Hi Again Guys,

As you all know from my previous posts, we have a 2001 vRS (AUQ). We have just had it back from the garage after having all the exhaust valves replaced. Engine is now running spot on execpt... The turbo isn't boosting under load. Along the flat and downhill the turbo boosts, but feels restricted. Uphill it looses all momentum, and feels like there is no power (other than what is supplied by the engine, of course!) often needing a downchange.

There is no smoke on start up, no smoke throughout the rev-range, no odd noises, no difference in running temperature, starts perfectly hot or cold

After checking all the hoses, we have found an oil breather from the top of the oil filter. It is a plastic hose that leads to a 'T' Junction, the right goes to the top breather, in turn going to the air intake pipe just after the MAF sensor. Back from that 'T' junction there is a bit to the left, someone has put a cable tied a bolt in there. I would like to know that pipe leads if anyone knows? I just can't see where it goes!

After reasearching on here, I have looked for air leaks, and cannot find any.

I have cleaned out the MAF sensor, this didn't make a difference. I have unplugged the MAF sensor, this has put the Traction Control Light and Engine Light on, the car feels more torquey and responsive. The turbo is boosting better, but still feels a little restricted and is still on and off.

Another thing is, after the MAF sensor, there is a little black box with a plug and 2 pipes plugged in. It has a flathead screw inside. Does this need playing with to make it run better? I haven't touched it yet

If anyone is local to me with the same AUQ engined vRS, would we be able to pop over and have a nose under your bonnet to see where these pipes lead and to double check ours is all ok? We would really appreciate it.

As always, advice is much appreciated.

David & Martin

pics might be good. I wonder if you N249 has been deleted, is the box you describe on top of one of the coil packs? If it runs better with the maf unplugged then it sounds like you need a new one. Get a genuine one not a cheap eBay special. Is the car remapped?

I don't think the car has been remapped, If it has, I would be very dissapointed in it!

We couldn't take a Toyota Yaris on an uphill stretch in the A39, and this was at about 60 in 5th.

Have popped up a pic with the bit circled.

Picture is not my car, another briskoda member with a Red vRS Estate from NZ. Sorry if this has caused any offence.

David & Martin

Thats Rob Clubleys car - As mentioned before, I have VCDS but shame i am the opposite end of the county from you.

Yeah, I did think of messaging you. Shame you are 65 miles away.

I am going back to the garage that did the work on the car tomorrow morning, if no joy there we may have to pop over to see you.

But, in the meantime, any ideas on what to check would be great.

David & Martin

... i was flying through you're neck of the woods today (sunday), and i had vagcom with me ...

there's a small chance i might be going 'up north' again at some stage later this week

Update...

Been to the garage and had the car plugged in. It is coming up with 4 fault codes relating to the 2 Lamba Sensors and a sensor above the intercooler, by the drivers indicator. But the mechanic feels as though it is the MAF sensor, so we are giving a new MAF sensor a try tomorrow. A Bosch one, from GSF so not cheap crap.

David & Martin

Might be the boost sensor "thrust sensor" down by the intercooler. I know on the dervs that sensor is down that end of the car. Goes into the boost pipework, held in by a couple of screws.

The garage called this afternoon, they got the MAF earlier than expected so it was fitted this afternoon.

There is an improvement, but it is just not as it should be. The turbo isn't spooling as it should be, and when it does, it cuts itself out. The garage has offered to take it in Wednesday to try changing another couple of sensors to see if that makes any difference.

Keep the ideas coming!

David & Martin

map sensor can be a bitch to change as the bolts seize.

MAP sensor looks like this

Stands for "Manifold Absolute Pressure" and monitors turbo boost (and boost temps) so is fairly key to the whole car performance. They don't go wrong often, but when they do, causes a bit of a mess.... Should be a fault code saying something like "Thrust sensor, implausible correleation"

Just an update!

We have sold/p.xed the car on and got our selfs a lovely 2001 seat leon 20vt cupra. As we couldnt see the point in putting anymore money into it ;-/

Again thank guys for your input and help!

Cheers

David & Martin

map sensor can be a bitch to change as the bolts seize.

I tried to get mine out a while ago and I could not get a screw driver onto the screws due to the stupid angles they are put in at :-(