Harsh 'detonation' noise - Pump Deuse diesel.

[syncrodoug]

It happen quite suddenly without any prior indication. I've had a good look and listen around the engine and gearbox but have been unable to find any obvious cause.
However, if you squeese the silicon tube in the intercooler pipework you get a distinct feeling on a 'thump' coinciding with the harsh detonation noise, it increases in tandem with the revs and increases in intensity.
Grateful, for any comments/observations as to the likely cause!
Many thanks
Doug

[SYNCROSPARESUK]

could be the knock sensor ( pre detenation sensor ) I think the diesel ( electronic version has this type of sensor) in some form or another

[toomanytoys]

I;d be ripping that donk out and fitting a nice 2.5 scooby if I were you... or I could build the 2.5 wbx....

Whats that Doug? Di it end in "off"????

Sorry mate.. seems just when you get to the bottom of one "chalenge" another rears its head... Prob better to go on one of the VAG TDi forums for that info... your prob the only PD T25 on here Eh?

[syncroandy]

Doug, sorry to hear about this. If not already I think you should post about this on vwdiesel.net TDi forum.

http://www.vwdiesel.net/forum/index.php?board=5.0

[syncrodoug]

Just had a look at the cam and valves - exhaust valve cam follower in no. 4 cylinder isn't there! Apparently a known problem with the 150bhp PD engine.
Fortunately I have a spare engine!
Thanks for all the help...
Doug

[toomanytoys]

Blooming heck mate... thats an a***......... where have all the bits gone then? or has it just ground away?

[syncrodoug]

Simon, the bottom of the 'bucket' is worn away leaving the sides in place.
Today, I've taken the engine out and swapped the ancillaries over to the 'new' engine. I've left it suspended with the sump off to drain any residual oil before taking oil pump out to swap over.
I hoping the local VAG garage keeps spigot bearings as stock.
Aidan may be interested in what I found in the bell housing after my 'extreme' wading on Salisbury Plain - it's just a little splash he said as the van started to float - it appears that the snorkel tubes went under as there were signs of dirt on the inside of the tubes and the friction plate had a layer of sludge adhereing to it, no wonder I've been experiencing some slip.
Oh, I had to replace the starter motor last week - now there's a surprise!

[toomanytoys]

Wor it away?? cam ok or fubarred too?



well you will go off road in it... floating eh?? that must have been good.. locker must have been a little damp then...

I'll tell Aidan now...


Just told him.... he started giggling loke a school girl and he says "he is very sorry for egging you on..."

[syncrodoug]

I have plans to extend snorkels and wrap starter in Denso tape!

[toomanytoys]

WBX were sealed with silicone sealant...
Raising the bellhousing snorkels would be a good idea..