Head gasket jobs... DIY? Blee?

[FC]

I did my research and it seems these '94-'95 E320 wagons are damn near bullet-proof except for two items:

- The engine wire harness that runs ~$500 and

- The original poorly-designed head gasket

Both usually have to be changed at ~100k miles, which of course is the mileage the wagons I'm looking at have.

How tough is it to DIY a head gasket job? Assuming of course, that I would have the proper paperwork to follow? You'd think an I-6 engine would be fairly easy relatively speaking.

Thoughts?

[lip277]

The wiring issue with all mid-90's Mercedes' are not limited to the engine harness. ALL the wiring is suspect. Mercedes (sometime in the early 90's) got the green bug and stipulated that the wiring (insulation) had to be 'recycleable'. This was great except that the supplier they chose didn't do the durability/longevity testing adequately. This situation lasted till the late 90's.

The insulation starts flaking away as it ages. It becomes brittle and falls off. Yeah - Lovely. The engine area tends to show this more than other parts of the car as the heat and vibration cause failure sooner than in (for example) the rear door locks or the like.... I've heard of seats shorting out and moving in funny ways also. Maybe the radio might be intermittent. This issue shows up in all sorts of fun ways.

I've looked at some SL's of that generation and (if I was to get one) would factor the cost of replacing ALL the wiring in the purchase price. As I recall, the engine harness is about $900 for the V8 (via mail order).

Head gasket - Be careful..... Mercedes has a habit of making special tools necessary for many 'simple' issues nowadays.... I'm not sure about the car you're looking at.
Check out http://www.mercedesshop.com/ or http://forums.mbworld.org/forums/index.php or http://www.mbnz.org/forums/

Good luck.

[FC]

The wiring issue with all mid-90's Mercedes' are not limited to the engine harness. ALL the wiring is suspect. Mercedes (sometime in the early 90's) got the green bug and stipulated that the wiring (insulation) had to be 'recycleable'. This was great except that the supplier they chose didn't do the durability/longevity testing adequately. This situation lasted till the late 90's.

The insulation starts flaking away as it ages. It becomes brittle and falls off. Yeah - Lovely. The engine area tends to show this more than other parts of the car as the heat and vibration cause failure sooner than in (for example) the rear door locks or the like.... I've heard of seats shorting out and moving in funny ways also. Maybe the radio might be intermittent. This issue shows up in all sorts of fun ways.

I've looked at some SL's of that generation and (if I was to get one) would factor the cost of replacing ALL the wiring in the purchase price. As I recall, the engine harness is about $900 for the V8 (via mail order).

Head gasket - Be careful..... Mercedes has a habit of making special tools necessary for many 'simple' issues nowadays.... I'm not sure about the car you're looking at.
Check out http://www.mercedesshop.com/ or http://forums.mbworld.org/forums/index.php or http://www.mbnz.org/forums/

Good luck.

Well, shit. You just scared the crap out of me. ALL wiring? I mean, it makes perfect sense, and I believe you, it just seems a bit excessive to have to do all that. Then again, if it is required, then it is required.

As far as the head gasket stuff, yeah I remember having to use a special tool to do the vale stem seals on my 190E, but aside from compressing the springs, what else is really tricky?

Of course, I could pay for the dealership to do it, but if I can avoid $1500 in labor, then that would be best. Another option is to look for 89-92 300TE's, but I'm afraid they will just be too old.

Thanks for the help man. ;)

[lip277]

Just remember.....

I said "suspect" - Not "discrepant"

It may be fine. It may not. But.... you really don't know till you get a look at the car. I do not know if there is a 'lifetime' to getting problems or not....
Meaning if you have a car of a certain age and it does not have any discrepancies in the wiring... That you are likely OK?

I've never been into this situation enough to warrant finding out.

I still lurk around several Benz Boards and I'll keep my ears open....

[blee]

Can't help you much on the wiring thing, except to say that wiring harnesses can be a little tricky to replace without pulling out things like the engine. It's not a difficult thing to do, though -- A goes into B, C goes into D, etc. Some connectors probably fit at least one other connector on the engine, so you would just need to take your time. Maybe a lot of time.

As for head gaskets, the process itself is not difficult. There's a fair amount of disassembly required, though, and you may need one or two special tools (but not necessarily -- the S14 doesn't need anything more special than a Torx socket, except to re-adjust the valves after putting everything back together). OHC engines will require camshaft removal, which means you'll be temporarily taking the timing chain or belt off of the gears. Just be careful when you put it all back together. The typical procedure is to have the engine at TDC before you start your work. You'll also want a service manual with the correct torque values for the head, camshafts, etc. The manual will probably also give you the torquing order for the head bolts. These are both good things.

Other than that and the head gasket itself, everything else you need is available at your local parts shop. You might need a drop or two of silicone goop, depending on the manual's recommendations (not on the gasket itself, but sometimes there are areas where two metal parts mate that need a drop), and you may need or want some assembly lube to prevent anything from grinding on first start-up. Doing the head gasket is kind of fun because you get to see the pistons up close and personal. It's time consuming, but you'd spend a lot of money to get it done at a shop, so why not do it yourself and learn a thing or two?

