Porsche Enthusiasts Club Forum

Good Morning

I now have the head on my engine but am a little confused on the sensor plugs at the back of the engine,

I have two round plugs one has 3 pins but nothing to connect in to, AFAIK that one was not plugged in prior to me stripping the engine
the other round one has a cap on the end and again is how it was before I stripped it

I also have two square connectors i'm guessing Ref & speedo, problem is, I can only find one socket, is the other one hiding back there? or am I looking in the wrong place?

help help help!

Hi there, just popped out and took some photos. The 16V has two sensors on the bellhousing, however only one is connected to the DME, the rectangular one. The round one usually has a rubber cap on and has three pins - this is only used to connect to the DME diagnostic tool. The two sensor connectors are mounted in the metal bracket on the back of the engine. You can just see the diagnostic plug cap in the first picture:



Here's a shot from behind the engine so you can see the bracket:

There is another round plug at the back that sits in a plastic clip on the bracket, it has some kind of link (it is shown at the top of all above pictures). I am uncertain as to what that does, but it doesn't connect to anything.

The other rectangular connector goes to the vacuum pipe switch.


Hope that helps!

the round one i think is the connection for the O2 (lambda) sensor well it is in the same place with the same plug on the 968

Wow thanks Rhett,
To be honest without you, i doubt i could have got through the rebuild! your info on the lfiters was most helpful, i will have to have another look at the back of the engine tonight and will let you know my findings

i have the ones connected to the bracket exactly as you have pictured but i seem to be hosting two extra plugs which must be hidden on yours, i will see if i can get a good photo later

i suspect it may be for the speedo sensor and the three round pins would indeed replicate an 02 sensor however i don't have an 02 sensor..
as i think i mentioned before, the three pin round socket was not plugged into anything before i stripped it..

speedo sensor is on the gearbox, that might just be a bit of forward thinking if it was empty before and no O2 sensor, its maybe just provision for one at a later date

Possibly, just want to do everything right is all! see below photo of what I'm working with..

Hi..I think the photo fell off...

Whoopsie

Ok, have you remembered to reconnect both the Idle Control Valve and the Throttle Position Switch? The ICV is under the inlet manifold, the TPS is on the throttle body. The connector you are holding in the photo could be one of them?

As apart from the vacuum switch I have shown in one of my photos, I don't recall anything else on that side of the engine that you would have disturbed when taking the head off.

There are two anti-knock sensors on that side of the block, but you should not have had to disconnect either of them as they are mounted lower.

Hope that might help??

You bloody genius. It's the tps better get splicing and extending! I'm putting an s2 mani on

Glad to be of assistance! You will have to report back to let us 'S' owners know how well the S2 manifold upgrade works as it is something I have considered in the past.
Good to hear the project is progressing nicely...

So i started it, it ran great, for about 15 seconds, POP Hisssssssss
Oil filter gasket popped out the side and covered the driveway, i'll admit, i didn't line up the OPRV thinking it would be okay, guess i'm draining the coolant, loosening the housing and refitting that after work today!

side note- if you fit an s2 mani, get yourself the silicone vacuum kit from somewhere too, i can do a quick thread on how to fit the vacuum lines up as it took me a few hours of trawling to figure it out.
Ensure you get the part that bolts on to the afm into the nose panel as i had the pleasure of cutting up my afm & attempting to stuff some cold air intake ducting through there, it has worked but i feel you will have a much better time using the original part.

I'll get some pictures up tomorrow!