lack of power on hills [Archive] - VW T4 Forum - VW T5 Forum

lack of power on hills

kalamity
08-10-08, 18:31
i have a 2.5tdi (silver i) 2001 coachbuilt camper and it has only just done 25,000mls. the last two times out it pulled ok on the flat but on a slight hill climb then power seem to disappear and changing down a gear didn't seem to do anything struggling to get over 40 then back on the flat could get it back up to 60mph. after first trip i noticed that the exhaust had broke in front of the first box ( no different in noise) so last week had a complete system fitted and then tried a run again but still no different, anyone have any ideas whats the cause.

Rhosneigr Gaz
08-10-08, 19:31
could be a number of things. Try get it on vag com and see if there is a Maf problem (start with easy and cheap!)
Getting any fault codes will be a big help to start with!

kalamity
09-10-08, 06:33
cheers gaz i was thinking about doing that, but have read elsewhere that it could be the cat strangling the power, last year it was knocking now the sound has gone and this happens otherwise engine is fine. the exhaust boke just before the front box and there was no extra noise until it rattled on start up and it was sheared of just in front of the first box qiuck inspection the pipe looked complete had to get undervan and look close to see the break.

veedubnut
09-10-08, 18:34
cheers gaz i was thinking about doing that, but have read elsewhere that it could be the cat strangling the power, last year it was knocking now the sound has gone and this happens otherwise engine is fine. the exhaust boke just before the front box and there was no extra noise until it rattled on start up and it was sheared of just in front of the first box qiuck inspection the pipe looked complete had to get undervan and look close to see the break.

ALso get your diesel pump timing checked and static timing..
I have jsut done timing belt and other stuff including the IP and it has transformed the pump.;

before my van was always slow as well and hated hills....now it literall flies up them.
its like a new van T:

kalamity
09-10-08, 18:47
have just got a new cat/fitting kit from europarts. the bottom of the old one has a few dints where the mechanics have knocked it when it rattled. so the inside has probaly broke down and blocking the exhaust (like the old spud trick.) hope this works.

Van'Cooke
09-10-08, 19:08
dont bother with the VAG for air mass metre. Just disconnect the AMM take it for a spin, if it improves performance. replace it. job done

buy genuin part the retro fits are

kalamity
11-10-08, 19:36
if i knew what a AMM was i might try it but you have lost me.

Rhosneigr Gaz
11-10-08, 20:54
Air Mass Meter, MAF, AIR FLOW METER, kts a small collar in line with the air box feed, looks like this.........

http://i139.photobucket.com/albums/q300/RhosneigrGaz/03082008296.jpg

steve fh
10-11-08, 14:43
did you ever cure this ? my van has the same symptoms. No fault codes and it has a new MAF.

Camper
23-03-09, 20:05
I have a 2003 T4, 2.5 ACV just been on rolling road and see I have 47 BHP! Unplug the AMM and it only goes up to 60bhp. Should be 102bhp. Any ideas?

Big Bad Bear
23-03-09, 20:20
I have a 2003 T4, 2.5 ACV just been on rolling road and see I have 47 BHP! Unplug the AMM and it only goes up to 60bhp. Should be 102bhp. Any ideas?

Could be a number of things your EGR valve could be blocked with Gunk, when was the last service done, air and fuel filters? if you have an increase in power with MAF off then change it makes a lot of difference

oskins
23-03-09, 20:31
I have a 2003 T4, 2.5 ACV just been on rolling road and see I have 47 BHP! Unplug the AMM and it only goes up to 60bhp. Should be 102bhp. Any ideas?

That just goes to show the MAF not working and the 60bhp is probably the result of the ECU substituting a reading to keep it going (limp home mode)
Change the MAF and test it again. Should see a vast improvement

waveride
24-03-09, 08:25
I had a similar problem with my 88hp 2.5lt - it was driving in "safe mode", i put a new MAF in and that made no difference, ended up in garage where they found a problem with some electrical connections, which they cleaned up and it cured the problem.

kalamity
24-03-09, 21:18
it turned out the cat was completely blocked, got a new one from europarts for 67 + 10 fitting kit and it only took 1/2hr to fit, now engine back to power again.T:

BigPurpleOne
24-03-09, 21:38
need to replace my maf too,(2.5TDI 102bhp) removed cable and huge increase in power!. next day back to sluggish, assume in limp mode, vw want 68 + vat!

part number from vw is 074906461

this one from ebay any good?? only 39.99 delivered with 12 months warrenty

http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item=370160216788

chunder
24-03-09, 21:50
hi guys just a quickie, most people think that if a MAF goes down then the ecu puts its own safe figure in.... this is not the case, what happens is that if its faulty then your van will be sluggish cos of poor readings between sensors:confused: if van is sluggish best way is to disconnect MAF sensor and then try, 9/10 times this will be massively improved because the ecu then reads the THROTTLE SWITCH instead of MAF sensor, result is throw away MAF sensor and get a GENUINE one, DO NOT BUY CHEAP IMITATIONS THEY ARE ****E AND HAVE NOT BEEN CALIBRATED PROPERLY!!!! if ITS still the same then another problem is causing the fault.... hope this helpsT:

surfdaddy
24-03-09, 23:05
Interesting thread: my Multivan has identical problem, it just hates a gentel slope!

Will get my cat looked at then. I know some people have de-catted altogether. Is this legal/truly beneficial? Or can you get a 'performance' cat that gives best of both worlds or did I just imagine that one?

Also been told replacing the air filter with an induction kit will help (improving cold/dense air or summat), is that true or just justification for under-the-bonnet pimpage?

mickandkerri
25-03-09, 18:43
i had the same problem.never heard of a an air mass meter but the garage was spot on. van performed as normal straight away.