Please help! Glow plugs or injectors

[NAV2795]

hi all,
Sorry if you've read something similar before but just couldn't find the answer i was looking for. Ive got a 2007 stx 2.5 diesle with 175k on it. On start up its idles a little rough, but once i go for a small drive and let it idle its good as gold. Aswell as this, it seems to push out some black smoke at around 2000 rmp or more when accellerating only. My oil levels are fine and changed the fuel filter only 2000km ago, and just recently cleaned the MAF sensor. My question is, are the two problems related? If so is it because of a stuffed injector pushing too much diesle in the engine, or could it be the glow plugs not burning off the fuel? Appreciate all the help i can get cheers!

 

[JPMC]

Did you reset the fuel learning value when you changed the fuel filter (The pedal reset of ECU)?
If you haven't it's likely the fuel pump could be pumping a little to much fuel into the engine.

 

[NAV2795]

Thanks JPMC,
But yes did that at the time but still no joy

 

[Old.Tony]

Before you start looking at expensive solutions let's try the cheaper ones first.

1) Is the air filter clean?

2) Do you have a catch can fitted?

3) Is there any sign of oil leaking OUT of the air hoses between the turbocharger and inlet manifold (follow it all the way, intercooler and all)?

4) Have you looked at the glow plug relay on the sidewall beside the battery? Does it look in good nick or has it burned out?

5) Have you looked at the ends of the glow plugs to make sure they don't look like they've overheated/corroded?

That's a start. I don't suspect turbocharger actuator/vacuum lines because it's rough idle on a cold start and the turbocharger is barely ticking over at that point. It's possible that there's some gunk in your intercooler (blow-by). You might also have a slightly sticking EGR valve - make yourself a gasket from 1mm thick stainless steel (or slightly thicker) and put it in the intake manifold side of the EGR pipe (the gold pipe that runs around the front of the engine).

 

[NAV2795]

Hi Tony,
My air filter is quite clean, and no i dont have a catch can. AS for the oil leaking out the air hoses i havent checked but will do. I havent looked at the relay as of yet or the glow plugs, thanks for the suggestions will definetly go give them a shot and let you know how it goes. Also is it possible to clean the egr as im not keen on blocking it off just yet? cheers