Head gasket/valve job 103 engine
 

Finally, I been putting this off for a while but, I think I am ready (I think) now to take a big jump and remove the head myself, in the next couple of weeks, and then send it to a machinist for a valve job.
I have the CD and read quite a few posts on this job. However, I need to double check on the parts needed. So far I came up with this list:
- Cylinder head gasket kit. Do I need all that or individual pieces?
- Cylinder head bolts X14? What size is the twelve point socket?
-Time chain tensioner. Necessary?
- Timing guide rail (inner). Maybe...
- Timing guide rail (outer). Maybe...
- Timing guide rail @ tensioner. Maybe...
- Bypass hose, since I am already there.
- Sealant front cover 002 989 73 20 10 (loctite5900)
- Sealant "U" gasket 001 989 89 20 10
- I know I need a 6 mm? bolt to extract the guide rail pin.

I already have the valve cover gasket. I am planning to leave the intake manifold in place. I have a good number of tools but, I am wondering if I need any "flex" sockets/extensions or any special tools.
Any tips an/or missing anything?
Thanks!

12mm(?) double hex for the cylinder head bolts. I got a 4 piece tip set from Pep Boys for ~$10. The tips fit in a 1/2" socket. If you plan to get a 603 engine, you'll have the 10mm(?) tip for that too.

If the head gasket set is more expensive than the head gasket and manifold gaskets, then just get the pieces. The exhaust manifold gasket is 5 of one shape of gasket and 1 of another shape of gasket.

There's a hose from the idle valve to the intake manifold that's a PITA to replace with the engine in place. It's much easier to get to with the head and/or intake manifold out of the car.

How old are the distributor pieces?

How old is the water pump?

Sixto
95 S420
91 300SE
87 300SDL
83 300SD

Will the shop take care of R&R'ing the valve springs and fitting new valve stem seals?

Sixto
95 S420
91 300SE
87 300SDL
83 300SD

Early era Benzmac info. You may have seen.

http://www.peachparts.com/shopforum/tech-help/4000-300e-valve-job.html?highlight=valve+job

http://www.peachparts.com/shopforum/tech-help/4674-1987-260e-valve-job.html?highlight=valve+job

Thanks for the replies!
 

Sixto,
I'd seen the 4 tip set at Pep Boys but I was not sure if that was going to work...Did you use that with success?
The distributor was replaced within the last six months and the water pump is about 3 years old. Injectors are about 1.5 years old.
As far as the shop taking care of new valve stem seals and valve springs. Yes, to the stem seals. I am not sure about the springs. However, I want them to do as much as they can (instead of me) while the head is out. I will inquire more when I take the head in.
The machine shop is recommended by a local VW dealership where they also work on MB and BMW. So they know what they are doing.
I talked to them in the past and the first thing they told me is: "You will need valve stem seals" (based on milage alone). I have around 250K.
Keep it coming...

The Pep Boys tips work fine. I've used them on the 603 and 103. I can't see spending more for dedicated sockets.

You might dip the tip of a rag in the bolt heads to soak up the oil otherwise the double hex tool might not sit properly in the bolt head. If the expensive tools have a hollow bit then that'll save a step. Still not worth more money to me.

Sixto
95 S420
91 300SE
87 300SDL
83 300SD

JH - the cylinder head job is a piece of cake compared to removing/replacing a dashboard. In my opinion.

J,

When did you plan on doing the work? Drop me a line and I'll help out as much as possible.

Btw, I need to return your a/c manual.

Jim,
I HOPE it is easier than the dashboard.:eek:
David,
I am planing to remove the head the first/second weekend of July. Are you going to be available? I will let you know for sure. Remember, two heads are better than one. No pund intended!;)

Any other advice?

JH,
Just got mine back from the machine shop today (Friday).

Here is the itemized bill:

valve job w/cam.....125.00
pressure check........35.00
mill........................37.50
install guides...........72.00
rmv broken bracket.....n/c

This came back with the lifters/cam installed and the lifters bled.
The guy who actually did the work had already gone for the day, but a couple of other guys at the shop said the valve guides were shot.

