Boost problems

[dh00001]

Hi guys, been reading the forum for a while and finally decided to post, sorry if its a stupid question, i searched but couldn't think of a decent key word.

Started having problems with my Leon 180. The car will boost to around 1.1bar under full load.
Recently at full throttle its been boosting to full then dropping back to 0.7 back up and down between those two levels.
Naturally my garage told me the turbo needed replacing, but i was thinking i could be a n75/dv problem instead?

forgot to mention I already have a forge dv so its not a stock one, but does have standard spring. had it off and serviced it but didnt make a difference

 

[adam cupra 20vt]

Is it mapped? 1.1bar is not standard 9-10psi is standard

There is a thread in this section [today] where a chap has a standard LCR and he was boosting 20-21 psi instead of the 14psi Normal.....his was cured by replacing the N75 valve

 

[adam cupra 20vt]

This sounds like your problem [obviously you boost less not being a 'R']

http://www.seatcupra.net/forums/showthread.php?t=231334

 

[dh00001]

car is stage one mapped, i don't know who by as it was like that when i got it. I also bypassed the N249 so it cant be that taking pressure.

I think I have my standard n75 laying around somewhere. Currently running an ECS race valve so would an N75f still work? Bit clueless on this part of the car

 

[adam cupra 20vt]

I think the uprated one just lets you hold the boost a bit longer but the standard one would work ok......if you already have it theres only one way to find out

 

[CupraUK]

Yes, its worth trying the standard N75, pulsing can be caused by faulty N75 (I had to try and couple before it sorted itself out)

Does it do it on full throttle or just part?

 

[amarillo leon]

turbo problems AAAHHHHH

Hi guys

Not read in detail all the posts, just wanted some help with a turbo problem i am having at the moment.

i have a seat leon TDI 110 remapped to 140bhp with superchips.

The problem seems to occur when i give the leon the beans in third, it will boost and go but as soon as the revs hit around 4000rpm the turbo is knocked out.

Have done this on two occasions and on both occasions it has done the same.

i have checked the turbo itself to make sure it is not sticking on any part of its travel, recently changed the MAF and N75 Boost Control Solenoid.

I have checked as much of the piping as i can and everything seems in tact.

Just wondering what else i can check since this is spoiling the enjoyment of the leon.

any help would be greatly appreciated.

Kindest Regards

Andy

 

[Witalik]

could this also be my problem ? the N75 valve ?

http://www.seatcupra.net/forums/showthread.php?p=2559844#post2559844

at the bottom of the thread

 

[swilky23]

Hi guys

Not read in detail all the posts, just wanted some help with a turbo problem i am having at the moment.

i have a seat leon TDI 110 remapped to 140bhp with superchips.

The problem seems to occur when i give the leon the beans in third, it will boost and go but as soon as the revs hit around 4000rpm the turbo is knocked out.

Have done this on two occasions and on both occasions it has done the same.

i have checked the turbo itself to make sure it is not sticking on any part of its travel, recently changed the MAF and N75 Boost Control Solenoid.

I have checked as much of the piping as i can and everything seems in tact.

Just wondering what else i can check since this is spoiling the enjoyment of the leon.

any help would be greatly appreciated.

Kindest Regards

Andy

Does the car still sound the same with these problems.

 

[amarillo leon]

Does the car still sound the same with these problems.

Hello
the car sounds the same but without the turbo hiss and dump noise.

Also the car just does not go very slow.

cheers

andy

 

[amarillo leon]

hello

Yeah could be the n75 valve but before shelling out £32.00 for a new soleniod valve, check the turbo freeness and the maf is all working correctly.

Check the pipes you can see as well to see if you have any splits or cracks, but being honest it is covered by the fabric braiding so abit hard to see if the pipe has any defects.

