g-mack

check vacuum by pumping pedal and hold the pressure on pedal whilst starting engine. if you have good vacuum the pedal will sink an inch or so, if it doesn't move when you start engine you have a vac problem. vac problem is either: 1. hairline cracks in servo 2. split in vac hose 3. failed vac pump

spanner monkeys washington if you are a southerner! mastoria alnwick if your a northerner

Kurt- i might give the pump timing a go, thanks chicken- i get pressure at the inlet manifold!!!! never driven another tdi, only td5s, it never used to do it!! i would be surprised if its normal as once i hit 50 i can't hear the engine!

slightly mad that rear is so much more than front!!! supply and demand i guess! rear is a popular conversion for older 110s!

^^what sort of prices is he asking for puma axles? i think i might replace mine in the summer

kurt, not checked but will! retro, yep exactly what I'm saying! so I'm back to thinking this has got to be a timing issue! now as the engine runs smooth, it seems bizarre the timing could be out, unless the keyways have worn and allowing slightly off cam !

well after hours of researching turbos last night, i can say 100% its not my turbo! removed inlet to intercooler top pipe, NO more air coming from air box! if it was turbo related i would still feel air. there is also a constant flow of air out the inlet pipe at the engine. so it is 100% engine related!!!!

interesting http://www.crturbos.co.uk/index.php/blog/articles/what-is-surging/ also found this quote on another forum but i would also check the turbo, ive had one before that was leaking exhaust gases out of the compressor side of turbo, this made a loud induction noise that was probably actually from exhaust side, take the inlet to turbo off(2 bolts) and rev it to check for back pressure. winterheating Transit Extremist Posts: 10676 Joined: Tue Jul 01, 2008 10:21 pm Location: Co.Durham Darlington

i find it hard to tell if i can detect it at turbo or inlet, i think as the diameters are much bigger its difficult. i can defy feel it at the oil breather inlet just before turbo!

I've been thinking about that too, but surely a worn cam lobe would mean inlet valves are not opening fully, can't see how it would make them open early. for gases to be escaping into inlet it must be happening on the exhaust stroke. so exhaust stroke : exhaust valve is open, inlet might be open a fraction to early as the next stroke is induction, (only stroke the inlet valve is open)

Update: fitted new down pipe with flexi today. Made NO difference!!!!! been having a good look and listen again today, its definitely being caused by the back pressure! the booming climbs and drops with the revs, basically sound like an exhaust!

so kurt, is your booming gone? i used compressed air to blow water out block threads!

steve its a twin box system, but both have been changed made no difference.

new exhaust rubbers! tick over i can hear it quietly as I'm tuned into it now! rev it in neutral can hear it easily. worse under load, high box low box diff lock whatever, its still there! it can only be heard from inside, I've walked alongside as my mate drove it in low box so it was really bad inside, but i could not hear it outside!

exhaust is standard too. rear and middle silencers, both renewed made no difference. down pipe is solid pipe, not flexi type. changed offside engine mount (gen part) no difference. i think i might try putting new gearbox mounts next. getting fed up shelling out on replacement parts that don't cure it!! removing props makes no difference either!

OK here is a vid i done a while ago. you need a good set of speakers as the booming is very low frequency

^ standard paper filter. I've driven without filter makes no difference.

No, if i remove the crank breather (from cyclone filter) near the turbo i can feel it there too! not i must say from the cyclone pipe, but from the air intake pipe!

I'm not worried about the pressure, my issue is the overwhelming booming in the cab. I'm gonna try a new downpipes next, with flexi pipe just incase its got a leak I'm not finding or its resonating at a frequency the car doesn't like! but I'm 99.9% sure the booming is coming from the air box!!

snagger, neither of us have any crankcase pressure!

your a braver man than me! I did mine outside on a nice summers day!! no way would i be doing in this weather!! so still booming too? its gutting after the work involved a cost of the new head, but at least its done and will be good for a good while now! and it eliminates it from the search!!

yep i think the last one is due off the line at 10 or 11am. very sad

nope no egr here either!

just thinking out loud here, if it was a valve,cam, rocker timing etc issue and exhaust was making its way out the intake, surely it would smell exhausty !!! mine definitely doesn't !!

i removed my turbo to check waste gate, all working fine.