Low power after head rebuild

**ryan1396** · 01-01-2014,02:26 AM

The timing belt was done by a mechanic as I'd never set one of these before. He's done quite a few PD's although I have noticed the belt seems too tight (slight whine from it)
I have a known good AMM but it's from a 115 PD engine and a different part number. I just find it odd that the AMM could be faulty after simply rebuilding the car, although they are a fragile unit, so maybe it's got knocked about whilst it was stripped from the car.
I may buy a new AMM, blank the EGR as I know it's definitely not working as it should be, and go from there.
Really driving me nuts this

**Crasher** · 01-01-2014,02:46 PM

Do you know if he used a pulley locking pin and crank locking plate? Setting the timing doesn’t require any special tools above what a normal mechanic should own so if the timing belt is too tight, alarm bells starting ringing as that is the easy bit so I go straight back to basics, peg and plate and set up before doing anything more. With a rebuilt head on a PD you have to know the cam timing and injector stroke are perfect as if they aren’t you are wasting your time going any further.

The 115 AMM is useless to you. If you do buy a new one it MUST be the exact correct part and only purchased from a VAG main dealer or TPS, absolutely nowhere else no matter what anyone else says, this way you can be 99.5% sure that the new AMM will be perfect so you can fit and forget.

Which year is the car and is it an AWX or AVF? Do you know if it has the hydraulic or friction belt damper?

**ryan1396** · 01-01-2014,04:54 PM

The car is a 2001 with AWX engine, and it uses the hydraullic damper
Yeah the mechanic who set the belt used the correct timing tools. The whine from the belt isn't that noticable (some people say they can hear nothing, but I can). The company who did the rebuild of the head have an extremely good reputation with VW engines, especially PD's, but yeah I can appreciate what you're saying about the injectors.

I am going to order an AMM when my local VW dealer re-opens, and get the EGR either removed or replaced.
If that doesn't solve it I'll check the injectors and get the timing re-checked. A real pain having to go through this all again though, but has to be done
Many thanks for your help

**Crasher** · 01-01-2014,09:08 PM

Leave the EGR system for now and do not ultimately remove it, that makes me very grumpy....

The hydraulic damper system is a complete **** to set up, ask your chap what he set the "gap" to.

**ryan1396** · 01-01-2014,09:23 PM

He set the gap to 4mm, and I rechecked it after he had left too

**Crasher** · 01-01-2014,09:44 PM

Excellent. So now we are sure the timing is correct but you could do with checking the belt tension ALTHOUGH what is shows when it has been run is not representative, you have to de-tension and start again but I am happy the relationship between crank and cam is correct. Next you need to check the stroke clearance on each injector to make sure it is within 180 degrees of bind point at max injector lift, for each cylinder. I do this with a dial gauge and use a blade to mark and set my start and end of lift points on the pulley for each injector so I can accurately find the centre point of lift dwell.

Find maximum lift

Use a blade to mark the start and end of peak lift so you can see where lift is reached and starts to fall again and then back off 50% to find the centre point

Turn adjuster clockwise until a firm stop is felt

Use a protractor to wind back 180 degrees

Make a note of roughly how much you tighten it down before backing off.

**ryan1396** · 01-01-2014,10:06 PM

Many thanks for that. I'll get my DTI and stand from work on Friday and get it done as soon as I can.

**ryan1396** · 02-01-2014,03:30 PM

Okay managed to get this done today. Checked the angle as i was tightening the adjuster, and 3 of them were set to roughly 225 degrees, and one was set to roughly 205 degrees. Set them all to 180 degrees and it definitely helped a little. Sounds alot better on startup, but still some smoke and roughness when idling from stone-cold. It's definitely a little more powerful than before, but still nowhere near what a 130 should be

**Crasher** · 02-01-2014,05:25 PM

Well it's progress and we now know the timing and injector lift are spot on so for me the next step is a genuine VW TPS supplied AMM.

**stevegrass777** · 08-01-2014,05:48 PM

Originally Posted by ryan1396

Yeah the head was rebuilt and setup properly by a reputable engine overhaul company. AMM readings look to be fine (from my limited knowledge of VCDS anyway).
I'll make up a couple of blanking plates for the EGR and try that. By the looks of the diaphragm inside the EGR it had melted and split. I do recollect the inlet manifold was left very close to a pile of burning rubbish when it was removed from the car (long story!), so thats probably whats happened to it

If the egr diafram is split won't this leek vacuum and leave the turbo on less than full boost.
If you don't mind the fault code you could try taking the pipe off the egr and put a small bolt in and get the egr replaced if it works.