311 CDi losing power, but only at sustained 2500+rpm???

220805a

New member
Hi all! First time posting, long time lurking - could use a hand diagnosing a problem!

I've recently bought a 2003 311 CDi, MWB Minibus (2.15L Diesel) with 135000 Miles on it. Used to be a school bus in the UK, my girlfriend and I have fitted it out with a bed/storage setup to spend 12 months in Europe and Turkey.

About a week back it didn't start - turned out we'd cooked the starter, but I noticed leaking diesel lines while checking gearbox signal cables and we had them patched up in the process of putting the new starter in (the short sections in this pic).



All went well for a while, but 30 mins into our onward trip, sitting between 2500-3000rpm in 3rd gear for about 20-30 seconds, we lost power (felt like taking foot of accelerator for 4-5 seconds) and the EDC light came on with the fuel filter light (dash one, not the console one). Some experimenting proved we can repeat the process - always above 2500rpm, sustained for a 10 seconds or more, in 3rd gear or higher, only once or twice in second gear. It is temperamental though, seems to happen easier when the engine's 80 degrees or more and earlier power loss seems greater than it does now (post-duct-tape).

After the first power loss it's in what I'm guessing is 'limp home' - just cuts accel any time it goes over 2500rpm. First thought was dirty filter, but it only happens when the right conditions are met, it's consistently the same, no trouble starting or cruising or going over 2500-5000rpm in bursts.

Looked under the hood for cracked turbo hoses and sure enough, this hose (anyone know what it's called?) has a gash in it from rubbing on the heat shielding.



Looks like shielding has been bent in an earlier crash. Duct tape and cable ties seems to have decreased the severity of the power loss, but it still happens if I sit above 2500 long enough, and doesn't explain the fuel filter light - does it? Other hoses going to-from turbo look ok.

It still runs and drives fine to me having never owned a turbo or a giant van before, just my driving style (slow and steady) mostly keeps the rpm under 2500 except to jet up a short hill etc. and being from Australia where most roads are 100km/h, I'm happy to cruise at 60 on the motorways at 2100-2300rpm. Drove 2 hours being semi-careful about rpm yesterday without incident.

So I'm guessing that the stuffed turbo hose has something to do with it, but curious about the fuel filter light. Have run about 1/2 a big tank through since problem started, several hours driving over a few days. Same problem or just two concurrent issues? Budget is super tight and we live in the van, so I'd LOVE to be able to DIY fix this (everything in UK costs about double to us Aussies!).

Any thoughts, suggestions, notorious parts? Is it all the turbo hose? Water in fuel? Air in fuel? Busted filter? Something else? What to fix first?


There's also a host of other issues and quirks I've noticed that may be related/telling:
  • There's a loud hissing noise from the turbo, audible in the cab, especially at lower rpm. Having never driven a turbo before I figured it was normal, but it's loud enough to have to half-shout over in conversation. Read it could be this seal?
  • After 20-40 minutes of driving above 40 miles/hour or on hitting a smooth dip or sharp bump at speed, the ESP and take off assist warning lights come on, and stay on until re-ignition.
  • In the ignition click before starting, the glow plug light comes on slower than it used to - before the new starter.
  • The glow plug light stays on all the time, once it's on. Has always been like that.
  • There's a little can-thing near the repaired fuel lines that looks like its cable is really tightly wrapped around it. See here
  • There's a spade-ended lead under the hood on the right, under the battery that has been looped up (see pic) but is not attached to anything. That safe?
  • The minibus used to have a speed limiter, a fancy second odometer and a wheelchair lift wired in. They were removed by the company we got it from, except for one of those little push button/dongle things that we push to stop a beeping noise. If left beeping, it just beeps, not an immobiliser or anything.
  • The drivers front tyre is balding on the outer edge somewhat faster than all other tyres. Heh.
  • After starting from a stall, or quickly after shutting off ignition, it will run with the EDC light on.
  • Switching ignition off one click from running, then back again, won't start. Have to turn key all the way back to 0, then forward again.
  • Occasionally has trouble finding first or second, needs quite a push to get it into gear. Pumping clutch has no real effect when this happens, so I resort to strong-arming it in.
  • Checked the battery as a potential culprit for when starter was dead, seems ok.
  • The door-open-sensor-things on the passenger side are fidgety - sometimes doesn't detect door is open, sometimes does. Probably just old switches though?
  • General pics of the bay
    and
    here.
 
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220805a

New member
Also, we're near Bath/Bristol at the moment if any UK people know good mechanics or clubs in the southwest!?
 

lindenengineering

Well-known member
M8
G'day mate!
My brother has small diesel shop in south Gloucestershire on the A38 in Moreton Valance.
Tel 01452 725932 Gordon the Engine. He is Sprinter and Transit/ Ducato savvy, & dealing with things crooked!

You might like to call him and say his Bro Dennis gave you his number.
Dennis
The Transatlantic Mechanics.
 

220805a

New member
Thanks Dennis, will see if we can get up to Gloucester :)

Bought myself a Haynes manual, it looks pretty useless but I did manage to figure out that the torn hose is the breather hose... Now not so sure that's the problem.

I've read people have trouble with the brake sensor, and that the second stage of the sensor (first stage does lights) will kill the turbo if tripped.

Does anyone know if the second stage of the brake switch only chokes the turbo above certain RPM?
 

Tooth Fairy

Away with the fairies.
Does anyone know if the second stage of the brake switch only chokes the turbo above certain RPM?
The computer is being told there is a problem so restricts the revs, get the split hose sorted first and see if the problem goes away, take it one step at a time. :thumbup:
 

220805a

New member
Went in for a diagnostic, pointed at the fuel pressure being low/out of whack. Put a new filter on it to no avail, and the split hose turned out to be just the heat shielding on the crankcase ventilation hose, which is otherwise fine.

Culprit was a T-junction that we had repaired 2 weeks back, over crimped hose sections crushed the plastic line, letting air in at sustained high rpm (had to drag the air fwd from just in front of the tank, hence the 10-second delay).

Still seeing a few bubbles in the clear lines under the filter but looks solved as far as the rpm/limp home trigger is concerned. Drive home had a few good spots above 3k rpm with light boost req. All holding together so far :)
 
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