Golf TDI hesitation, then complete power loss on motorway

[davey_boy]

Hi Folks,

I've got a problem with my 2000 Golf GTTDI 115bhp AJM engine 142K miles. Just recently I noticed some hesitation under load, ie when turbo kicks in, next day I got on the motorway and after about 10 miles, the car began to gradually lose power, I ended up in 2nd gear on the hard shoulder and just manged to get onto a slip road, there the car died, and upon immediate cranking post stall, wouldn't start. RAC was called and came about 40mins later, to my amazement when the guy cranked the car it started no probs and revved up fine. Luckily the guy offered to follow me, got about 2 miles down the road and the same happened again, RAC guy told me he saw some white smoke when it stopped the second time. (RAC guy suggested possible exhaust problem)
Since then I have run the car on short journeys, sometimes it is fine (power seems good), sometimes there is some hesitation, power deffinately not as it should be.
Just to note, I put a new catalytic convertor on the car about 6 weeks ago.
Some more info on the car:
Re-mapped to approx 150bhp
130/150bhp injectors installed approx 30-40K ago (does smoke a bit)
I noticed that the car is losing a small amount of water.

I am thinking maybe cat problem? but then why would the car seem ok sometimes, if the cat is ******, wouldn't there be a consistant problem?

Head gasket / water jacket crack has been suggested, but there doesn't appear to be white smoke during short trips, also, would this make the car completely die one minute, then it start up fine a short time later?

EGR fault? - Am contemplating stripping EGR and inlet out as I've heard these get gunked up pretty badly, I've had this car for 7years/70K miles and not cleaned, so its well due.-But again, would this cause engine to stop.

Any ideas / help /suggestions would be greatly appreciated.

Thanks

Dave

[FLENG2008]

sounds like head gasket and overboost problem same as me, same engine code?

not sure why it dies on you though??

[davey_boy]

overboost problem?

[FLENG2008]

yer loss of power on the motorway, probs a overboost problem caused mainly by dirty turbo vanes, chucks it into limp mode
thats a common problem too along with the head gasket

[zollaf]

a code read, thats what you need first. it could be the turbo vanes, but doesnt sound like it to me. get a code read done and post the results. incidentally, after spending all that money increasing the power, why have you put a new cat on it, rather than a decat pipe, which is much cheaper.

[davey_boy]

Thanks for the responses gents.

Got the RAC bloke to read the fault codes, came back 'no faults found'. - Would I be right in assuming that this rules out sensor faults? (MAP/MAF)

Yeah, with hindsight should have gone with the de-cat pipe.

Don't think this was limp mode to be honest, at first it felt like fuel starvation. But for it to start again 20 mins later and rev up fine, can see why the RAC bloke suggested exhaust problem?? Not sure if clogged turbo vanes would cause the engine to die, and not start up again. - Will have a play with the control arm this weekend and see if they're free.

Have put some k-seal in so will monitor coolant level over next few days.

Going to take egr and inlet monifold off when i get a minute and give a thorough de-gunking.

[davey_boy]

Hi folks,

dug out my OBD2 lead and thought I'd check the fault codes myself,

turns out there is a code after all:

17958 - Charge pressure: control deviation
P1550 - 11 - 00 - Control limit not reached

any one come across this before?