10

Failure Modes Mechanical thermostats fail in one of two ways: Stuck-closed The pintle/spring doesn't retract to permit flow at the set-point temperature that is usually stamped on the thermostat itself. which can lead to the engine running at hotter than expected. If hot enough, this can lead to serious issues such as a compromised head gasket or warped ...


9

You don't need to, but since your coolant system is already drained, it would be a good time to. Standard thermostats are only about $10 and a $2 gasket. Changing your thermostat is typically 2 bolts and a gasket.


7

Basically, the thermostat regulates the temperature of water/coolant in an engine. When you first start the car it should be closed, essentially blocking the water/coolant from traversing the radiator thus allowing the engine to reach its optimum temperature as quickly as possible. Of course, everybody knows that an overheating engine is bad news but most ...


7

I had no idea it would be called this, but the article in Wikipedia describes the "low level" detail of how the device works. Wax thermostatic element Basic operation There is an optimum temperature for the engine coolant (not too cold, not too hot) and a simple mechanical thermostat helps make that happen. When it's closed, the water pump circulates the ...


7

It might seem easy to integrate a sensor that detects the opening/closing of a mechanical thermostat's pintle (LVDT, for example) but here are some challenges which would need to be addressed: Cost vs Benefit Is a "smart" thermostat really worth the extra hassle and money when its dumb counterpart has the following to offer? : it's already cost-effective ...


7

You will know the thermostat is open when the engine reaches operating temperature. The thermostat opens just before or around the operating temp of the engine. Most modern vehicles have some sort of temperature gauge in them. If it's just a needle, you'll notice where the needle rests under normal operating conditions (most that I've seen sit right in the ...


7

The spring remains largely the same. There is a capsule of thermoreactive "wax" which heats up and expands, acting against the "closed" spring pressure, and causing the "valve" section to lift allowing coolant flow to the heat exchanger "radiator" to lower coolant temperature. If it's flowing through the thermostat, it's going to the radiator for heat ...


5

Seeing as how changing your thermostat is a variable in this. This sounds more like an HVAC or blower motor issue. If the thermostat fixed it and you now have issues again during winter along with clunking, I would say it's probably a compressor or blower motor issue. Those can cause a clunking sound. Typically you can diagnose a problem with these sounds ...


5

Found out this actually requires another O-ring, not a gasket. Another O-ring came with new the thermostat and I was able to use that.


4

The thermostat would have been my first guess too. It doesn't need a sealing ring, the housing will slightly clamp it when you put it back together. It is entirely possible that the temperature sensor has 'drifted' and is reading lower than the genuine temperature. I have experienced this more than once in my own cars. It's worth as try as they're usually ...


4

No that's not the location. It's in the thermostat housing (attached to the engine) that the outlet radiator hose attaches too. This hose runs from the right side (passenger side) of the radiator to the engine. Drain the cooling system Remove the air cleaner outlet duct Remove the radiator outlet hose from the thermostat housing Remove the bolt and bolt/...


4

I would suggest investing in a Haynes Manual for this car. One minor repair like this that you can do yourself will pay for it in savings. This is the part you are looking for, it's the thermostat housing, that I found on eBay. If I recall, it was for the 2011. Here is a video on how to change it a thermostat for a Vauxhall Corsa 1.3 (2004). Now it may ...


4

It very well could be the thermostat. However, did you check the obvious things, like coolant levels and make sure you don't have any air pockets? I had an overheating issue that would manifest after 20 to 40 minutes of running the car, which was due to an air pocket. Usually if it overheats at idle you check the radiator fans, radiator fins bent or ...


4

Orthodox antifreeze is based on ethelyne Glycol. It does depress the freezing point and raise the boiling point of the cooling system. This is desirable and the suggested concentration is roughly proportional to how cold you think it's going to get. As a coolant, water just can't be beaten so that's why it's still used on the internal combustion engine over ...


4

A thermocouple merely generates voltage according to the temperature, while an automotive thermostat is basically an autonomous temperature sensitive coolant valve. You can't replace a thermostat with a thermocouple because their functions are completely different. You could replace a coolant sensor with a thermocouple, but resistive sensors are more ...


