First post and a sucky one lol
I have been reading this forum a lot since buying my c63 7 months ago and has been a wealth of information.

Sadly had a bit of an incident on my up until then immaculate and perfectly running 2012 coupe a with 78k miles so though I'd document my journey here for others in case useful.
Was driving back from in laws and mile or 2 from home and gave her some beans up sliproad onto 70mph main road (all up to temp etc) and she pulled like a train but when I let off the car misfired heavily.

Pulled off the main road and shutt off the car and called recovery. They checked car and could see misfires and car was now running beautifully and smooth as silk. So drove home like Mrs daisy and car drove perfectly.

So next day knowing she has recent service with new plugs and I changed all the coils in last few months I assumed maybe injector issue but didn't hydrolock , to be sure I hand turned engine incase a cylinder had filled over night and all was good

Started car briefly and again all perfect. The exhausts were very spooty so looked like over fueling and I pulled dip stick which level was fine but sniffing oil smelt of petrol. So ordered 8 new injectors
firing was "straight forward" well would have been if the end of on whadnt snapped the plastic ring that holds the o ring, and that broken part hasn't fallen into the damn head lol. So wanted to change PCV anyway and had new stretch bolts gaskets and PCV so pulled manifold managed to fish out injector part from top of valve and replace pcv and slapped it all together.

So also got new oil and filter, dropped oil (sump and cooler) and it smelt of fuel and seemed a bit runny but is 0/40 it didn't look massively sparkly with a torch on it but was some faint sparkles

Then pulled filter no massive chunks but lots of glitter. Damn. Put in new filter and refilled. Car started and ran smoother than ever, but could here a tick/knock, brief light rec and noise accelerated with engine revs.

So looks like injector held open after coming of WOT (but did then close so no hydrolock) and fuel compromised oil film and toasted big end bearings.

Cars now in to a good Merc/Porsche specialist who do rebuilds. And willp be engine apart to see if any bore wash/wall damage, see what cranks like etc.

Going to hurt financially, looked at second hand engines but they are like £7k and 1.5+ to remove and fit and you have no idea what you are getting.

Initial quote for a regrind, bearings, chain+guides, later valve buckets , all bolts gaskets and sundries with Labour at (£3.6k) is about £8.5k obviously if intake cams have wear and if crank is too damaged that will rise.

Hoping that it's not to bad as car car runs perfectly so will just be a polish or grind and new bearings with other bits preventive maintenance to refresh engine to almost new.

Will update those thread when I hear back from garage.

I have had m3s, 911s and the c63 for me kills them, not as good handling as 911 but the comfortable Merc cruising but with a modern muscle car beast side to it when you want it. My favourite car I have owned so super gutte this happened, but laughing about it as best I can, only a car at end of the day.

So please people when you change plugs change those injectors!!! Bosch ones can be for for less than 1 mercedes rebranded one £200 is cheaper than £8-10k rebuild lol

 

I changed my injectors around 68k and was surprised how nasty they looked. Interested to see how your situation turns out. These cars are so much fun but really sucks when they break.

 

Ouch, yes that one hurt a bit. I don't know if previous owner of mine did it but as Skull said, when I pulled mine they were nasty, I waited until 100k miles though to be honest.

I'm trying to get pro active rather than reactive for my approach to this lovely m156.

Keep us updated how it goes, interested to see how it goes.

 

Cheers chaps

Will find out next week when they pull it apart the scale of it (will get some pics hopefully), trying to be positive in that I wanted to supercharge it and keep it for a long time so having it rebuilt is going to add life to the car. Even if bores need sleeving arguably good for boost down the road.

She will also come out with the wavetrac LSD I bought a few days befor the engine popped lol so at least will have an upgrade

Not a rich man but have these cars with the understanding I can cover a big bill (see big credit card and ability to clear it in 6 months or so lol), I sold my 911s (997) a few years ago. Due to being realistic about maintenance costs and lack of funds.

 

Sorry to hear about the mishap.

You intend to increase power on a 10 year old engine with known weaknesses and approaching 100k miles, and hope to keep it for a long time.

Daily driver or weekend car?

