BKD rough idle - suspect timing wrong

Hi guys, so I bought an old Mk5 Golf 2.0 TDI BKD engine. And a scan returned several faults - one of which was the camshaft sensor - so it took slightly longer to turn over. As this involved removing the timing belt I gave this job to it my local garage (who seem great). Now no fault and it starts bang on first crank. But it's so lumpy now! They advised me that my injectors needed servicing, and that's what's causing the lumpy idle. however the cost of servicing injectors are high, and since having the car for a month I needed to change the DMF/Clutch/Slave cylinder, then my injector/glow plug was playing up so changed the loom and glow plugs whilst there. Then the freewheeling clutch pulley was seizing - causing then you engine the rattle hard - drive belt tensioner was bouncing. So it's had a new alternator clutch pulley, tensioner and belt (why not for an extra 8 quid?!). So it's had lots of work done that I didn't initially expect. So that's the history. All labour at same garage. So I'm concerned with this timing, thinking that it's off. I've been researching loads and about torsion values and my baseline reading is way off! So far that I don't know what or how this has happened?! I'm hoping you guys or girls could advise me what to say to the garage? Also my idle fuel consumption is low either 0 or 0.2L! So surely something hasn't been timed correctly? Please help and see pictures of vag-com vcds screenshots. Oh and the car doesnt feel as nippy as it did! It's worth noting that when extra load is on the alternator (headlights and heater or AC) then the rough idling virtually disappears. I plan to upgrade the car - turbo and injectors - hence why I don't want to fork out for servicing these ones really!
Many thanks.
Dean

Something isn't right. In measuring block 4 the Torsion value S/B about minus 4 to plus 4. Usually, a Torsion value of minus 62 would revert to a never changing value of Zero meaning that the minus 62 value is not reliable and ignored by the ECU so it uses a default value of zero.

That's what I thought from reading about! But I kinda need some expertise mechanical explanation to go back to garage. Not be like "this value here should be between -4/+4, fix it". Cos I swear the timing needs altering to get it sweet. But I got no good datum to work with.

You might have some broken rockers with the front cam so far out, these are so easy to time up I can't see how it's so far out! You want to be at +1 (ch4) on the front and 0.6 on the rear (ch15)

The BKDs are usually a tiny bit lumpy but that's just way too far out, the worst I've ever seen.

Excellent news! Back to the garage. Many thanks.

No need to remove timing belt to change the cam sensor. It's tricky, but doable. I suspect improper timing belt reinstallation.

JB05 said:

No need to remove timing belt to change the cam sensor. It's tricky, but doable. I suspect improper timing belt reinstallation.

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Really?! On the 16v BKD?! I looked at it and couldn't think how to do it without dropping or lifting the engine and removing the belt. Anyways... This lumpyness has gotten worse since they have fitted new glow plugs and wiring loom.

I'm going to garage tomorrow morning. See what they say?!

If the engine is running irregular by meaning the same cylinder sounds weak, it is either cylinder compression or fuel injection. Certainly, since the PD's as a whole have valve lobe profile issues, the easiest thing is to examine the lobes.

If the issue is a general rough running, but not applicable to a single cylinder, then I would tend to think it is overfueling.

In general, the PD's tend to have lumpy running due to a exhaust valve lobe that is badly worn. Galling on the base circle is the usual obvious sign, but loss lobe height/ worn lifter is the cause of the symptom.

Franko6 said:

If the engine is running irregular by meaning the same cylinder sounds weak, it is either cylinder compression or fuel injection. Certainly, since the PD's as a whole have valve lobe profile issues, the easiest thing is to examine the lobes.

If the issue is a general rough running, but not applicable to a single cylinder, then I would tend to think it is overfueling.

In general, the PD's tend to have lumpy running due to a exhaust valve lobe that is badly worn. Galling on the base circle is the usual obvious sign, but loss lobe height/ worn lifter is the cause of the symptom.

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Thanks for this technical information . But would this affect the torsion value as shown?

I didn't see that crazy torsion value number earlier. As far as I know, that number is virtually impossible. We have had bonified torsion value numbers of -5.7, but once you get outside a mechanical range that the cam sensor should be able to read, the ECU reverts to a 'default' 0. Basically, a 'no read'.

The engine will start with a 'no read' cam sensor, only not as well. I definitely would suspicion the cam position sensor as faulty and replace it. You may want to check pins back to the ECU to make sure none are open or short to ground. Although the brown lead should be ground.

Before I would ever get the injectors worked on, I'd be making sure that 1) the cam is not badly worn. The injector deviation could be all about a worn cam. 2) I would use a injector purge to clean the injectors before spending a ton of money on 'fixing' injectors. We have found very often that running products like LubiMoly Diesel Purge, run directly into the tandem pump, then back to the can; run until the can is empty (put an inline filter on the suction side), will often get injectors that are misfiring or out-of-range running well again.

You will not be happy if you find your 'repaired' injectors come back doing the same thing and your cam was worn out. Even worse, if the injectors either lose fuel economy, as is many people's interest, or end up in worse condition than they were to begin with. These two simple, inexpensive methods should be attempted first.

Inspect the cam by checking to see if the cam chamfer on #1 lobe is gone and the edge is sharp enough to cut you. If that is the case, on average, we find that .015" is worn off of the cam lobe, or more than 2x the wear limit of .006". Actually, you should check each lobe, but exhaust are where most wear occurs. #1, 3, 6 and 8 are exhaust valve lobes. The other dead-giveaway is galling on the base circle of the cam.

So, first, fix the obvious problem cam, cam followers, cam sensor. Then see if the injectors really need the service. You are "putting the cart before the horse".

BTW: Your fuel consumption numbers are a wonder...0.0 is impossible, so that is a 'no read' number. At idle, we use that number, along with idle balance and fuel economy for the setting of the cam's torsion value setting. Idle, .6 lph and 2000rpm, 1.8-2.2 lph for a BEW engine is appropriate.

Franko6 said:

BTW: Your fuel consumption numbers are a wonder...0.0 is impossible, so that is a 'no read' number. At idle, we use that number, along with idle balance and fuel economy for the setting of the cam's torsion value setting. Idle, .6 lph and 2000rpm, 1.8-2.2 lph for a BEW engine is appropriate.

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Many thanks for the information here. I shall investigate. Thank you again.