can anyone help me my my99 has a problem holding boost pressure it will build up fine and then drop off to about 8 to 10 psi and then back up to 14.5 i have a few mods dump valve, exhaust, itg filter please help

 

Have you tried cleaning your wastegate solenoid...?

 

no wouldn,t know where to find it tryed ecu reset after filter change and cleaner down actuater pipes just incase.

 

Click here for a picture of it. If you look just under the words "Driver strut tower", it's the small blue cylindrical device, with either 2 or 3 pipes going in/out of it.

You know how to do an ECU reset then. If you just use the green connectors to put it into test mode, then remove one or both of the hoses going into the solenoid and spray the brake cleaner inside whilst it's clicking.

You say you've had a filter change. Air or oil? If oil, have you changed the oil then? And if so, has the oil been over-filled...?

 

Im having the same problem mate! Mine a MY99 & when im acc. it boost up to 1bar then drops off to .6bar, you feel it best in 4th! does yours fluctuate between them figures while you foots to the floor??? ive replaced my MAF, plugs,leads, vac pipes theres no faults listed in ecu cleaned out solernoid & stiil the same!
Keep me posted on what you find, I'll do the same 4 you

Martin

 

i had this with mine aswell (my99) now in dealership getting the engine striped as it's low on compression

 

changed oil and air filter oil is at max but not overfilled tryed the brake cleaner trick and still the same thanks anyway lads! and yes mine does the same as yours martin i,ll let u know if theres any change mate.

 

cleaned wastegate solenoid problem seems to have gone boostwise but still seems a bit slower than usual diagnostic check says there is a problem with the wastegate solenoid.

 

Max isn't ideal when it comes to oil level. Try draining some oil out, so it's about halfway on the dip stick. Then clean the wastegate solenoid again (in test mode), and surrounding hoses. Might sort it, otherwise the solenoid may genuinely be shagged...

 

Hi Mate,
I will say youve got a problem with you solernoind because you had it disconected! or was the fault there b4 you cleaned it??? it may not be the solernoid causing your fault though as when the solernid stops working it causes the car to over boost, but your loosing it like me. see what else you can come up with! ive just done a full emisions test today so i know my cats & o2 sensor is ok!
I youd like to keep in touch by private e-mail 2 solve our problem just let me know.

Martin

 

I had a problem on WOT in 5th on a MY00 where boost fluctuated between 17psi and 10psi. Would settle after a few oscillations at the normal 14psi. Didn't see it in any other gears.

Serviced dump valve and much better.

Cheers

Mark

 

I thought it could have been my dump valve so i took it off & refit the original one, still the same though!

 

cleaned wastgate solenoid again and reset ecu problem is now solved diagnostic check is fine now too

 

Hi all, seem to have a similar problem.About a month ago a bought my first scoob,it is a my98 uk turbo,and allready had a full h & s fully decated exhaust,and an itg panel filter fitted.I thought it would be a good idea to perform an ecu reset on it.The reset flagged up a problem with the o2(lambda) sensor,and after further investigation found that the o2 sensor had been electrically disconnected,i re-connected the sensor and then did another ecu reset,it solved the fault and the ecu now is fine,but since then i have noticed a real drop in power,the turbo does kick in at around 3000rpm but it doesn't seem any where near as fierce as it was before,could anyone help me out please !!!!!!!!!!!!!

 

how do you clean the wastegate solenoid ?

 

If the car's drop in performance has only occurred since resetting the ECU, it might be MAF related. The ECU would have learnt its way around a failing MAF, keeping things smooth. But after resetting it, all the learnt values would be lost, and the failing MAF would stick out like a sore thumb.

To clean the wastegate solenoid, click here for a picture of it. If you look just under the words "Driver strut tower", it's the small blue cylindrical device, with either 2 or 3 pipes going in/out of it.

You then need to put the car into ECU test mode, by connecting the green connectors together under the steering column. It's the same procedure as here for the diagnostic read mode, only using the greens instead of the blacks. Whilst all the relays and solenoids are clicking, you can disconnect the pipes from the boost solenoid, and spray brake cleaner inside the solenoid and the pipes, then put all back together again.

 

no good on computer mate so i dont know how to send private mail, my car seems fine now anyway i think it must have been the oil in the solenoid good luck anyway.