Engine started! w108 m117

[vandor]

A friend came over to help today and we got the engine running. Amazingly it started after the second turn of the starter! After it started it was obvious that we have a vacuum leak because of a loud hissing noise. Turns out the injectors 6 & 7 did not seat correctly and there were huge vacuum leaks there.
I got them to seat, but I can still hear some hissing, so likely I will try a different type of seal (round instead of square cross-section).
I still need to adjust ignition timing and install the fan and the belts. Does anyone know if Dextron 6 is OK to use for the power steering?

Here is the video of the second startup after we fixed the vacuum leaks.
At the very beginning is the starter noise mentioned in the other thread:

72 Mercedes - YouTube

I am very excited that I will be able to drive it soon!

Csaba
72 280SEL 4.5

[Adv_rider]

Congratulations!

[Palolo]

Woo Hoo!

[Tomguy]

Awesome job! You must be quite happy

The vac leak is quite large by the sound so how's the intake plumbing? The connection to the throttle body, the rubber piece there; the twin tubes to the intake manifold - are they tight; the aux air system and its hoses - any cracks? Those are the major places. There's also the D-Jet MAP sensor, the door lock system, the brake booster, and the transmission modulator valve that all connect to the intake vac as well but other than the booster those wouldn't usually cause such a large hissing.

I am assuming, because it's in place, the air filter assembly is actually connected and has a filter. If not, there is likely your issue. The air filter assembly muffles a massive sucking sound from the throttle body

[DieselPaul]

Dex 6 is a pour in replacement for Dex 3 which is what the power steering takes. However Dex 6 is synthetic so if you're system is leaky like a lot of them it may leak more on dex 6.

[vandor]

Hi Tom,

I will check those areas, but most of it was by the injectors.
The idle air rubber hoses on top of the manifold are all new. The air filter was just set in place, it was not tightened down.

Paul, thanks for the info, I will try and find non-synthetic Dextron.

Csaba

[Graham]

Great to hear you got her running!

Bit puzzled by "Turns out the injectors 6 & 7 did not seat correctly and there were huge vacuum leaks there. I got them to seat, but I can still hear some hissing, so likely I will try a different type of seal (round instead of square cross-section)."

The proper seal for where the injector goes into the manifold is, according to manual part 116 078 04 73. So called top hat seals. I use those on my 72 M117.



There are the other kind used on some cars 116 078 07 73. (So called green seal)



These latter ones were apparently used on California models from engine # 019517
Federal models from engine # 026126.

[Tony H]

The massive sucking sound is coming from my wallet as I progress on my 5.6 project. I just called the machine shop that's holding my 4.5 block ransom again today. He promissed to have it done on Friday. He has had it more than 2 mos now.

Originally Posted by Tomguy

Awesome job! You must be quite happy
The air filter assembly muffles a massive sucking sound from the throttle body

[vandor]

I put the belts/fan/shroud on, sucked out the Dextron 6 from the PS reservoir, added Dextron 3, changed injector seals, adjusted ignition timing (set it to 0, will see how it does), let it idle for 10 minutes or so to be sure everything was good and then I went for a drive!
It runs well and runs strong! Since I am seating in the rings I did not go much past 1/3 throttle, but it seems to have plenty of power. I drove it around the neighborhood, probably a total of 10 miles.

Graham, I will get the proper seals, what was on there came from the injector rebuilder and was just a generic seal.

Tony, sounds about like my machine shop... took them ~6 weeks to get the heads done.
bye,

Csaba

[WANT '71 280SEL]

Great to hear, Csaba! As you've mentioned, now that it's drivable it would be great to compare your 108 to my 109. I'm curious to see the power difference as well since I'm not sure my car's running 100%.

Best of Luck,

David

[Graham]

Originally Posted by vandor

Graham, I will get the proper seals, what was on there came from the injector rebuilder and was just a generic seal.

Csaba

I included pictures when I posted about the seals - but for some reason they are not displaying. Here are links:

http://www.pelicanparts.com/cgi-bin/smart/imgdsply.cgi?pn=1160780473-M200
http://www.pelicanparts.com/cgi-bin/smart/imgdsply.cgi?pn=1160780773-M213

These don't open properly either - must be a problem with Pelicanparts site?

[Tomguy]

Originally Posted by Graham

I included pictures when I posted about the seals - but for some reason they are not displaying. Here are links:

http://www.pelicanparts.com/cgi-bin/smart/imgdsply.cgi?pn=1160780473-M200
http://www.pelicanparts.com/cgi-bin/smart/imgdsply.cgi?pn=1160780773-M213

These don't open properly either - must be a problem with Pelicanparts site?

Weird, they're loading fine for me? I've never seen that 2nd seal before. The 1st one is the correct D-Jet manifold seal for 3.5s and 4.5s.

[Adv_rider]

Originally Posted by Tomguy

Weird, they're loading fine for me? I've never seen that 2nd seal before. The 1st one is the correct D-Jet manifold seal for 3.5s and 4.5s.

The 2nd seems like the W116's

[alabbasi]

Odd the first seals look like they're for CIS injectors.

[Graham]

Originally Posted by alabbasi

Odd the first seals look like they're for CIS injectors.

Nope - those are the EFI seals used on all the early D-Jets.

For anyone interested, you can find the different types in the M117 shop manual - Sections 07.4.1 220/6 & 7 (near end)

PS: I see those pics now - Site must have been slow at loading them last night.