engine blown @ 5000 miles
 

well as mentioned above car is brand new and done only 5000 miles. The car was running fine for months, but few weeks back was doing 150mph and engine blown in a matter of seconds. The only mods on the car were RalliArt sports ECU (my car is an Evo 7) and 76mm exhaust system starting from downpipe.

after inspection the dealer said that one of the cylinders showed huge increase in temprature, and apparently the conrod bolts got bent and broke loose which made the piston drill a hole like a bullet in the crankcase.

dealer said after inspection that it was factory defect and engine needs to be changed, i say something fishy about the ECU as i bought it second hand (maybe flashed in a wrong way or something similar).

The reason could also be coz of the fuel we use. The RalliArt ECU needs 99+ octane, while we are using here octane much less than that. Not sure how much, but its around the 90. But I dont think it would be a problem as many of my friends own M3s and M5s and all of them require 99+ octane as well but they same fuel i am using without problems. so probably something there caused a problem (not a good technical person, sorry)

well ur opinions are greatly appreciated, let me know what you all think!

Thanks

I think it's definetly the fuel problem, your engine was running too lean(therefore detonation occured), if you run high octane gas that's not a problem, but cheaper gas requires the A/F to be tuned richer

I just reread your post, you mean 99+RON right, because 100octane (in US) is racegas, and 91-93 we have at the pump

I am not located in the US

Yes it 99+ RON (according to japanese instructions manual)

if the problem is with fuel, then how come all the M5s and M3s over here work fine without engine problems?

How can i solve this problem? I need the ECU to avoid fuel cuts

I think its a bad idea to assume anything based on another manufacturers car. Used, non-stock ECU is an obvious possibility.

Boosted cars tend to be more sensitive to knock. If you have a lean or detonating condition, it can wreak alot more havoc on your turbocharged motor.

Yep. RalliART ECU is for sports set-up (hi octane fuel needed, probably has more boost). I think it even says it on the RalliART site that you need higher octane than usual pump gas.

Street gas + higher boost than stock = detonation = blown engine.

Wait........the dealer is paying for it???

sounds like the ecu, but is the dealer is gonna replace it for you?
:eek:

nope, theyre not paying for anything, warranty is void. time for modded engine hunting.

thanks everyone

too bad you didnt replace the original ECU before you brought it to the dealer =)

yeah, but then they would check the ECU for misfire code, and if they don't find it........, I don't know what would happen

either way they wouldn't warranty your engine and you'd be in the same situation your in now...

anybody know if a USDM Evo8 shortblock will fit into Evo7, if it could you might find one at a cheaper price than a brand new 4g63

well thanks for the help evo542, but i think i might be able to find a JDM Evo 7 engine at a cheaper rate over here.