n75 n18 swap now no boost /limp mode?

[Degsy]

Hi guys
had a go at changing glow plugs today but my socket was too large so doing them tomorrow. so as the car (04 lc pd15o) been running with a hesitation at low rpm I read a test is to swap over the n75 and n18 valves to see if it cures so I set to and done the swap. while i was under there i also took off the top boost pipe from egr to see how dirty it was and the end of the pipe had oil in and the egr and butterfly valve looked pretty clogged up oiled and sooted. so i got a clean rag and cleaned the end and wiped the butterfly valve as couldnt work out how you get the egr off as couldnt get to bottom bolt??
anyway put everyhting back together cleared the codes as posted in my other thread and started the car, was happy it started so left it at that. went out in the car this evening and it seems like i have no boost at all?? struggles to get over 2k rpm is it in limp mode?
I wouldnt think swapping over n75 and n18 would cause this or would it is ther anything else that could be causing it? i had air hose from airbox off and that top boost pipe only? have i done something by disturbing the oily crap on the end of egr.
I got the reader out when i got back and its throwing the following codes

17964 - Charge Pressure Control: Negative Deviation
17664 -P1256 - Engine Coolant Temperature Circuit
17506 - glow plug cylinder 2
19586 - EGR system,upper threshold reached

cleared but still no boost...
what next i presume change n75 and n18 back and check all the pipework...or have I managed to clog the butterfly valve by disturbing the soot...

any thoughts or help guys

 

[Degsy]

do i clean egr or use one of these
http://www.ebay.co.uk/itm/Allard-1-...arts_Vehicles_CarParts_SM&hash=item2a1a1e176a

car is standard no mods

ta

 

[sssstew]

i would say that its probably just a vacuum hose or elec plug to the N75/N18, most likely N75. Negative deviation means too low boost for what its expecting, like a boost leak, so also check that top boost pipe connection is good.

 

[Degsy]

cheers stew, is it possible to get them electrical plugs the wrong way round or do they do the same thing..

thanks
D

 

[Degsy]

well put it all back together and hey presto i have boost again..in fact the car drives better than it did before. i checked all the vacum pipes and had a split and a kink in one of them, swapped valves back round to right order straightened pipework and checked the rest. once back together checked the rest of the pipework for any leeks, found a small hole in the vac pipe that goes around the top and back of egr looks like from wear onto the housing so sealed that one.
then moved onto all the boost pipes and joints all the boost pipes look in decent condition so can you just buy the oring rubber seals?? as a few leeking a bit of oil.
what i did find is the pipe that comes directly off the turbo looks a bit dirty so may replace this one. anyone got a part number

I did find something else while under the bonnett there is a hole in the top of the gearbox casing and you can see inside unsure if there is a cover missing is this an inspection hole or something and what should be covering it.

any help guys

thanks
D

 

[Muttley]

The hole is for access to the timing marks on the flywheel, and should have a rubber bung like a hot-water bottle top in it. It's giving access to the clutch bellhousing, not the gearbox, so there's no danger of oil getting out, however the bung stops things getting in.

 

[Degsy]

cheers muttley ill get that hole covered, anyone got part number for hose directly off the turbo..

I have now got EML back on reading 19586 which is the EGR code fault again, anyone got any ideas would it be worth replacing the n75 and then get EGR blanking kit??
I can clear code but it comes back on after about 12 miles...

thanks
D.

 

[sssstew]

So are the valves still swapped?

 

[Degsy]

Hi Stew, no mate i swapped them back and checked all the pipework..and i had boost back cleared all the codes and all good. until yesterday done about 20 mile trip and eml back on throwing back the code 19586 - egr reference... Do you think the n75 knackered as if i clear the code it comes back after few miles. any ideas? was thinking of getting the EGR off thiss week on my day off and give it a good clean, if no joy I suppose replace n75 and then look to getting EGR blanking kit as if the light is going to be back on it might as well be on because of the kit and I know what it is.

what do you think?

D.

 

[Degsy]

just done my usual drive to work cleared the code before i set off to see at what point eml lights up , it seems to do it about 3/4 miles and when engine temp comes to normal position.. is that right if its related to EGR fault code 19586.
cheers
D.

 

[sssstew]

The N75 is for the turbo, so if youve put them back then no this wont be at fault. The N18 is the EGR control valve. I would swap them over again and clear the EGR error and see if you get it again with them swapped.

 

[Seatmann]

My tdi has been having the exact same hesitation issue so I disconnected the egr and plugged the vac line for it, the car ran totally smooth all the way up. I've reconnected it for now as the car just wouldn't warm up the same but it'll be disconnected as soon as the weather picks up. Fortuately I don't get a light for it when it's off.

 

[Degsy]

stew, but when i done the swap thats when it ran like a bag of S*** and I lost boost or do we think this was down to vac pipe?
thinking maybe just cleaning EGR this friday, clear code then make decision if it comes back to do egr blanking kit so wouldnt need n18 anyway, but if I left electrical connection connected would that stop EML??

thanks
D.

 

[Seatmann]

No, you'd need to get that tuned out but it wont cause any problems, it'd just be a bit annoying.

 

[Degsy]

it does annoy me as had the eml on for a few months now and knew it was glow plug error , done them last week removed error no light so was happy to see no light for a while ha ha now its back on...DOH!

D.

 

[sssstew]

i would swap them again and see if it still runs crap. if it does i would replace the N18 and see.

 

[Degsy]

cheers stew..ill give it a go going to clean egr Friday so will swap them then. I swapped them last time by unbolting and swapping valves over, tubes and electrical connectors can i just swap pipework while valves in their proper mounts?

 

[sssstew]

when i did the swap the pipework wouldnt reach around so had to unbolt and physically move/swap the location of the valves. but yes, if yours reach then why not.