Proper ID: 1995 E320 with 104.992 engine

First problem: I got the timing cover off but am having trouble removing the pin attached to the right guide rail. I used an M6 bolt and threaded it about 5/8' inch into the pin with sockets as spacers and the bolt snapped. Now I'm stuck. There is about an 1/8" of the bolt showing outside the pin. I'll try to drill/back it out. If I can't get it out, can I take off the head with the pin still in there?

Problem 2: I can't get the timing chain off. I got the tensioner out completely, that gave me just a little slack. The sevice CD procedure shows taking off a small sprocket below the other 2 but my engine has the right guide rail in that location. There is no 3rd sprocket visible without taking off the bottom cover. So I was considering taking off the exhaust sprocket. The Torx bolts holding the exhaust sprocket are not giving way easily(bent my cheap Torx bit). If I get a good torx bit, will applying pressure on the cam shaft do harm to the valves as the cam try to turn? The crankshaft is at 0 ( for cylinder #1 at TDC). Alternately can I get enough slack in the chain by moving the crank to <30 so that I can move both sprockets and then remove the chain?

Thanks in advance for any help or ideas

Here's a great write up on a head gasket replacement on a '95 E320:

My head gasket replacement notes (long) - M104 '95 E320

__________________
Paul S.

2001 E430, Bourdeaux Red, Oyster interior.
79,200 miles.

1973 280SE 4.5, 170,000 miles. 568 Signal Red, Black MB Tex. "The Red Baron".

Thanks, Suginami. The write up is a big help is reviewing what I did right and what I did wrong.....so far.
I got the timing chain off by removing the exhaust gear. gave it more torque than I was comforable with but the 3 bolts finally gave way and only moved the engine a little (from 0 to 10 BTDC).
So, now I have to deal with the drivers side guide rail pin. As I mentioned, the M6 bolt snapped off in there. I tried getting a dremmel to poke a hole thru the center of the broken bolt so that I could insert a EZ-out but there isn't enough room between the pin and the radiator - only about 6 inches. So I can't get a straight in angle. The bottom of the guide rail is definitley attached to something so I can't just lift the head with the pin still holding the guide rail. I'm going to sacrifice the pin. Has anyone remove the pin by using a vise grip or flatenning the sides to get a grip?
Most everything else is undone. I still have to disconnect the EGR and the heater core return hose from the head, then I'll be in position to lift the head off.
I am lifting the head with the intake & exhaust mainfold attached so what I plan to do is re-attach the timing chain cover and use the engine lift hook on that and on the back of the engine.

Tan Man,
I just removed a head on my 300SE Friday. On removing the pin there is a homemade tool that you should use. It consist of a long bolt that fits the threads inside the pin, a scocket and some washers used for support aginst the head. Worked well for me. There are also a couple of hoses that are a bear to remove under the intake. One is metal the other is plastic. Here is another link that someone did and made some notes of the job. There are also two bolts that brace the manifold. Unless you've done this before you will most likely miss them. Read both articles as I found both to be very helpful.

My head gasket replacement notes (long) - M104 '95 E320

I will be putting my car back together starting tomorrow.

Good luck!

OK, I got the pin out. you all don't know to what lengths I had to go. after the M6 bolt snapped off in the threaded pin I went thru 6 drill bits before I finally decided to destroy the pin if I had to in order to get it out. Finally used a dremmel to grind it some and then vise grip plier to twist it out. I leaned on the wrong thing for leverage and chipped off part of the lower right guide rail so I have to replace it. anyone know how the bottom of the rail is fastened in place? I can't see that far down into the bottom cover.

OK, I got the head off.
Who ever says this can be done with 2-3 strong men - they must be VERY strong. It is auckward position to lean over and lift, a real back injury waiting to happen.
While I have the head off...is the oil dip stick supposed to just ly there loose?
There was one bolt holding it in place at the top of the manifold but now that I have the head/manifold off, the dip stip/tube holder is just loose. Shouldn't there be something to fasten it to the oil pan openning?

