D5252t crank sprocket later round keyway help
 

I would be grateful if someone knowledgeable with D5252t can help

I am trying to redirect a v70 2.5d from getting scrapped, I bought it not going a risky idea.

The cambelt had been done 5000 kms prior and car “just stopped”

On taking off cambelt I see it has had trauma and tensioner I also has some rub on engine side,

No apparent damage to tappets

I found keyway sheared off crankshaft sprocket, I have purchased a new sprocket only to discover inbuilt key is square but my engine is round keyway.

I cannot find part number for this or anything online even, except for 1 post here stating there was a change in later management cars 1999- to round type.

Nowhere in trawling internet can I find any record of this later sprocket design.

Does anyone have one know of part number or any way to obtain one 2nd hand or new?

A lot of parts are now NLA (no longer available) from Volvo so it can sometimes be more fruitful to search for VW T4 engine components seeing as it's a VAG unit...

https://www.brickwerks.co.uk/t4-part...cyl-96-on.html ;)

I hope the crankshaft keyway isn't damaged and the top end (valves) for that matter. It sounds as though the crank bolt/screw wasn't properly torqued up allowing the damper and sprocket to rattle loose and or someone failed to fit the diamond coated washer (see pdf).

Many thanks Liam,

It turns out the brand I bought list the parts incorrectly causing a lot of confusion for me
So I did buy correct part even if by chance, but it’s wrong.

Yes mine was missing washer I’m afraid.

I might have to take head off yet.

Morning , I used these people for my diamond washer & woodruff key .
https://www.heritagepartscentre.com/uk/ The engine is the same as the Audi AEL 5 cylinder ( think that is right ) and was used in the VW T4 vans . Nice people were very helpful and prices very reasonable .

From experience of this problem , if the key has sheared , you will be removing the cylinder head & replacing a couple of valves ! . The engine is an interference fit & the pistons will bend the valve heads over .

At the very least I would order new crank bolt , woodruff key & crank sprocket and diamond washer ( kid you not ) The washer is most certainly required to stop any slippage / movement of sprocket & damper on crank . The bolt you wind up to 120Lbft & then turn through a further 180° and that takes a lot of doing . If it has not got the washer or been tightened fully , you end up back at your starting point

hope this helps

Thanks for help guys,

Finally got right parts but verified what I found earlier which was

Engine was out of time but turned over fine, camshaft needed to go couple of teeth, when I tried to do this but it won’t allow me - guess it’s valve hitting on number 4 Cylinder as that is only other piston high with no1 at tdc and have valves down.

I can’t understand why it turns over fine slightly out of time, but won’t get in time - surely that would give more valve clearance? Maybe valve head in bad way sticking down

next step is taking head off do you agree?

Another thing I have a manual and the flywheel marking is not how I see all over internet, I don’t have small notch but further back I have a partially drilled hole is that correct for tdc?

Ok trying to understand fully before I take head off, if someone can concur with me all good

This is with no1 at tdc. Valves closed. Only other piston high is no4 (288degs rotation?)

I assume that because it only turns over with cam timing slightly retarded (can not advance to be correctly “timed”)then it must be an inlet valve that is damaged protruding down, the rate at which the valve descends when I try to rotate the cam must bring it into contact with piston.
I assume it’s not the exhaust valve as this is coming to it’s seat at this point as I advance.

It has most probably bent a valve or two, as DingoV70 has alluded to, when it stripped the pulley key. You're probably just achieving clearance in its "out of time" state and is making contact with the bent valve when you set it up correctly. You've nothing to loose by removing the camshaft and lifters (noting their positions) to determine which valves are not seating properly but this will only confirm your suspicion. It's looking like head off time I'm afraid.

The small notch in the flywheel ring gear, lined up with the arrow/marker on the gearbox housing, is your TDC. All other slots/holes are for either tooling at time of manufacture, balance and or locking the flywheel at TDC via the aperture adjacent to the fuel pump with a suitable locking pin.

I assume you're using an endoscope down the injector or glowplug aperture to determine TDC? Either way all will become clear once you've removed the head.

Another one damaged by folk who can't tighten a bolt! Tbf many garages don't even have 3/4" socketry, so just tighten it as best they can and send them out. Sooner or later they come loose.

Does sound like a bent valve as won't let you get it on time, but will turn over if out sightly out of time? If you do get it timed up, worth doing a compression test to see what you have. Think 24 bar is at the low end, these will mage 30 bar per cylinder if in top shape.

remove the head some times if a valve has been hit and bent it can fracture the valve guide the part in the combustion chamber and it can come adrift ruining your good work. do it once do it right and you will end up with a relieable engine fuel pump timing is also critical good luck with the rebuild

Well I got head off,( I found this engine the most awkward I have ever worked on fwiw)

My reconditioner man has found no valves bent, so I’m at a loss quite frankly. This should be logical and easy to diagnose.

2 tappets seem stuck compressed that is all but I can’t see this is as significant. Unless they took the impact. No mushrooming of top of tappet though.

5 tappets have minor crazing/ cracking on top

I will keep investigating/inspecting but may have to reassemble and see how I go.