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This motor has been declared to be running very lean from the appearance of the pistons showing no carbon build-up. Can anyone confirm that? The intake valve above this damage happened to be closed when I took off the intake and had oil pooled on top of the valve, none of the other closed valves showed this. If oil was coming past the valve guide it would pool on top of a closed valve. I have been advised by another mechanic that oil burning at a particular place would cause a hot spot. The tuner swears the tune was not lean. A faulty injector just leaning out one cylinder would have been picked up by the ECU would it not? Thanks in advance.
Do you run meth in your setup? I'm not sure the results but may be a reason for a cleaner piston with less carbon buildup? Not sure just throwing it out there.
Do you run meth in your setup? I'm not sure the results but may be a reason for a cleaner piston with less carbon buildup? Not sure just throwing it out there.
Just a stock E55 with ONLY an 83mm SC pulley and a tune
running too lean...maybe melted a ring land which scored your cylinder walls?
do all cylinder look like this? if so your tune is not correct...wayyy too lean for a boosted engine. pictures of each piston top and cylinder wall needed for a proper evaluation. but from the looks of the piston also shown...you are running VERY VERY lean.
please post all cylinders. you also seem to have valve to piston contact.
I have a sunnen cylinder hone that I am going to be selling if interested ? has some stones but not sure on sizes its been 20 years since I have used it.and 20 years before that my day used it ,,,, old stuff is good stuff
I have a sunnen cylinder hone that I am going to be selling if interested ? has some stones but not sure on sizes its been 20 years since I have used it.and 20 years before that my day used it ,,,, old stuff is good stuff
what cylinder what bank ? 8 seems to get a high incident rate
if there is issue with a specific engine only having issues the same cylinders for the majority of owners, that would boil down to inaccurate head intake port casting, intake manifold flow restrictions, or sound resonance to that runner/cylinder.
reading through these forums for a couple of years and s like #8 on the 55's can pop from to lean a situation ,, its the last cylinder on the rail and could be the reason from fuel starvation -- I don't know if that is an accurate diagnosis or just a supposition - may be from dirty fuel pumps/pressure ?
These are cylinders 1 through 3, I can't see a lean condition in 1 and 3. The tail pipes have always been black with carbon and the tune has been in place for over 2 years now. I removed the valves to check the guide and seal which were fine. I will now get the injectors tested for that bank.
With out an AFR gauge you have no way of knowing how the fuel system was working. Meaning if the pumps got weak, one stopped working or filter clogged up your fuel pressure dropping will cause it to be lean.
Also...the tops of all the pistons look to me like they where all lean.The far right piiston looks like the carbon was starting to melt with little tiny spots showing that at the very top of the piston. Could be wrong.
you may have had a faulty injector, but I do see that your tune runs lean and rich at different parts of the fuel map based off the tops of your Pistons. rich because your squish is cleaner than the rest. a perfect tune should emit the same amount of carbon build up across the entire piston which would signify a complete burn.
it does look like all of your Pistons have balled up aluminum bits scattered around signifying a significant amount of detonation and lean run conditions.
ignore my previous comment about valve contact. it seems the M113k has a piston marking for orientation. who is your tuner. they like that baby running lean.
you may have had a faulty injector, but I do see that your tune runs lean and rich at different parts of the fuel map based off the tops of your Pistons. rich because your squish is cleaner than the rest. a perfect tune should emit the same amount of carbon build up across the entire piston which would signify a complete burn.
it does look like all of your Pistons have balled up aluminum bits scattered around signifying a significant amount of detonation and lean run conditions.
ignore my previous comment about valve contact. it seems the M113k has a piston marking for orientation. who is your tuner. they like that baby running lean.
I have had this diagnosis from others of forum. The tune had been in place for 2 years and 20k km. How does a tune go bad? Besides getting the injectors and fuel pressure checked what can I do? I have a 51k km S55 engine coming and I sure don't want this happening again. Cheers.
the tune may be at the fine line of being not bad to being bad...still not good. an engine will make the same power output with a range of air fuel ratios and a GOOD tuner should NOT choose the leaner side. tunes that fall closer to the leaner side will greatly be affected when temperatures run hot. if your coolant or air temps run hot that leaner of the range air fuel will emit detonation and can cause engine failure.
Who knows where the tune is. Could have been spot on. Maybe the pumps started dying,fuel filter clogged, injectors dirty etc etc. Fuel pressure gauge and AFR are mandatory with these cars.
can't speak to the M113K but the M156 has a fuel pressure sensor on the rail since the pump is pwm controlled for flow capacity to maintain fuel pressure at given rpm.
I don't want to name the tuner as I have not determined for sure it was the tune. Do these tuners disable the knock sensors and the pull back of timing when pre-ignition or too high ITAs are detected? If not then why didn't the ECU save the motor? I am now very disillusioned as I also have a low 11sec SL 55 that I am very worried about now, same tuner. Both cars have had their tunes for over 2 years now. Could I have had a tank of regular put in by mistake? Sometimes the delivery drivers screw up and put regular into the premium tanks. I guess I will get the fuel tested for octane also.
Get a fail safe from AIM for the future along with some AFR/Fuel pressure gauges. Will help greatly in keeping an eye on everything and keep it safe. Sucks the block is done but they are cheap enough to find.
Wow...they look terrible. something was going on for a while.You have oil, fuel and detonation going on....specks all over the plugs.
Three looks worse for ware for whatever reason. For sure check out the injectors and get them tested to rule them out.
from the looks of everything 2 years time is about the time it took for either your fuel system or your tune to take your motor entirely. you can see on the spark plugs you have lots of oil being burnt over a long period of time. beyond that, i can't really say more. could be a bad tank a gas, but i doubt it for the fact that your plugs are gummed up with oil over long periods of time. oil passing your rings or through valve stem seal will not cause an engine to blow if leaking through wear and mileage. your head gasket seems to have had a perfect seal so that is ruled out.
someone correct me if i'm wrong, the M113k has a narrow band oxygen sensor. with a narrow band oxygen sensor, your engine really won't throw lean run codes as the sensor itself is lacking the resolution to determine actual air fuel mixture. really sucks you have had an engine failure. highly recommended for tuned boosted engines with narrow band oxygen sensors that you run an external wideband sensor at all times for overall monitoring.
from what i estimate, could be fuel injectors, fuel pump, or tune causing lean run conditions. in my experience though, fuel pumps fail, they don't run slow unless you're pulling more fuel than the pump is capable of delivering. cylinder #1 though, does seem to signify your engine was running lean like for a naturally aspirated engine for a long period of time. with maybe a rich idle. hard to say with certainty with the oil build up.
05-18-2020, 03:58 AM
