bikz

Hi guys, new to this part of this forum. Bought a used C32 amg 2002 which had 125k KM on it. Car was sitting unused for nearly a year before I bought it. When I got it first changed the engine and transmission oil, cover gaskets, and multiple other smaller repairs.
It was running great for 4 months, till the idler pulley jammed, belt snapped on the freeway. Could not stop immediately and I did the dumb move of driving for another 5km before exiting at the next off ramp.
Got the belt / idler fixed, car was running good again for about 800km, and then the misfiring started, and started burning oil.
Tocut the story short, piston at cyl 5 was cracked ( pic attached)
Now my options are:
1. Get a second had engine- proving to be very difficult as these engines are rare in this part of the world
2. Engine rebuild

So I'm going to go with a rebuild. I known a machine shop which can re-bore the block ( which is mildly damaged)

The question is, do I rebore and install larger 6 pistons ( and which pistons?)
Or
Reborn and sleeve the 6 pistons.

Another which in found out, the crank pulley is an oversized Kleemann piece which has to be changed as well ( rubber part is coming loose , will probably go back to stock size)



Scarpping the car would not be an option , and shipping a c32 engine is going to cost as much as doing the above.

Thx in advance guys.

Khan 55

Find out the specs on the piston you have. Hear from the machine shop what's the viable option. Either over size or re-sleeve. Then check what aftermarket companies keep pistons for this engine. Someone like Arias or Mahle or whatever other brand names people know of in your country. Import those and see from there. It would be better to go oversize then to re-sleeve. If you were on a tight budget, you could re-sleeve just that failed cylinder and fit a new piston with rings std size from agents. I would inspect the crank journal for wear due to this. If everything turns out okay after the machine shop inspects and measures the crank, you could install std bearings from agents however I doubt the rod journal will be fine and may need to be machined for oversize bearings as well. Inspect the cylinder head combustion area and valve seating area for that cylinder for any damage. May need new valves there or unless you doing the entire heads with new valves. Check agents pricing or you could buy from aftermarket like Ferrea or the likes. I think SS valves would be best to use that's if the head doesn't already have those from the factory.

Morphh

Put an v8 kompressor from e55.slk55 etc, have seen it done

bikz

Thx khan 55. I have consulted an experienced machine shop here. They will be able to bore the block and do the lining. But getting a piston is gonna be a issue.
Just emailed Mahle, cp carillon and wiseco.
Just to clear up, one of them said the block is Alusil bore that will only work with the special copper coating . What does that mean?

suicidal4life

Even though your car is not a W211 you may want to check out the W211 AMG page. There have been several discussions over there on the Alusil coating and how to deal with it.

Khan 55

You contacted the right people. As for that part, I aint an automotive machinist but a diesel fitter. For one, AMG engines are made from aluminium. Now I am not sure if they have dry or wet sleeves.
follow that link. It explains it in more detail. Ensure the machine shop can do this correctly if you are going to bore all cylinders. Apparently its just silicone mixed with aluminium that works as an anti-corrosive wear agent on the cylinders.

bikz

after much research and many emails, i have come down to three options. Cost and time taken to ship items are important as well. I am gonna keep this car as stock as possible, not going to go hunting for more power....yet (maybe 5 years down the road). Going to go back to stock Main pulley (previously fitted with Kleeman oversized pulley by previous owner)

Option 1:
Buy original 1x piston which will cost RM 2700 (USD681) all in all, 3 weeks to ship from Germany to Malaysia.
Bore all 6 cylinders, and the machine shop will re-sleeve with cast iron (no one does alusil here) and balance it. So the other 5 cylinders will be reused
Question - do the pistons come with alusil coating as well? will cast iron sleeve make much difference?

Option 2
CP Carrilo will fabricate all 6 for about USD1500 (so with customs tax would come upto USD 2000). they have the most helpfull so far. they will coat with which ever coating that is request.
But shipping will take about 6 weeks.

