Let me get this right, it boosts ok in 3rd and 4th but won't go past 70mph in 5th and at the same time doesn't go into limp mode?

???

 

Yes in as such as I don't need to reset it or anything. Trust me I've researched and the symptoms are out there for others too. Summing to do with the n75 valve and the n18 (I think) tubes connected incorrectly or at fault? People have either put new n75 valves on or switched the tubes round and it's restored boost. I'll c if I can find the link:*

 

This link describes similar as I can't find the original but I don't get any warning lights as some do just very sluggish at 70 unless downhill where it will go to 85 if I was that way inclined to speed which I'm not

http://www.pistonheads.com/gassing/topic.asp?h=0&t=809211&d=11112.72340&nmt=

 

If you get stuck mate you an always pop over to us, we can check a few things for you, we accept biscuits for just checking things lol.

 

It could be to do with the intercooler if it has one.

 

Pmsl I tell ya what I would work money free for life if given a life time supply of fox's crunch creams!!!!!,

Kind offer terry.

 

Yes it's got an intercooler bud.

 

oh right, its just that on my Audi A2 1.4 tdi (the run about car) I had to replace its intercooler. It just to suddenly loose its power going up hills and on the motorway but wasn't quite 'limp mode' just a massive reduction in power. I fitted a new intercooler as the existing one was leaking. Immediately the car had so much power and acceleration. I'm probably wrong but you never know it might be worth checking that the intercooler has no cracks where the large dia plastic inlet and outlet connect onto the aluminum body.

 

Yes okay buddy I'll check it although I did think this and check for wet patches or obviouse signs and there was nothing. To be honest my trail of thought would be n75 valve or a dodgy pipe attributed to it or the MAF so I'm gunna test the MAF nest as its simple to rule out.

 

I had the same on my t5, thought the turbo had gone as it just seemed to go into limp mode, mine was n75 valve, cost me £53 for the valve and took me 5 mins to do as just 2 bolts and a couple of hoses and has been fine since!

 

I’ve swopped out my n75 valve but I’m wondering if it’s possible for it to drain my battery anyone know whether that is possible ?

 

Wot happened in the end?

 

Well I swopped the valve over for a cheap cable off eBay £20 the management light stayed on and it kept losing power and the battery was dead the next day, so I put the original back on, the management light turned off and it was fine but still quite loud and making a mooing noise then the management light came back on. But never lost power and never drained the battery.
So I bought a £45 n75 valve from eBay which wasn’t Chinese fitted that but the engine management light stayed, never lost power but tried to start it today and the battery was dead.

 

I would guess that your old N75 is bust and not trying to do anything.
Your new N75 which works is doing stuff by what it is doing is running your battery down.
This could be trying to adjust your EGR, turbo actuator or simply sending information back to the ECU which is trying to adjust something. This something could be stuck (EGR cooler flap or turbo actuator) so it is constantly working or creating an earth or leaving connections to power something like glow plugs on all the time.

I had a recent thing on a Caddy where the ECU had got corrupt and was sending all manner of false signals, caused bad MPG, stalling, oil light, glow plug flashing etc. I got a second hand one re-written for £200 and it was the best thing I ever did.