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Discussion Starter · #1 · (Edited)
Hi All just thought I'd share my recent experience with the my previously fault free GT, it's a '07 Blackline Edition bought for my wife about 8 months ago. All my mates thought i was mad and asking for trouble buying a Alfa but a late model car, nice condition, nice spec, full MOT for £750 seemed a no brain'r and so for it's been a joy to own. The first thing i did was service it I always do this when I get anther car, just to be sure it as decent oil and familiarise myself with the car so new oil, filters basic stuff plus cambelt w/pump tensioners etc (a gates kit came with the car which was nice, the previous owner had intended to have it fitted but didn't get round to it) with the basics taken care of I discovered the front brake pads were v low and a O/S drop-link was rattling sorted these and the car has been totally reliable until last week.
I started to notice a puff of smoke, this was first noticed at night and showed up in the headlights of following cars. Well the smoke has gotten progressively worse over the last week to the point it was clearly visible during the day under normal driving also there is a noticeable drop in power.
It is a grey/black smoke so I figured most likely over fuelling, the excess diesel been burned off, white smoke tends to be water/coolant, blue smoke oil so I was pretty sure it was fuel related.
The weather has been great and yesterday was the first day I'd had time and it wasn't raining so I thought I'd have a look, first job check the MAP sensor (easiest jobs first) this turned out to be caked in oily sooty crud, quick wash with carb cleaner and refit, test drive and... still smoking OH well on to the next item. The infamous EGR !! removed this to find it has blanking plates fitted, the ones with small holes which if I understand this correctly allows blanking without triggering the MIL, so I guess it's a partial blanking solution ? Refitted test drive and ... still smoking NEXT.

Lets have look at the MAF, unfortunately this is inconveniently situated down under the battery, as I don't have the radio code I was reluctant to remove the battery so decided to call it a draw and leave the MAF for another day. But before packing up I thought I'd have look at the hoses, the lower boost hoses are again sited down in the depths and to access from above would again need the battery removed to get at so I had a look the best I could and all seemed OK, next the top boost hose also looked OK until I had a proper feel around and found a 1" long split at the back just before the inlet. I removed the pipe and had a better look and discovered the pipe to be quite badly perished, now obviously I didn't have replacement pipe to hand so it looked like game over. But not to be deterred I had a look through all my boxes of bits and bobs ( yrs of jap turbos means I've got a decent range of various lengths of silicone pipe and plenty of alloy link pipes) but unfortunately I could cobble together a replacement pipe so now to a proper bodge.
After cleaning the pipe with carb cleaner I applied a liberal amount of Sikafex adhesive/sealer to the spilt (if you've not used it this stuff will stick almost anything and once stuck it stays stuck!!!) OK it's not a permanent solution but should be OK till I source a new pipe.
I allowed the sealant to set overnight and refitted the pipe this morning, the smoke is no more and the lost power is restored so it appears the split boost pipe was the cause of the problem, new pipe now ordered which I'll fit once it arrives and hopefully I'll have permanent fix. However given the state of the upper boost pipe I have fears the lower one won't be in great shape so once I've got the radio code I'll have the battery out, clean the MAF and replace the lower pipe at the same time.
This isn't a definitive solution to the smoking issue there are other potential causes but may help point people in the right direction to at least eliminate some of the likely culprits.
 

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If radio is original you don't need a code, removed my battery several times over last five years and never needed to recode
 

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Discussion Starter · #5 ·
If radio is original you don't need a code, removed my battery several times over last five years and never needed to recode
yes OE Bose system (although I don't think the head unit is Bose just the speakers) as mentioned above if it does need a code then they are available but it would be nice not to have to bother with it.
 

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The split boost pipe will defo cause black smoke due to metered air being lost. The ECU will fuel based on what incoming air the MAF is reading. If you then lose boost it will be over fuelling,not enough to cause the grey unburnt smoke but black smoke from poor combustion.

Should be spot on once you replace the damaged hose.
 

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Discussion Starter · #7 ·
The split boost pipe will defo cause black smoke due to metered air being lost. The ECU will fuel based on what incoming air the MAF is reading. If you then lose boost it will be over fuelling,not enough to cause the grey unburnt smoke but black smoke from poor combustion.

Should be spot on once you replace the damaged hose.
it's quite difficult to gauge the exact colour of the smoke it was making after all I was watching it in the rear view mirror, but it definitely looked grey > black. Had it persisted I would have got the wife to drive the car about a bit and follow behind see if I could better judge the type of smoke. But now I've bodged the pipe (Sikafex is a wonderful thing) the smoke is no more, I had a good ride round in it yesterday and didn't see anything in the rear view so as you say once the new pipe is fitted all should be well.
New upper boost pipe is ordered and presumably is winging its way to me at this very moment, I was pleasantly surprised by the price, I ended up paying £15 delivered ( ebay) which seems to be a bargain and a lot less than I was expecting, I've also got a pair of Mikalor clamps to replace the dodgy looking OE items.

I will endeavour to get at the MAF and give that the once over, replace the air filter (it's the only one I didn't do when I got the car) and probably the lower boost pipe while I'm at it. I'm also not happy with the crankcase vent system, with it having a oil separator I would have expected to see less oil making its way into the inlet system. Is the OE separator baffled in any way ? I know it's not a major problem and is to be expected, but I can't help thinking it would be better if no oil was getting into the inlet tract. I've had various big power Jap turbos ( highlights been GTi-R and 200SX Nissans / 400BHP Scooby ) and in all cases I've used a baffled catch tank system. The trick to avoid nasty cabin smells is to either locate the outlet into an air stream (inner wing area) or plumb is back into the inlet, the extra tank should go some way to reduce the ingress of oil and clean up the inlet tract.
But the design of the actual tank is quite important the cheap ebay ones are a waste of time unless modified to include a internal baffle to remove the oil from the fumes. Anyway I'm probably getting ahead of myself I'll get it all cleaned out and then decide whether a catch tank is worth the effort.
 
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