[FC]

Can't help you much on the wiring thing, except to say that wiring harnesses can be a little tricky to replace without pulling out things like the engine. It's not a difficult thing to do, though -- A goes into B, C goes into D, etc. Some connectors probably fit at least one other connector on the engine, so you would just need to take your time. Maybe a lot of time.

As for head gaskets, the process itself is not difficult. There's a fair amount of disassembly required, though, and you may need one or two special tools (but not necessarily -- the S14 doesn't need anything more special than a Torx socket, except to re-adjust the valves after putting everything back together). OHC engines will require camshaft removal, which means you'll be temporarily taking the timing chain or belt off of the gears. Just be careful when you put it all back together. The typical procedure is to have the engine at TDC before you start your work. You'll also want a service manual with the correct torque values for the head, camshafts, etc. The manual will probably also give you the torquing order for the head bolts. These are both good things.

Other than that and the head gasket itself, everything else you need is available at your local parts shop. You might need a drop or two of silicone goop, depending on the manual's recommendations (not on the gasket itself, but sometimes there are areas where two metal parts mate that need a drop), and you may need or want some assembly lube to prevent anything from grinding on first start-up. Doing the head gasket is kind of fun because you get to see the pistons up close and personal. It's time consuming, but you'd spend a lot of money to get it done at a shop, so why not do it yourself and learn a thing or two?

Re: harness... apparently most machanics require 2-3 hours. I figure a whole day for me.

Re: head gasket... I have the patience and intuition to do the job. I also should have the time. I'd like a buddy to help along (at least for moral support), but unfortunately my best friend lives too far away.

On the plus side, my 190E is officially no longer being driven as of today. The engine was about to overheat today. The little coolant leak has developed into something more serious. Not to say it could not be fixed, but I am done with it.

I have the distinct feeling that I could get more out of it for parts than selling it whole, so I may do that and take to opportunity to take the engine apart and learn from it for when I do the head gasket job on the wagon (same engine, different head).

Just thinking...

[blee]

If you plan to take apart the 190, definitely pick up a shop manual and follow the head removal procedure. I did it for the first time on my S14, but it's probably a safer bet to do it to something non-critical first.

Also recommend parking the 190 in a location where a heap of metal won't be an issue. If you have a large garage, consider buying a set of car dollies to push the car around when needed.

[FC]

If you plan to take apart the 190, definitely pick up a shop manual and follow the head removal procedure. I did it for the first time on my S14, but it's probably a safer bet to do it to something non-critical first.

Also recommend parking the 190 in a location where a heap of metal won't be an issue. If you have a large garage, consider buying a set of car dollies to push the car around when needed.

I have a 3rd car garage/carport where I currently keep my snowblower, but when winter is over I can keep the 190E in there and put the blower in the empty tool shed. Parting out the car also has the potential benefit of having spare parts for the E320. I'd have to figure out how to get rid of the carcass though. That could be a problem. We'll see.

Thanks.

[lip277]

FYI-
Manuals are only available from Mercedes on CD-ROM. You may find an old paper one on e-bay or something, but.... you never know.

Also - On the manuals. The paper ones are seperate for the engine, chassis, trans, AC. Yep They were pricey when available as well. $40-$80 each.

I have a set for my 420SEL, but..... nothing else.

If you want help on finding a manual (paper or CD ) just drop me a line.

Good luck-

[FC]

**Double post**

[FC]

FYI-
Manuals are only available from Mercedes on CD-ROM. You may find an old paper one on e-bay or something, but.... you never know.

Also - On the manuals. The paper ones are seperate for the engine, chassis, trans, AC. Yep They were pricey when available as well. $40-$80 each.

I have a set for my 420SEL, but..... nothing else.

If you want help on finding a manual (paper or CD ) just drop me a line.

Good luck-

I have the CD for my 190E and there is a guy that could provide a CD for the E320. But if that fails, I'll let you know. Thanks!

[FC]

I found this great article about the head gasket job in question. It also mentions the dreaded flaiking harness.

There is some stuff I don't understand, but overall I can follow it.

http://www.continentalimports.com/ser_ic100345.html

[lip277]

That is a VERY good article/guide. While it's not the same as having a full blown step by step process, it really gives a good look at some issues.

The pic of the wiring is spot on. The insulation just crumbles away from the conductor. Ugly ugly issue if you need to replace one. The costs of going 'green' can sometimes bite.

Good luck

[FC]

That is a VERY good article/guide. While it's not the same as having a full blown step by step process, it really gives a good look at some issues.

The pic of the wiring is spot on. The insulation just crumbles away from the conductor. Ugly ugly issue if you need to replace one. The costs of going 'green' can sometimes bite.

Good luck

Thanks.

I'm still not completely sold on whether getting this wagon is the right thing to do. But if I do get it AND I chose to do the job my self, rest assured I would not just rely on this article. I'd get all the documentation I could get a hold of. Bentley manuals, service CD, etc.

[blee]

Looks like a good write-up. Again, not all that difficult in concept or execution, but it can be a pain. On a side note, those wires look horrible! If it weren't for planned obsolescence, we'd hear a lot more about this kind of problem.

[lip277]

On a side note, those wires look horrible! If it weren't for planned obsolescence, we'd hear a lot more about this kind of problem.

You hear plenty about it in the Mercedes forums and MBCA get-to-gethers.....

Just like we talk of exploding E46 (M3) engines and i-drive here..... :D