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Discussion Starter #1
I am using VCDS-Lite and it shows my timing to be retarded. It's still on the chart but below the bottom line. How do I sort it?

I have spent ages reading all sorts of threads about this and am much more confused then when I started. Some people talk about adjusting the cam sprocket, some about undoing three bolts on the pump and adjusting something with a 22mm spanner, some about undoing the pump pulley and advancing retarding it. Even others talk about adjusting the tensioners and idlers to make a small adjustment. I can't find anything that looks definitive about this.

It might fall into place a bit more when I get the timing cover off but it would be really nice to have a clear idea about how I'm going to proceed.

Can anybody help?
 

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It should be adjustable enough using the adjustment on the idler/tensioner pulley.
Done with the engine up to temp and running..so watch your fingers!
Spanner on the pulley bolt, and an allen key in the centre to adjust.
When you get it right, tighten the nut back up.
You either need to be able to see the laptop screen, or have 2 people to do the job easily....otherwise it's adjust one way, tighten the nut and then check the screen....possible but time consuming and frustrating.

IF you have to adjust the pump pully, note it is a taper fit....chances are you'll need an air ratchet to undo/tighten it, and moving a FRACTION of a degree is all that's needed (unless the belt has jumped a tooth!)

Forget the 3 bolts....that's not for the 2.5 TDi.
 

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Problem I found....even with the laptop on the dash, screen to window, there's that big lump of metal called a "bonnet" that stops you seeing the screen! LOL (And I did have the advantage of LHD, so the laptop rested on the steering wheel, so was at the correct side.)
You adjust, holding the tools, bend/twist to look at the screen, and suddenly feel your fingers losing skin on the belt!
BE CAREFUL. (y)
 

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Discussion Starter #5
I have a long usb extension cable. It doesn't always work - depending on the car and what you are doing but it's worth a punt.

Failing that, I'll train the dog to bark when we're between the lines!!
 

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Dogs are not reliable....many are colour blind (like me), so would have trouble with the lines on the graph.... :oops:
 

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Discussion Starter #8
Another question... how does adjusting the tension square with, "...the moving pointer is aligned with the lower edge of the tensioner fixed pointer" (Mr Haynes)?
 

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I've wondered the same too because if you're adjusting the idler pulley you need to adjust the tensioner to compensate ? So possibly taking it beyond the pointer limit ?

Don't take much notice of me though as I've not adjusted timing (yet) Just trying to gather info along the way.

I think if and when I come to do it I'll probably slacken the cam sprocket and adjust it that way using a counter holding tool to hold the pulley while undoing Then move the pump pulley a small amount. I have seen it done with an air gun also.
 

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Discussion Starter #10
Yeh - I've seen it now. There are two idlers/tensioners (I can't tell which is which). One has a 13mm lock nut, the other a 16mm. The 13mm one has some sort of arrow arrangement and the 16mm one might have too but it's different.

I'm back to having no idea.

There is (he said somewhat frustrated) a surprising lack of useful documentation. Despite loads of documentation!

I think the plan is to 'adjust' the rear one (presumably the 16mm nut one) until it's correct and then reset the tension on the front (I'm expecting the two arrows to move apart). And then, I expect, do it several more times until it all goes right. I'm just waiting for the temp to get high enough and then we'll find out o_O
 

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Discussion Starter #12 (Edited)
Right, done it, worked. Van drives much better - we'll see what cold starting is like tomorrow. Salient points...

1. Put the radiator in service mode (you might get away with not but it's not worth it for the 5 mins it takes.
2. Move the pipes out of the way and remove the two 13mm headed bolts from the cover. Remove the cover (bit fiddly)
3. I tied the pipes out of the way so I could get at the two pulleys
4. Get it running and up to temperature. Get VCDS working and the timing graph displayed.
5. Slacken the idler pulley nut. This is the one with the 16mm nut just enough so you can move it with a 5mm allen key
6. Adjust clockwise to advance, anticlockwise to retard. It's not that sensitive. To get from 10 to 55 was probably 20-30 degrees on mine.
7. Check the tensioner (the one with the 13mm headed bolt). If the two arrows behind the pulley don't line up, slacken it and line them up (also 5mm key).
8. Re-check the timing - resetting the tension made no difference to mine.
9. Tighten the two bolts (13mm is 15Nm, 16mm is 20Nm)
10. Check one last time.

As an aside, when the timing was out switching to 'Basic settings' in VCDS made quite a difference to the running. Once it was correct switching made no difference at all.

Job done... time for a cup of tea.
 

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Great job, glad you got it sorted. Didn’t sound too bad a job either. You managed to see the laptop screen ok from under the bonnet ?

When I’ve registered my VCDS I’ll be checking mine as I’m not convinced it’s absolutely correct, although it drives fine and starts ok from cold the timing was set using a hand held scanner device and I don’t have much faith.
 

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Discussion Starter #14
In the end, I just left the laptop on the driver's seat. It was relatively large movements to make a difference so I could adjust it a bit and then go and look. I'd nailed it in about three iterations.

It still doesn't start like a new diesel but it's a lot better than it was. It was 2 degrees this morning, so perhaps that's ok.
 

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With mine it starts straight away from cold within a couple of seconds of turning the key so I don’t think it’s too far out.

The guy who did mine said that when the pumps are worn like most of them are these days due to high miles, setting the timing at 55 isn’t the best. How true it is I don’t know but he mentioned setting some at 65 but he also said that each van is different.

I think what I’m saying is if you’ve set yours at 55 maybe you could advance it a bit and see if it improves the cold start?
 

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Discussion Starter #16
Ok - good advice. I've only recently bought it. It's got a mountain of history but nothing in the last couple of years. The next job is an everything service - see how we get on with that!
 

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It's all fun and games with these old T4's ! I've got loads on mine to do also including some dreaded rot that has started to come through on the sliding door runner for one. Not half as bad as some I've been seeing lately but bad enough to need a welder.
 
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