4

The heater core may be plugged, if fluid is full and there aren't any leaks. Check this when the engine is hot, if one hose is cold or warm and the other is hot the heater core is plugged. The temp gauge fluctuations may be an electrical issue or there's air in the system. If you backprobe the temperature sensor have someone rev the engine and look for ...


4

I see no reason to do them together unless you have reason to believe the thermostat needs to be replaced, or unless you have an unusual vehicle in which the thermostat is hard to access without taking apart the same things you'd take apart to get to the water pump. Usually the water pump requires taking off the timing belt cover and a lot of other adjacent ...


4

Go to a site for parts diagrams with a VIN/chassis number lookup like http://www.realoem.me. Give it a try, I think it will be quite helpful. Using that site based on an ASV engine I believe you need 044121113


4

Are there failure modes besides "stuck open" and "stuck closed?" Absolutely. This has been the bane of many an E39 M5 owner. If the coolant is able to navigate through an alternative flow path besides the path it is expected to take, a mechanical thermostat will modulate temperature at slightly lower than expected. So what could cause this? The ...


4

Code P0125: Insufficient coolant temperature for closed loop operation. The code sets under these conditions: Engine run-time at road load over 6 minutes at which time the PCM detected the Engine Coolant Temperature (ECT) sensor signal did not indicate the required engine temperature value to enter Closed Loop within a specified amount of time. The amount ...


4

The engine, if the rest of the cooling system is in good order, will run too cold. This will affect fuel consumption, emissions and perhaps power delivery. While this is often done for short periods, ie to deal with a faulty 'stat, it is not advised for long periods. Best thing is to get the thermostat replaced.


3

It sounds like the issue is with heat rejection. The tell-tale sign is that the coolant temps rise into the red when the car is at idle (low RPM, little air flow across the radiator), but when the car moves the temps drop back down to normal. So what could cause this? A couple of possibilities: low air flow Are the radiator fans turning on when they ...


3

Is it necessary to remove the thermostat since it's going to open when engine reaches temperature? No, it is not necessary to remove the thermostat. In fact, some cars you don't want to remove the thermostat while running the vehicle. The reason for this is that the thermostat can be used to direct coolant flow. If it is out, parts of the engine may not be ...


3

There is no way to put sealant around the outside of the housing to get it to stop leaking. You could possibly put a sealant within the coolant system, such as Bar's Radiator Stop Leak, which may or may not solve your leak issue temporarily (may solve it permanently, but I never trust it). Your better bet is to just replace the gasket. This is a ...


3

The thermostat is a valve that helps your engine cool correctly. When the engine is cold, all engine coolant flows within the engine block; the thermostat is closed in that condition. As the engine gets warm (generally at 195 deg F), the thermostat opens, and hot coolant flows to the radiator where it is cooled. As you might expect this is important in ...


3

The rubber seal around the outer edge of the thermostat should provide the seal without the use of RTV. 3+mm would be enough to cause a leaking issue, no doubt. As for the RTV which you now have on there, you'll need to clean it up because I believe you'll run into sealing issues with it there. Since the piece is plastic, you'll have to take extra care not ...


3

The most likely cause is the thermostat. The on the road temp is the clue, it should be at the thermostat open temperature which is specified to be 180 deg F. This is the lowest temperature that should be seen on a road test if the thermostat is working normally. It is possible that the sensor is reading 20 deg F low but it is not at all a common problem. ...


2

I think you are on the right track with the thermostat. No it should only take a few minutes max, even in colder temperatures for it to warm up. The thermostat is a cheap part to change and usually pretty easy to get to, so I don't think you are going to lose much by changing it out.


2

I have been filling in coolant once every three days. wondering if this ok to get by for few more months? You can probably get by with this, but realize that if the thermostat housing is cracked and leaking, it could easily crack further, causing faster/greater loss of coolant at any time. By not doing the fix, you could end up trashing the whole engine if ...


2

Just ran into a variation of the stuck open failure. Thermostat opened and closed at the correct temperature (195 F) when tested in a pot of hot water. However, when installed, the thermostat would allow water to pass at temperatures 40 F cooler. Replacing the thermostat fixed the problem. Edit for dlu: I can read the coolant temperature on the vehicle info ...


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