B5 A4 1.9 TDi 110 AFN, Remapped, Boost Question

[EdgeyA4]

Hi there Everyone,

I have a quick question i hope someone can help me out with,

I have a110 TDi AFN remapped to supposedley 140 BHp by CC Tuning,

I installed a boost gauge the other day, and noticed that when Accelerating UPTO 2K RPM Obv Boost increases, After 2K RPM the boost drops off, but not all the Completley, Just wondering if this is normal?

Also im only seeing Peak boost of around 18-19PSi, i thought this was Standard? surley Re-mapped would be higher?

Just begining to think it could be Boost Leak? is there any easy way of testing this?

Thanks in advance

 

[EdgeyA4]

Could this be the n75 playing up? Or turbo nearin the end of ts life? I plan on cleaning the n75 tommorrow, what can I clean it with and how should I? I'll also replace the vacumm lines

 

[fARQUARE]

if you have vagcom, do some data logging to see exactly whats going on before buying anything.
if the car is new to you i'd recommend doing the following first;

- clean out the inlet maniifold, it's free and no parts required but is a messy job. you should probably fit an ecu blanking plate when you re assemble too
-replace all vac lines, go to ecp or gsf and get 1m of .4 and .6 id hose. dont bother with sillicon, just ensure you plumb it all in correctly
-clean out the map sensor vac hose, the map sensor is in the ecu, open the ecu and replace the hose in there too, clean out the one running along the bulkhead with some compressed air.

now you can start ruling things out but please use vagcom unless you dont like money.

n75 and n18 are interchangable, give that a shot to see if it makes any diffference.

check the actuator on your turbo, if there is any stickyness on the actuator refer to evilscotsmans guide on here before doing anything else.
buy a vac guage so you can measure hg to the turbo actuator (mine was 20 off ebay).

dont replace the maf, n75 or turbo until your sure its the culprit, 99 times out of 100 the small things let these motors down,

where are you located? there may be someone local to you who can give you a hand withe vag-com or swapping pars over.

 

[EdgeyA4]

Hi there,

Unfortunatley i dont have VagCom, which i know i really should do, but i diont tend to keep cars long enough to justify spending £100s on the software and tools, i will try cleaning the inlet manifold next weekend, is it hard to remove? also i was going to start replacing the Vac lines today but i couldnt find how to remove the N75 to make sure i replace them all correctley, Also for some reason i dont have this Vac line to the MAP sensor in the ECU for some reason?

Can i clean the N75 or do tests with it at all? how to i remove this?

i am in Stourbridsge just outside of Dudley and Birmingham if anyone does fancy lending a hand?

Thanks for the Very Informative post

Chris

 

[tdia4]

Mines also a mapped 110, dont have a boost gauge though so not sure what boost it makes. Have a look for boost leaks first, the pipe near the egr valve is a common one that splits, Also the intercooler pipes become loose after time so check them all and tighten up the clamps if needed.

As mentioned clean the Inlet out, easy enough to remove with the right tools, just make sure you torque everything back up properly, block egr valve off aswell, easy enough to do and will stop the inlet caking up in **** again.

Maybe give the exhaust side of the turbo a clean out to, easy to do with mr muscle oven cleaner, my car wasnt going into limp mode but I cleaned the exhaust side of the turbo out and it did run better after, theres a guide on here in this section somewhere on how to do it.

 

[EdgeyA4]

Hi there, yeah I think I will look for leaks first, seems to be the easiest and cheapest point to start, i know it's easy to look over the pipes but is there any sure fire way of finding them I.e spraying fine mist of water over the pipes?

I will have a look at taking the inlet manifold off, I'm not very good when it come to tools lol

I have already blanked the egr off as I have done the mr nuclear clean but I don't think I did it very well so I will proberly do that again as it was easy enough to do, iv made sure the blank is not lowing also

Thanks again

 

[tonya4]

Why not bother with silicon vac hoses?

tony

 

[EdgeyA4]

I Have got some Pipe to replace the Vac lines, just need to know how to remove the N75 so i can do it properley,

It doesnt seem to bad today, Still More laggy than usual,

I think i may give it a Oil and filter change, Air filter Change and Fuel Filter cahnge, to see if that help it along

Thanks

 

[fARQUARE]

Why not bother with silicon vac hoses?

tony

it's only a vac line. standard hoses have stood up for around 15 years so replacing like with like will cost you less than a fiver. by all means use silicone if you can get it for less than that but I wouldnt view it as a performance enhancement.
they always tennd to be horrible colours too but thats preference.

there are a few threads by me and evilscotsman which have the vac plumbing maps, have a search mine were wrong when I got my car.

 

[EdgeyA4]

Hi again everyone,

Had a bit of a mess with the car when iv had the time, (not had much due to Stock take at work, moving factoys etc havnt had a weekend loL), however i have replaced the Vac pipe from the N75 to the Turbo Actuator, seemed abit better until warm then i guess the pipe goes soft and collapses under vaccumm? i also found a couple off boost leaks on my EGR blanking plates, aslo seemed to go abit better then aswell, but what i have noticed is that the problem seems to be worse at "Wide Open Throttle" as if i feather the throttle the problem doesnt seem to bad but that could just be me, the next plans are:

1) When i get some free time, Re-clean the turbo and re-seal EGR Blanks
2) Get a Manual Boost Controller to stop spike and hopefully hold boost

 

[aragorn]

An MBC probably wont work.

TDI's dont send boost to the actuator like a petrol engine does, it sends vacuum instead.

 

[tdia4]

It's probally down to your egr leaking, get a proper blanking plate for it and it should be fine.

The egr pipe on my old Bora snapped which caused the car to loose the turbo altogether, so a little leak is going to effect performance.

Just replaced all my vac lines the other week with silicone hoses, got 3metres for like £6 off ebay, alot of my old hoses were frayed and had little slits in them.

 

[EdgeyA4]

Thanks for the info and Advise,

right, when i get some free time i will clean the turbo again, as the first time i fell it could of gone better lol, i will reseal my EGR Port,

Also what Diameter Hose should i get as i brought some 4mm before and i feel that if it is too much it may not help with the vaccumm?

Thanks again