W116 6.9 vacum advance temperatur switch

[ramiro]

Hello,
As i am still not satisfied with my engine temp on the german highway i found the attached note in the manual.
It states that some cars had a valve to disable vacum advancing when the engine is hotter then 90 C , i find it very odd that there is no mention on which cars and for what reason , most likely to reduce engine temperature ?

I am pretty sure that when driving constantly at 180 - 200 kph the vacum advance is active because you need very little throttle input for that also i can see on my AFR gauge that the wot enrichment is also not active , it really only comes on above 220.

So maybe they only installed this valve on cars that were pushed and had complains ?

[Randys01]

The photo depicts a V8 with K jetronic..so that limits the scope.
The arrows point to the distributor  port that ordinarily connects to the vacuum valve on the firewall to increase the advance when the a/con is switched on.

I cannot see what the other arrow is indicating. I cannot read German so it's a bit hard !
but the gizmo /temp control sender seems unique.I've not come across this before.

Why they need to do this seems crazy coz if ever a car was going to run hot at hi speed it would have to be Australia and they are not fitted to 6.9's at least !
The article you are referencing appears to be a full service manual extract..ie .it is not a "bulletin amendment?"

Let's see what else presents!

[ramiro]

The picture clearly shows an 6.9 Engine.
The screenshot is directly from the 6.9 section in the service manual it is also the only engine where this is mentioned.
I would translate the text but it only says that this switch disconnects the vacum advance above 90 C engine temperature , sadly i was not able to find a part number for this exact switch only 1 with 63 C but without the vent hole.

Maybe because in australia there was no legal way to drive > 110 constantly ?