You do need a 12mm double square socket to remove the head bolts. I ordered mine from Snap-On, but someone posted that Autozone has them. (save you about $15)

Sixto is right about removing the oil from inside the bolt heads. Put a plastic straw in a can of carb cleaner, and shoot some in the bolt heads. It will dilute some of the built-up crud and make soaking up the surplus oil easier.
I did get a 24" breaker bar from Autozone, and it made removal a breeze. Hope it does the same on double 90 angle torques.

I got the guide pin out with a 2" 6mm bolt, a washer, and a socket (smaller, maybe 10mm)
If you have any difficulty getting the rotor bracket out, cut it off before you crunch the orange plastic disc behind it. Bracket is about $23. orange disk is $60.
The guy at the machine shop did tell me several times I was not the first person to bring one in with the rotor bracket broken. And he took the broken one off at no charge.

If any exhaust manifold studs come off with the nuts, put them back on the head. The machine shop will clean them nicely. If you leave them on the shop floor, you will have to get the nuts off, try to remove the rust, and then reinstall.

I got 316 stainless nuts for reinstallation, and wanted matching studs, but I did not plan ahead, and at 4:30 on Firday, this was not happening. As a point of reference, the guy at Capitol City Bolt 'n Screw ID's the nuts as silicone bronze. He did not have any of that material, though, which explains the stainless.

I took SteveB's advise to heart, and got a gasket set from MB. Even though I already had an intake gasket.
It includes such things as the o-ring for the heater pipe from the water pump.
I also got new head bolts. You might take one out and measure to see if it is less than (I think) 108mm. If so, you should be able to reuse yours.

Any timing rail or guide replacement will require removal of the lower timing cover, which will probably add close to another day of work. Since I got the head off without breaking anything, I am leaving the guides alone. The sprocket looks fine, and the chain did not show any signs of wear on the links I can see.

I am using locktite 5900 for all resealing on the timing cover.
I also am taking a clean engine compartment opportunity to replace the water pump, all the hoses, belt tensioner, belt, motor mount bracket (mount seems ok at around 30mm height) and clean all the ground points.

Sharpie now makes a silver ink permananent marker, which is great for marking the cam sprocket and chain links after they have turned dark from oil.

I left the intake on because 1) there were only two bolts to remove from underneath, and 2) I need to replace the motor mount bracket, water pump, and belt tensioner, all of which is easier with the intake out of the way. I think the ease of leaving the intake in the car depends on how far you get the car off the ground.

Thanks Zhandax,
 

Great info!:D
Did you take the head to the shop with the cam still on the head? and, do you have any pictures before and after? I would love to see those...

A tip that I picked up before I pulled my head:
 

Buy some ziplock plastic baggies to put nuts/bolts/small parts in and label the bag, to know exactly where each part goes when it's time to re-assemble. Don't rely on your memory, you'll be overwhelmed with nuts & bolts & brackets! :D

Feel free to email me as well JH, as you go along.

I'll also add more tips to this thread as I remember them.

G'luck

Thanks Paul,
 

I remember your offered some tips last year. I may need them...
Keep it coming!

I use the black Sharpie to mark on the plastic zip baggies what the fasteners/brackets are for. Also, use the digital camera and take shots of where the different size studs, etc.. go prior to disassembly.

JH,
I took it to the shop just like it came out. I did remember to remove the spark plugs. The shop said they would return it at any stage of reassembly I wanted. I had them put it all back together. They even bled the lifters. He indicated the car might not start until this was done. Saves me yet another learning curve.

I remembered another Autozone bargain you will need. They have a 3 piece hex socket set with (I think) a 12mm, 14mm and 17mm. The 17mm will remove the timing chain tensioner cap, and the 14mm will remove the threaded ring inside.

Here is a before pic. I will take some 'after' shots and post them Sunday night.

Here is an after pic.

I have a new water pump, new belt tensioner assembly, new motor mount, new motor mount bracket, the head is in and the bolts are finger tight.
That is it for this pilgrim for a short weekend.

While it is fresh, if you use a chain hoist, angle the rear of the head down when you lower it. Will keep you from breaking the chain guide, and the rear hoist ring will get in the way if you do not. Also, put the bypass hose all the way on the head, then slide it over the water pump spout and put the hose clamps on afterward.

