me7logger the default profile will include knock voltage and ****** angle for each cylinder.

 

[<tuffty/>]

Whats the knock sensor fault code?

<tuffty/>