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S62 Engine Failure? Comments Please...

61K views 142 replies 34 participants last post by  xrviz 
#1 ·
Hi all, just buy a M5 last week with engine problem, the engine had a strange sound like a rod sound but that was not. I took of the engine and tale off the oil pan. There was no trace of copper in but the bottom of the oil pan was cover of dark grey stuff. The sound was from the rear of the engine so I start to remove the rod cap on the number 4 and 8 and there no trace of wear on the bearing, then I was confuse because I try to find that sound since a wile... Conclusion, there couple of cylinder with gripped pistons. lot of aluminum stick on the cylinder. Am quite confuse about that. These 2 cylinder, the spark plug was really cloged of carbon. Look like the carbon damage the cylinder. Now the engine block is damage, solution is to put a new block but here in Canada, the M5 is quite rare so the spare engine is really hard to find... The problem is to rebuild the block... When I was younger I had some dirt byke and of course I blown some engine, that was the same story about the Nikasil coating on the cylinder but there a company near to my house who are specialist for recoat the cylinder with nikasil where I use to send my cylinder before for recoating. I will call monday to check how cost for recoating all the cylinder. The S62 engine is Alusil coating, basically kind of hardened aluminum but soon you start to grip, it's easy to wear the cylinder more fastest, the Nicasil is way more harder so if they can do it, I will send my block for get a Nicasil coating. The other option is to install new sleves but by personal experience with sport compact engine with sleve installation, that was bad so I will prefer to recoat... I have no idea how many people live this experience but that not funny and expensive. I will verify this option and if it's possible to recoat the block I guess lot of people will go for that better to buy a 7000$ empty block ouich. If you have any better idea, please feal free and comments.
 
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#2 ·
Dark grey stuff might be your bearings.

Look, this engine sounds trashed... unless you KNOW the crank, rods, camshafts etc are good (perfect, optically no marks) you may be chasing a loosing battle.

I can NOT recall a single successful 'recoating' of a cylinder. One member had a light honing of a cylinder, which was likely an experiment by BMW just to avoid an expensive new motor. There have been one or two sleeved motors.

At the end of the day, you will spend close to the cost of a used motor- any money you 'save' will likely be due to trade offs you make in the rebuild/inspection, which will increase the risk of future problems.

Why did you buy this? Very cheap?

A
 
#3 ·
Well, everithing is fine, just the cylinder and pistons are damage, for get a used engine, am not in california here, I saw 2 M5 in my life here, the first about 5 years ago and the second...mine. I had very very bad experiences with darton sleeve in honda engines before so I don't reallt want to risk to broke this block. I will call tomorrow for the coating then will give me a better idea. Am just worry about the pistons, I don't really want to pay the price at the dealer...ouich
 
#4 · (Edited)
I think what Ard was trying to say is if there is already that much damage to the engine and you do not have a defined cause, you may be in for massive headaches.

If you recoat and have a bad rod bearing or a bad crank bearing then you are going to toast all you efforts in a matter of seconds. If you crank is scored, valves are damaged...etc...

If you cannot, 100% pin point the cause of the problem. I WOULD NOT start throwing parts and ad hoc repairs at the S62. It has proven to be cost inaffective.

Getting a used motor has proven to be much more cost effective in all cases I have seen.
 
#5 ·
Am really confuse because, when I took off the valve cover first, there is no sign of oil smoke stick on the metal, also the oil pan after removed, also no sign of oil smoke stick on the steel, All the bearing look brand new with no scratches. Seem that engine been open before and been rebuild...I will try to trace back the story because the cylinder look very scratched. I saw actually many pictures on the board of many engine open and all their interior are cover of oil smoke and they have less milleage...I don't know how to spell that in english abiout the oil smoke but more the engine take oil or get wear, the oil color stick on the steel...
 
#6 · (Edited)
I understand your fustration, but as you stated above "I am really confused". I would not make any repair decisions until you know what the issues are with this engine. Do a leakdown, compression test..that will give you a good starting point. I am concerned that you say the engine has a knocking sound. A scratched/scored wall should not produce this sound. If the wall is badly damaged it should show in a compression test.

On a side note: You do know that the S62 will have a slight "diseling" noise to its valve train ona perfectly healthy engine.
 
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#8 ·
Sorry, not today, I will finish to open the engine tomorrow and I will take more picture. As all german cars, you need special tool as torx but long one for the flywheel...ouich This is more complex that any other engine that I seen, need lot of room to disasembly this guys...Will let you know...
 
