Vw 2005 2.5 Tdi T5 Transporter

[bigtee]

Hi Can Anyone Help I Have A T5 Transporter 2.5/130 Tdi Recently I Have Been Losing Power But Only When I Boot It Or When Using Higher Revs Ie Steep Inclines It Seems To Lose Power Or Goes Into A Limp Home Mode If I Turn Ignition Off Then On Again All Is Ok ? Until Next Time I Boot It I Have Been Living With This Problem For A Few Weeks Also I Recently Changed The Fuel Filter And Car Has Not Run Since Have Had New Starter As Burnt Old One Out With Too Much Cranking Also Replaced Fuel Pump On Engine Still Wont Start Vw Have Had My Vehicle Now For 2 Weeks And Still Wont Start Their Are No Errors Showing They Don't Seem To Know What The Problem Is Does Anyone Know If All These Problems Are Related I Already Have £800 Bill And A None Running Car It Is Still Within Its Warranty But I Have Been Using Biodiesel From A Reputable Supplier To The Right Bs Standard As Stated In Vw Hand Book But They Are Saying Using This Fuel Has Caused These Problems Any Help Would Be Appreciated....tony

[millhouse]

I have a 2.5 TDi T5 transporter 174ps and have been having exactly re same problem. The van has been to a VW dealer twice to try and sort it out but without success. Last time they replaced part of the turbo but the problem continues. It is very occasional and only occurs when at high speed (80+). Loss of power reduces speed to around 60mph, and is only cleared by stopping momentarily and restarting the engine. Have you had any joy in sorting out your van?

[blue250]

Replace brake light switch,poor internal contact which make the van think you are braking and therfore not needing any acceleration,had it a few times.

[touche]

more like youre turbo is overboosting but it should log codes. If its overboosting cos turbo vnt i ssticking then it maybe a new turbo required, you can strip and clean them or fit a refurb but a master tech told me the only sure way of curing is new turbo. personally i'd chuck a couple of cans of turbo cleaner in diesel tank with some posh fuel and thrash the **** out it for a week. If you are taking it to JCT600, dont bother...........

[touche]

vacuum pump can develop faults, the vacuum is used to control allsorts including turbo vnt, often no fault codes despite what the usual numptys say- 'these modern ecu systems pick up everything' - absolute ballcocks.
the vnt pwm solenoid can play up also. check all vacuum pipework and diagphrams too, easy, just suck on vnt pipe and hold the vac on diagphram for 10 secs.
hope this helps.

[Vagnum]

i would say start with getting someone to check your Air mass meter readings

[Brian Considine]

i would say start with getting someone to check your Air mass meter readings

I would second that - I had exactly the same with my T4 - replaced the air mass meter & problem cured.

Although personally I would not touch biodiesel I think its going to get a lot of blame when garage's cannot find the actual faults.

[Brettvee]

I have a similar problem where VW TDI 2.5ltr T5 2004 model did the same thing before it progressed further and then the problem was consistent. Lack of power.
My T5 would not accelerate past 130km an hour when going up an incline. On the flat it was not to bad but still lacked the power I remembered when i first got the van.

Solution: Take your MAF sensor out the vehicle and clean it with Carby/Injector Cleaner. You will find your sensor is located just after your airbox and has a cable/plug into it. Remove and spray with the cleaner. The sensor is inside and should not be touched with your hands or anything else, only spray it with the cleaner. Allow it to completely air dry (Do not blow dry or use an air gun) and then re-install. You will not an instant response.

If you want to test this is the problem before removing just unplug the cable and take it for a drive. You should feel an improvement if it is the sensor because you just bypassed the problem.
Do not continue to drive with the cable unplugged.

Cost to clean is no more then $10, or you can buy a new sensor and pay hundreds.

[Brettvee]

Sorry I forgot to mention, you only need to remove the MAF Sensor Housing and not the sensor itself.

You can clean the sensor whilst it is still in the housing as the spray can reach the sensor by the using the small tube that comes with the cleaner attached to the cans lid.

It is important to remember, don't touch the sensor itself with anything other then the cleaner or you will stuff it.

The sensor looks like a rectangular piece of metal inside the plastic housing, about the size of a mobile Sim card. You will notice once cleaned and re-installed your Van will feel alive again and fun to drive.

[scotty33]

Hi

I suggest you read this excellent write up by Martin1810 and follow some of the tests, you may find the problem, also see MAF/AMM section on his website.

https://sites.google.com/site/1810martin/home/b5-vnt-turbo-problems

[lee lt]

Oven pride oven cleaner in the turbo pal will do the job look at the lt35 losing power thread, worked on mine.