jlostlen

Hi there guys,

I have a 93 300ce that has a bad head gasket. Water has been emptying into the motor, and mixing with the oil. Id like to try and do this task myself to save money. I know this is likely to be a very expensive part at the dealership. Is there another source I might check for better prices?

Is this a very difficult task on this specific model?

I have been forewarned that removing the head gasket sometimes involves changing the wiring harness as well due to this years environmentally friendly wire insulation that seems to give out in the heat for many owners.

Any tips, warnings, notes, links etc are greatly appreciated.

Thank you

James

ps2cho

If you do a search there are tons of threads on this. I just mine about 2 weeks ago.

jlostlen

I'm looking more towards the specific questions I listed regarding a source for the head gasket and if others have had experience with the wiring harness issue. I was not able to find anything like this on my search that I performed before I posted the thread.

GEDaggett

I recall either here or on the benzworld forum a thread that had the part numbers listed and showed you how to see if your harness was a replacement or original equipment. I checked mine this way. You will have to do a search though because I can't remember where it is. Most likely if the harness has not been replaced then it will need to be done. new harness is about $700 -$1000.

Quicksilver500

You need to buy some special tools. You need two good T40's, the Hazet head bolt socket. I decent breaker bar and torque wrench. You'll need a tool to get the pins out of the chain rails, and a tool for getting the fan and fan pulley off. Other than that stuff, everything else is pretty standard. Send the head to a good machine shop!!!

-Mike

Kestas

If you're resourceful, you can cobble up a tool to remove the chain rail pins, out of the right-sized bolt and a dozen washers, and use an allen wrench for getting the fan off.

In a well-stocked tool box, the only special tool you'll probably need is the triple-square bit for the head bolts.

jlostlen

Kestas, Quicksliver

Thanks for the tool tips, very helpful. I am fortunate enough to have access to a well stocked garage.

Is the cheaper headgaskets something to avoid? They are a little more than half the dealer price of 215$.... I wonder if they are going to hold up as well as the dealer part.

I will track down the wrench and continue my investigation before performing surgery on the car, I do not want to open it up until Im fairly educated on what can go wrong and what to avoid etc...

Thanks all

ps2cho

Buy all your parts from autohausarizona.com for the best prices around. They only quality parts and OE/OEM are stated.

Kestas

The triple-square bit is sold in most automotive stores. It looks like a torx bit, but with 12 serrations, and goes into a 1/2-inch 6-point socket. I forget the size (M12?).

pifcat2

I've followed the M103 head repairs (ps2cho's was excellent) but I'm also curious what the differences are for the early M104 since I have one too. I expect the extra machine work with more valves and an extra cam.

btw, I wouldn't scrimp on the gasket quality (if any) considering all the work to replace it. IIRC, there was an improved gasket to chose.

jlostlen

I bought my tumbler from autohausarizona, great price, good part. Getting the jammed tumbler pins free to turn to position 2 was another story.

I can size the triple sqaure bit with some calipers....

Thanks for the posts everyone Im feeling confident to do this job and will post helpful linkis in my research as I find it.

Kestas

When I replaced my headgasket (preemptively), the replacement gasket had reinforcement in the trouble-prone area, when compared with the original gasket. I heard the gasket redesign has gone through a number of iterations.

jlostlen

Where did you get the gasket?
Ive heard about this gasket being reinforced with metal in the trouble area, yet still not recall for the car. I saw a thread that was petitioning for a recall due to the imminence of the gasket failure at early miles.

Kestas

It's not a safety issue, so there's no stimulus for a recall.
I bought my replacement gasket from MercedesShop.com when I did the job six years ago.
Original head gasket: 104 016 25 20
Replacement head gasket: 104 016 28 20
This was for my 104.992 engine.

jlostlen

Update / Further Questions

I am trying to determine the health of my engine wiring harness before I rip the head off and replace teh headgasket and resurface the head.

I have attached some pictures of the front drivers side, near the power steering pump. These pictures are to show the wires I examined.

I sliced open the tubing to get a glimpse of what these wires look like and they look to be in great condition with no signs of cracking or brittleness. They feel very pliable and fresh. How strong of an indicator is this particular section of harness? Can I assume that the rest is in good condition? I am particularity interested in the health of the harness due to the error codes :

12 Heated oxygen sensor heater circuit open or circuit short
21 Purge switchover valve circuit open or circuit short
26 Upshift delay faulty

Any help greatly appreciated this will help make my decision in repairing the car.

James

Kestas

From the pictures the harness looks fine. Can you look at the part number found on the tag on the wiring harness? This is located a foot or two from the bulkhead connector. IIRC, the replacement wiring harness on my model had a prefix "S" in front of the part number. The original had no prefix.

appatula

For those of you that have done this, what brand headgasket did you do the job with?

Is Victor Reinz considered a quality aftermarket gasketmaker??

jlostlen

Is the Bulkhead Connector the relay box? I looked around on that strand of wires I had opened up for the picture and wasnt able to find anything on them....

Quicksilver500

The labor is the killer on this job, I am doing it right now on my bro's car and its about 300 in parts and maybe another 125 for machine work. Give yourself another 150-200 in case you break some plastic/rubber stuff on the way through. Make sure you get a good machinist to do the head. This car has 155k on it and the tappets/lifters and cams are worn out. Don't know why, and don't know how, but its VERY unusual. Someone has been in there before and maybe they didn't put the timing chain back on right the first time around.....the tappets are beat to hell. I found a set of used tappets/lifter/cams for 400$, but list on the cams like like 900 each. So just be careful, sometimes it can be a bigger job than you think.

-Mike

helios16v

I would be comfortable w/ the Victor Rienz gasket set. I installed their head gasket sets on both my GLi and Rabbit. They are actually an OE supplier for VW. I would be surprised if they didn't supply some of the gaskets for BMW and Mercedes as well.

landspeed124

Since we're on the topic, on either of the motors(m103, m104), do you need to replace the head bolts? I've done lots of reading and can't find a solid answer.

Saijin_Naib

I've read that the bolts are torqued so that once you remove them they are stripped and need replacing. Hey, even if I mis-read, it certainly won't hurt you (maybe your wallet a bit) to replace them anyway to be on the safe side.

rayhennig

My view is that it may be worth trying cheap parts when they are easy to get to if things go wrong. Surely, a head gasket is the exact opposite of that.

If you or someone else is going to go to all the effort of replacing the gasket, I'd want to make 100% sure it's the right part from the outset.

I did the reverse recently by installing a cheap Bremi rotor arm. After 18 months it failed and now there's a nice new MB one in there and all's well. But a rotor arm can be changed in 10 minutes, even by the roadside. Not so a head gasket.

Good luck to you but I think you're pushing your luck if you source a "cheap" head gasket.

All the best.

RayH

landspeed124

I'm not going cheap on the gasket. I just don't want to spend more money than I have to.

Kestas

I reused the head bolts when I changed the head gasket on my car. The manual says it's okay to reuse the bolts unless they've stretched beyond a certain length. All my head bolts were well under the discard limit. Once you've studied the stress-strain curve of steel in as much detail as I have, and learn how it applies to torque-to-yield bolts, you develop a lot of confidence in reusing the bolts. Others don't understand how they work and are a somewhat squeamish about reusing the bolts.