stumped on this one

[bigal23]

on my a3 140 the anti-shudder valve had stopped working which is a common fault so I replaced the part and its working

but I still get a horrid shudder on shut down. now this happens 98% of the time only maybe 4-5 times its not made a shudder on shut down I have taken it two darkside and they carnt figure out why its doing it and neither can I. I have replaced fuel filter cleaned inlet manifold out replace seals checked its working on shut down everything I could think of do you guys have any ideas as me and darkside have no idea what to do with it

 

[Bramley]

fuel pump??

 

[bigal23]

why would or could fuel pump cause this?

 

[Geraldy212]

Bigal, are you 100% sure that your new anti-shudder valve is working properly? If it really cuts off the air, the engine should stop immediately. The only reason not to stop is if there is a source of oil getting into the intake manifold. Hope this is not that case, but I would certainly check the valve again.

 

[TDI140]

Was the oart brand new or did u buy second hand if its second hand u need to buy a new part as they made a different part number as the old ones were faulty so the new one has been strengthened

 

[bigal23]

brand new from eurocarparts with a nice 30% discount.

its working I popped the pipe off and looked in when I switch the engine off and it closes for about 2-3secs then opens.
don't see how oil could get in had everything checked over no oil in fuel or anything.

all I could think when I watched it close was is it closing quick enough? could it close to slow and leave you with the shudder

 

[bigal23]

this is one I bought Pierburg Audi | Euro Car Parts UK’s No.1 Car Parts Retailer

 

[Geraldy212]

Bigal, you are right to worry about ASV closure speed. As far as I know, the flap is spring-loaded to stay open, and the motor has to force it to close on switch off. Any unnecessary friction or low voltage, or bad contact may indeed cause it to close too slowly. If you can find another BKD engine to look at, you might be allowed to pull off the pipe and compare. When a diesel is told to stop by having its fuel injectors shut-off, it will try to scavenge any oil (or fuel) it can find from the whole intake system, and therefore try to run-on. If by chance the intake system is contaminated by oil residue, or oil leaks from the turbo, then this oil will be happily sucked into the engine on switch-off. Causing a slight run-on if the ASV does not do its job well, or perhaps quickly enough. Good luck.

 

[bigal23]

could this be the battery not supplying enough voltage? I have tested the battery with a multimeter and all is good but when I turn the car on and the radio or mp3 is on and lights it all cuts out for a second the other days I do the same and nothing cuts out at all

 

[Geraldy212]

Trot around to your nearest auto battery shop or local garage and ask them to test the battery with a load-tester. That should give you a good indication of the general health of the battery. It is a worry though if there is an electrical cut out at any time. Get the shop to check on battery terminals and grounding points for corrosion, and possible loose fuse(s)/holders too.

 

[TDI140]

this is one I bought Pierburg Audi | Euro Car Parts UK’s No.1 Car Parts Retailer

same one i bought so it didnt fix it, u need car plugging in mate wont figure it out u til its plugged in and diagnosed

 

[bigal23]

the asv works fine and is not faulty car battery is good connections are all clean.

tdi140 I plugged the car in to a friends vcds and I have two faults one is egr as I have deleted it but not mapped it out and the other a glow plug 3 fault, there is a couple of others but there to do with the fact I have xenons but without the auto levelling s come up with two faults for that.
am lost with, I did have one idea could the injectors be leaking slightly and its running on from this slight leak?