Symptoms of faulty n75??

[W11TTX]

What are the symptoms of a n75 playing up?

 

[yellonvi-R]

Limp mode, lose of boost, to much boost. It controls your boost so anything to do with boost issues. You need to explain the problem more.

 

[W11TTX]

Well sometimes I get a bit of a surge low revs then it eases off and comes back again. Also sometimes it feels like it holds back of boost and then go off and on the throttle and comes back! It's not all the time just sometimes!

 

[BoostHard]

Would a bad N75 all ways through a code?

 

[leon cupra r]

I think my N75 is goosed, couple of times a week I get no more than about 5 psi boost on the gauge, Vagcom shows requested boost is normal but actual boost is nowhere near... Fault code is stored... either clearing codes or simply turning engine off/on again restores back to normal... If I unplug N75 I get same boost levels so suspect this is the problem.... New one on order from Dave @ Sere...

Ben

 

[BoostHard]

Mine is the other way round, I keep getting 'maximum boost pressure limit exceeded'

 

[leon cupra r]

Where u based? actual vs requested boost and N75 duty vagcom logs might be useful.. Would imagine its either N75 or sticky/clogged wastegate though

 

[W11TTX]

That means over boosting doesn't it? I'm not gettin any lights on and not scanned for a bit. It's just seems to offer up less boost then it will Offer up full boost?

 

[leon cupra r]

Well sometimes I get a bit of a surge low revs then it eases off and comes back again. Also sometimes it feels like it holds back of boost and then go off and on the throttle and comes back! It's not all the time just sometimes!

To be fair reading that it sounds like it could be DV opening... is N249 bypassed? If not if you go full throttle -> part throttle -> full throttle again you will see lack of boost for a second or two then when DV closes full boost will return...

 

[W11TTX]

Done the n249 bypass and services the dv 5 months ago! It hasn't got the new service kit on it tho So may look at getting the new service kit.

 

[JDUB 20V]

Done the n249 bypass and services the dv 5 months ago! It hasn't got the new service kit on it tho So may look at getting the new service kit.

I have a similar issue, just fitted new revised piston in Forge valve but still same.. I have a feeling i have a boost leak from billet adaptor on turbo with mine but waiting for new turbo so all can be changed/resealed... With your car get a smoke test/boost leak check done

 

[W11TTX]

Interesting so you don't think it could be a faulty n75? Ill give it a good once over at the weekend when I get time to see if I can see anything! I did have a boost leak but that was on the pcv system !

 

[JDUB 20V]

I had a boost leak too from the PCV, replaced that pipe, changed N75 but still have same issue. Guessing need another smoke test and thorough diag.

 

[W11TTX]

Very strange then be interesting to see what the outcome is! I may change back to the standard DV for a while and see if that makes a difference! What type n75 did you use as there's loads of versions?

 

[JDUB 20V]

Very strange then be interesting to see what the outcome is! I may change back to the standard DV for a while and see if that makes a difference! What type n75 did you use as there's loads of versions?

Thats worth a shot too My N75 is from dealer from my car Reg no. Think it ends with letter E

 

[W11TTX]

Ah right I kno mines an f version but that's was replaced by the e version supposedly! Ill change them over tonight and see if I notice any difference over the next week or so but in the mean time ill email forge and try and get a service kit and maybe try it with some shims in as I'm running the yellow spring at the moment .

 

[tom t]

Would connecting the n75 pipes the wrong way kill the n75?

 

[W11TTX]

Bringing and old thread back, iv got the revised piston in my 007 and iv mounted it both ways. And still every now and again the car feels like it hold back slightly, sometimes the boost is there and pulls hard then some times its just seem to hold back slightly, it still boosts just feels slightly less, very confused unless its just me thinking there is an issue when there isn't?

 

[Gnollins]

What petrol are you using? I find that with V-Power I get great boost all the time, but with BP Ultimate or normal fuel I get exactly what you describe - slight hesitancy and less boost.

 

[W11TTX]

It's always run on v power, never use anything different.