^^ and there’s an expert
He’s right

 

I won't invest a dime on a rebuild without first finding out what caused the problem, no guess work here, need to know the culprit, period. A person comes in with an abdominal pain, sick and vomiting , you don't want his abdomen opened up without first finding out what's causing the problem and only then you want to go in

 

dude you've been a pioneer on this forum and I always appreciate it, I knows others do as well.

congrats on that sweet new ride, drive it in peace and good health - I know you'll carry the w213 amg torch for so many enthusiasts!

 

I had a tune which always ran lean. I switched tuners and now the car doesn't, with comparable power. So it can certainly be tune related.

 

100 octane RON (Europe) is comparable to 93 octane AKI (North America) and not having any ethanol is a disadvantage as ethanol cools cylinder temps.
Is your dyno on the first post in WHP? If it is 740 whp is a lot of power to be making on only 93.. Usually that kind of power is made with E30 blends. Would be interesting to see a log.
Long, high speed, sustained load generates a ton of heat. Either fuel enrichment was insufficient for cooling or the injector started failing.

 

It’s power at the crank, 740 BHP.

How can I find out about what exactly caused this, is there any way to run some type of diagnostics? Do I need to look for something? My mechanic said that he never understands how companies like RENNtech and other do same tunes for many cars - meaning that each car is individual and requires its own map. I guess he has the point there. So then RENNtech Stage 2 tune is a total ****?

Also, please, keep in mind that on this tune alone I drove almost 3 years and 40k miles. After the tune I was slowly adding more modifications during all these years - started with exhaust, cats, downpipes, then went for turbo-backs, then added Weistec TCU, then Blackboost intakes. Last mod was done a year ago if I don’t count Weistec (NGK) colder plugs. So can it be that this really is a slow and gradual process? Wouldn’t it already occur much sooner then? Or maybe all these mods increased already critical power levels behind the limit for this engine?

Any kind of deeper explanation would be extremely helpful. Doing this 20k+ USD rebuild and then if it happens again is unimaginable to me.

 

Better take it to a dyno with a reputable tuner that can tune the car for its modifications and watch real data. There are no guarantees with this game you are playing, regardless of how much you upgrade the engine.
Adding parts to increase power without retuning is a recipe for disaster.

 

I've sent emails before to RENNtech HQ and told them that I've added exhaust/race cats/downpipes/turbo-backs/intake - all they said was that there is no need to modify anything in their ecu tune and it is completely fine to keep it as it was.

 

I mean ... despite all appropriate precautions... śhit happens ...

 

If I really run 1.25 - 1.4 bar of boost, as I was advised by the RENNtech, I should probably be looking elsewhere for issues. I was driving for about 3 years with this tune.

 

I would stay with stock plugs if not running crazy boost. When did you switch over? If it was recently, I'd really look hard at plugs/indexing/heat range to start.....

These cars needs plugs, indexing, coils, timing, Intercooler, to be perfect when bumped on a tune. Need to get a logger like HPTuners and keep an eye on things.

 

Plus tuning in-house instead of canned the tuner is logging and keeping an eye on things and will often find issues that need addressing that do not trigger a Check Engine Light but will quickly toast the engine.

 

IMHO looking backwards to find the cause maybe impossible. I'd move forward and find the problem while breaking in the new engine. For example maybe you have a bad fuel pump, bad injector, you won't know until it's running, you start leaning on it and logging.

My $.02
Rebuild with brand new ignition coils and I'd stick with stock plugs.
Break it in stock tune while logging, fix any issues.
No issues proceed to WOT logging still stock, make sure no issues like fueling, IC temps, knock retard etc if all pass then tune
If keeping the Renntech tune apply it on a Dyno while logging, make sure there are no issues keep eye on ignition, knock, fuel trims. If any issues repair.
If custom tuning tune and log and fix any issues, there maybe none - keep an eye on ignition, knock, fuel trims.
Enjoy life!

For me after such a $ rebuild it's a no brainer to custom tune it.