#11 ·
Ok, gents, this morning I go for the surgerey, will take picture as well, thanks mate for the word varnish, yes that is the term... I talk to friend of mine who worked about ten years at BMW in quebec as mechanics. He give me a lot of infos about this engine. Specially about the cylinder head remove procedure... It's different but not rocket science. Will let you know later in the day...:cheers:
 
#13 · (Edited)
Ayoye! ;)

How many miles on this beauty? Was this car driven in the wintertime? I have seen a few 2stroke pistons that looked similar from starting the motor in very cold weather and getting on it right away.

BTW: even if the clearances on the lower bearings look good, get new ones, these also wear out overtime and can lead to diaster as well.
 
#14 ·
I get some trouble to upload these pictures. Also I have more pictures but it's long to upload... Ok now it's time to talk about that, I had a look about these cylinder, sorry for that gents but it's probably the worse cylinder cast that I never seen in my life, BMW did remove the Nikasil in their production but to be honest! May be better to keep it. I just take a screw driver today and in one of the damaged cylinder and try to scratch it...So easyouich I blown many dirt byke before with Nikasil cylinder and the only thing that I had to do it to put some acid in the cylinder for remove the aluminium then just re-polish, new piston then bingo!!! Now the complete block is damage!!!! Tomorrow, I will check with the guy who is do the Nikasil coatin at home to see if is possible to recoat... If yes I will go for. I get a lot of comments from many people about buying a used engine but am not so interrest to get an other used engine and guessing to get the same problem again because look like everyone with oil burning have the same problem than me... About the rest of the parts, that look ok, the crank is perfect, the main bearing are good, the rod are just normal used so I will just change it. The head are not twist and the cams are not scratched. Everyting else look fine around the block. I allready clean all the parts and now am ready to rebuild. I will let you know about the progress. This is the most beautiful engine that I never seen in my live about the technology but about the way they build it, strange... I wish to all the M5 owner than my story will not happend to you ouich
 
#18 ·
...........I blown many dirt byke before with Nikasil cylinder and the only thing that I had to do it to put some acid in the cylinder for remove the aluminium then just re-polish, new piston then bingo!!! Now the complete block is damage!!!! Tomorrow, I will check with the guy who is do the Nikasil coatin at home to see if is possible to recoat... If yes I will go for. ............
Nikasil is quite soft and offers less life than alusil. This is why BMW and Mercedes began moving away from that technology over 10 years ago.

Make sure you tell your guy the block is made of alusil. This is not an aluminum block and the impregnated silicone introduces many challenges to folks wanting to coat. Some BMW and Mercedes engine rebuilders use special cylinder treatments, but to my knowledge none are nikasil. I have never heard of anyone applying a nikasil coating to an alusil casting. Also be aware there are no S62 pistons available for Nikasil. It would be very shortsighted to refinish cylinders using methods or sizing that's incompatible with available pistons.
 
#16 ·
you will need to carefully measure the depth of scoring in order to determine whether oversize bore/hone will correct the problem. The gouging looks quite serious. Oversize piston availability is limited.

After pricing boring, honing, refinishing & oversize pistons...you may be better off getting the block done at VAC with their steel sleeve kit & pistons. The gouges will be a non-issue with sleeves.
 
#17 ·
Thanks mate for your help, like I said tomorrow will get better idea about what I will doing. About the sleeving, I had really bad experience about that with head gasket blown all the time so if I can save that will be very happy. About the scoring I know it's pretty depth but I also rebuilt some 2 stroke cylinder with really bad condition as broken ring between the piston and the cylinder and this guys fix it, just came back without any trace of damage... But for now I guess it's better to wait till tomorrow and ask the good people for get the good answer...
 
#19 ·
..........I had really bad experience about that with head gasket blown all the time so if ...
Sleeving performance & head sealing is largely a function of sleeve design and the quality and accuracy of machining. Loose sleeves or improper installation is a recipe for failure.

fyi, the sleeved S62's I'm talking about are generally an upgrade mod chosen for 500+ HP supercharged S62 applications. Folks are getting this sleeve upgrade to improve durability on race engines that have no cylinder problems. There are many threads about it. It is not cheap though.
 
#20 ·
Good morning, just call this morning the guy for the Nikasil. He tell me that this block is possible to re-hone over size. So I will bring the block to him this morning and will see what our possibilities. If I can save a coating will be great. Also if I have to do the treatment, it's 925$ for all 8 hole, I was expect more... Will let you know...

Sonny :byee55amg
 
#21 ·
Thanks for the updates & photos Sonny. Sorry to hear of your situation. You never mentioned the story of your car... did you purchase the car for cheap and were you aware of the sick engine?

In any case, those pistons look atrocious. I am aware of a couple of carbon scoring diagnoses on S62s. I could be wrong, but I'm not seeing carbon scoring behind this mess, partcularly since you mentioned that the engine was clean and apparently had been apart previously.

Any other theories on what happened?

