MOT Day and some boost problems why today!!!

[MURRAYS444]

Going to Drop my car off at the Garage this morning but on the way I had some problems with the boost I pulled over to check the hoses and nothing seemed out of place I gave the car a few revs and there was no boost noise from the turbo then ten minutes later it was fine could this be a MAF issue as I have been changing between filters from the Jetex cone to a K&N panel filter!

Any help appreciated!!!

 

[DaveA3]

when you change filter it takes a while for everything to adjust including the throttle body mate. it was probably just that. there is a procedure you should do after changing it to resolves this straight away. or you can go for a drive until it corrects itself. MPG probably dropped for a lil also. Should be back now. see if it continues if not it was probably as above.

 

[MURRAYS444]

Car failed its MOT only thing was due to a broken spring which is to be expected due to the horrible Edinburgh roads can relax now until next year!!!

 

[DaveA3]

ahh ok thats good news fingers crossed its alright from now on then mate.

if ur after some second hand springs to get u through u should ask on here or try ebay.

 

[MURRAYS444]

I just got it ordered by them it was £50 so it was a ok price I need the car for work but thanks anyway!

 

[DaveA3]

just 1 spring? should be changed in pairs mate if poss. Handling may feel ***** afterwards

 

[MURRAYS444]

Haha yeah you could be right i'll find out tomorrow when I pick up the car!

 

[jcs356]

I had two coil packs go on the way to my MOT last year. Unsurprisingly it failed the emissions test!

 

[MURRAYS444]

Got the car back and had it scanned over had one fault come back relating to boost had it reset and all is good!!!

 

[Westy]

Got the car back and had it scanned over had one fault come back relating to boost had it reset and all is good!!!

Can you remember what it was? Was it by any chance "Maximum boost limit exceeded"? That will mean that you have hit soft limp mode at some point. It cuts your boost down to about 6psi until the car is turned off and on again. This might explain you original issue.

Mine used to do it quite a bit and it turned out to be a faulty N75 valve.