J

JebLZ

Member
Drove through some puddles in my Disco 2 TD5 after yesterday's terrible Manchester rain storms - nothing too high, maybe 100-150mm. Noticed a loss of power straight away. Thismorning I can't accelerate properly at all - the disco isn't really drivable past 10mph.

In neutral, tickover is completely fine, and I can accelerate fine if it is VERY gradual - tried it to about 3000rpm. However, putting my foot down makes it jerkily accelerate and a lot of white smoke comes out the back.

Checked the ECU codes, got some historic air flow faults which I cleared and re-tested - no faults appear now. No engine management light is on or anything. I disconnected the air box, same symptoms, didn't seem to have any effect.

Any ideas?

It drives fine if you don't put your foot down so I can probably limp to the garage. Could the exhaust suck in any water that will have screwed the turbo?
 
Ok will try.
Garage suggested sniffing the exhaust to see if it's unburnt diesel or oil. Also suggested disconnecting one of the intercooler pipes to see if there's water in it.
Internet searching points towards the ECU having water in the little air holes at the bottom. Also the MAF sensor or intake system in general, or boost modulator.
 
Well for MAF sensor you can disconnect and take for a drive, as the engine will go to default. If it drives better then would indicate a new Sensor is probably required, But I do not see how that would cause your white smoke.

Have you checked the airbox to see if there is any water inside? In case you went a little deeper /faster than you thought.

What diagnostics do you have access to? If possible can you get live reading from it?

Cheers
 
The ECU is actually quite waterproof and should be alright, plus quite high up is a Disco. As above MAF is easy to check, just unplug it, if it needs replacing only buy genuine ones.
 
No water in the airbox, and with the airbox disconnected and the electric connection unplugged that goes into the airbox, the problem was exactly the same. There are 2 electric connectors into the intake system though, didn't try unplugging the one further downstream. Could try that I suppose.

I have a Hawkeye so I can see faults and Live data from the 'EMS', I think that has some air pressure / MAF voltage stuff in it.
 
Did you try unplugging the electrical connection that goes too the MAF? ( round black sensor with a wire mesh inside it, behind the airfilter box ) If not worth trying.

But still do not see why it would give white smoke. Have you checked all the inlet pipes to make sure you have not got a whole that has allowed some water in? Or as your garage have suggested, have you got a collapsed intercooler pipe?

Cheers
 
Will double check that I actually unplugged the MAF. I thought I had, but I was in a rush to get to work. Ended up driving the wife's car. Will try all these things when I get home. Quite frustrating I can't try it now :)

The smoke may not have been white - it might have been a bit grey, was hard to decide what colour it was. Probably unburnt diesel, as I don't get any smoke at all when I gradually accelerate by pushing down the accelerator very, very, slowly.

Don't see why the MAF would die after going through water though, especially as the air box was completely dry. Certainly does feel like some kind of air intake issue though.
 
Maf failure would normally be a bit more subtle than this. A lot of people have had them fail and not noticed the real difference until they fit a new one.

But a very quick thing to check and knock off the list.

Good luck.

Cheers
 
Seems better now, but not fixed

Still very poor acceleration between idle and 2000 rpm. Lots of I burnt diesel out the back.

MAF sensor disconnection had no effect.

EGR stuck open error code now (code 3144). I had previously been getting a 'stuck closed' message.

Not had the EGR blanked ever, could my symptoms be explained by EGR failure?
 
Personally not sure if the EGR could cause that but buy a blanking kit (£30) and get rid of it. Its total crap.
 
see if the air filter didnt get wet, if you dont have new within reach remove it and test drive it so....read live data for manifold pressure(MAP) and report...can you hear the pump running?
 
Last edited:
What pump do you mean? If you mean the turbo then yep I can hear that, sounds healthy and behaves just like before the trouble started.

Certainly does feel like an air flow issue. Quite slow from 1000-2000 revs before the turbo kicks in. It's burning far too rich during this period as I get some smoke smelling like unburnt diesel out the back.

I thought I'd ruled out the air filter as I'd disconnected the pipe leading to the air box completely, allowing to pull unfiltered air. However during this experiment I also unplugged the cable going in to the air box (EDIT: This is the AAP, Ambient Air Pressure, sensor). What is that? It's not the MAF sensor, that's further downstream and I'd left that plugged in. I haven't felt it to see if it's wet though. Could try that.

It's not the MAF sensor as I'd unplugged that separately and the issue was the same. Still might spray it with some carb cleaner just in case. There are some other sensors involved in the air intake system (MAP, temperature) so I'll look into those too.
 
I didn't drive it, just revved it in Neutral on my drive and the throttle 'jerkiness' was still present.

I did get some Air Flow errors, yep. I remember seeing an 'air flow HIGH' and 'air flow LOW' error. Cleared them after the test.

I'll check the fuel pump too, not something I've looked at yet. Not sure that would be a problem though - if anything its over-fuelling, not under-fuelling. If it wasn't working I'd get no pressure on my fuel lines though so it wouldn't even start up?

Top priority when I get home tonight will be to squirt the MAP, MAF, AAP with some Carb cleaner and test drive it like that.
 
If the fuel pump's HP stage fails it will start and run on LP but completely gutless and can't rev it above 3000... live data readings are relevant to see how the sensors are working and as long as no faults logged the problem is with the fuel supply cos that's not covered by diagnostics...or the crank sensor might not throw a fault code if gives erratic inputs only.
 
Ah ok didn't know that about the pump. I can rev fine past 3000 though, in fact at high revs/when the turbo is at max boost everything is happy. Think I revved it up to about 4000 or so, way past what I normally would use whilst driving.
 
I understood something else from your first post... then check if the wastegate is not stuck open or turbo hoses delaminated but if you still get that EGR fault you should check that first or better get rid of it
 
Turbo wastegate sounded like a good possibility, however the diagnostics show that it is at 0.00% at idle, then when I rev (in neutral) it goes up to about 6-10% engaged. Couldn't actually see the gate visibly moving though. I tried operating the gate with a pair of pliers to see if it was stuck. The rod was fully towards the front of the car. I managed to push it back (with quite some effort!) towards the back of the car. I never played with it before this fault occurred so I don't know how it should behave. Does this all sound ok?

I gave both the wastegate and EGR valve a good tap with a big spanner jsut in case, didn't help though.

The EGR fault code didn't re-occur after I cleared it down - in fact no faults at all are reoccurring, making this quite tricky to diagnose.

Think I'm about ready to throw the towel in and take it to my local landy specialist! :)
 
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