 

Probably ironic coming from me but they are stout engines, I don't really class this as an engine failure as really was taken out by ancillary component lol. lots of boosted m156 with no issues rolling about. It was trouble free and strong prior to this failure at 78k so if a would see another 78k or more it's worth it.

not the boost that kills the engines normally oil issues, cams, buckets, chains etc, later cars don't have headbolt issues. So with new chains , revised buckets (hopefully not cams lol) going into this should be a solid engine for some time to come.

Only planning stage 1 SC as won't want to fight MOT on sports/decat or mess the sound of the stock exhaust up and also save me doing gearbox clutch packs hopefully. But the rebuild will steal my SC fund so won't be for a year or so now.

I daily it(but don't drive every day) and also not my only car I only do about 3-4k a year it it goes another 30k with out issue that's 10 years . I buy cars to use them be they a 911, m3 or C63 they carry my kids and shopping and need to function as a car as well as be fun and interesting.

 

Have them check the compression before they tare it apart.
I had the same happening to me and two of the cylinders had very poor compression. I had quiet some sparkles (chunks) in the oil and the knock you described appeared as well. I considers the particles in the filter picture as chunks not just sparkles.
For me it didn't make sense to have it rebuild since the car had a book value of $18k and I was able to sell as it was for $8k.

 

Sorry to hear that man. I’m actually in a similar situation myself. ECU failed causing Bank 2 injectors to suddenly dump fuel and washed out the rings. Dropped 30-40psi each cylinder on that bank. I’m having it disassembled to inspect bore, and I hope the walls are OK cause I’d hate to make a decision to sleeve it or buy a low mileage motor. Problem is finding a P31 motor isn’t easy. Small mishaps like these makes you realize anything can happen at anytime regardless how strong any motor is. Hope you get yours resolved soon

 

Yeah is a toss up on value of car and cost of rebuild.

Will make the final call once they inspect engine. If crank is knackered beyond re grind, cams dead and cylinder bores destroyed then it will be over as new crank is like 3k cams about 2.8k and sleeves another 3k? Which would be like 18k.

If just one of those possibilities happens on base 8.5k cost that would be doable as under 12k garage is fine with good used crank or big parts but obviously will be checked and caveats in rebuild warranty so have to factor that in on short term saving

second hand lump you just don't know anything about and with labor to swap them it's not that clear cut cost wise against rebuild.

For me value is about 23k so 8.5-10k is I think is what I want, 12k doable.

As was said as is (parts car) i'd get 8k ish and lose 15k odd so that gives the tip over point
Also have to consider things like chain and guide change is "not needed" but a while you're in their cost so really should be separated from the "fix" cost, also reslalw benefit of w fill rebuilt engine will add some value.

there is the bloody minded part of me about that doesn't want to be defeated and it's my car so feel a duty to fix it. I have modded and messed about with various m3s , 911 etc and have lost 10k + on each on unrecovered cost of Mods etc so I have form at losing cash on cars. (My othe car is a 2k 26 year old land rover which has probably 12k in it lol)

First time in 25 years of motoring had a big car failure so there is that too.

Still I'm laughing about it now, the Moment car died and we pulled over I remember my sigh, then looking at the miss as chuckling "well that's 10k" lol in hindsight wishful thinking

Cheers all for comments and sympathy, if one person changes their injectors off my miss hap that will be a result.

Steve

 

The financial analysis in my mind is:

Option A: repair the car for XX cost, expect YY years of service with ZZ maintenance cost per year
Option A total cost during the period: XX + ZZ * YY

Option B: buy or lease a new car for AA cost per year for YY years and CC maintenance cost per year
Option B total cost during the period: (AA + CC) * YY

 

So when a garage asks you to come in rather than discuss on phone and use the words "never seen that before" you know it's good news

Going in tomorrow to see and get some pics but to summarise

It did hydrolock at so bent rods.

Bore wash and scored bores so dead block

Bigend bearings pushed out like squirty cheese. Dead crank
Bearing material pushed through oil galleries into cam so ate head cam bearing surfaces . Dead heads and dead cams

So think that's pretty much no components left lol
One dead injector took out the whole engine.

Is what it is , probably scrap car for parts is probable outcome.

Will post back with some damaged engine part pics and final outcome.

 

Damn. Sorry to hear that! Blown up because of an injector. Only in a Mercedes.

 

Can happen to all engines with direct fuel injection.