Also, if you get the head assembled by the machine shop and it is not on TDC, there are two unused, unthreaded holes on the cam sprocket pully. Put undersize bolts in them and use a screwdriver to turn the cam to TDC.

Bon chance, off to bed.

Zhandax,
 

I am glad everything is working out for you!
A few of more questions while they are fresh:
1. What was the turn around from the machine shop?
2. How long is the guide rail pin?
3. I understand there are two different sealers for the upper timing chain cover. One for the actual cover and one for the "u" seal. Did you get just the 5900?and from where?
4. I am not clear if you left the intake manifold on the engine or on the head. I guess you got the bolts from underneath with what? extension...13 mm socket?
I bought a 24" breaker bar, the 12 point "star" from Pepboys.
Sorry for all the questions but, it is getting close.
I will keep you guys posted...

2) About an inch.

Sixto
95 S420
91 300SE
87 300SDL
83 300SD

JH,
Poor planning on my part, I took it in on Monday, and really did not need it until Friday, and simply asked if he could get to it that week. When I picked it up, I overheard one of the guys tell a customer on the phone if it came in by Monday, they typically had it ready by Wednedsay. Would have saved me a 200 mile round trip if I could have picked it up on the way to work Thursday.

Without measuring, the guide pin looks like about an inch.

Someone posted a rather detailed description of the various part numbers of sealers. If they did not explicitly state, it sure sounded like the 5900 would pretty much work for the whole job. That is all I bought. I will double check before I install it, but it seems you want to avoid getting sealer on the U-seal. I seem to recall Larry Bible having a post I want to re-read about the details of installing the U-seal.

I left the intake on the head during removal and reattached it prior to reinstallation. Since I needed to replace the motor mount bracket, motor mount, water pump and belt tensioner, it seemed easier to have the intake out of the way. Also, only the two intake support bolts must be removed if the intake stays with the head. I reached them with about 15" of extensions and an impact wrench.

You will be really happy you got that 24" breaker bar. Given the choice, I would probably take it over an impact wrench.
I did remove the exhaust manifolds prior to removal of the head.

Zhandax,
 

When are you putting the head back on? I will be all ears, well...eyes:eek: , to hear (see) the outcome of your project. I am planing to remove the head on the 5th July. I may help from a fellow poster here, otherwise, I am on my own...
I do not have an impact wrench. Hopefully, I won't need it.
BTW, I was thinking about sending you a PM but, after I saw the number of hit on this threat, 365 right now, I will keep it open for other posters to see the outcome.
Peace!

The sealant you need and some advice.
 

I personally use Loctite 5999 and not 5900. I have access to the 5999 and checked the data sheet for both and they are the same thing. It is by far the best sealant I have yet to see to block oil and water at low and high temperature. Check the website for "Loctite" and locate a dealer that sell it. The one I have looks like one of those silcon tubes you buy at Wal-mart.
When you pull the cylinderhead in your car, DO NOT BREAK THE GUIDE RAIL THAT HAS THE PRESSED PIN. Be extra extra carful otherwise you just added another week of work to remove the lower cover.
You can easily remove the head keeping both manifolds in the car. It is a hell of alot easier job to leave them in the car. Push the intake back with you hand 1/2 inch and that's all you need to seperate it fom the head. Good luck
Meza
93 190e 2.6L

Re: The sealant you need and some advice.
 

It's a hell of a lot easier than what? Pulling the head with the manifolds isn't difficult.

Tastes great! Less filling! Tastes great! Less filling! ...

Sixto
95 S420
91 300SE
87 300SDL
83 300SD

Technically, the head is on , but the bolts are just finger tight. The eastern sky was getting light, and I put the bolts in to keep the holes clean (insects, condensation, etc) more than anything else. I had shot carb cleaner in the holes to clean them out and then blew them out with compressed air.

This brings up a question. Normally there would be some oil in the bolt holes. Since mine are clean, would I be better off putting some oil on the threads to ease torquing, or put anti-sieze on the threads? I guess I will still put oil on the washers.

A couple of other notes; I went out and looked at the tube, and I got my 5900 from Mercedes. I just asked for the part number I saw in the post here I mentioned last night. It is in a syringe about 1.5" dia, and about 6 inches long.

