D5254T - snapped cam belt?

[Double_Trouble]

Hi all,

My first post - and it's a sad tale. On my way to work this morning my much respected V70 Tdi expired. I fear it's terminal...

I was just setting off, and had got just about 50 yards (and was at little more than tick-over in 3rd) when it gave a brief but nasty mechanical cough and lost all power. I quickly de-clutched and it stalled instantly.

I tried the starter once - briefly. It turned over but was very uneven and didn't try to fire. "#@$£!" I thought - "that's not good". I abandoned it outside my house (and brought my wife's T5 to work)

The diesel has circa 140K showing on the clock, I've owned it 6 months and done 6k miles in that time. I had it serviced at an independent a couple of months back. They asked me about the cam belt - but I said it would be okay as the garage I bought it from assured me that the belt had been changed "as a precaution" about 3 months previous to my buying the car.... They even produced an invoice to "prove" it.

I wonder if they spoke with forked tongue? OR is it possible the tensioner has departed - the car was just developing an intermittent noise which I thought sounded something like a dry bearing in the alternator (for want of a better description) - I had planned to investigate it this weekend...

Can anybody tell me is the Audi D5254T motor an interference design? Am I looking at bent valves? how bad is it likely to be? What else is likely to be butchered?
Also is this a job I should farm out? I've a fair degree of mechanical experience and a decent selection of tools, but I'm thinking it might be too much to take on but, obviously I'm worried this might cost more than the car is worth.

Any tips or advice gratefully received.

Thanks in advance
Mark

[Double_Trouble]

All,

I know it's bad form to reply to your own posts - but, think an update is in order.

After speaking to a couple of friends in the trade and a mechanic at our local main dealer I have learned the following:-

1/ The motor is an iterference design - if the cam belt parts, then damage is inevitable.
2/ there are two belts - Belt one is from the crank to the cam, Belt two is off the other end of the cam to the fuel pump.
3/ The mechanic at the main dealer told me that the second belt is often "forgotten" by back street garages and, as a consequence, they've seen a number of these snap.

With that in mind I set too and pulled the plastic covers and the cam cover.
I discovered that neither belt was obviously broken and nothing else was obviously wrong.
So I put it in 5th, and rocked it back and forth gently - the cam rotated with the engine (phew I thought). I sat a while and pondered, plucking up courage then I tried the starter twice farily briefly.... The motor turns over (as does the cam) - but it doesn't start or sound normal.

I then poked about a bit more and discovered that belt two (fuel pump) looks *old* and is *VERY* slack - I was able to remove it and put it back very easily without undoing the tensioner. That can't be right.....

I'm about to try setting it back to tdc (and whipping the tensioner into line) - but I'm also worried about the cranking noise...

Normally it has an even "ahuh - ahuh - ahuh - ahuh -> start"
Now it goes "ahuh - ah - huuuuuh - (slight click) - ahuh - ah - huuuuh"
(good this eh? sound effects via text... hope you understand what I mean)

I'm worried the main belt slipped - leading to the cam miss timimg the valves (that slight click) - with associated damage.

Just come in to try and find out what the timing marks look like. so I can set it up.... more to follow.

Mark

[Double_Trouble]

Bossed the fuel pump belt tensioners (one had frozen on it's bearings - it'd been stationary so long)

Couldn't find the crank timing marks - (found them later - who thought behind the driver's side wheel under the engine - behind all that old oil was a good place?) so I did the "poke something down the glowplug hole" trick - got number one around tdc

And guess what? the cam was a good 70 degrees out, and quite by chance right at the TDC mark on the belt cover - there was a fresh nick out of the side of the (new looking) cam belt. What is confusing me though is that the cam lobes for number one are both "up" i.e. the valves are closed. (but they are nowhere near symetrical)

Then I tried to rotate the engine from the crank pulley (and in doing so I found the mark) - sure enough it met resistance with a metalic click - same if I turn it eather way....

As I had found a place that will source, fit and lapp new valves and followers (aparently these can get mullered too) and set it all up - if i take the head off. I begin to take the head off - only to find a number of stripped and bent bolts on the manifolds....

I don't know who had been "servicing" this car, but they're off my Christmas card list.

I'm going to look for a new head/engine from some breakers..... ;-(

[Double_Trouble]

I have a new theory:-

I can't be 100% sure but I think the dowel (or key?) which keys the cam to the pulley has sheared, allowing the pulley to turn some on the cam....

I'm thinking that because the car could not have run with the fuel pump belt so slack (for long), so I recon that belt (which is very old) stretched until the belt "climbed" up the pulley wheel teeth causing it to go tight - this pulled the tensioners back, stopped the cam and sheared the pin - the rest was inevitable from there....

My next problem is that I cannot find a Volvo 5 cyl tdi motor at any breakers.
I have found an Audi A6 5 cylinder - now I know the engine is near identical, as far as I can see, but I'm wondering if it is really the same (where I can't see)?

