1956 Laurentian Factory temp gauge in a 350 question

Poncho Jode · Veteran Member

1956 Laurentian Factory temp gauge in a 350 question

dualquadpete · Canadian Poncho Superstar!

Sounds like you've got the wrong sending unit in the block [assuming it's a electric guage, think 55's were mechanical] Guess you don't have orginal sender??? May have to hunt one down!!!!

Taylor55 · Poncho Master!

The factory temp gauge is mechanical on a 56 Can Pontiac. I used the original gauge with a 350 in my 55 and it worked correctly. If I remember right the gauge should start at the fully cold position and then move to the right or hot position as the engine warms up. I think your gauge itself is not working correctly.

Al

Poncho Jode · Veteran Member

Dang. I guess I am now on the hunt for a correctly working gauge. My car was an original v8 and now is a 350. So it seems the gauge isn't working right. The wire (or bendable cord thingy) is different from my 6cyl parts car. The 6cyl one is not long enough to reach an intake port.

dualquadpete · Canadian Poncho Superstar!

If your 350 heads have the screw in plug for temp guage, you could go to the pass. side [right side] & use the plug at the rear side of head!!! if the "capillary"[thats the correct name for the bendable cord thingy] tube will reach instead of trying to go to intake or if long enough use the frt. left hole on drivers side head????

davelacourse · Poncho Master!

You can use American Pontiac gauge, they are all for V8 and will fit right in your dashboard, and the tube will easily reach anywhere. Do a search on eBay (and set it to send you a email whenever one becomes available), might take a while but eventually you will find one. Make sure you get it with the tube and bulb attached or it will be no good. No calibration issues since USA and Canada both used 'real' measurements back then i.e. degrees Fahrenheit.

Dave

pontiax · Poncho Master!

If the gauge sits a midway with a cold engine, you may have pinched the capillary tube when doing the engine swap. Mechanical temperature gauges are built with a small bit of vacuum" negative pressure" in the line. Heat will increase the line pressure and move the needle. So if the needle is in the middle, you have a hole in the capillary tube.

Poncho Jode · Veteran Member

Do you have any idea of how to locate the hole and repair it at all, or do I have to try to replace the guage?

pontiax · Poncho Master!

easiest thing would be to replace the gauge. you may luck out a find a similar sweep (170 deg.) or which ever yours is and rebuild the factory gauge with the inerds of a new gauge.