Author Topic: Doing 6.9 head gaskets soon, please offer advice/tips/etc  (Read 7167 times)

3l33ter

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Re: Doing 6.9 head gaskets soon, please offer advice/tips/etc
« Reply #15 on: 27 November 2014, 01:03 AM »
There is only 1 bolt remaining for the upper intake. I can get the intake to wiggle, but it won't come up off of the headless bolt.

Hopefully this weekend I'll get a chance to go back to it and extract that demon bolt.
'75 280S
'77 6.9
'82 300TD

3l33ter

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Re: Doing 6.9 head gaskets soon, please offer advice/tips/etc
« Reply #16 on: 08 December 2014, 01:26 AM »
I tried a bolt extractor, and the tip just broke off. Yikes, that had me seriously worried. But I managed to pry the intake up off of the bolt with lots of wiggling and some penetrating oil. The corrosion around that bolt was so bad, it was holding the intake firmly.

Then I spent 2 sessions of about 3 hours trying to figure out how the hell to lift the intake out. It just didn't want to come off. Finally I realized that the EGR pipe was getting hooked under a protrusion of the driver side head. I had to unbolt a small clamp which anchors the EGR pipe to the rear of the intake manifold, which helped very little, but enough for me to tug the pipe around the obstacle. Then I removed the driver side valve cover, to give the EGR pipe more room. And after a whole lot of wrestling, the intake finally came off.

I still have to deal with the broken bolt. With the intake off, I cut off about a centimeter of the bolt so that the screw extractor remnant is no longer there. I think I'll try welding on a nut next.
'75 280S
'77 6.9
'82 300TD

marku

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Re: Doing 6.9 head gaskets soon, please offer advice/tips/etc
« Reply #17 on: 09 December 2014, 10:29 AM »
Welding a nut or another bolt to it if it is too near usually works as the heat frees it up. I broke off an extractor in a stud that had sheared off in the head. Took it to a friendly workshop who said that the broken extractor couldn't be welded but they knew someone who had a spark eroder. This took out the tip of the extractor allowing a bolt to be welded to the stub which they did even though it was inside the head.
450SE silver green/bamboo velour/green vinyl roof
Mercedes Viano Ambiente 2.2CDI LWB

3l33ter

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Re: Doing 6.9 head gaskets soon, please offer advice/tips/etc
« Reply #18 on: 12 December 2014, 05:14 PM »
I want to take off the brake booster now. I can't find the relevant information in the workshop manual PDFs. I have the haynes and chilton books for the w116 at home, but if anyone has any tips, I'm all ears! :)

I'm also going to paint it while it's out. I've heard a w126 booster can be used - is it an upgrade? Should I get one?
'75 280S
'77 6.9
'82 300TD

TJ 450

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Re: Doing 6.9 head gaskets soon, please offer advice/tips/etc
« Reply #19 on: 13 December 2014, 09:15 PM »
Four nuts on the inside, and the one bolt where the brake pedal attaches. You can leave the master cylinder attached, and it is a very tight fit in there... a bit of brute force is needed to jam it up past the strut tower.

There is also supposed to be a seal where it attaches to the firewall.

Tim
1976 450SEL 6.9 1432
1969 300SEL 6.3 1394

3l33ter

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Re: Doing 6.9 head gaskets soon, please offer advice/tips/etc
« Reply #20 on: 02 January 2015, 02:49 AM »
The driver side head can be removed without removing the brake booster, and without jacking the engine to tip it over. The only bolt which poses a problem is the rear top corner one, or #18 in the WSM (the larger one holding the rearmost cam bearing tower).

All you need to do is use a short 10mm allen socket to unscrew the bolt, pull it out a couple of inches, and use tape or something to hold it from falling back in (I used a small magnet). Then undo the cam oil tube, and remove the camshaft including all bearing towers except for the rear one which can't come off. Now simply remove the head with the rear cam bearing tower and single bolt.

*Don't forget to put that rear bearing tower and long bolt back in BEFORE mounting the head!

Honestly, the SLS was more of a problem for me. The brake booster was basically a non-issue.