Option 3.
Mahle will fabricate for upwards of USD2000a, and they would prefer one piston be shipped to them. so time would take easily 9 to 12 weeks for the whole process.

Although i would love option 2 or 3, time and cost matter alot

So i am going to go with option 1, that is one piston and rebore and resleeve all 6 cylinders on the block. Would this be a good or bad decision?

Khan 55

I would have to agree however. Well firstly is this piston fully aluminium? Yes I think it is but could be wrong and it might contain magnesium or other materials. Does it have an Alusil coating? No idea and on cast iron? I am not so sure if those two going together will gel well.
Option 2 would be most viable if time were on your side. Just google the type of piston AMG uses. Then google wear properties of aluminium to cast iron but hey Toyota engines were made that way back in the day. Nowadays everyone uses aluminium cast blocks because of their weight being the number one benefactor. Other properties are there as well like corrosion as compared to cast iron.

Khan 55

http://articles.sae.org/13533/
http://articles.sae.org/10507/
above is a good read on how the 6.3 litre engine block cylinders are made and more insight on Mercedez using steel rather than aluminium pistons in their newer style engines. I will look for info on the older generation V8 and V6 engines.


Here is a great read on M112/M113 blocks for anyone who is interested. Great help this information is and many thanks to Signal to Noise on writing this article
http://www.fitzhughmedia.com/MBF/rebuildable.html


You can also google Wolf Gang's ML page for more insight on your engine.


So thanks to you I have learnt more. Aluminium pistons indeed but the block was cast around the sleeves of this engine. They did mention they are aluminium type sleeves but they made with different material. Then after they are made the coating is applied to them by dipping them for an hour into an MB type of bonding agent. None the less, should you take the time to read the above, you will be able to make a good decision. Good luck and do respond to us once your engine is done and rebuilt.

bikz

So an update to this thread, decided to rebuid the engine. A reputable machine shop here has already bored then sleeved the block (cast iron) - from what i have read, should not be problem.

The issue now is the freakin piston which i had ordered from Mercedes (took 3 weeks to arrive from Germany)
- on the box its part number is correct (there is no part number or the piston as far as we can see)
- but it is different from the pistons in my car (different dome volume , old 9.6cc, new 19.7cc, different weight - by 30gm)

- this car has had a engine swap (im the third owner), but from the engine number it does look like a c32 amg (plz correct if im wrong)
11296160164xxx

- here are some pictures of the two pistons.

So does my engine have a different block, or was the piston that was delivered to me wrong?

Anyone has pictures of their C32 AMG Piston Head

Lenin

The piston numbers that I see in EPC say A1120303217 piston replaced by A1120306817 piston Standard 89.90mm

bikz

Sorry if I sound dumb but what does this mean actually? Mercedes changed the type of piston used ?

The new piston I received was the 1120303217

Lenin

I don't know exactly what is different. Most likely a different manufacturing processor different materials used. Usually nothing major otherwise the EPC would say "don't use the old part" or something like that. Obviously the size and dimensions have to be identical.

Khan 55

But now you mention the weight differs. You have to get the number from the old pistons you removed and order accordingly and try to tell them that this is the wrong part number and hopefully they can accept it as a return. Usually they say if you order a part by giving them the number, they don't accept returns which means you will have to order a new one.
You obviously cannot just chuck it in with the rest as it will be like running on two different size shoes and obviously a big problem. The same issue the engine will experience.

