does not go over 80mph

**arman123** · 04-10-2009,04:23 PM

hi can anyone help i have an audi a4 1.9tdi 54 plate engine code BKE took the car on the motorway today and it was not going over 80 full pedal to the floor changed the maf about a month ago goes likr a rocket when driving around urban areas but same problem on motorway no codes when checked on vag-com no light on dash any ideas people

**Alan02** · 04-10-2009,05:00 PM

How long has the fuel filter been on for? Change every 40K.

**arman123** · 04-10-2009,05:03 PM

changed it last year done only 5000 miles so far can the feul filter cause limp mode?

**nevo** · 04-10-2009,07:36 PM

Take the fuel filter off and check the contents for oil ! you could have a tank full of oil blocking the filter,not allowing enough diesel through,

**Alan02** · 04-10-2009,08:19 PM

Originally Posted by arman123

changed it last year done only 5000 miles so far can the feul filter cause limp mode?

You haven`t mentioned Limp Mode.If it was in Limp Mode,it wouldnt rev fully when stationary,and you should get the warning lamp on the dash.Seeing as you never mentioned this,thats why i asked about filter.Always best to check the simple basic things first.

**Martin F** · 04-10-2009,09:36 PM

You have checked there is nothing blocking the accelerator pedal, like a loose mat or similar ?

**arman123** · 05-10-2009,12:01 PM

no people nothing blocking the peadal lets start from the beggining as you reach 80mph you can feel something go as the car goes into limp mode but no lights on dash it wont go over 80 and struggling to floor it by the round a bout if you switch the engine off and back on the car back to normal chnaged the n75 valve about 4 months ago when i was having a overboost problem and the car was going in to limp mode was fine after i changed the valve had a new maf put in about 2 months ago genuin bosch one car pulls like it should on normal roads but every time on the motorway reach 80 when taking over same problem no codes coming up on vag-com could the egr valve cause limp mode as the does have 124000 miles on clock and i dont think the egr valve been changed but not smoking when floored

**nevo** · 05-10-2009,12:24 PM

You say its in limp mode, when it does it can you rev it to red line and hold it(with car stationary)if you can it may be insufficient getting through,remember the engines not under any great load when stationary

**arman123** · 05-10-2009,01:02 PM

yes i can hold it at high revs when stationary in limp mode but under load on motorway looks like turbo cuts out at 80mph need to turn the engine off and on again to get it back nightmare when taking over in third lane

**nevo** · 05-10-2009,04:44 PM

No codes stored,you feel the sudden loss of power at 80,you're going to have to do a systematic, one at a time search,could be number of things, check the n75 vacuum pipes, renew probably the best option check the vavle itself,listen if its ticking,take the egr valve off clean out and check operation with a vac pump (cant do it with your lips)check vac pipe to it,turbo could be sticking giving a overboost, faulty thrust pressure sensor,although strange no codes showing ? sorry can't give you the magic bullet for this one , give that n75 valve a good look at ,was it a genuine part? could be a reoccurrence of your previous problem,I appologise in advance if you've tried all these ,this sort of problem makes you pull your hair out. PS can cycle the turbo acuator to check its operation