I also got a replacement chain guide pin. The bolt stuck in the pin, and I was concerned holding it with vice grips to remove the bolt might mar the surface. Another pin was maybe a buck, so I got the replacement.

Also, Butch, who does the head work for Erol's in Nashville (legendary local independent) , showed me a great gadget for cleaning the top of the block. 3M makes it and it is called Rolok or Rolox. He recommended the green version. The only place I found that knew about them on Saturday was out of stock. You may have to call the Jax 3M distributor during the week.

If you will ONLY remove the head, you may as well leave the manifolds in the car. That said, if you intend to replace the water pump in the next 100k miles, you might prefer to do it with the intake out. If you think you might replace the driver's side motor mount, it is far easier with the intake out.

On that topic, one last question...the driver's side motor mount went fine. However, on the passenger side, I stripped the bottom hex cap screw trying to remove it. Absent a better suggestion, I will drill the head off.
Does anyone know the dia, length, and pitch of this bolt so I can get a replacement tomorrow?

Zhandax,
 

As far as the bolts, I think I read in the MB CD that the bolts were updated. The new bolts do not have/need washers. I may have misread it. I will double check/read that portion.
An extra chain guide pin is a great idea. The water pump is fairly new so, I do not plan to change any accessories (I hope).
On other news, I talked to the machine shop today. They are expecting the head on Monday and, they will take the whole head and dis/assemble for me. Two days turn around, unless the have to order parts.
Will continue...

I found it!
 

Read job 01-4050 "Checking, tightening cylinder head bolts."

The updated bolts (M12X102 mm) have no washers.

You shouldn't oil up the threads on bolts that need a torque spec...the oil will cause a misread in the torquing, and can allow the bolts to loosen up.

conversekidz is right..
 

Last weekend 70 miles after I put the head back on my 190e 2.6L, water mixed with oil and I narrowed it down to bad torquing because of the oil I put on the bolts.
Meza
:eek:

Section 01-415 step 28 says "Oil the thread of the cylinder head bolts and also the contact surface of the bolt head and insert." Then 70Nm, 90-degrees, 90-degrees.

Did you use a tap to clean the bolt hole threads in the block? Did you blow out the bolt holes to make sure there was nothing left inside?

Sixto
95 S420
91 300SE
87 300SDL
83 300SD

if you are going to use anything, I would only use assembly lube, and not common motor oil.

JH,
If the new style bolts do not require washers, logic would dictate they would be shorter by the thickness of the washer. If the new ones are about 5mm shorter than 105mm, I should omit the washers to insure the same thread depth and bolt stretch. I will measure them tomorrow, but does this sound about right?

The other question; what is the practical difference in assembly lube and anti-sieze compound?

The new bolts are 102 mm...
 

and the head looks as if it already had a washer built in...
If you still have the old ones, just compare the two of them.

For Sixto and Zhandax,
 

I did not see job 01-415 step 28 but, "01-4150 Removing and installing cylinder head" has only 26 steps. Step 25 refer you to job 01-4050 which, was discussed earlier. Also, in that job #, the tightening torques in Nm are:
1st Stage 55 Nm (NOT 70)
2nd Stage 90 degrees tightening angle
3rd Stage 90 degrees tightening angle
Are we looking at the same thing/vehicles?:confused:

I forgot to mention that I'm looking at the M103 section of the W126 manual. Covers the 88-91 300SE/L.

Good thing you're alert.

Sixto
95 S420
91 300SE
87 300SDL
83 300SD

A minor omission that could have been BAAAAAAD!
 

Keep it coming!:D

W124 01-4050 does say 55Nm and does say to oil the threads and contact surfaces.

Sixto
95 S420
91 300SE
87 300SDL
83 300SD

Yeap!
 

Now we are talking!:D

Also says that the cylinder head won't form a perfect seal of the cooling system until the engine reaches operating temperature. Maybe Meza should change the oil and coolant and give it a second chance. No mention in the W126 CD manual.

