HI all

I have been having bad luck my Avenger. The thermostats are not acting well at all. This past week I am getting 18-19 miles per gallon in a half tank or I go through 8 something in gallans much to fast.

Would u change both thermostats or try one first? Which first. anything to look for ? Then do the second install or not?

I swear, i'll never buy another Dodge again.

MY 2010 Avenger is sooooooooooo quirky its sicking.

Any help would be appreciated thank.

air-eek

There should be only one thermostat on the engine. Unless the motor is over heating (or maybe not heating up enough?), I'm not seeing a need to replace it.

HI all

WOW, my English was bad last night, I wonder what that was? Anywho, on a 2010 Dodge Avenger there are two thermostats a 170 and a 200. I don't know why. The problem, in this cold weather I keep getting bad gas mileage, on the current tank I am running 140's for a half tank, the tank is 16.9. There are also conflicting running procedures. Sometimes it runs warmer than other times. Sometimes it idles at 100 rpms or so more than most other times. I bought the car in Octotober so I have no sunny recollection as to how it runs. The car is advertised for a gas mileage of 21 to 30. The highest I have gotten was 24, and that was with some heavy freeway driving.

My question is should I change one or both thermostats at the same time.

OH, get this. From O'reilly Auto parts, the thermostats are gonna be like 100 bucks with tax, for the pair.

God I wish I could upgrade back to a GM car.

Thanx,

Ear-ick

edit: Oh, and while also in the cold, when I warm up the car, I run sometimes like 10 minutes and the gauge needle is still on the C for cold, after 10 MINUTES.

[This message has been edited by pavo_roddy (edited 01-05-2014).]

Never heard of an engine with two thermostats - learn something new every day. A quick search found the info below from a Dodge Caliber forum Here:

You might have to pull the thermostats out and physically check to see if one (or both) are stuck open, although I think you'd get a check engine light / DTC code for engine temp low.

According to the dealer service manual:

The engine cooling thermostat is a wax pellet driven, reverse poppet choke type. The thermostat is designed to provide the fastest warm up possible by preventing leakage through it and to guarantee a minimum engine operating temperature of 88 to 93°C (192 to 199°F).

The primary thermostat starts to open at 77° C (171° F) and is fully open at 89° C (193° F).
The secondary thermostat starts to open at 95° C (203°F) and is fully open at 108° C (226° F).

The thermostat is operated by a wax filled chamber (pellet) which is sealed. When coolant reaches a predetermined temperature, the wax expands enough to overcome the closing spring and water pump pressure, which forces the thermostat to open. Coolant leakage into the wax pellet will cause a thermostat to fail in the open position. Do not attempt to free-up a stuck open thermostat.

If the thermostat is stuck open or allows coolant leakage through it, the engine will not operate at the proper temperature for obtaining engine fuel efficiency, performance and emissions levels. If this condition occurs, a diagnostic trouble code will be set and a MIL light will be turned on. Refer to the Powertrain Diagnostic Procedures manual for further information and diagnostics provided.

Thermostat diagnostics is included in powertrain control module’s (PCM) programing for on-board diagnosis. The malfunction indicator light (MIL) will illuminate and a diagnostic trouble code (DTC) will be set when an “open too soon” condition occurs. Do not change a thermostat for lack of heater performance or temperature gauge position, unless a DTC is present. For other probable causes, (Refer to 7 - COOLING/ENGINE - DIAGNOSIS AND TESTING). Thermostat failing shut is the normal long term mode of failure, and normally, only on high mileage vehicles. The temperature gauge will indicate this (Refer to 7 - COOLING/ENGINE - DIAGNOSIS AND TESTING).

HI all

Well the trouble code thing does works some at least as I've had it go off for low air in tires, lol. Thanx for the heads up. Going to end up taking the car in to mechanics, hopefully it won't be exspensive, at least I got paid 3 times in Dec.lol.

Thanx all,

Air-eek

I would think the tire pressure monitoring system is separate from the engine check light--it is on our dodge, my silverado and on my sister's F150.

quote Originally posted by carnut122: There should be only one thermostat on the engine. Unless the motor is over heating (or maybe not heating up enough?), I'm not seeing a need to replace it.

Two thermostats? Well, today wasn't a waste as I learned something new. Let us know how it turns out.