strange cooling issue
 

i'm a noob on this forum. i searched. honestly. go ahead and flame away.

anyway, a bit of history.

i own a 97 non turbo, mostly stock. it has a jackson cai and an a/c delete. 143k. good running car. good compression. when the weather started getting cold last autumn, (around 45 degrees), i noticed the car wouldn't get warm. the heat wouldn't work and the temperature gauge read C. i didn't believe the gauge, so i tested it with a digital/laser coolant temp thingy. the gauge was correct. it wasn't warming up.

i thought, "----. i'll throw in a new thermostat." i put the new one in, and did a coolant drain and fill with 50/50 antifreeze. it didn't fix the problem. i stored the car for winter, and said ---- it. last week i took the car for a ride when the weather warmed up to around 40 degrees. it didn't come off the cold mark the entire time i drove. i stopped and felt the coolant hoses, which were both around 70 degrees. (est.)

i noticed that when i stopped to check it, the car warmed up nicely after two minutes of sitting at idle. then as soon as a went down the road at 25 mph, it cooled right off again. so i ghettoed it up. i put plastic masking paper over the grille in the front. the water temperature acted copmpletely normal, and the heat worked great.

i guess that was a bit long. sorry. anyway i would like to know what the problem is, and if its hurting the engine to drive around with the water temperature at 90 degrees. my other 1.8 miata warmed up normally, so i'm assuming i do indeed have an issue. thanks miataturbo!

It's not great to run at cool temperatures, no. That's why everyone will say to let it warm up before flogging it, same goes for normal driving.

That is a strange problem, have there been any changes to the stock cooling system? Over sized radiator? Changed heater core routing?

It sounds like you have a "racer" reroute, which returns the heater core line to the upper radiator line, cooling any and all water. Stock should have water going directly back to the water pump, so it isn't cooled and helps warm up the engine.

im the third owner. the original owner was a young girl, and the second owner was her mother. :giggle: i never did a coolant reroute, and i doubt either of them did. next time i get the car out of storage i'll check it for sure though. if i have to i'll just not drive it til it warms up to 60 degrees here in pa, but that's harder than it sounds!