Sixto
95 S420
91 300SE
87 300SDL
83 300SD

Update:
 

I started today with the "light" work. I drained the oil and coolant. I removed the all the front accessories (belt, fan, rotor) down to the camshaft sprocket. I did not remove the chain tensioner yet nor the guide rail pin. I 'd loosen all the intake and exhaust manifold bolts. I will continue tomorrow morning. Hopefully David, a fellow poster from this forum can help me out with the "heavy" stuff.
No problems so far. The only problem I see now is the 6mm bolt I have to remove the guide rail pin seems too short (40 mm?). I may need a longer one or get a miniature puller.
The second problem is, the guide rail is too close to the head and since I do'nt have an engine hoist. I'm afraid that I may break the rail while removing the head. Any tips on how to do it?
My digital camera is broken so I may just take regular pictures and post at a later day.

Happy 4th of July!

I just did my 103 head gasket last weekend and the only special tool needed was the headbolt socket , also a 17 mm hex for the inner part of the chaintensioner (the 17 mm didn't come with any set I could find for cheap ) . The shorter bolt will probably work , mine just kind of screwed itself out and I did damage the pin with vise grips trying to get the bolt out . I touched it up with a little emory cloth and it tapped in just fine. To lift the head I screwed a 2X8 across a couple of trusses in the ceiling of my garage and attached an eyebolt to it and rigged a 6-part rope pulley to it . Just to double-check the strength of my 'crane' I put my full weight on it and nothing happened :eek: ,it handled the 30-40 pound head no problem.To lift the head (without manifolds) I used the factory lifting eye at the rear and a front cover bolt in the lower lefthand bolthole , instead of a chain I used a 3/8" nylon rope (SWL 700 lbs)to take advantage of it's energy. After everything was unbolted the only thing keeping the head from coming straight up was the stud in the center of the intake , I put some tension on the crane until the sling was stretching,wiggled the head a little and it was free. I landed it on top of the fuel distributor and rad support (cushioned with a wad of rags to protect the valves) and then lifted it from there onto the bench.It went back on in the same manner , hooking the stud back into the intake with tension and then lowering it down the rest of the way. Piece of cake :D NOT !
P.S. J.H. the guide rail is close but there is room , I paid $10Cdn for my rope hoist and it worked very slick , good luck.

Just flew in from Cleveland...
 

... and boy are my arms tired.

The 300SDL head bolt tightening spec is 15Nm, 35Nm, 90-deg, 90-deg. There's some discussion about the W124 M103 vs W126 M103 but since my W126 manual says 70Nm, 90-deg, 90-deg, that's what I did. Man, I was waiting for a head bolt or to two snap. No wonder there were a couple that were hell to break when I pulled the head. If you're going the 70Nm, 90-deg, 90-deg route instead of the W124 manual's 55Nm, 90-deg, 90-deg route, find a 36" breaker bar.

FWIW the OM603 has 26 head bolts to the M103's 14. The OM603 manual says to wait 10 mintues between 90-deg sets so I did the same on the M103.

I pulled the head with the manifolds. Made it easy to maneouver the head into place with a second pair of hands and no hoist (working outdoors). I forgot to install the new stubby coolant hose but it was easy to tilt the head to fit it. I might leave the exhaust manifold in the car if there is a next time since all the studs backed out with the nuts. Those precats make it hell to remove the downpipe flanges.

Sixto
95 S420
91 300SE
87 300SDL
83 300SD

JH,

Thanks for the heads-up on the new bolt style. Sure enough, mine were the new 102mm type. I took off the washers and so should have sufficient thread depth.
And I used 30w motor oil, rather than anti-seize, for reinstallation.

Sixto, I think the pause between the first and second set of 90° turns is for the mechanic, not the equipment. I had a beer and a cigarette between mine. Once again, JH will be happy he got the 24" breaker bar.

One thing you might want to check out...
According to both Haynes and Techbooks, the correct head bolt torque for the SOHC6 in round one is 70nm (52 ft/lbs). The 55nm torque is for the M104 engine. (even though the PDF shows up in the M103 folder on the CD).
I went with the majority, and torqued mine down to 52ft/lbs for the first round.

Also, unless you start before Home Depot opens, a block and tackle like Kyle describes will make the job a lot more pleasant, and a lot less risky to your guide rail. It is not the weight, it is the control.

