Engine never warms up need help!

[Lewacool1]

Hello, I've tried everything I can think of and have had no luck so I'm hoping someone has something I haven't thought of. Since I bought the car I have had issues even in the summer time of the engine reaching operating temp. I have changed thermostat and heater core just because it was clogged. My engine never gets to thermostat operating temp of 188F unless I let it sit and idle for about 30 minutes. However as soon as I drive down the road it will drastically drop down to 130-135F It is a 2015 mirage DE hatchback with a 5 speed manual. I have verified with a manual temp probe that my temp sensor is reading properly. I read in another forum it could be the thermostat gasket that I swapped from my old one however if it didn't seal properly it would be leaking coolant as that's the only means of the thermostat elbow sealing to the block? Also, if it was a water pump issue you'd think I would have the opposite of it over heating? Any suggestions are welcomed.

[Johnny Mullet]

Totally sounds like a thermostat issue. Even though it was done, for the price, maybe get another one and tear down and inspect. If it is not sealed or housed properly it will not work.

[Lewacool1]

Thanks for the reply Johnny, I bought an OEM one today with the new gasket I will report back if it fixed the issue. I understand now how it wouldn't leak but could be leaking around the flange of the thermostat and around the inside of the lip.

[Top_Fuel]

Someone just posted about the same problem a couple of weeks ago.

[Lewacool1]

Yeah I see the post from a couple weeks ago and asked the question how it could leak by internally without visually seeing a leak and got a better understanding.

[spiritorb]

It seems that with the Mirage, some replacement parts are better to be OEM. Thermostats are one that I would rather spend the extra, and go original. Drive belts are another one I have found OEM to be better. I tried a Gates belt and it was squeaking, even when tensioned correctly. Some aftermarket parts are not calibrated the same as OEM.

[Fummins]

Hello, I've tried everything I can think of and have had no luck so I'm hoping someone has something I haven't thought of. Since I bought the car I have had issues even in the summer time of the engine reaching operating temp. I have changed thermostat and heater core just because it was clogged. My engine never gets to thermostat operating temp of 188F unless I let it sit and idle for about 30 minutes. However as soon as I drive down the road it will drastically drop down to 130-135F It is a 2015 mirage DE hatchback with a 5 speed manual. I have verified with a manual temp probe that my temp sensor is reading properly. I read in another forum it could be the thermostat gasket that I swapped from my old one however if it didn't seal properly it would be leaking coolant as that's the only means of the thermostat elbow sealing to the block? Also, if it was a water pump issue you'd think I would have the opposite of it over heating? Any suggestions are welcomed.

I assume you installed the thermostat gasket properly, As shown/explained in the other thread(The thermostat fits inside the groove of the rubber gasket/ring), and the jiggle valve to the top. Or did the thermostat get put into the hole, then the gasket pushed up against it with the housing? It wouldn't leak that way but wouldn't work right(just like the guy in the other thread iirc).

If that's not the problem...What did/does the coolant look like? If it was full of crap, did you flush it all out? Did you replace the thermostat and heater core at the same time? Does the rad fan run at all? Any Check engine lights or stored codes, I'd expect a 'not getting up to operating temp' or similar code.

I'd start with what's already been suggested though, thermostat o

[Lewacool1]

Thank you all for the motivation to do my job twice. Best tip I can give anyone is to purchase only an OEM replacement thermostat as all aftermarket ones do not have the rubber seal the thermostat pushes up against when it closes. Also aftermarket ones have the jiggle valve installed backwards causing a constant leak through the jiggle valve hole. Put in an OEM thermostat last night and works perfectly. Also OEM is the only one that comes with the new gasket unlike motorad or others from big box chain stores. Buy OEM off a dealer or on rock auto!

[Johnny Mullet]

Glad we were able to help!