are you sure its not a small split in a turbo hose?
thats exactly the symptoms mine had.

 

sounds like either boost cut or fuel starvation.

 

had a quick read of the other thread but...

Not sure if you answered\have done this, but have you wound the actuator right in yet to drop the boost?

If you know that boost is set to well below 19PSI eg for testing set it to 16 or so, if the problem occurs then it has to be fuel starvation and not boost cut...

 

If you read the thread by jay_mz89 entitled 'more boost/higher boost', you may get some useful info. Personally, I think you have boost cut. Try lengthening the wastegate linkage & see if the problem persists.

 

its not boost cut because the boost gauge doesnt drop, also the tu1 prevents it.
i unhooked the actuator completely so it made no boost and it still did it.

its not starvation because of the black smoke.
and as i said ive checked both hoses.

im convinced this is a fuelling issue from the fuel ending up in my oil. i cant explain the sudden loud engine note though unless its a valve/head issue

 

its not boost cut because the boost gauge doesnt drop, also the tu1 prevents it.
i unhooked the actuator completely so it made no boost and it still did it.

its not starvation because of the black smoke.
and as i said ive checked both hoses.

im convinced this is a fuelling issue from the fuel ending up in my oil. i cant explain the sudden loud engine note though unless its a valve/head issue

The TU1 doesn't prevent boost cut on many cars (mine included).

black smoke could indicate an EGR fault.

 

im not too sure, somebody mentioned it could be a leaky injector

 

Also, i worked out my last tank to be 35mpg. my foot was nowhere near the floor for the whole tank, no speed limits were broken, basically ive been doing everything i can to drive economically.

Dont know if that bears any relevance :S

 

oh and my egr is unplugged, it is also blanked off where it connects to the inlet manifold because i didnt bother putting a hole in the gasket for it, as an attempt to block it off.

Im sorry if ive sounded a little harsh guys, im really really annoyed with this car, it just seems to be a total money pit, i bought the car for £600 and have spent at least another £800 on it fixing and upgrading it. All within about 25,000 miles. Just when i thought i had it perfectly sorted, this started happening. It had been running 24-26psi fine for months before this started happening, could not fault the performance apart from low MPG figures.

 

It had been running 24-26psi fine for months before this started happening, could not fault the performance apart from low MPG figures.

On a standard turbo?

If so then you've probably found the problem!

I'd be checking the turbo for play. Could well be mullared and performance at 26psi is going to be less than 19 on a 600.

 

24-26psi, on a STD turbo that's mad, are u using any kind of boost controller or just adjusting the actuator arm? I didn't think those boost levels would be possible on the arm alone. Maybe u have a defective gauge and your running alot less boost than u think? Just a thought.

 

24-26psi...!! lol i would get that down to 19 asap

 

im running just short of 19 now. I used washers to space the actuator away from the bracket. I had to because without it would only boost to 16psi

 

I recently had a simmilar problem, it turned out to be the boost/map sensor was faulty, got one for £30 off ebay

 

If playing with the TU1 alters it, then chances are it is reading about right. If it wasn't reading atmospheric pressure right then the ecu warning light comes on. You can test it easily enough with a multimeter.

 

hmmm ill go harvest one off a scrap yard somewhere. Will the map sensor from any 2/4/600/25/45 work?

 

Now where is that shaking head smiley....

Could well be more than a knackered turbo too.

 

Dakta its not munched one yet, its still on the same one. Never got round to changing it in the end.

My spare has also developed shaft play from just being sat there :S so i cant even change it now. Also i noticed the actuators arms on both turbo's are different designs and not interchangeable (i tried changing the actuator).

The one on the car has a nice little knurled wheel you can turn to change the boost. yet the spare one just has a bar that you unhook and turn. Any thoughs on this?

Is it really going to be a turbo problem? it holds boost just fine. The only thing i can fault it on is seeping a bit of oil out. Does the fact that the map sensor hose having a bit of oil in it change anything?

 

My spare has also developed shaft play from just being sat there

Nah they do that, the oil in the journal bearing usually absorbs some of the play, so if a turbo is left to dry it develops a little bit of play. Itl go when it's put into use as long as it isn't silly excessive from some unknown wear.

The other actuator is pretty normal too, normally find them awkward actuators on sd turbos rather than sdi, though i've seen em on both (my sd had the knurled type, but ive never seen an sd with a knurled type since and i've tuned a few).

I'd have imagines that they should be swapable though?

 

nope the knurled type was a bit shorter surprisingly. I thought they'd be the same too. Do you guys think i should just swap the turbo anyway and see if it stops? how long does it take? im gonna guess around 3 hours. And is it nessecary to drain the engine oil?

 

Doesn't surprise me to be honest, heard plenty of tales of 'my sd won't adjust to 19psi!' That said I suppose it's down to luck what actuator you get.

Your symptoms arn't exactly what i'd expect from a totally dead turbo but certainly well within the scope of one on it's way out, and let's face it it's had a hard life :dddc: (I read through the threads where you thought it'd seized). I did think you'd fitted the replacement though.

 

Nah im a very lazy boy sometimes. I supposed id better get my arse in gear on monday and change it then.