Also do you get any warning lights on the dash come on when you lose the turbo, since my diesel glow plug light used to come on, when my turbo went. i tracked it down to a faulty brake switch, located on the back of the brake pedal.

apparently the ecu is looking at all inputs and the first thing it knocks out is the turbo.
the brake switch is one of them since if you are accelerating and the brake switch is sending info that the brakes are on then the ecu goes ahhh!! and knocks the turbo out to protect the turbo and engine.

Hope this helps

cheers

Andy

 

[Phillc]

Yeah could be the n75 valve but before shelling out £32.00 for a new soleniod valve

£32 more like £50

 

[amarillo leon]

£32 more like £50

No serious if you go to Andrew Page for a boost control soleniod valve n75 for a seat leon with asv engine 110bhp £32.00 pounds. honest no lie!!

What type are you buying and where from?

cheers

andy

 

[james walker]

asv engine??

what is this andrew page? link

 

[dh00001]

The n75 change fixed it! at first I was unsure as performance with the F valve was so down on what I'm used to.
Borrowed a J valve and its almost back to normal, just got to wait for my ECS to come and hopefully that will be that.
Who knew a flimsy bit of plastic could cause so much bother

 

[amarillo leon]

boost problem fixed i thnik !!

I had problems with my boost, and everytime i gave the car the beans in third gear, when the revs would get round to 4000rpm the turbo would be knocked out and the car would go into limp mode.
Well i checked the MAF, turbo freeness and replaced the N75 solenoid with a new standard one.
I fitted sometime ago a carbonio air induction kit bought from Awesome GTI now everything was fine but since i had my remap from Superchips done i never have really booted the car until now.

Now in the standard leon air box there is a hose connection which goes to the boost solenoid valve. But on the Carbonio intake there ia spigot that you just push into the side of the carbonio induction pipe body.

this spigot doe not point into the airflow and hence does not get the full airflow pushed into it, now it may sound crazy but i removed the spigot and put a right angle onto the spigot, abit like a pitot tube you find on the front of aircraft so that the spigot is pointing directly into the airflow inside the carbonio intake system.

i thought it was a bit of a long shot but i was was just ruling out everything, put the system back together, went out for a drive and voila, gave the beans in third went right round to red line, did this 6 times on the bypass it usually failed on ,and no loss of boost turbo running the whole time.

Have tested on various times after and still no boost problems. not bad for £1.49 peice of rubber/plastic that points into the intake airflow.

This only applied if you have changed from the standard leon airbox, if you still have the original airbox fitted you wont have this problem.

My guess is the problem on my leon is as the pressure increases on the turbo more air pressure is required to the solenoid valve, now if the sensor is not pointing into the direction of airflow on intake air then the pressure is reduced to the solenoid hence positive pressure deviation, not enorgh pressure for turbo to open up, and then turbo gets knocked out due to this. I think that is how it works anyway.

Anyway hope this helps anyone who has refitted ther eintake with a Carbonio system.

Cheers

Andy

 

[182@wheelsleonj]

hi, do you have a picture of what you`ve done with the intake kit piping. i`ve got a similar problem on my 1.8 turbo not holding boost properly. tried almost everything

cheers

 

[amarillo leon]

Can't get pick on to here since not allowed just yet on the forum since i am a newbie.

Basically thought you just need a right angled piece of rubber, like from a windscreen wiper attachement.
all you are trying to do is increase the airflow into the boost valve pipe that leads to the sensor.
if you just have a piece of plastic at right angles to the airflow in your induction kit intake pipe, it is fine most of the time, but as soon as you want to give it more on acceleration, i don't think the way the piece of plastic in the induction kit is fitted allows optimum pressure to be recieved.
so i fitted a right angle onto it so it face directly into the airflow to get max airflow.
So far (touch wood) no other problems but i had to go though checking the turbo, all the pipes for splits, check the MAF and the boost Control Solenoid until i thought of this but i may still fail but as i say o.k. so far and where it has failed before it isn't doing at the moment.
you could try looking in Halford or motorworld for some type of moulded right angle piece about 3 -4 mm across will do, have alook at your pipes first and work out size best fits.

hope this helps!!

Kindest Regards

andy