I'm asking if anyone else has experienced such problems with the 3A90 (1.0 L) engine. Please report!
My car has about 20 000 km on it, and is only used for long-distance driving. It had no history of any problems at all. The engine is 1L, 3A90, no AS&G and consequently no EGR. Remember, this is a non direct fuelinjection engine, fuel is injected before the combustion chambers and not into them.
Coming home after a 300km drive on the autobahn, driving at 100 - 130kmh, the car was parked in the garage. Next morning it refused to start, but cranked normally and began smelling like fuel.
After telling the dealer about the problem, he said it would take 3 or four days in the workshop, but perhaps longer, and
Mitsubishi would see the bill taken care of. After all, the car is under waranty and there is a mobility garantee.
I asked him how he could tell without having even seen the car. He replied he'd already seen numerous with that problem in his tiny workshop...
On the following day using a mini endoscope camera, the dealer confirmed the problem. The intake valves were not closed because of massive "gunk" or carbon deposits all over the intake valves.The massive buildup did not allow the valves to close, and without closed valves no compression, no starting. He reported the problem to Mitsubishi, asked for permission to perform the waranty repairs, and ordered the parts Mitsubishi allowed him to replace.
The next day the cylinder head was removed, valves removed and cleaned manually. The removed carbon deposits were "hard as rock". The original valves were to be put back in and grinded in the late afternoon or next day, which is tomorrow.
I will keep you posted on this matter, but am travelling throughout Europe and don't always have Internet.
Update:immmediatly after repair:
It seems this issue is not uncommon in 3A90 engines.
A local service-provider with five or six SpaceStar's has seen the same problem at least once with each one, albeit at maybe half the milage. Their Space Star (Mirage) are used for short-distance customer to customer hauls, and are equipped with AS&G. The A390 with AS&G supposedly have EGR, the non-AS&G don't.
The dealer said, there will come a new software for these engines sometime in the unspecified future, which should address and hopefully remedy this problem. Currently no new software is available for this car yet...
UPDATE, March 12 2016
1) The dealer briefly showed me a picture of badly fouled exhaust valves, but did not let me take either the photo with me or to photograph or copy it. He said:"The picture (supposedly of my car's valves) is Mitsubishi property and may not be disclosed, copied or given away!"
2) Since the repair, I have noticed higher fuel consumption and lower top speed. Driving to work the bult-in display showed around 4.3 to 4.5 L/100km before repair, and now afterward always more than 5L/100km, usually about 5.2L/100km. The top speed on a flat autobahn with no wind was displayed at around 172-175kmh according to the car's speedo. Now it reaches around 160kmh under the same conditions.
After visiting the dealer about this, I was told new software was flashed into the ECU.
I hope to find out more, or get the situation resolved.
I will post updates.
UPDATE September 2019
Valves look just as clean as ever. Perfectly clean, just as inside combustion chambers.
Ever since the car was "repaired" and carbon removed, the compression has been much lower at around 9bar (about 130 psi) on all cylinders, and fuel consumption is consequently about 10% or so higher than before. This car has a compression ratio of 11.5 : 1 and therefore compression should be much better.
Does anybody have the official figures for compression of the 3A90? I do have the figures for the 3A92, but they don't apply.