CigarXO

'95 C36 AMG

I've posted recently about a possible head gasket and fan clutch issue which led to a recent P0301 code (misfire), rough idle and running hot.

I'm trying to diagnose. I'm now conducting a compression check. A preliminary step is to disable fire to the cylinder (disable ignition, coil, ?). How do you do that on this vehicle?

Thanks!

Sulaco

95's have the Overvolt Protection Relay. If it's disabled then the engine will not fire.

It's the little silver box, passenger side left near the computer stuff. It'll have a white top with a clear door on it hiding a blue fuse. I THINK pulling that fuse will disable spark, try it. If not, just unplug the entire relay (pry the connection off the bottom) and the car will crank but never start.

Twichel04

If that doesn't work, remove all of the coil pack/plug leads (since you have to do that anyway for a compression test, and also remove the fuel pun relay, or just unplug the injectors.

CigarXO

Sulaco -
Great. That component identified.

Twichel04 -
I will pull plug connections. Not fluent in all the names. Been looking for my Chilton's Service Guide and a good diagram or thread which identifies.

Surprising how much more material I find when I work on my Jeep - almost too much because of the varied opinions. Says something for how much better engineered the Mercedes (Diamler Chrysler) is than the Jeep (Chrysler)...

I did conduct my Combustion Leak Test and found no compression gases to be in the coolant. I'm hoping that's a sign my gasket is leaking, but no significant damage. And, my fan clutch is the cause for the overheating and possible area of coolant lose?

I'll be moving into dis-assembly soon if you have a good thread for the repair/build. I am most concerned about maintaining the Timing/Cam positions so this doesn't get more complicated. Any hints?

Sulaco

I know there are plenty of folks out there who've had this same issue (in regards to maintaining timing) since nearly every single C36 has had a head gasket job by now. It was a design flaw from their part supplier that they did not know about until gaskets started failing after accidental overheats, or the dreaded oil leak started. I digress. I know i've seen posts somewhere that spell out how to maintain good timing. Dig here or benzworld.org or club202.com for results. They put that same engine in other cars, such as the E36 AMG, so that should broaden your search. But you're right about the lack of a market for DIY stuff. It's a good and a bad thing. Good, because by the time these cars need it, they're too old to generate attention from most car buyers. Bad, because it can be treacherous territory for us shadetree mechanics who don't trust anyone else.

The AMG m104 is a fantastic, old school straight 6 that's extremely hard to replace. I'm jealous of every C36 owner. And that C36 exhaust note... mmmm...

CigarXO

Working toward a head gasket job, but stopped in my tracks with the fan, fan clutch assembly. - Oh, I am replacing the fan clutch also as it is free-wheeling. -

I can't get anything on the Pulley to stop the rotation so I can free the 8mm outer bolt. I see the Mercedes special rod tool online/in forums, but as I understand it, that goes in back of clutch and since mine is free-wheeling, securing the clutch doesn't work. Tried to jam in wrenches, screwdrivers, etc against pulley bolts, but no luck.

Help!!!

Day #1:
Jeff 0 Mercedes 1

Super B

Strap wrench works well. Get one as big as the strap will fit in the pulley. Snake it through the pulley while rotating. Once you get it to the other side and secured you can remove the clutch fan. Once removed you can easily get to the four pulley bolts and remove pulley.

https://www.google.com/shopping/prod...ed=0CHsQpiswAA

Sulaco

Yeah I bought a big strap wrench and strapped it around the actual fan clutch itself (the finny area) and just rotated it and wedged it against something solid. Did the trick. I use that same strap wrench to hold pulleys, like when I did the belt tensioner or water pump jobs.

CigarXO

I should have included a Strap Wrench in my list of methods failed. There is so little room to work it's hard to get the handle on the strap and a tight hold, but even when I did the pulley gave before the 8mm bolt. Holding the clutch doesn't work because it free wheels from pulley shaft and bolt.

I'll hit the nut with some breakfree lube and try the strap wrench again. It could be the wrench as its a cheap HarborFrieght version.

Sulaco

try it on the pulley again, but buy a can of belt dressing. it will sticky up the connection between pulley and the rubber strap. be careful not to spray any of this stuff in the alternator! I killed 2 m104 alternators with it.

CigarXO

Try#2: lubed the 8mm, used some belt dressing to get a grip, broke the strap wrench - ugh! Spent the morning looking for a higher quality strap wrench, but nothing...

Twichel04

Can you put the fan blade back on the clutch and use that for leverage? That's what I used to do on my old 201's. I haven't had to tackle the issue on the 202 yet... not sure that I want to now....