Also, when I put the head back on, should the engine be at TDC or 30 before TDC (for adjusting the cams)

You'll need to remove the dip stick. It should just pull out. Reinstall the dip stick after you replace the head.

On the cams; were you able to insert the 4mm pins in the back of the intake and exhaust cams? This is a very important step!!! If so, you are OK.

If not and you have turned the crank without confirming that the cams were aligned, your bottom end and top are out of sync. You will need to remove the cams, place the crank at TDC then install the cams with the #2 cylinder cam lobes point straingt down. At this point you should be able to install the 4mm pins.

Caution on removing the cams:
Be very careful because the cams are under presure from the springs that will be pushing up. So lossen the the cams a little at a time untill they can be removed.

After getting everything back together make sure that you can rotate the engine with the chain installed a couple of times.

After replacing the head gasket, I had to do this because I could never get my engine to rotate. Valves were hitting the pistons. So, removing the cams then placing the crank at TDC installing the cams as stated above was my only solution. Engine now rotates smoothly and I should be ready to fire it up in the morning.

I got most everything put back together. Now just waiting for new wiring harness.
A few points I'd like to mention:
- Although many people explain the timing chain set up at great length I still didn't understand until Phil's tech guy gave me the ultimate explanation:
Engine is at top dead center. The chain is already attached to the lower sprocket. Then attach the chain to the intake sprocket making sure there is no slack. Any marks you may have made when disassembling would serve as a guide to let you know if you are off. Even though it may feel tight, there may be deadly slack. So here is where you turn the intake cam clockwise (when facing it) and then attach the chain to that sprocket only. Turn the intake sprocket counterclockwise to take out the slack. You are aligned if you can fit a thin rod thru the alignment hole in the sprocket and the rod lays even height with the engine head.
Now the right side of the chain is tight, move to the exhaust sprocket, turn it slightly clockwise, attach the chain and turn it counter clockwise to take out the slack. If properly aligned a thin rod will fit thru the alignment hole and be even with the height of the head.
The rest is easy, insert the top guide rail when attaching the timing cover. then insert the chain tensioner. The idea is that any slack in the chain should only be in the area between the exhaust sprocket and the engine crank sprocket. That way the chain tensioner will take up any of the slack. Slack in any other areas is dangerous.
Regarding the timing cover, I struggled with it for an hour. Every time I tried to put it in place the green U shaped gasket moved. I finally came up with a way to install it without risk of moving the green gasket. Coat a spatula on both sides with oil and lay it on top of the green gasket. Then slide the timing cover in place. Any forward exertion at the bottom of the timing cover will slide over the spatula while the gasket stays in place. After installing the timing cover, pull out the spatula. Because of limited space I used 2 very thin 1" wide spatulas because I could insert them sideways (otherwise the radiator gets in the way).
When I get my new wire harness I will finish the job. I'm hoping the engine will start and will not leak. I am sure little bits of dirt fell in places it shouldn't have. I took too long to do this job and had a lot of rainy days so some of the clean shiny interior metals are showing a bit of rust. If I had to do it over again, the part that gave me the most problem is removing and installing the timing cover pin. That really set me back. I could definitely do this job next time in 15 hours or less.
My next post will either be a happy one proclaiming the engine started or a sad one asking for help.

Everyone reset the chain tensioner pin ???

__________________
A Dalton

I don't quite understand how the tensioner pin does its ratcheting, perhaps the "C" clip compresses allowing it to move forward one indent at a time along the inside ridges in the hollow tensioner tube.
In any case, I took apart the entire tensioner, inserted the main body to proper torque and then inserted the guts of metal pin with "C" spring clip and plastic pin with coil spring. I hope that is what it means to reset it. It was a bit of a bear to close up the tensioner, fighting against the spring pressure and trying to turn the sealing bolt at the same time.
I have some parts left over from the head gasket kit: 4MM "O" ring, two 2MM steel washers, two 1.5MM copper crush washers and one 1.5MM steel washer. If anyone knows where these are supposed to go please enlighten me. I did replace the "O" ring in the timing cover, The "O" ring in the front hot water tube and the seal gasket at the tube that connects to the exhaust manifold. I'm hoping the extras are there because the head gasket set is universal for multiple engines and have uses in those other engines.