Now, I have to get these heads ready for the machinist, and strip down all the parts that are to be cleaned in the solvent tank.
« Last Edit: 02 January 2015, 02:55 AM by 3l33ter »
'75 280S
'77 6.9
'82 300TD

3l33ter

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Re: Doing 6.9 head gaskets soon, please offer advice/tips/etc
« Reply #21 on: 02 January 2015, 02:53 AM »
I also want to note that the special tool for the head bolts is necessary after all. The job can't be done without it (well, maybe disassembly). I'm going to make one myself - I'm good at fabbing and I usually make my own special tools.
'75 280S
'77 6.9
'82 300TD

oversize

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Re: Doing 6.9 head gaskets soon, please offer advice/tips/etc
« Reply #22 on: 03 January 2015, 03:19 AM »
I still think it's easier to pull the whole engine....
1979 6.9 #5541 (Red Bull)
1978 6.9 #4248 (Skye)
1979 6.9 #3686 (Moby Dick)
1978 6.9 #1776 (Dora)
1977 450SEL #7010 white -P
1975 450SEL #8414 gold -P

3l33ter

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Re: Doing 6.9 head gaskets soon, please offer advice/tips/etc
« Reply #23 on: 07 January 2015, 03:07 AM »
Well, now that the heads are off, looking back, it wasn't that bad of a job. Even with the nightmare of figuring out the EGR pipe, I'm glad I didn't take the whole engine out.

I got the broken bolt out by welding on a nut. I also had 1 broken exhaust stud which came out easily with an extractor.
'75 280S
'77 6.9
'82 300TD

3l33ter

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Re: Doing 6.9 head gaskets soon, please offer advice/tips/etc
« Reply #24 on: 07 January 2015, 10:51 PM »
I don't know where to get a parts catalog for Mercedes. I had to make a trip to the dealer, but the parts guy was super helpful. I got a list of all the parts we thought I'd need for this job. I wanted to list them here in case it ever helps anyone.

100 016 28 20 - head gasket
100 016 29 20   - head gasket
000 997 05 98   - chain link
000 997 79 94   - roller chain
100 052 01 16   - slide rail
100 052 02 16   - slide rail
115 052 07 16   - slide rail
116 050 27 16   - sliding rail
100 050 01 15   - tension lever
100 050 05 11   - chain tightener
115 050 00 67   - valve stem seal kit (kit of 8 )
100 050 49 24   - valve guide intake
100 050 56 24   - valve guide exhaust
100 016 12 21   - valve cover gasket
100 016 11 21   - valve cover gasket
100 140 04 65   - intake manifold connector (upper to lower)
100 141 16 80   - manifold gasket
100 141 17 80   - manifold gasket
'75 280S
'77 6.9
'82 300TD

3l33ter

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Re: Doing 6.9 head gaskets soon, please offer advice/tips/etc
« Reply #25 on: 13 January 2015, 07:03 PM »
My machinist says one of my exhaust valves is cracked. Yikes!

So I'll make a stop at the dealer tomorrow to see if they can even get one for me, and how much it would cost. But if anyone has any leads I'd appreciate it.
'75 280S
'77 6.9
'82 300TD

oversize

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Re: Doing 6.9 head gaskets soon, please offer advice/tips/etc
« Reply #26 on: 14 January 2015, 05:14 AM »
Better to find that out now and have it fixed than the alternatives!
1979 6.9 #5541 (Red Bull)
1978 6.9 #4248 (Skye)
1979 6.9 #3686 (Moby Dick)
1978 6.9 #1776 (Dora)
1977 450SEL #7010 white -P
1975 450SEL #8414 gold -P

TJ 450

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Re: Doing 6.9 head gaskets soon, please offer advice/tips/etc
« Reply #27 on: 14 January 2015, 10:05 AM »
Your best bet is to contact the Classic Center for the parts if you must go genuine.

Tim
1976 450SEL 6.9 1432
1969 300SEL 6.3 1394

ptashek

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Re: Doing 6.9 head gaskets soon, please offer advice/tips/etc
« Reply #28 on: 14 January 2015, 12:01 PM »
I don't know where to get a parts catalog for Mercedes.

If you're willing to pay a, relatively small, yearly subscription: http://service-parts.mercedes-benz.com/ (it's a legit Mercedes service)
In Europe it's 20EUR/year + tax. Well worth it if you're planning to buy a good deal of parts.
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1979 "Icon Gold" W116 450SE (history, resto)
1977 "Milan Brown" W116 350SE (parted out)

3l33ter

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Re: Doing 6.9 head gaskets soon, please offer advice/tips/etc
« Reply #29 on: 10 March 2015, 12:02 AM »
OK, I can't believe 2 months have gone by, but now I have some time to resume this project. I bought a genuine NOS valve, and 16 aftermarket valve guides from SI Valves. The heads are at a shop getting welded, then they'll go back to my machinist to get worked on.

In the mean time, I'd better clean the block surface. I also need to order the parts for the chain job. Wallet, brace yourself!
'75 280S
'77 6.9
'82 300TD