[RJK]

Hi guys/girls

Probably been answered a lot.

Lot of black smoke under acceleration. Slight lack of power.

Removed lower turbo hose, all in good nick.

No splits on pipe from intercooler to engine.


There's oil splatters around air intake between air box and turbo

however an Alfa specialist said over the phone that a leak before the turbo wouldn't cause black smoke...

Any other ideas??

EGR??

Thanks in advance.

 

[_The_Editor_]

Checked the rubber hose between the turbo and the MAF sensor?

This is where the crank-case vent joins the induction air.. Splits/leaks here are fairly common, and will result in un-metered air entering the engine..

 

[halftone]

EGR sticking + MAP sensor covered in carbon are also possibilities. Both are easy access.

 

[RJK]

Thank you sir

Will check both tonight

 

[halftone]

Wiggle the MAP sensor gently to remove it. After you take the screw out it snaps into the manifold c/o an O-ring. Below that is a small protective plastic cage around the sensor element, and if the cage is crusted with carbon/oil goo too much force will bust it. Some carb cleaner will soften the goo and help remove it.

 

[dgmayhead]

VNT hoses that start at the bonnet catch are the cheapest and easiest place to start fault finding. Even the smallest crack causes a loss of vacuum and effectively results in your turbo vanes being stuck on low pitch. No fault code is generated. All the hoses can be replaced with silicon tubing for less than a fiver.

 

[RJK]

Thanks guys.. Haven't been able to check anything tonight.

On it first thing tomorrow.

Complete noob.. Where and what are the VNT hoses?

The oil splatters are towards top right of engine cover.. by EGR..

What would be most probable cause in that location?

 

[_The_Editor_]

Thanks guys.. Haven't been able to check anything tonight.

On it first thing tomorrow.

Complete noob.. Where and what are the VNT hoses?

The oil splatters are towards top right of engine cover.. by EGR..

What would be most probable cause in that location?

VNT hoses are the small diameter hoses (about 6mm from the outside) that hook up to the actuator on the turbo.

In the front of your engine bay, look down and spot the turbo actuator, and the small hos line that comes out is the vac line for the VNT system... Trace these hoses as far as you can, and if you see splits they need replacing..

Top right of the engine cover is where the crank case vent valve is located.. Could have a failure in this area would release oily muck into the general area... Follow the 15-20mm diameter black rubber hose (runs along the back of the engine, into a UFO looking thing, then along the RHS of the engine to the front) and look for damage on this.

 

[dgmayhead]

Search vnt on here. Loads of threads and pictures. It's a very common fault and easy fix.

 

[RJK]

Brilliant

Thanks again guys

 

[halftone]

.. Follow the 15-20mm diameter black rubber hose (runs along the back of the engine, into a UFO looking thing, then along the RHS of the engine to the front) and look for damage on this.

The UFO is the vacuum oil separator, which takes oil-laden crankcase fumes, and drains liquid oil to the sump. There's often oil in the area around the top, not least because where the rubber hose connects is a stub of brass tube that is supposedly retained in the separator body by a push-fit clamp. The clamp breaks or goes missing, so the brass piece just sits there with no seal, and oil fumes leak out. You can easily tell, by gently tugging upwards on the hose. If it lifts along with the brass piece, the clamp is knackered.

There are 3 options, replace the whole separator unit, or bodge some sort of seal or clamp to hold the tube in place, or ignore it and just clean the area from time to time. Mine only leaks a very little, though the clamp is long gone, so for now I'm ignoring it. I might get round to devising a bodge someday.

 

[_The_Editor_]

The UFO is the vacuum oil separator, which takes oil-laden crankcase fumes, and drains liquid oil to the sump. There's often oil in the area around the top, not least because where the rubber hose connects is a stub of brass tube that is supposedly retained in the separator body by a push-fit clamp. The clamp breaks or goes missing, so the brass piece just sits there with no seal, and oil fumes leak out. You can easily tell, by gently tugging upwards on the hose. If it lifts along with the brass piece, the clamp is knackered.

There are 3 options, replace the whole separator unit, or bodge some sort of seal or clamp to hold the tube in place, or ignore it and just clean the area from time to time. Mine only leaks a very little, though the clamp is long gone, so for now I'm ignoring it. I might get round to devising a bodge someday.

