willysmjeeps.com

I've owned my M38A1 for only a couple of months. To me, the engine temp always has seemed to be running high. I have been operating without a thermostat and the temp on the gage is about 220º. I replaced the sending unit with one from DeBella. This made no difference. So, I figure I do not have a thermostat problem (because there is not one in the jeep) nor do I have a sending unit problem (since two different units are giving the same results).

Yesterday, I decided to test the temp gage. I placed the temp sending unit in a coffee pot and extended the wires from the jeep to the sending unit. In the coffee pot, I had a super accurate glass mercury thermometer. I watched the gage and the thermometer as the water heated up. I found that the gage is reading 35º to 50º high.

That was a long story to say that I will be replacing the temp gage (which is made by Fabia). I would appreciate any advice regarding a good temp gage to purchase. I am considering one of those linked below, but would consider other recommendations. Thanks!

Stewart Warner gage from Ebay

Reproduction gage from DeBella Parts

I recently replaced my temp gauge with one like the links show. Since you do not need the sending unit, get the cheaper one. Works very well in my M38A1. The only difference was that my original??? gauge indicates 240 degrees and the new one peaks at 260. Minor difference in looks from the original and only the pros will know you changed it in my opinion.

You get what you pay for! If you want a reliable gauge at a reasonable price then go with any quality made mechanical gauge (i like VDO) which has the correct range on it's dial. Two problems on these engine can cost you several hundred to a thousand dollars. Over temping and low oil pressure. Don't skimp on these two gauges. If your jeep is a driver I would go with quality mechanical gauge not ancient NOS surplus stocks of electrical gauges and senders with no warranty and you can never find out weather they were surplussed out because they were not needed or because they were defective.

cabinfever wrote: I have been operating without a thermostat

Nothing to do with the faulty gage but in doing so your cold engine
is taking longer to reach operating temps thus increasing wear and
deposits.

Running without the thermostat is not a smart choice. In addition to the above remarks the engine will often run hotter without the thermostat slowing down the flow across the radiator which cools better the longer the fluid is in the radiator.