My Octavia TDi 110 just started to overheat the other day and the heater went cold. I suspected the water pump, and as it turned out I was right. The impeller was spinning freely on the shaft. So I replaced the water pump and the cambelt at the same time. Rather than to use the correct method of timing the engine which is to measure valve lift on No1 with the piston at TDC I referred to the painted marks on the pulleys and casing which had been there since the last time the belt was replaced. After I finished the job I started the engine and it ran perfectly fine, but the traction control light was on. At first I thought it might be because I had the car on my two post ramp at work and had run the engine with the wheels off the ground. Some drive is often transmitted through the gearbox even though it's in neutral, and this often brings on the ABS lamp. I thought the lamp would go out when I drove up the road, but it did not. When I got home I plugged in VCDS and noticed following fault codes.

Address 03: ABS Brakes Labels: 1C0-907-37x-ASR.lbl

Control Module Part Number: 1C0 907 379 K

Component and/or Version: ASR FRONT MK60 0103

Software Coding: 0021505

Work Shop Code: WSC 31480 000 00000

VCID: 3260EA81D4A9

1 Fault Found:

01314 - Engine Control Module

013 - Check DTC Memory - Intermittent

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Address 01: Engine Labels: Redir Fail!

Control Module Part Number: 038 906 012 CL

Component and/or Version: 1,9l R4 EDC 0000SG 3359

Software Coding: 00002

Work Shop Code: WSC 31480

Additional Info: TMBGP21U732691866 SKZ7Z0A1206237

VCID: 5CBC6439E6AD

1 Fault Found:

17656 - Start of Injection Timing Regulation: Control Deviation

P1248 - 35-10 - - - Intermittent

Readiness: N/A

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I cleared the codes but they came straight back, so I checked the base injection pump timing using the TDi Timing graph. I had done this several times in the past and mine was slightly advanced of the correct position. This time it was so far advanced it was off the scale. So a few adjustments later it's now back to where it was before.

Where is this going? Well it just goes to show what a difference changing the cambelt can make to the base pump timing, and that's why the fault codes were generated. The traction control cannot work properly if the fuel injection pump is mistimed, and the ECU cannot accurately control the timing if the base setting is outside the limit. I found out today that a regular check of the base timing can be very worthwhile, and worth checking if any other fault codes are present.

Hope this might help someone out there. Happy New Year to you all......

did you crack off the cam pulley off its taper when refitting the belt? there is no mention of measuring valve lift for doing these engines just line up the tdc mark on the flywheel and fit the cam locking tool and 6mm pin in the pump.

I always set the pump timing back up after road test and its amazing how even just slacking and retightening the bolts on the pump will alter the graph sometimes.

lol just checked back thru this years work log and I've done over 50 vw tdi cambelts in 12 months :think:

No I didn't slacken any of the pulleys, I used the marks which had been painted from a previous replacement. I didn't know about locking the camshaft on this engine and I did look on Autodata too. I didn't see anywhere on the pulley where a pin might fit. It is possible then that the valve timing could be very fractionally wrong because I don't know if the camshaft pulley had ever been slackened before. Assuming they had not the timing could not possibly be wrong because it would have to a whole tooth out, or multiples of teeth. That is clearly not the case otherwise it'd be pretty obvious. Please could you tell me where to find the flywheel TDC mark, and also the camshaft locating point. I will then check the timing again to make sure it's spot on.

Interestingly my engine does not achieve the MPG that others claim their's do. I get about 44-45mpg as an overall average, and I do have a slight hesistation when accelerating. Very slightly retarded valve timing could be the cause so I'd like to double check.

ok no problem, the tdc mark is on the bellhousing at the top of it there is a big plastic grommit to take out and you will see a small pointer there(it is hard to see) there is a tiny mark on the flywheel that aligns with it, the correct way to do the belt is remove the vac pump off the end of the cam and there is a tool that locks the cam via the slot in its end. it can be done with a flat plate and straight edge to make sure the slot is horisontal, then slacken the bolt that holds the cam pully on and I usually give the sprocket a wack in the middle where the bolt was with a plastic mallet, the sprocket is tapered onto the camshaft and may take a few hits to release it.

the idea is to tension the belt correctly with the pump and camshaft sprockets loose (camshaft one just about able to move) so that it is able to easily pull the slack from the whole belt run when you tension it.

when fitting the belt i put the loose sprocket inside the belt and on fit it to the camshaft with the belt already on it it is soo much easier to do.

hope that helps, what autodata were you using as all mine show the correct procedure

oh and I have come across a few that have been out by 1 tooth on the cam and they run ok, i tooth retarded = runs or bit flat but 1 tooth advanced = 8 bent valves if you rev it hard

Edited 1 January, 201115 yr by felicia16v

Thanks for that Felicia16V. We have Autodata at work, and I'm sure it mentioned you have to measure the lift on one of the valves on No.1 cylinder. I will double check when I go back to work on Tuesday. Just one more question please. I've heard mentioned that a 6mm pin is used to lock the pump. Whereabouts on the pump is this pin to be inserted? Presumabley the pin must fit into the pump body and somehow lock the shaft, but I can't see anywhere on the pump a pin could be fitted except for one 13mm hexagonal headed bolt on the right hand rear of the pump casing as you look from the front. I have not removed this bolt because I don't know what it's for.

We may even have a timing tool set at work for an ASV engine. I'll check that when I go back. In the first instance I just want to check that the valve timing is spot on, but if I do have to adjust it the pump must surely have to be locked too otherwise as I rotate the crankshaft (even if only by a tiny amount) with the camshaft locked I cannot be certain that the pump won't rotate with it.

It will either be a 6mm pin or some of them use a larger peg to lock them in place. Depends on that type of pump is fitted. Some the pulley is adjustable (6mm peg) and some are fixed and the pump rotates (larger peg).

Like this

Edited 1 January, 201115 yr by Tech1e

Thanks Tech1e, I appreciate that. I've returned to the motor trade after 3 years away. Previously I worked in a Vauxhall dealership for 15 years, and then a Patrol for both the AA and then the RAC for another 12 years. Things move so fast, and it seems I have a lot of catching up to do.

Looks like it's not necessary to slacken the large nut on the pump pulley? I assume the three smaller bolts need to be loosened which will allow the pulley to rotate by a small amount with the pump locked?

ok yes i use a 6mm pin in the pump, as a pic speaks a thousand words (or more if ite me trying to explain stuff)

timing mark on bellhousing

tool for cam and pump with handy diamensions

where the pump pin goes

if you dont have autodata send me a pm with your email addy and i will email you the screen shots of your engine

oh and pump timing just below the upper line for econemy (around 68-74 in the timing ref figures)

if you dont have autodata send me a pm with your email addy and i will email you the screen shots of your engine

Cheers Felicia16v, PM sent.