I was actually talking about the UFO shaped thing on the top-right of the engine where RJK was mentioning the worst of the oil mess - little thingy in the middle of item 7 below.. It's the disc thing that sits right on the top-right corner of the engine block, and turns the crankcase vent line under the inlet butterfly valve before the line gets down to the turbo inlet...

Separator is more towards the left/mid of the engine block I though, right at the back tucked under the fuel filter, and a pig to get to! Would have thought if this is making a mess then you'll see it on the fuel filter area first!

 

[RJK]

Halftone - on the money.. Was going to ask you guys about this as traced the line and the brassy piece of the piping you mention is literally sitting in the engine.. Not fixed in anyway.

Answered my question before I answered it.

No leaks or splits on any of the intake or on the VNT hose


Can I only assume the maf needs a clean up or faulty egr..

So one more question..

When I blank the egr as I plan to when the plates arrive, is there any sensors I need to disconnect or do I leave everything as is?

Thanks again - the been a massive help

 

[halftone]

Ah, sorry. That's a pressure control valve. More oil-mist laden air. Supposed to be replaced when they clog up as they cause excessive crankcase pressure and oil leaking out. Cheap, I think.

[EDIT: should be replaced too, if leaking, else excess pressure can blow engine oil seals etc]

 

[halftone]

Can I only assume the maf needs a clean up or faulty egr..

Given what you've said, I'd suspect the MAP sensor (different from the MAF) is coked up before either of those. The MAP sensor is on top of the inlet manifold - single wire connection. Undo the single retaining screw, pull it out and clean off carbon from the small protective plastic cage around the sensor element, using brake/carb cleaner.

To test the MAF, try running with the MAF disconnected. It'll be lumpy and give you a temporary MCSF light, but if you get your power back then it's the MAF at fault.

The EGR - well, it'd be a good idea to clean it anyway unless/until you have it mapped out as well. You leave it connected to the ECU, which will try to operate it even though the gas path has been closed off by the blank. After blanking and mapping I think you could disconnect it.

BTW mapping out the EGR doesn't just prevent the MCSF light caused by P0401 insufficient EGR flow. It also tweaks the fuelling to suit the lack of exhaust gas. I was really quite surprised at the improvement it made to low-end smoothness and torque after Autolusso did mine. If I lost anything by de-swirl-flapping this more than put it back.
[/QUOTE]

 

[_The_Editor_]

Ah, sorry. That's a pressure control valve. More oil-mist laden air. Supposed to be replaced when they clog up as they cause excessive crankcase pressure and oil leaking out. Cheap, I think.

[EDIT: should be replaced too, if leaking, else excess pressure can blow engine oil seals etc]

Know of a source for one? Mines a lil gunky in that region.. Will get it done one day..

 

[halftone]

I don't. I don't even know for sure what it is called, it could be called a breather valve, or breather pressure valve or vent valve or filter or similar. I've not looked as mine is still nice and dry at 80k. What does Eper call it? It might even be possible to clean/unblock it, I don't know.

Might have to ask <wince> Alfa Romeo.

 

[halftone]

Ah.. and now I read that it's a valve to prevent runaway, ie crankcase oil being fed to the inlet side of the turbo by excessive crankcase pressure. I think I don't know enough at this point. There seem to be conflicting ideas about what it actually does. Phone a friend? Ask the audience?

 

[_The_Editor_]

Eper has the whole assembly of pipe and valve/UFO listed as "hose" or something equally useless...

Part number seems to link to the whole assembly...

End goal is to replace all the rubber hoses with silicone, and then a new UFO as well!

 

[RJK]

Ok cool

So MAP clean

And MAF disconnect and run..




So to throw a spanner in the works:

Took battery and tray out today whilst I checking intakes, vnt, oil breather pipe thing, but etc.

Gave everything a clean up, and battery was probably out for around an hour hour and a half.

Drove to training this evening, dramatically less derv smoke??

It's still somewhat smokey bit nothing like it's been over the last week.

Any thoughts?? I would the battery being out that long have "reset" the ecu.. I absolutely clutching at straws, I really don't know what else would cause the smoke to clear so much