Pansu

Maybe your block&pistons are non turbocharged model (high compression)

bikz

That is one of my suspicion, it would be ideal if I could calculate the compression ratio. There are numerous online calculators, but I don't know many of the values ( combustion chamber and deck clearance )

There doesn't seem to be a part number etched on the the Pistons, at least not a mercedes number. There are some numbers on it, maybe I have to contact the manufacturer to confirm.

jvakos

Bikz - bummer to hear of your rebuild issues and situation. Did you find a shop to do the rebuild? How long did it take and what did you pay to have the rebuild done???

my c32 is sitting idle now with a bent rod. other than that is been exceptional. i didnt realize bad fuel injectors around 100k miles should get replaced as i had a stuck open injector that caused a hydrolock on cyl 1 and caused my bent rod. note to others if your on original injectors at 100k miles or more you should probably get them replaced....its pretty cheap maybe 500 bucks total from an indy shop with bosch injectors.

husqvarna

Do the old pistons have AMG sign inside the skirts? My pistons do.
M112 N/A pistons don't show AMG inside, only mercedes logo

husqvarna

i have a spare connecting rod if you think the postage from Europe will not be an issue...

husqvarna

I can confirm your engine was build from someone with N/A pistons!!
Look at the pictures for comparison between C32 piston on left and C320 piston on right.
Thats why you have had piston failure... There was a lot ot stress on these weak pistons with high compression ratio







My guess is that you have 3 alternatives (except buying whole engine)
1. Return that C32 piston and exchange it for C320 piston and drive it easy
2. Ask me to ship you one USED C320 piston and again drive it easy
3. Buy a set of WISECO pistons for C32 at about 1300$ (ask RobertAMG fo how to do it)

bikz

i did find a shop here in malaysia that bored and resleeved the block. it was "cast iron nitrogen cooled re-sleeve". no one does custom pistons here though.


thx for the infor husqvarna,
i managed to source an engine for a good deal (with the gearbox). i used one of those fibre optic cameras and confirmed that the "new amg" pistons were the right one, like the one you have posted. the car is runnning well now. (only problem is the REAR SAM -> any idea if it is the same as other W203?)

however, now i have a bunch of stuffs which i am not sure what to do with:
1. Engine block - has been resleeved (cost quite a bit), and rest of the engine part from supercharger till the flywheel)
2. 5 x C320 pistons which are in good condition
3. 1x C32 piston (brand new, bought it from merc dealer, AMG / Mahle ) -> cant be returned as it was a special order item)
4. 5x piston rings (band new -wanted to change the older pistons rings)
5. 6x conrod bearings (brand new)
6. Kleeman oversized pulley (which my car originally came with -> changed it with an original pulley)

So basically i have a whole engine, with new parts, and only lacking one freaking piston.

Based on ur suggestions, i am now contemplating of doing either:
1. just keep everything as spare,
2. rebuild the engine and swap it into my SLK 230 R170 either:
a. getting the C320 piston from u
b. getting a set of new Wiesco pistons (dont have the cash now though)
3. rebuild the engine with C320 piston and sell it off to someone who is willing to use is it slow
4. Sell parts seperately.

husqvarna

You can take every w203 rear sam and use it on your car, only difference may be the fuel level sensor settings, but you can change them with STAR.

I think you will not be able to use the old engine for parts, only salvageable parts will be the camshafts
I guess best will be to find one 320 piston and close the engine, at least will be one complete unit till the time you find what to do it

bikz

​​​​
that's good news for the reae Sam. how about the front Sam, is it interchangeable with other w203 as well?

in that case, I think I might as well make the engine complete. how much would it cost for your c320 pistons ?

husqvarna

Front sam is interchangeable with many w203 but you must search from same body stile like yours. If your is wagon and you put from sedan, the rear window washer will not work.
Best is to take front sam from facelift car, you will gain 2 more options:
1.mirrors folding when the car is locked (if you got folding mirrors)
2.cornering fog lights

Will check how much will be the postage for the piston to Malaysia

bikz

Just got both my front and rear sam changed, and coded.
Only problem now is the Auto Headlight function does not seem to work. Is there a way to make it work, or does that involve coding via STAR as well?

and thx for the advice, i got my self a front sam from the face lift version. but how do i get the folding mirrors and cornering fog lights to work?

and is the piston still up for grabs?