Dave
 
#22 ·
Well, I have no idea now, it's very hard to say. Now for me it's time to find a solution. This morning I been at the Atelier Adrien Bernard. They are specialized for Nikasil coating, when I arrive there, the guy said; well the best way for you if you don't expect any blower later, I will suggest to you to just re-bore the cylinder and put 8 brand new BMW piston, I said ok cool so I will order the piston and will bring you everything when I will get the parts. This morning I also been at the dealer for ask for 8 piston oversize, the girl say; well I don't know the price because that never been order in all the Canada... Ok well check then call me back. After ride back from the coating shop I got a call from the dealer....WTF:eek::eek:. 580$ each piston!!!!!!!!!!!! Are you crazzy!!!!! Now it's time go go with B plan. Also this morning I talk to Chriss at VAC motorsport, really good guy. I ask for a set of factory compression piston. He can provide me these piston. So the solution for me will be 8 forged piston and a full Nikasil engine block. All that job will cost me almost the half price of the set of BMW pistons... Just for help you when you will buy a M5 with around 80K, try to get a fiber optic lens for check your cylinder. If you see a small sign of grip, don't touch it. When I buy that car I was already know that car had a engine knocking, the seller get a quote from the dealer and the dealer said to him the problem was in the head. Yes the sound was from the head but in fact the piston squirt was so used the piston had an off angle to be able to touch the head...That was the sound. It's not easy to find that trust me...Sound like a rod bearing because is not constant knocking... I hope I will be the only one will live that story. Yes I paid the car quite cheap but still couple of thousand dollard that I will inject on... Also I do my stuff by myself that help. I wont live that story if I have to pay some one to do that ouich. Will give you an update about the progress, I hope the car will be ready before am going back to work in Korea in the end of july!!!!!

Sonny :cheers:
 
#24 ·
Bad news!! I call VAC and they don't have my pistons in stock. So I will not be able to run that car before going back to work :crying2: But It's may be better for me and the car, I will take the time to re-build her and don't try to do it to fast then get a sloby job after... Any way, I order the parts and will wait to get back from the job next trip... :cheers:
 
#25 ·
Sorry to hear that, but I can't say I'm surprised that they don't keep this stuff stocked. I'm sure they don't get orders everyday, or even every week .. every month? for S62 piston heads :) Anyhow, hopefully all goes well with the rebuild. Best of luck.
 
#26 ·
Well they have a big bunge of piston in stock but not my model that I need, I just want factory compression ratio and the model they had was low or very hight compression ratio. If I want mine, will take 4 week or 1 week overnight with a lot more money... Like I said, I will take my time to re-build her and I guess that will be better...

Sonny :byee55amg
 
#27 ·
You are actually going to have that damaged engine and block Nikasil coated??? and then drop $4k worth of new pistons/parts/bearings/etc into a great big unknown??

By a company that specializes in lawnmower and ATV repair.http://www.cvtech-aab.com/contenu/replacageNikaTech_techniqueDeReplacage_ang.cfm



Has anyone come out and said "this is the best way to fix this"? Did VAC say "honing/ coating Nikasil onto an Alusil block and using factory pistons is the best way to go"?

I'd be interested to hear of any qualified shop willing to do what you are proposing, and willing to stand behind the repair.

DO NOT CONFUSE input here and from shops that says "yes we can" or "good luck" with "good idea" or "that will work"

Should be interesting... near as I can tell this will be the first time this is being attempted


A

PS I always tell people who ask about buying a damaged car that any time you rely on a dealer ESTIMATE you are potentially going to get screwed.
 
#28 ·
Their seems to be a very common misconseption on this board about the S62 and it being this very rare super crazy impossible engine to rebuild. It is an internal combustion engine like any other, as long as the cylinder was has enough room between the wall and the water jacket to be bored, it can be bored or honed. Their is equipment to test this very acturatly measure this.

Look at it like this, when D/A or Dinan and or any other tuner disassembled their first S62, how did they ever rebuild it? Their is nothing magical.... The same actions you take when building a SBC is the same you will take when building an S62, sur emore caution must be taken to avoid weakening of the block by to much over bore etc. but the steps are the same.

The block shouldnt be touched until the engine builder has pistons in hand as you have to hone the block for the pistons and the rings you have.

The biggest part is cleanliness and the actual piston to wall clearance and ring clearances. As long as everything is in spec the engine will not have any issues. It doesnt take a rocket sciencetist to build an engine even if it is a an S62. It is all the same, you measure all the parts and make corrections until they are within spec. If all the parts fall in where they are suppossed to and the engine builder is very clean their shouldnt be an issue.

It seems like many put the S62 on this pedistal. Yes it is a great engine but.... it is just an engine!

