When I turn the key to the first position (without starting engine) the temp gauge immediately "pegs" all the way to the right. It stays there under all driving conditions, never changes. The car does not show any signs of running hot or leaking coolant, so I assume it is ok. The fuel gauge and lights on that cluster work fine.

Is this an indication the gauge is bad, or something else? If it is a "ground" issue, how specifically do I find the right ground wire - I am "electrically challenged". A picture showing the ground wire on an early 944 would be great. Thanks.

 

sounds like a wire or bad sensor.

I would start at the gauge and work back. On the 83 the gauge is run off one of two plugs under the intake manifold. I AWALYS forget which one is which, but one runs the DME and the other the gauge. My guess is the wire came off, got cut or the temp sensor went bad.

 

Had an 85.5 with the same problem. It was a bad ground. Can't really remember, but beleive it was on the back of the engine block.

 

Can anyone provide a very specific description of where I find the ground, and what it looks like? Or a picture would be great.

 

bump

 

main engine ground is a large cable running to the back of the intake manifold area. I forget if it attaches to the maifold or the bell housing, but it is back there.

 

Jim,

The temp sensor for the gauge will be the second sensor on the block, above the driver's side balance shaft cover. The first sensor you'll see will be blue and the plug on it won't have the metal retaining clip on it (don't know what happened to it on your car) and this is the DME temp sensor. The next sensor will be gold color with two spade connectors on it. This is your sending unit for the gauge. If it shorts to ground will read low, a break in the wire or if they're touching will read high. Check to be sure they're on the sensor and that the two connectors aren't touching each other. Follow the ground cable from the battery to the back of the engine and make sure they're making a good connection. The will be located on the driver's side of the bellhousing for the main ground and the driver's side of the block for the DME (IIRC). If you pull them for cleaning be sure to put some tape over the hole in the bellhousing that allows you to check for TDC. I believe Porsche magnetized the flywheel so they could get a good laugh out of every shade tree guy who drops a bolt down the inspection hole.

 

Boy I wish I'd read your post two days ago!!

Yesterday I cleaned and tightened my ground connections which seems to have fixed a starting problem, but I did loose a bolt - probably in the flywheel inspection hole. I pulled the nearest flywheel sensor ( a strong permanent magnet) carefully expecting to pull out the bolt. But no bolt. So I started the car expecting to hear grinding in the flywheel housing - but none. I'm hoping that the bolt went elswhere but I can't find it. Do you have any experience retreving a bolt dropped into that hole??