It's mounted longitudinally in the Audi, so I'm wondering about the gearbox bolt pattern, the clutch and flywheel, the starter, the ancillaries and the manifolds - then there's the ECU....

Anyone able to offer any advice? At all?

Mark

[jor]

AFAIK there is no such thing as a volvo 5 cylinder motor for the car, it's made by Audi. So there should be no difficulty in replacing the engine, or if for some reason there is why you couldn't just replace the head only after inspection of the pistons.

john

[Double_Trouble]

John,

Thanks for the tip. That's what I thought for the Tdi badged cars - Not sure about the 'D5' though, that's a different unit. I have a feeling maybe even Volvo in-house design?

All,

Have been having some trouble finding a garage that'll take on my engine swap in a reasonable time frame.

In ringing around I've had a couple of comments like "oh that Audi engine - it runs nice, but is prone to problems with the belt tensioners".

One garage told me that they've a customer with an Audi all-road. He had bills (from a previous) garage for £1200 to fix it when the tensioners went at 38K (no idea why this wasn't a warranty job), and then again at 76K! The guy brought it to them at 110k and said "change everything that moves" - he went home with a bill for £800.... All that and he's still driving an Audi - there's no accounting for taste eh?

The other thing I've heard a lot of is "Audi / VW / Skoda / SEAT - they're the worst for changing engine details between models and years - swaps between them are very risky". I've gone right off this VW / Audi unit....

I wish I had the courage to "do it properly" and drop one of the later D5 motors in. I think the ecu issues would be a nightmare though! Probably cheaper just to by a whole new D5 :-)

Mark

[jor]

I'll mention your plight to a good mechanic in Wembley Mark. Another person worth sounding out is your register keeper jod t5, who is handy with the spanners.

john

[Clan]

A sad tale , When that engine came out first in the 850 it was prone to VW cambelts stretching and quite a few engines failed. Volvo redesigned the belts for VW and there was no further problem . I guess people may have fitted non-volvo belts at some point resulting in this failure .

Fitting new cam belts and fuel pump belts and setting them up on this engine is a specialised job , there are no keyways on either cam pulley they will fit on in any position and the pump has to be timed staticly to get it running and also dynamicly when running with the special volvo instrument . the cam has to be timed with a special tool , and the TDC Mark by the way is on the bottom of the flywheel through a hole and pointer in the belll housing , the mark at 7 o clock on the pulley is only an indication it's not accurate enough .
Good luck with the repair its not a bad old engine when running properly .

[Double_Trouble]

Thought I'd conclude this thread, with a positive report - the V70 is back on the road again.

I was nervous about having the head/valves fixed, as I've a friend who's son's pegueot diesel snapped a rod 2 weeks after he'd had his head fixed after a similar event. I guess the rods had been overstressed when the pistons met the valves, and one let go in the outside lane of the M6 causing the engine to sieze, lock the wheels and - you can guess the rest. He's ok but the car is not (nor are the two other cars that hit him)...

Keen to avoid this experience I sourced a second hand engine. The only one I could find was from an Audi A6. I then just had to find a local garage to drop it in for me... and hope. Now I can reports it works - eventually!

The issues included:-
Sump and oil pickup had to be swapped (as the motor seems to be tilted over in the A6)
The top plastic cover won't go back on (as the metal cam cover is different, and cannot be swapped for the volvo one, without some welding - also the support bracket for plastic cover this has to be chopped back).
The core plugs at the rear of the motor had to be swapped (one has a special coolant pipe in the volvo - this had to come from Sweeden - on a boat - slowly!)
The head is essentially the same, but is missing a drilling for the coolant bleed pipe (which goes to the header tank - this makes bleeding the air out "fun" - I'm not brave enough to drill it - so I think I'll make a 't-peice' for from the radiator top hose, sometime.
All the ancillories, belts and brackets had to be swapped over too.

All told it took the garage 6 weeks and they said they think it would have been easier (for them) to just fix the damage to the old head - but I'm pleased with the job they've done.

It's early days yet but I can report it seems to be a good job. If anything the car seems down on power to about 2000 rpm and pleasingly up on power above 3000 rpm. I'm not sure if there's a different cam fitted to the audi - or if it's just an issue with the fuel pump timing. The old motor always was a smoker above about 3500, especially after a bit of a cruise - so bad it could be embaressing.This seems to be impoved now, and I'm wondering if the pump timing was out previosly (this makes sense as the pump belt was way slack).

The economy now seems a bit down too - but I think that's cuased by handbrake sticking on slightly (mot due in two weeks typical eh?).

Hope the info contained here is useful to someone!

Kind regards and thanks for all the comments everyone - happy to provide more detail or contacts if required.
Mark

[tfb]

Glad it all turned out well for you in the end and thanks for updating us all

Regards
TFB