bad oil pump o-ring leads to engine failure?
 

i stumbled across this recently, the one who made this video has (had) a twin-charged E55 with turbos in the trunk (quite the interesting setup) and the engine had a catastrophic failure on the track. after completely tearing down the engine, he found that an o-ring by the oil pump had broke, which he believes led to the engine becoming suddenly deprived of oil


has anyone else heard of such an event occurring? i've seen some of these cars get really abused with many miles on them and never seen this happen. either way he's a very knowledgable person and even did much of the programming himself on the build, so i have much respect for him. no way would i ever do any of this to my car lol but i can appreciate that someone has gone to these lengths

Already discussed here https://mbworld.org/forums/w211-amg/...mp-o-ring.html but considering it was a twin charged track car, I don't think many of us will be seeing those same temperatures and resulting failure. I would say it is very rare.

oh whoops i even checked before i made this post but missed that thread somehow... anyway yea this isn't something i imagined the average user needing to worry about too much. is the o ring breaking actually what led to the failure though?

I think it probably is. That small chunk came out of the seal as it became brittle. That would have caused mild starvation issues as the oil pump would be drawing in normal oil from the pan but also air through the cracked seal. I don't know what the normal oil level is relative to the the height at which the seal sits but cornering would provide instances of air ingestion at the very least.

Maybe it was going on for a while which would explain why every single bearing surface is scored and spun until cylinder 5 got so bad it didn't turn much anymore. In my understanding, sudden catastrophic failure ie ringlands, snapping bolts, rods etc due to tuning, heat issues, often the rest of the engine is fine. Yes there would be metal particulate going through the oil but the thing blows up suddenly straight away, there isn't enough time for the bearings to get scored and destroyed.

Just checked mine for my pump replacement and still soft. Good info though !

About 1 1/2 months ago, I had to replace my oil cooler return line o-rings that run into the left side of the engine block. I had just taken my car to get it's safety inspection done, well the technician raises the car to check suspension components as this is a new requirement in the state of Virginia.
Well, he discovered an oil leak. The next day my car is at Benz Elite Automotive in Alexandria, VA. Well we raise my E63 up on the lift and track the leak to its source, apparently the o-rings harden up over time and become hard and brittle thereby causing a leak. Now this leak caused oil to be sprayed out everywhere, and we went thru 6 cans of brake cleaner and tons of shop towels. Well after cleaning everything, we managed to replace the o-rings which are very difficult to get to. It's funny how a $2.00 o-rings can ruin your day.

Rubber parts will always fail. To say that this won't happen to your car, on a long enough timeline, would be lying to yourself. E55 AMGs are known to run very hot.

To all the people who say installing a pressure gauge is enough - maybe if you're never on the track or maybe if you keep your eyes glued to the gauge. I lost my s2k engine on track despite having a pressure gauge. Why? It only takes 5-10 seconds of not looking at the gauge when pressure drops to trash your engine. Furthermore, pressure varies so wildly with RPM that simply setting a "low pressure" alarm wouldn't work. What I've thought about is how you could make a solution that looks at a reasonable PSI for a given RPM. If the PSI strays out of the reasonable PSI zone for a given RPM, an alarm should sound. I have not found a single solution in the market place that does this.

I'm trying to figure out how hard it would be to do this job. It seems there a few key things that make this annoying:

1) Have to support engine while lowering subframe. Can jack engine up or use an engine hoist (external or supported by fenders/struts).
2) Have to take off oil pan and hope you have access to the o-ring.
3) Have to reseal the oil pan when oil is constantly dripping out of the car.

Yuille36, can you tell me just how you replaced those O rings, on my E I can barely see those connections as the AC compressor covers most of that area.
Did you remove or loosen the AC pump or is there another method to get at the left hand oil return O ring replacement.
Did you or the Benz tech do the job ?
Thanks In Advance

Thank You Yuille36

Was wondering if it could be done without the AC disconnect.
It is one of those I can see it but cannot reach it LOL
O rings already. no massive leakage just small spot on underpan, still thinking it could be the valve cover ??

He didn't remove the AC Compressor, just loosened it. And the oil cooler lines from the oil cooler all the way were the cooler lines enter the engine block. It's a major pain, as I had my hands up in there as well. I'm glad that my tech allows me in the garage for some hands on. Others have issues with it, as clients aren't allowed in the work area.
Oh, I almost forgot to mention, he also drain the radiator as well, because you will need to drain and remove the engine coolant expansion tank for more room. There is a petcock, on the right or left side, can't remember. After everything was done, he refilled the coolant system. This is a pain in the a**.

Yes totally agree, what a place to put an oil return LOL.
Thanks Again

No. We would have known about it long ago.

He was running a twin charged setup, on track. He didn't even have long tubes, it looks like - which is huge in heat reduction. He seems to have had basically no prior knowledge of the M113K. Tuning was subpar, no doubt.

Worrying about this o-ring is unnecessary anxiety.

I've looked at his mods and what he's done to track a w211 E55 and no, just no. He's got some seriously wacky ideas that just dont work real world. and really hes the ONLY guy that has the problem and he Discovered the "Design Flaw"? how many trillion miles are on M113 series of motors?

Its a Non "Problem"

Also letting the engine cool down is highly recommended!! Also wear gloves, as it's in a very tight stop, near the exhaust headers. :y

Yep... Just driving down the values more by claiming he found a "design flaw."

Once again, someone here says he was right there, but no explanation about how to remove those Oil Cooler Lines specifically, using what tool as leverage or whether it was busted free from the block by merely using hand strength? I’m 6’2” 225 and curl 40lbs per arm and I couldn’t “bust” it loose manually. If I manage to figure a way, I’ll chime in and explain exactly how to get the job done! I will say that the A/C is out in my case and while “in there” I removed the Oil Temp Sensor that’s hidden behind the A/C Compressor using a 3/4” (Not 19mm-Too Big) wrench and socket to tighten the new sensor. You have to remove the P/S Bracket (T-45) as it covers the two T-45 Torx bolts that secure the bracket clamping the Oil Cooler Tubes to the Engine Case. I loosened both from underneath finagling one hand under the other to make sure the ratchet was level. Then just used the bit in its sleeve and removed each by hand. Also remove Torx bolts securing Tubes mounted to the bottom of engine. Using a bit and an appropriate wrench is the only way to do this without raising the engine and disco’ing the engine mounts! I had to remove one of them closest to driver side by hand as the was no room for the bit to fully extract the bolt without the bit hitting the subframe! Then, theoretically you should be able to “pull” the hoses out supporting both side with your hands, but alas, NO GO for me! I’m thinking of taping each of the tubes to keep them from getting scratched or marred while using some tool to lever one out while using the other as the pivot, but the jury is still out on that…..

From your post, you are indeed going in the right direction. Those oil cooler lines are a *****, we used a small pry bar with a microfiber to leverage them out.
I had mine done in 2019 , and those O-rings were hard as a rock, hence my oil leak issue.