For the guide pin, I think a 10mm 3/8 drive socket is what I used. With a washer, and thread room, I think I used a 55 or 60mm bolt.

Hi Zhandax, you're right about the control not the weight.It would be awkward to try reaching across the car and lift the head off . The block and tackle made it a no sweat, no visit to the chiropractor operation.

The head is out!
 

With the help of Neumann, we took the head out.
A couple of problems:
I had to buy a new T40 for the timing chain sprocket (wheel) since the one I had was just cheap and could not loose one of the bolts. I did not wanted to risk stripping it.
The next problem was the chain guide pin. The bolt that I had WAS short. I tried different ways to pull it out but, it did not come out. Finally, I ended up using that bolt and a socket with a few washers, praying that it would not break the chain rails. It did not and it come out.
To remove the head, I used David and my son (also David) holding a metal bar accross the engine and some nylon rope attached to the engine hooks. They pulled up while I manipulated the head. It worked!:D
The head is going to the machine shop on Monday. I will clean the engine tomorrow. The head NEEDS a valve job. It looks like it has never been opened before but, it does not look like it has a blown gasket.
The breaker bar made the removal of the bolts easy, maybe too easy. Now, what torque should I go for 55 Nm or 70 Nm? :confused:

and...
 

what do you use to clean the built up from the top of the pistons? I read the archives but it is not too clear. :confused:

My pistons cleaned up easily with light scraping with a blade, the kind you'd use to remove windshield stickers. The rest of the block cleaned up that easily as well.

Next thing would have been a toothbrush and carb cleaner.

Sixto
95 S420
91 300SE
87 300SDL
83 300SD

Sixto,
 

Did you clean the pistons when they were in up position? and did you have to turn the engine to get them up? I have the engine at TDC right now and I don't want break anything at this point. Specially with the timing chain still on.
Number 1 and 6 cylinder are in the up position...

It took some Rube Goldberg thinking for me to plan it. You can spin the crank twice to be back in phase with the cam although I suppose spinning the crank once does the same thing since there's no phasing of the crank. The Dieseler in me says to spin in 720-degree increments. If you marked the cam sprocket and a link you'll lose the relationship unless you know how many crank turns gets a link back to the same spot. You can't count links without turning the crank so math's not an option. It might be if you have access to a another chain. You can zip-tie the cam sprocket to the chain loose enough to let the chain flow but tight enough not to lose timing.

In the end it seemed like a lot of work so I used a vacuum to pick up what I scraped off with the 2-3-4-5 pistons lowered :) They're not spotless, but I must have knocked a point off the compression.

Sixto
95 S420
91 300SE
87 300SDL
83 300SD

I have used a plastic "scrubbie" like the ones used to clean teflon kitchen pots and pans. Won't scratch metal.

Haasman

Thanks Sixto,
 

I will clean as best as I can but, I will not spin the crank at all.:eek:
Tomorrow the head goes to the machine shop and the valve cover will get a powder coating. I am still debating if I should coat the exhaust manifold (similar to jet coat) in this place that is about 45 minutes from my house and, if it is worth it. I will investigate further tomorrow (Monday).
Wish me luck!:cool:

Update:
 

I received a call from the machine shop. They checked the head and there is no problems just normal wear and tear. It will be ready on wednesday (I hope).
I also took the valve cover to have it powder coated, it should be ready in 5 days (Friday).
I decided to coat the exhaust manifolds with Metallic Ceramic Coating. It is a small place about 45 minutes from my house. It is suppose to lower the temperature in the engine bay and it will not rust. They had some samplesof their work and they look GOOD.
I figured, with the money I am saving by DIY...I should invest that money in the rusted looking manifold while it is out. It should be ready by Friday also...I hope.:rolleyes:
On more thing, I talked to Phil, from PartsShop, and he said they don't sell the sealant anymore (something to do with the government. He recomended to go to NAPA.
I called local distributors of Loctite and nobody has 5900 in stock. I may end up buying from the stealership for $22, buy the "right stuff" from Pepboys, which I read some people used it with success or NAPA for a product Hylomar? as Phil suggested.
I will take some pictures and post when I am done (I hope).
Peace!