CigarXO

Twichel04 -
Thanks for trying. The Fan has never come off. It's on the clutch assembly held by the 8mm bolt, but it is free-wheeling so didn't help for leverage - just in the way, pinching my hands... Pics below demonstrate tight space on C36.

Called stealership to see if I can get spanner wrench/holding tool I've seen online YouTube used on E-Class M104, but they do not recognize part??? No luck finding it online...

https://plus.google.com/photos/10666...CMXf7bi3vufnUA

https://plus.google.com/photos/10666...CMXf7bi3vufnUA

Super B

*edit* ignore this first post. Phone slipped out of my hand and accidentally hit he send button before it was ready.

Super B

Man Jeff you got a bad one. Well to help you can take the black plastic grill cover off the electric fans, un-bolt the the one bolt in the middle and any other you can find on the front and the 4 bolts on the top holding the upper core support. Undo and remove the clips on the radiator then lean the radiator/AC condenser forward that will give you some more space.

After that you can sneak in with an Allen wrench and remove the 3 bolts holding the fan on and get that miserable thing out of the way. Now what I did was use a small piece of pipe as a cheater bar on the Allen wrench when trying to get that center bolt while holding the pulley with a strap wench but sounds like yours is seriously stuck. Since you said your clutch is toasted already I might be tempted to sneak in there with a small propane torch and put a little heat on that bolt see if you can't get it loosened up. As long as you haven't rounded out the bolt head you still have a fighting chance.

I've never done it this way so maybe another member can chime in if it's possible. but If you round the head out or can't get it loose. I wonder if you can just remove the fan support bearing bracket and say hell with the bolt. Since your going to replace the clutch and because you're right there and have everything tore apart. probably want to replace the fan support bearing anyway as they are some what of a high mileage maintenance item.

CigarXO

SuperB,
Thanks for sharing. Sometimes there's a "duh" moment in another's thoughts which make you say - why didn't I think of that. In this case, I'll return to the car and remove the fan and see if that gives enough room to work the pulley/8mm bolt.

Fan shroud has been off, as shown in pics. As far as the radiator mounts - I saw that idea in a thread, maybe an E-class. On this car, the top of the radiator has the removable clips, but the adjoining mounts are molded plastic on top of the radiator unit and do not remove so the radiator cannot slide but about 1/2 inch forward with clips and core support screws removed. Better than nothing, but still prevents me from slipping traditional serpentine belt wrench with 8mm hex socket in there - even after milling down wrench and cutting down socket??? Let me go back to remove fan and post my results.

Super B

Yeah you don't get much leaning the radiators forward but with the upper core support removed (all but hood release) it gives you that bit extra to get the fan off and an Allen wrench in there. Also, I took the air cut off wheel and cut down my Allen wrench so I could have even more clearance then slipped a pipe over the Allen wrench to extend the handle so I had something to really give it hell with. HOWEVER take your time! Slipping with that Allen and rounding the bolt head out while running your knuckles across the radiator hurts.

CigarXO

OMG!
DIY mechanic work can be so humbling.
After 3 days of trying to remove my Fan Clutch, I was about to try to fabricate a "counterhold" wrench - tool 1714 for future reference - but I gave the pulley one more close examination wondering how folks were removing it with the little 3/16 inch rod -

http://zdmak.com/wbstore/main.asp?ac...CTMP=1&LowCt=0

they keep referencing inserting in hole in back of fan clutch, but mine was freewheeling separate from pulley/shaft. So, I looked one more time from the driver's side behind the pulley and saw two small holes. So the holding tool goes in the back of the pulley, not the fan clutch! I'd looked there before too, but w/o seeing them. I inserted a small Allan Wrench in the hole and rotated the pulley until I gained leverage against the harmonic plate on the cam shaft. Then I cracked the 8mm hex cap bolt loose with a Allan wrench (not enough room for the extended one even after cutting down socket) and it worked!!!

5 minutes and 3 days later - I'm ready to continue tearing down the engine to the head gasket. (Scary I know).

Still looking for a great head gasket r/r source.

Thanks for all your suggestions. "Look for the little hole."

Super B

Glad to hear you got it. Hopefully the rest will go smoother

Somalia757

Yea its a *****... Just did my serpentine belt this week... Took out radiator shroud, intake, and fan. I used a Allen wrench 7mm I think took me awhile and a lot of sweat. They gave me the wrong belt so I had to order one from my shop with my vin this time and it went smooth after that. I use the continental belt which is amazingly built to last!

I held the fan blades with one hand and broke the bolts with my other... Took a bit of fighting with it.
Don't give up

CigarXO

Somalia - Your method would not work for me because my fan clutch was wrecked so the fan would free-spin.

Since then I also pulled the fan flange to find the bearing is bad.

Still working the head gasket replacement... see new thread.