Crank pickup ring damaged? Polo 1.4 tdi (2002)

[Lemon]

Hi everyone!

It's been a long and rough few months with my poor Polo, also a really long story, so I'll try to keep it brief. After four months off the road, two sets of baffled mechanics, and a third mechanic with diagnostics, finally an independent VW specialist (not VW) managed to diagnose my non-starting issue: the crank pickup ring inside the engine is 'broken and incomplete'. It makes total sense, given the symptoms (I can explain those if anyone would like to know).

Firstly, has anyone had a similar problem, ever? I'm very new to this mechanicing stuff, bit it seems unbelievable that a part sealed inside the engine, pressed onto the crankshaft, would randomly destroy itself one day. Plus, access to it is very difficult - as though VW weren't expecting it to break either?

My other question is: What to do now?

a) Try to replace the ring? On some models it looks like you can access the ring through the sump and if you remove the rear main seal. Anyone tried this or know if it's possible on the 1.4tdi/AMF engine? Otherwise I believe it's a case of lifting the engine out, stripping it, taking out the crankshaft etc... which sounds like an enormous task and probably not worth it in such an old engine.

b) Replace the engine? Again, a massive job. I do have access to a workshop with all the tools needed and a small army of home mechanics, but even without paying a garage labour costs (totally unaffordable!) you're looking at £600-800 for a decent donor engine, the fluids and doing the clutch at the same time (it's ok but could do with being replaced if the engine's out anyway). Again, probably not worth it on an old car. Plus, this car apparently has some demons so I wonder how long it'll be until the next expensive part will break.

c) Throw in the towel and break it for spares? This is what the VW specialist recommended. It makes sense given the first two options are not guaranteed to fix the problem... however, I have sunk a lot of money into this car (over £1k) trying to keep it happy and it's a great car when it's working! I have replaced the following parts in the last year: brand new alternator, new cambelt and water pump, four brand new tyres (honestly, they've driven less than 100 miles, it pains me to think about it), new windscreen, new auxiliary belt tensioner and belt, and wearable parts on the suspension replaced (CV boots/bushes etc.). As you can probably tell, this option saddens me a little and I don't feel overly hopeful on how much money I can recoup.

It's the 1.4 tdi S (AMF engine) Mk 4 Polo, 2002, 125k miles on the clock.
Many thanks for reading all the way to the end of a lengthy post. Advice, insights and wisdom appreciated.

[Rob69]

This got me curious and looking around over a cup tea. I've seen a photo of the AMF crank and the reluctor ring seems to sit between the flywheel end main bearing journal and #3 crank pin and would need the crankshaft out to replace it. It also looks like it would come dangerously close to the piston skirt at BDC, is it possible you have a bent conrod or other internal damage that has knocked teeth off the ring?There are balance weights flying round in there underneath the crankshaft. How did your mechanic diagnose the ring as being damaged - has he had the sump off? If not I think it would be worth dropping the sump to confirm or satisfy your curiosity.
You're between a rock and the hard place, IMHO, option A is a non starter, option B risky on such low residual value car, option C painful but maybe best in the long run. If you can be bothered you might recoup some cash flogging bits and pieces on fleabay.
I've found this thread on another forum showing someone elses damaged reluctor ring ( hope I'm allowed to post it!)
Crankshaft reluctor ring, anyone ever had a problem? 1.4 Tdi

[Crasher]

The ring is £25 for it and the three screws BUT it is basically engine out to install it as the crank has to be removed so you into a rebuilt bottom end and new flywheel/clutch whilst you are in there, i.e. it's FUBAR if you have to pay the labour.....

[Lemon]

Excellent detective work, Rob, thank you for your post and research
There could well be some internal damage in there - the car did run for a brief time (after the initial stalling and refusing to start for a while) with a horrible top end knock and idiot mechanic #1 decided to drive it around (to my dismay)... I've heard people say that diesel engines can cope with knocking, but I wonder if him driving it did cause some damage. The car stalled and died forever after that so...who knows.
I'm actually not sure how the VW guy diagnosed it - my army of home mechanics and I replaced the crank position sensor after the diagnostics mechanic had a look, due to the 16705/P0321 error code. Replacing the sensor didn't cure the problem which is when we shipped it off to the specialist. He plugged it back in, got the same code and from there I guess had a poke around. I don't think he had the sump off, though... very good idea to take it off and have a look myself. I've had a niggling feeling that I need to see it for myself (he's probably/definitely right, of course) before we start tearing the car apart and selling bits!
Thanks also for the link, it's somehow reassuring to see someone else with the same (obscure) problem!

[Lemon]

Thanks Crasher! It's definitely not an option to pay labour to do it... especially considering the money I've already spent. How feasible do you think it is for a bunch of home mechanics to attempt a bottom end rebuild? They're good at fixing stuff but I don't think they've attempted an engine rebuild before

[Rob69]

it's an awkward installation for the ring and totally inaccessable to driveway mechanics! I can only think it is placed there to maybe minimise engine length and make it possible to shoehorn it into the Lupo and Fox or whatever else they were dropped into.
Maybe the initial knocking and stalling was some more serious damage occuring and the ring being damaged is just a symptom of that damage. Can't see any real reason for it to fail otherwise. All it has to do is spin round and smile at the pickup. You'll have to drop the sump and post back with what you find!!

[Lemon]

I hear you! We do have access to a big workshop with engine hoists and all the tools and whatnot, which is the only reason I'm entertaining the idea of trying to fix it. If the only option I had was to pay a professional to do it, I'd have already thrown in the towel I think.
Yeah you're probably right - I guess the engine has had its day. I always thought those engines are solid and go forever, it's the main reason I bought the car.. alas, it was not to be!
Absolutely, when I eventually have time I'll drop the sump and update you with the findings

[Crasher]

It's engine out box off but pretty routine stuff, compared the the S6 bottom end I am doing.....

[Sebibv93]

I'm facing a similar issue but can't find the reluctor wheel for sale anywhere. Do you remember where you found it?

[Lemon]

I'm facing a similar issue but can't find the reluctor wheel for sale anywhere. Do you remember where you found it?

Hi mate, I ended up scrapping the car because it just wasn't worth the engine-out repair job. Also I remember struggling to find the part for sale anywhere! Sorry I can't be of help! Interesting that you're having a similar issue, it's such a strange thing to go wrong. I hope you find the part