Then forever use HPTuners to keep logging/checking codes regularly. These cars will have problems, set a code, but NOT set a Check Engine Light and proceed to destroy themselves over time. For example my intercooler pump broke, nothing told me it was broken except the car got slower. Logged it and posted it on mbworld and everyone said "WOW your intake temps are too high, check that!" and sure enough, blown Intercooler Pump, massive heat, lots of pulled timing, lots of knock sensor and knock retard. Yet my car would knocked itself to death if I didn't log it and fix the IC pump. And it was still almost fast - I was still beating C8's LOL so it's a fine line between sick car and healthy car and you'll never know unless you really really are good at butt dyno and feel however Logging and looking at DTC's regularly is much safer.

I think you'll be fine just plow forward!!!!!

 

Weistec colder plugs very recently. Probably 6 months or even less. Before had OEM plugs, but had occasional misfires. On Weistec had none.

 

it was a great discussion:

https://mbworld.org/forums/w212-amg/...scan-logs.html

 

Did you have occasional misfires the whole 40k and 3 years? Or just recently which prompted the plug change?

 

Check dtc's once a week if tuned is easy and reasonable

 

no way a reputable tuner like Renntech would send a lean tune, anyway if it was he should toast the engine long time ago.

NO one should run any stage 2 tune without Data Logging and without Meth for cooling,
i don't run my car hard or any tuned car without logging: IAT, Boost, Timing, AFR, Fuel Pressure, plus knock and wategate, and as "I.T. Guy" mention those cars need coils and plugs before any tuning, then logs should be sent to tuner.
the other important thing is water/meth, i don't flash a stage 2 tune or any aggressive tune for any customer if he don't have a water/meth for cooling, i have seen more then 10 M113k engines with melted pistons/cylinders cause of high air intake temp, when running high boost the efficiency of the stock intercooler will not be sufficient even you install 10 front radiators.

 

I had them for the whole time and it was 99% of the time Cylinder 5 Misfire Code P0305. What happened 2 years ago on OEM plugs was this. It was not melted, but the piece was missing, already had a tune back then. Nothing happened, but that’s when I thought that I need to move away from OEM plugs.

 

Basically there is a few things that happened recently:
1. Weistec colder spark plugs - installed Nov. 2022
2. Blackboost CAI - installed Nov. 2022
3. Weistec TCU - installed Dec. 2022

Everything else is “old”, RENNtech is the oldest - from May 2020.

I should really look into plugs + fuel injectors, pump, intercooler. But I doubt there was anything wrong with it. Car was as strong as ever.

Could it be that nothing was wrong really, but the material itself (piston) simply failed over time, perhaps there was a small weakness, then it gradually turned into a crack and then it all just snapped?

 

Sorry I'm asking again I can get confused - you are saying there was misfires for years mostly on #5 with stock plugs, and misfires went away just recently with the W plugs?

 

Bent rod = detonation or too much torque.
Melted piston = detonation.
Because you have both it would be a good guess detonation caused both the melted piston and bent rods.
Now you need to find the source (if it still exists) of detonation on your new build while carefully running it in. You may find nothing until pushing it on the highway again while logging. Pushing it on the highway is a lot different then a dyno run or 1/4 mile run.

 

Yes, exactly as you said.

 

@GMBALL man sorry to see this happen for you... am just catching up on this thread and was curious how many miles on your coil packs when this happened?

my coils on #5 and #1 started to misfire within 2-3k miles of having a basic AMS93 tune on my E63S. Boost was about 18psi plus and seems the excessive heat from the higher boost with the turbos on #1 and #5 aggressively degraded the coil pack so now I'm changing coils & plugs every 5k miles going forward as insurance.

 

I have not run my E40 tune yet.
If and I mean *if* I do I am doing plugs and coils first for sure.
I would love a 10.x before moving on from the W212 (I just bought a W213)
But also need a saleable W212 the last thing I need is a bent rod or break an output shaft or something because I'm sick in the head and just need to run a 10 for closure
LOL