Good luck,

Sonny


You are actually going to have that damaged engine and block Nikasil coated??? and then drop $4k worth of new pistons/parts/bearings/etc into a great big unknown??

By a company that specializes in lawnmower and ATV repair.http://www.cvtech-aab.com/contenu/replacageNikaTech_techniqueDeReplacage_ang.cfm



Has anyone come out and said "this is the best way to fix this"? Did VAC say "honing/ coating Nikasil onto an Alusil block and using factory pistons is the best way to go"?

I'd be interested to hear of any qualified shop willing to do what you are proposing, and willing to stand behind the repair.

DO NOT CONFUSE input here and from shops that says "yes we can" or "good luck" with "good idea" or "that will work"

Should be interesting... near as I can tell this will be the first time this is being attempted


A

PS I always tell people who ask about buying a damaged car that any time you rely on a dealer ESTIMATE you are potentially going to get screwed.
 
#29 ·
The thought that you can apply Nikasil to a homogenous silicone-impregnated alusil block really scares me. Unless this has been done before and it's tested/proven, I would not make such an assumption. A top shelf professional mechanic is surely not qualified to make such an assumption. I seriously doubt if a scientist doctorate degrees in material science and metallurgy could even make such a call with any level of confidence. This would just be an experiment with unknown outcome.

This is the basis of my concern, not to mention the fact that the severe scoring appears to be well beyond honing repair. Sunnen & similar precision honing is generally only good for bore diameter oversizes <0.010", so a 0.005" gouge is right at the threshold limit. Beyond that, you're getting into boring and sleeving...especially with the S62 that's already hogged out to the max by BMW.
 
#31 ·
Well, after talk to VAC, this is not the first time they work with Nikasl engines and also they ask you for which kind of rings you need. Also the company they will coat my block use to coat many other block with Alusil cast before, this is not a rocket science... This Alusil cast is not use just in a rocket! but in many sport motorcycle engine and when they are damage, they coat with Nikasil that also the same in the Honda Prelude engine, they use Nikasil but soon you put a turbo on... oil and oil and oil burning. By experience yes it's a good product but it's way more softer than Nikasil, for the people who say no, try to scratch you damage cylinder block with a screwdriver... Yes you will get a nice scratch on Alusil, now try a Nikasil... No scratch because it's way harder.

About the last post about to buy an other use engine, am not really confident to get that kind of engine, I will get a new re-built one and I will be sure about the stuff put in. Ok well if am wrong find for the people who said that was a really bad idea but who paid? I will try it and if that work there a lot of people will be happy because to chose for 4800$ for 8 piston, 500$ for re-hone it, gasket and everything start to be pretty expensive compare to 1500$ for the VAC pistons and 900$ for the coating... Am really confident about that so I will go for... That will not going to be a secret if that work or not, I will let you know. Am sorry but that will be in a while because the delivery time is 4 week and I go back to work out of the country the 21 July and I will be out for 2 month...Sorry for the delay... :byee55amg
 
#39 · (Edited)
Well, after talk to VAC, this is not the first time they work with Nikasl engines
Most BMW's had nikasil engine. Since VAC specializes in them, they surely have experience.

.... this is not a rocket science... This Alusil cast is not use just in a rocket!
Rocket science & rockets were developed and proven over 60 years ago, long before alusil and nikasil.

.... but in many sport motorcycle engine and when they are damage, they coat with Nikasil that also the same in the Honda Prelude engine, they use Nikasil but soon you put a turbo on... oil and oil and oil burning.
Aluminum cylinders with Nikasil have been used in many motorcycles. Nobody is doubting that they can be repaired through welding and recoating, as this has been doine for the last 20 years. This has little to do with alusil.

From what I read, Honda cars do not use alusil or nikasil. They have some other interesting cylinder technologies.

Good shops can take damaged nikasil-coated aluminum block cylinders and weld up cylinder gouges, rebore, recoat with nikasil and hone to a condition that's equal to or better than new.,,,just like your buddy does for many motorcycles with nikasil cylinders. This is because nikasil motors are made of aluminum, not alusil. This sort of repair has been done for many years. Again, these are not alusil and the same techniques do not apply according to what I've read. There is plenty of information out there for BMW, Porsche, Mercedes, VW, Harley Racing, GM racing etc.

---------------------------------------------

I sincerely hope your shop has enough skill and experience to make these determinations and perform this work. Longevity will not be known for many years.
 
#33 ·
I must have missed the part about why you wouldn't want to sleeve the block. Why isn't that an option?
 
#34 ·
he didnt want to cause he didnt have any sucess with it in a honda but like he said hes footing the bill and calling the shots if it turns out a sucess whe have another option when rebuilding our s62s
 
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