Camsti

Hey on my 84 944 when i put the key in the ignition, my temperature gauge bounces up. When the car is on or driving the gauge does not read anything, so does that mean its just the temperature sensor thats bad? The fans do kick in, so i would think the temperature switch would be out of the question. Any input would be appreciated.

Grandpa#3

You might need to change out the temp sending unit where the head and intake meet up front or check the wiring as it gets frayed.

Cheers,
Larry

dally_de

or it could be the gouge itself

originalmotorhead

First off, the fan is controlled by a totally separate sensor. the coolant fan sesnor is in the radiator, drivers side. The sensor for the temp gauge is slightly under the J boot (intake boot). it is accesible without taking the boot off, just get creative with a box wrench or socket with wobble nuckle. Its a 1 wire sensor. The other sensor that is a little further forward is a multi wire connection and is the coolant temp sensor for the computer. You only need to mess with the single wire sensor, that is the one that runs the needle on the dash.

Also check for corrosion first, as it sometimes gets a green ish gunk built up and that causes intermittant readings. Might be able to squirt some wd40 or pb blaster on it and wiggle the wire around to do a half *** job of cleaning the contact point ;p

Another biggie is to check your ground wires at the main points. Good thing to notice here is if you have the car on and running and the temp needle jumps if you turn on your blower fan from off to high or turn on your lights and off. My 84 has a loose ground or two because I can turn the blower fan on high and my temp gauge then reads warmer by almost a half a bar, if i turn off the blower, the needle immediately drops back. Headlights are not near as intrusive but does cause the needle to move a little. I think my ground issue is the main one behind the dash, above the fuse / relay area.

good luck. check for corrosion first !
Tom

Camsti

Alright i just cleaned it with some wd40 and a rag, there was a lot of gunk around it and on the ground itself. My battery keeps dying in this cold weather and it wont start now, so i have to buy a new battery before testing the guage out.

Camsti

An update, I just installed the new battery and the temp gauge is still not working. So im going to buy a new sensor next.

max_boost951

I had a loose ground on the top of the bell housing tampering with my temp. gauge. Mine would read above the second line but below the red hash and never moved even when the fans kicked on.

Camsti

Well my temp gauge does a small bounce when i put the key in the ignition, but when the car is on..the needle is below the first mark.

smokin_944

Have you checked the temperature sender (brass plug, single wire) mounted in the block under the intake at the front of the engine? They sometimes go bad.

968workaholic

You can always try grounding the connection on the sender. That should make the temp gauge go to the top of the range. It will give you and idea if its the sender or wiring/gauge.

smokin_944

Originalmotorhead and 968workaholic are all over this one. The 1 wire temperature sender unit is iffy at best. Grounding on most Series 1 cars makes the gauges wonky.

Camsti

Well i just cleaned off all the green gunk off the ground and top of the temperature sensor, started the engine up and still nothing. So probably next week im going to order a new sensor and if that doesnt work then im going to get a new gauge.

Camsti

http://www.pelicanparts.com/cgi-bin/...28DME%29%20%20

Is this the right sensor i need?

Yarf

I believe this is the temperature sensor used on the 1984 944
http://www.pelicanparts.com/cgi-bin/...30%38%30%22%3E

smokin_944

Yarf has the right one, however the correct terminology (for the early cars/Series 1 cars) is sender as per the WSM.