When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
Well gents, it's officially time for me to eat some crow. I thought it best to follow up and let everyone know that I was wrong and guys like BLKROKT were right; if you have coolant leaking past the head gasket on these engines, do yourself a favor and change the head gaskets. Installing head studs will not fix the leak. At least in my case. I put about another 1k miles on my car after installing the head studs and although the frequency with which the low coolant light came on was far less than prior to installing the studs, I still got the light coming on occasionally. The first few times, I just assumed that the system was leveling off by working air trapped in the system out into the expansion tank. By the 5th or 6th time I had to top it off, I knew something wasn't right and sure enough, my Weistec oil catch can was full of milkshake a car guy never wants to see. So, back apart it comes and off with the heads this time. I'm crossing my fingers that the cylinder walls in the two holes I know had leaks previously aren't completely washed down to a mirror finish and the whole block doesn't need to come out. Wish me luck and let my little "experiment" be a warning to those for the simple fix: if you're leaking coolant internally, change the head gaskets, I know from experience that re-torqueing the heads will not stop the leak.
Jasonoff, you may be correct, I should have the worst side off tonight and I'll take a good forensic look at the gasket and see if I can make sense of what happened. My guess would be the Viton coating cracked somewhere and created a path for the pressurized fluid to escape. Truth be told, I should have changed the gasket during the stud install when none of the stock bolts had any issues. No rust, no cracks, nothing. Everything bolt I pulled out was sound and solid. But, having done one at a time and believing that the additional torque the studs provided would be enough to reestablish the seal, I tested the waters and failed. Hopefully the cross hatching isn't completely ruined.
That, I did not do. I may get out my mic tonight and see what they all measure out to. Yet another thing I could have done the first time I had everything apart to avoid having to disassemble it a second time. Hindsight is always 20/20.
2012 P31 C63 Coupe Trackrat, 2019 GLE63S Coupe Beast
Damn, sorry jclaus I was really hoping that I would be the one who was wrong. At least you're a pro at doing this now, and the second time should be a breeze for you. Keep us updated man.
Thanks for the confidence BLKROKT, I appreciate it. One thing is definitely sure, it will take me about half the time this time around because I know where everything is and the most efficient way to get it off. Getting the cam drive gear out will be the biggest challenge at this point, simply because I've never had that out and I don't have the tool for it. Everything is on order, should hopefully be here today or tomorrow.
That's unfortunate it didn't work. I would never preach improper repair procedures but sometimes short cuts do work, and this is a short cut some people have had luck with. I'm the kind of person that does it right the first time even if it's more work because then i have complete confidence in the repair. Hopefully this will be a good warning for others and it'll prevent them from re-learning what you've learned for them.
2012 P31 C63 Coupe Trackrat, 2019 GLE63S Coupe Beast
Oh man.... forgot that. You can't lift the heads off without pulling the engine if you do studs, right? I'm guessing you can't pull those studs out - trashing them in the process - by locking (or welding) two nuts on top?
Oh boy, good luck and sorry for all that headache. Make sure you try to replace bolts if you can because retorquig bolts can pose issues in the future. The head gaskets are a big one. I had my tech replace as much as he could while he was in there. I am keeping her so I wanted to be confident.
Yes, I will be reusing the studs and when I installed them, I made sure to clean any excess sealant off the top of the studs so as to have full access to the allen keyed hole in the top of the stud itself so I will be able to remove the studs and easily remove the head without having to remove the engine. That's not to say that I won't eventually have to pull the block anyway; I scoped the cylinder I had suspected as being the problem and it doesn't look good. Obviously, the resolution isn't 4k quality, so I can't be sure, but there is at least one portion of that cylinder that looks pretty much like mirror. So, I'm probably going to end up pulling the block anyway and doing a hone and rings. Once I can finally get the head off, I'll know for sure, but that's proving to be a problem. I have one guide pin that is rusted so bad that the thread was almost completely gone, tapping it proved useless, so tonight I'm going to try welding a bolt in it and hoping that it'll come out once and for all. One of the many reasons I was trying to get away with just doing the bolts; in my experience there is always collateral damage when you disassemble something with this many pieces and parts and it's not always an easy solution to repair that damage. However, at this point in that game, I will readily admit that I made the wrong decision and I more than likely caused damage that will cost more to fix than any collateral damage that might have occurred had I just done the gaskets along with the studs. Finally, I made sure to get ARP bolts for the cam caps when I did the studs, I wasn't taking a chance with the stock TTY bolts, so those will also be reused.
Ok gents, I need your help here. How does this cylinder look to you? I wouldn't normally think twice about putting this back together as is, but an informed forum member educated me on the m156 cylinder composition which is just the aluminum cylinder with a steel coating sprayed in it. There are no linerslike a traditional aluminum block would have and so I'm afraid now that some of this coating has been worn away as a result of lack of lubrication due to the coolant it's been burning. What do you guys think? As far as I can tell, there is no way to hone this material, because it's so thin, it would either need to be recoated(which would mean sending the block back to the Netherlands) or I would need an entirely new block. Please let me know what you guys think. Thanks.
Hard to tell by the pics but it appears the cylinders with the coolant leak and thus cleaner piston have a similar look to the cylinder wall as the ones without coolant leaking in?
2012 P31 C63 Coupe Trackrat, 2019 GLE63S Coupe Beast
Does it look that much different from the others? I think you have to do whatever you can and try to recondition the cylinder. Will honing take too much of what's left off? I mean, you can try, put it back together and see. Worst case is it doesn't work and you need a new block anyway? Gutted for you man, I hope someone more knowledgeable comes along with a good answer to this.
If you do need to get it repair/replaced Check with heller USA I think they are in Michigan they do the nanoslide cylinder lining spray and should be able to hone the cylinders too
I would say they all look pretty uniform, that one is definitely worse than the others in terms of looking "worn". I read somewhere that the coating is only maybe 10 to 15 thousandths thick and it really is designed to be more of a polished finish than the traditional cross hatching were used to seeing in a cylinder. Thanks for the sympathy BLKROKT, I appreciate it man. I too am hoping someone like Merc63 or roadtalontsi will chime in with some knowledge.
If you do need to get it repair/replaced Check with heller USA I think they are in Michigan they do the nanoslide cylinder lining spray and should be able to hone the cylinders too
That's excellent info, thank you deadlyvt, greatly appreciated.
Well gentlemen, the saga continues; I contacted Heller and the guy that I spoke to knew nothing about any arc wire spray thermal coatings, turns out they are a manufacturer and distributor of machine tooling. Specifically CNC machines. So, defeated by the lack of information about what constitutes "wear" with this lining and cylinder configuration, I got out my scotch bright pad and tried to clean up the cylinders a bit and this is how everything came out. At this point, here's what I'm thinking; sounds like this repair has been done dozens of times by many different people with varying degrees of knowledge and experience and so far as I can find, only the people that had catastrophic failures as a result of hydrolock had the entire engine replaced. Every other forum I've been on and of all of the people here that I've read that have done the job, I can find no one that has sent the block out to be reconditioned, re-sprayed, or just plain ordered a new block. Many of which had many more miles than mine. So, I've come to the conclusion that my cylinders should be fine. From what I've read, the coating is supposedly twice has hard as conventional steel as well as twice as durable, despite it's relatively thin composition. What I do plan on doing before I slap everything back together is getting my bore gauge out and seeing what size each of the bores are and hopefully that will give me an indication of whether one is more worn than the others. We'll see what that tells me. Wish me luck.
02-01-2016, 12:49 PM