Arthur Dalton explained the importance of resetting the chain tensioner in one of his post. He also went into the purpose and use for the C clip. Just do a search on chain tensioner. Good to hear you've got it all back together. My car is running after a head gasket replace, it went from cutting off at red lights to a current slight stumble that is improving day by day the more I drive it. Hopefully I can take it in for emissions on Saturday.

Correct.
Failure to do this can be broken camshafts..the tensioner has to be reset ANT TIME it is taken off for any chain dis-assembly/change b/c it has to find it's proper pin length for each engines chain. So, if you put one on that is already extended , it can be too tight for that new application. And b/c it locks as it extends, you have to reset it by pushing it thru and re-entering it from the other end b/c it can travel in only one direction.. it can extend longer, but never shorter b/c off the ratchet design of the clip. And the length is determined by each engines chain, all being slightly different.
A most important , and most over-looked procedure.

I have the engine buttoned back together, I proof read the entire procedure...which of course after having done it everything makes much more sense. But now paranoia is creeping in that I didn't do the procedure quite right. I think I am also getting confused because the repair instructions include engine model 104.98 & mine is 104.992 and there are differences.
My concerns:
- setting the cam/timing: My understanding is that while the engine is at TDC, the sprockets aligned on their dowel marks, I have to take a wrench and turn the cam shafts counter clockwise as far as they will go to retard them. That means there is some play between the cam shafts and the sprocket? Also, repair manual mentions to put camshaft adjuster in retard position - is that the spring loaded collar on the intake sprocket shaft end? how to adjust?

If you are unsure of anything STOP and recheck it. If you need to take it apart again then that is what you need to do. If you need the procedure for the chain tensioner R&R let me know, I think I have it in .pdf and can send it to you. One important step is to replace the seal with a new one. They can sometimes leak if you don't.

Did you take pictures before you took it apart?
As far as the cams go, this is very important. With the motor at TDC, on both cams there are 4mm holes that you need to insert dow pins in (I used drill bits). There are other holes, so it is important to make sure you have the dows in the correct holes (the smaller ones). If you are unsure of this again STOP, regroup until you know it's right. There should be no need to turn the cams again once the dow are in. Be very careful when installing the cams by tighting down a little at a time. Very easy to break a cam if not done slowly and carefully. To retart the cams there is a magnent sensor on the front of the intake cam. It moves CW and CCW, you just need to make sure that its CW all the way before putting on the chain. When you are placing the chain back on it is very easy to move the cams from the correct setting, so you may need a second person to verify that they don't move. Before you try to start the motor, make sure you can turn it by hand from the crankshaft. Only go in a CW direction and never go CCW because you will mess up the cam timing you just set. Something I learned here. If you are following this method you are going from Step 1, so you can forget about the markings that you did to line up the chain and sprockets. They can not be used as your reference any more. Just go slow, recheck everything and you'll be alright.

I agree with EHopkins in that you get to a point where the markings on the chain and sprocket no longer have any relevance. By appearance the cam shafts look like they are in the correct position, the sprockets are dowelled and in correct position, the engine crank is at TDC and the engine turns by hand without any binding or restriction.

I'm expecting the new wire harness on Tuesday. If we have good weather then I expect to be done by Thursday (allowing to install wire harness, run the engine and change the oil just in case I dirt got in the open engine, and flush the coolant.
Some additional thoughts:
- the readings on the crank shaft look something like this: 30/20/10/0/T/10/20/30. So is TDC as 0 or is it a "T"?
- several of the valve cover bolts didn't offer any resistance on being tightened. On removing them for examination I found thin coils of metal wrapped around the bolts - stripped! So I went from Metric to SAE of nearest size which is a light oversize. Did the trick on most of the bolts.

.....Almost there!