Sprinter CDI MAF + Injectors

[Cnics]

hi, bit of a funny one. 52 plate 311cdi. Should this van have a MAF Sensor, as far as i understand it, it should, and it should be between the air filter box and the turbo along the pipe. there is a sensor of some description there but it doesn't match the description of the MAF and i'm told by a reputable mechanic that its NOT the MAF.

the reason i ask is because the vans running like a bag of spanners at the moment, knocking under load, knocking even worse under not quite so much load if you understand, and the first thing i'd look at would be the MAF, only i'm told it hasn't got one. Furthermore, some time ago when i had problems with the turbo which turned out to be the boost pressure switch/sensor or something i went down the road with the mechanic with the diagnostic machine plugged in an it showed an error of NO air flow reading. It was at this point that it was confirmed that it should have the MAF but didn't.

Im not overly sure what my direct question is here, but just some info on this MAF business, could the van have had this removed at some point, and this has done damage somewhere over the last 80,000 miles since i've had it causing engine problems? Also, could it be an injector problem? i'm told they are prone on this age vehicle.

Also, i'm based just outside Worksop, my local mechanic is very good at the regular stuff but when it comes to anything more, he struggles for room and i think that a specialist would be better off doing the work or at least the diagnostic, does anyone know anyone in this sort of area, i don't mind traveling a bit.

cheers

 

[dava]

Look under the header tank pass side, the pipe that goes into the intercooler has an air flow meter, it just pushes in. Pull it out and try cleaning with brake cleaner try not to touch it as they are delicate. Also next to that is the turbo boost switch held in with two bolts they are prone also.

 

[Cnics]

thanks, i'll have a look tomorrow,

on my way home from my unit today (dark) i noticed the van smoking, the engine was fairly cold (left for 45 minutes) and i the headlights fro the car behind me i noticed it smoking, white smoke, and quite alot of it. Not covering the road, but certainly alot, this was going into a junction in 3rd gear and pulling from about 1500rpm up to about 2500rpm then changing into 4th, empty van so not really making it work. white smoke to me says fuel. any clues?

 

[dava]

White blue smoke is fuel, do you have any more info? Injectors when they go you have to wind them over for a bit to get the pressure up to lift the nozzles, so if thats a problem then yes it could be an injector, the only sure way of checking them is with a spill port test, this shows up the faulty one. Is it boosting? Any whoosing noises ? Drop off in fuel consumption?

 

[Cnics]

Van starts first turn of the key like it's always done, never once failed. Whoosing noises? It makes a few air style noises if i'm pulling hard between 1500 and 2000rpm as if there is an air leak or vacuum being created somewhere, there is a noticeable sudden change in pressure (if it is air) if i lift off the throttle quick.

Eg, if i am in 4th gear at 1500rpm and put my foot down i'll hear a building up of what appears to be air pressure, if i let my foot off quick it makes a horrible noise. Now at first i thought nothing of it, i thought it seemed to be the turbo winding up etc, but now i'm less sure, unless it is, and its not as it should be. it's done this but has got noticeably worse since i got the van.

fuel consumption appears to be the same, anything between 23mpg and 32mpg and this reflects how it's been driven as it should. this year hasn't been as busy work wise so my mileage has only been around 20,000 but the years previous its closer double that, and next yea looks to be the same. I've got the MOT next month (though i'll be doing it as early as i can) and i really want to get everything 110% but without spending more than i need to.

My opinion is, if it needs 4 injectors, then so be it, but if it doesn't, i'm not putting them in.

 

[dava]

The whoosing noise and associated loss of power is probably an intercooler pipe burst. Check the pipe that goes to the inlet manifold from the intercooler, look for signs of oil and try squeezing the pipe, as this will open up a split, also check the one on the drivers side, it goes from the intercooler to the turbo, less common than the other, though I have changed a few. Doubt it will be injectors from what you've said here and even if it was then never had to change all, one goes down and they are pigs to start. As for your MOT make sure he knows a bit about sprinters as most MOT guys fail them for bottom ball joints as they all have play, just make sure they read the recent VOSA bullitin on how to check them. Apart from lights and tyres, the obvious stuff they are a pretty good all round van.
Hope it helps.

 

[Cnics]

I had a new intercooler about 6 months ago (it all stemmed from some front end damage that was done outside my house) and a few weeks ago i replaced the hose that goes from the intercooler to the turbo, as it looked in bad shape and covered in oil at the bottom, although the turbo drips oil a bit, not bad, but i the van stands in the same place for 24 hours of so (rare) then there's a drip on the floor, i'm told to expct tha from 115k van but i'd sooner it not leak at all. i'll look at the hose at the other side aswell, and where you say the airflow sensor is.

As for bottom ball joints, my MOT station actually missed both on mine last year, which i only found when replacing the link arms, which did fail. They're one of the few testing stations in the local area that do Class VII so they're used to such vehicles, it must have been a one off.

Cheers, once again you've been most helpful.