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any suggestions where to start?2.5 ajt

5K views 31 replies 13 participants last post by  AirconAde 
#1 ·
2.5 ajt.when bought,ran like a canal barge,proper chuggy?
no history so cambelt/rollers/waterpump changed
egr cleaned/blanked.exhaust system removed,straight side exit fitted.
new 150 bosch injectors fitted.
now runs far better,so much that new clutch fitted.
remapped at chipwizards,timing maf etc checked before map.
wayne did state van had a strange power curve,like a petrol engine?
steady arc curve,rather than a steep climb like a diesel?
van pulls well at speed,but at idle,a bit lumpy?
can feel a vibration thru van at idle,and when revving up.
did a comparison test with stealtcampers 2.4 turbo"d van today.
his feels far smoother,as have other 2.5 acv vans ive been in?
where do i start?
vagcom?timing?
diesel pump specialist?
all filters etc new.
any suggestions from those in the know much appreciated.
 
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#6 ·
Im guessing it was the same with the old injectors as the new ones.

If it sounds chuggy then you would think it has to be a misfire of sorts.

I would def start with compression check - you never know what the previous owners have been upto on the engine.

I remember looking at a car once that had been through a big puddle and one of the conrods was slightly bent :-(
 
#7 · (Edited)
the old stanadyne injectors were far worse,used to take 2 miles to reach 70 on mway!
thats the main reason i replaced with the new bosch ones.as soon as they were changed,the van pulled and sounded far better,and once mapped i thought would run far sweeter.it is quite a noisy engine,you can feel like a rhythmic vibration thru the van if you hold revs at 1200rpm?if revved up,when the revs drop down to the 850 mark,the engine judders and misses slightly before idle settles.
no fault codes were found on the pre remap check.van goes well enough,but somethings not quite right.?turbo boosts up to 1bar fine on boost gauge.if it was a petrol engine,id suspect a sparkplug faulty?the miss can also be heard from the exhaust?
hoping to get it on vagcom at a local garage,see if anything shows up?
when the belts etc were replaced im wondering if things were set and adjusted,or just fitted without checking if adjustment was needed?
cheers for all replies
 
#9 ·
yes,it has the anti shudder in the egr.all free and moving when ive had the egr off in pastT:
just been out to pick the lad up,its not sluggish,just not as smooth as it should be?
would cam lobes or the cam buckets have any of the symptoms if they were worn?
 
#11 ·
Persistant niggle on mine from when i bought it. Very much what you are describing

Then a week or so back the pump belt tensioner let go with all the delights that entails.

Replaced it, whilst realising in terms of fuel pump timing there are 360 degrees, chosing 359 of them will cause your AJT's electronic brain to have a full on sulk.

That said since the timing was set properly with all the relevant toys the van is transformed.

I did a run to Brittany last weekend the van was awesome both in terms of easy speed on the motorway and ability to dismiss load.

Rhys
 
#16 ·
so took van to garage tonight also had an oil leak to check,undertray off to do that first...........waterpump leaking:( along with sump gasket:(
only been on for 18months/16k changed with cambelt,didnt last long!:*
so,not had anything else looked at,obviously timing will now be re done when waterpump changed.
losing the love for this van:(
 
#20 ·
.waterpump leaking:( along with sump gasket:(
only been on for 18months/16k changed with cambelt,didnt last long!:*
A lot of people on this forum keep saying to change the waterpump every time the cambelt is changed. My van has had two new belts & the water pump is original in 2001, mileage 122,000km. I know of another with 150,000km+ ['01] with the original pump.
The important thing is if you feel compelled to change the pump, make sure it is a quality one. I know how I would feel if I removed a perfectly good pump & replaced it with one that only lasted a short time. When I spoke to the service adviser at VW he said they don't change the pump if it's not leaking & it feels OK, so I did the same.
 
#17 ·
A Bon Jovi song springs to mind and I dont mean living on a prayer although we both are driving with weepy Pumps. T:
I'm in the same boat. Just want a dry day to pull it all apart and start again.

The song by the way was Keep the Faith. I:
 
#23 · (Edited)
right,finally got the list of jobs doneA:
waterpump failure was a core plug in the pump housing:( fitted a genuine one from tps nowT:
old pump

oil leak was narrowed down to crank seal(hopefully)so had that replaced,new cambelt also while its all offT:


mechanic says he couldnt see timing was out,but all redone...........van does seem to idle smoother?dont get me wrong,its not like a jag or anything,but does seem better?T:
vac pump had also packed in,so replaced that too......no xmas pressie for me sundayI:

couldnt see any scoring or major wear on cam lobes,175k of wear pictured


couldnt get it onto a vagcom,as the garage who was going to do it has closed for christmas
do have an oil leak from turbo outlet tho:(,so more work to come?
many thanks to martin at lingley autos near ikea warrington for doing all this today!
especially as a 1"drive airgun direct to compressor was needed to undo crankbolt!!!
he really didnt think it was going to come off without snapping!
*<:)>
 
#27 ·
as the weather has been cr4p,and i was back to work after boxing day,not had chance to get a look tbh?
waterleaks sorted n have brakes again!will have a butchers tmrw around undertray,but wont be able to see sump much?T:
 
#28 ·
Same here. Van is to big to nose into my Garage so its weather permitting.
I'm convinced my Noisy Engine is due to Timing being out despite it running OK and Vagcom telling me otherwise.
I have a theory. I will share it when I pull it apart and put it back together but im waiting on a DTI from your Ex neighbour and a bit of Sunshine.
 
#29 ·
just had a mooch under van...all is wellA:
gave the undertray a fingering:eek:,nothing there eitherA:
when my mate put everything back all timing checked mechanically,spot on.
still not had on vagcom,but does seem a bit smoother?
but,compared to stealthcampers 2.4turbo,a lot noisier still?
rubber damper on pulley all ok,cams looked fine?
just seems to be the way with a lot of the ajt engines?
call in if yr passing,compare sob stories over a brew!LOL:
 
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