Alfa 156 2.5 v6 mot fail

[shogun001]

I'm going to view this car tomorrow morning and have just found out through detective work that it failed an mot last week on :


Nearside Rear Registration plate lamp not working (1.1.C.1d)

Centre box Exhaust has a major leak of exhaust gases (7.1.2)

Exhaust emissions hydrocarbon content after 2nd fast idle excessive (7.3.D.4)

The reading it's getting is 242/200.

Exhaust emissions Lambda reading after 2nd fast idle outside specified limits (7.3.D.4)


I understand that it'll be the leak in the middle box causing the lambda to be out but what would cause the HC content to be high? It's running rich I assume?

Edited by shogun001 on Friday 20th January 22:10

[Liquid Knight]

Good luck. If it's crap and a manual let me know. I'm after a 2.5 V6 for my Cinquecento.

[Oilchange]

Get the exhaust fixed, it'll sort the emissions. Really, it can't be far from good with a solid pipe.
Mine failed on rotten sills, hell they must have jacked the car up with an ice pick but a bit of welding and £125 and it passed fine.
Even with a knackered exhaust they sound much like Sofia Loren having an orgasm so can't be bad eh?

Edited by Oilchange on Saturday 21st January 22:54

[jonesy000]

We had a 120 mile drive back from london in it yesterday. The exhaust was well and truely fked! So he had a nice cat back fitted! It now sounds lovely. and only a couple of small things to fix. Shame I cant insure one yet!

[shogun001]

The previous owner swapped the interior and didn't have a clue so have spent the day tightening every single fastener up

Few issues to sort now :

Air bag light on, later leather momo seats with the air bags have been fitted so assume it's just the passenger occupancy sensor? Is there a sensor on the drivers side as there is a two wire black connector coming out of the floor on the drivers side?

Engine won't stay at temperature when it's moving. When stationary it gets up to 90 and the fans come on. Assume this is fixed with a new thermostat? I can't find any motorfactors in the area which do them and I need one urgently as I do 50 miles a day and have just had a combined tankful mpg of 22mpg! This might explain why the HC was high during the mot?

[Liquid Knight]

The engine would fit in a Cinquecento bay anyway. Have fun with it.

[shogun001]

The engine would never fit! It's massive. My dad has a seicento.... hmmm.

Sounded awesome with basically a straight through pipe

[robsco]

shogun001 said:

Engine won't stay at temperature when it's moving. When stationary it gets up to 90 and the fans come on. Assume this is fixed with a new thermostat? I can't find any motorfactors in the area which do them and I need one urgently as I do 50 miles a day and have just had a combined tankful mpg of 22mpg! This might explain why the HC was high during the mot?

Mine did exactly this, and as you rightly say, it's just the thermostat. Or at least it was in my case. Water temperature struggled to stay at 70 degrees on the gauge when on the move. 22mpg sounds pretty normal to me to be honest, regardless of thermostat and MAF condition.

[jonesy000]

shogun001 said:

The engine would never fit! It's massive. My dad has a seicento.... hmmm.

Sounded awesome with basically a straight through pipe

Couldnt tell with the sunroof leak!

[shogun001]

robsco said:

Mine did exactly this, and as you rightly say, it's just the thermostat. Or at least it was in my case. Water temperature struggled to stay at 70 degrees on the gauge when on the move. 22mpg sounds pretty normal to me to be honest, regardless of thermostat and MAF condition.

I'm hoping this will improve when I get the thermostat sorted as I do 250 motorway miles a week and it's barely registering over 50 on the motorway. Otherwise this car is going to ruin me

[robsco]

shogun001 said:

I'm hoping this will improve when I get the thermostat sorted as I do 250 motorway miles a week and it's barely registering over 50 on the motorway. Otherwise this car is going to ruin me

Motorway mileage should improve that consumption figure to be fair, more like late 20s. But I did find the 3-litre in the GTV a slightly more economical engine than the 2.5.

[jonesy000]

When you decide to get rid, buy my mx5!

[waynedear]

shogun001 said:

The previous owner swapped the interior and didn't have a clue so have spent the day tightening every single fastener up

Few issues to sort now :

Air bag light on, later leather momo seats with the air bags have been fitted so assume it's just the passenger occupancy sensor? Is there a sensor on the drivers side as there is a two wire black connector coming out of the floor on the drivers side?

Engine won't stay at temperature when it's moving. When stationary it gets up to 90 and the fans come on. Assume this is fixed with a new thermostat? I can't find any motorfactors in the area which do them and I need one urgently as I do 50 miles a day and have just had a combined tankful mpg of 22mpg! This might explain why the HC was high during the mot?

http://www.ebspares.co.uk/alfa156/cooling_alfa156.cfm

[shogun001]

Thermostat changed. Hiccup has gotten worse. It only happens after the engine being revved highly. Will missfire until you reach 4k revs and then takes off like a rocket. After you leave the car for 10 minutes it's fine until revved high again. It's just hit 63k miles and I think the plug change interval is 60k miles? I'm unsure whether they've been changed or not and at £84 for them they aren't cheap

[Oilchange]

Have you gone onto one of the alfa forums, they might know the symptoms better and guide you to the right fault. Sounds a bit like a sensor problem or as you say the plugs but don't know for sure.

I had a sensor problem on my 146 Ts and with a bit of forum search figured out all I had to do was clean it and all was fine again. Might be a simple fix...

[robsco]

From memory, mine did this too. Changed thermostat, developed MAF problems shortly afterwards (think the Autodelta intake had something to do with it too mind). Does the car hunt slightly on idle? If so, that might be a tell tale sign that the MAF has seen better days.

Best way to tell is by unplugging the MAF and taking the car out for a spin. It just unplugs below the intake hose. The engine will struggle to idle and the economy will be atrocious, but if you notice a performance difference out on the open road, then you can be sure the MAF is on its way out.

Also bear in mind that the minor misfire will get worse and worse if the MAF is the culprit. Mine became virtually undrivable in a surprisingly short space of time. Replacement is dead easy, but the part isn't cheap.

[shogun001]

I haven't had a chance to drive it without the MAF yet however when I had the thermostat changed by a specialist I'm sure some water would have gone that way, as the engine was still hot when they did it and water went everywhere. I imagine if it was on the way out anyway then this would push it over the edge as it only started an hour after the thermostat was changed?

I've got a 1.7 diesel Astra MAF awaiting collection from Cenral auto spares for just under £80. Will just need to swap the physical sensor over and bin the tube. Should be able to do that this evening so the service will come after on Saturday. Will keep this thread updated in case it helps anyone in the future.

[shogun001]

Wasn't the maf, or the plugs, or the coils. Plugs were a nice tan colour, not sooted up at all unlike what I expected. No water or oil in the wells. That only really leaves lambda?

[shogun001]

Lambda it was! Replaced the wishbone and did an oil change at the same time. Person on ebay had sent me the wrong oil filter! Was the same just about 15mm longer. GRRR!