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Thermostats are cheap and easy man, get a new one in there and I bet you’ll pass inspection within a few days
Thermostats are cheap and easy man, get a new one in there and I bet you’ll pass inspection within a few days
Bingo. In order to reach closed loop operation (where the computer is looking at sensors and making fuel adjustments on it’s own) the engine needs to be up to operating temperature, in the ballpark of 185-205*F. When the engine is cold it runs in open loop, meaning it just runs default settings that are not ideal for performance, MPG, or emissions. You’ll have to work on the cooling system issue first before diagnosing the ECU.
Bingo. In order to reach closed loop operation (where the computer is looking at sensors and making fuel adjustments on it’s own) the engine needs to be up to operating temperature, in the ballpark of 185-205*F. When the engine is cold it runs in open loop, meaning it just runs default settings that are not ideal for performance, MPG, or emissions. You’ll have to work on the cooling system issue first before diagnosing the ECU.
Okay, so not setting Readiness codes. How many miles / what kind of driving have you tried? It would be helpful to use an OBD scanner to see if ANY of the Readiness codes are setting. Try performing a “drive cycle” like this:
http://www.lyberty.com/car/drive-cycle.htmlOkay, so not setting Readiness codes. How many miles / what kind of driving have you tried? It would be helpful to use an OBD scanner to see if ANY of the Readiness codes are setting. Try performing a “drive cycle” like this:
http://www.lyberty.com/car/drive-cycle.htmlECUs rarely fail in my experience. There are a lot of other things that can cause symptoms that would appear to be the ECUs fault, though. You would know if the ECU failed. The car wouldn’t run or would throw OBD codes like no tomorrow. Another possibility is it’s inability to set Readiness monitors for emissions testing. My Neon has had a P0601 come on every single time the car is started since I bought it a year ago. The suggested fix is to replace the computer but the car runs and drives perfect so I ignore it.
What kind of troubles are you having with your car that makes the ECU suspect?
ECUs rarely fail in my experience. There are a lot of other things that can cause symptoms that would appear to be the ECUs fault, though. You would know if the ECU failed. The car wouldn’t run or would throw OBD codes like no tomorrow. Another possibility is it’s inability to set Readiness monitors for emissions testing. My Neon has had a P0601 come on every single time the car is started since I bought it a year ago. The suggested fix is to replace the computer but the car runs and drives perfect so I ignore it.
What kind of troubles are you having with your car that makes the ECU suspect?
Did you try a new pressure cap? Seriously I don’t get it but those things always end up leaking after not too long. Had an old Cavalier that went through 3 in 8 months, would run great for 2 months then occasionally overheat and leak from the cap… it probably had other issues though.
Did you try a new pressure cap? Seriously I don’t get it but those things always end up leaking after not too long. Had an old Cavalier that went through 3 in 8 months, would run great for 2 months then occasionally overheat and leak from the cap… it probably had other issues though.
Hmmmm…. air in the system, low coolant level, clogged passages, poor circulation/pressure (pump/leaks), bad/stuck thermostat OR faulty temp sensor (false high readings on gauge) – is the order I would investigate things for the heater. We used to help coax out air bubbles by “massaging” the radiator/heater hoses. Even on my buddy’s car with the BHG he drove it for a long time like that by just bleeding the new air out of the cooling system every couple weeks.
Hmmmm…. air in the system, low coolant level, clogged passages, poor circulation/pressure (pump/leaks), bad/stuck thermostat OR faulty temp sensor (false high readings on gauge) – is the order I would investigate things for the heater. We used to help coax out air bubbles by “massaging” the radiator/heater hoses. Even on my buddy’s car with the BHG he drove it for a long time like that by just bleeding the new air out of the cooling system every couple weeks.
[quote=”roywrench22″ post=46383]I recently was working on a 2002 Tauras that was losing it’s coolant out of the pressure cap. It would blow off at about 12psi instead of the 16 it was supposed to hold. If your system isn’t pressurized fully you will overheat sooner. (water boils at a higher temp. at a higher pressure)[/quote]
I agree, the pressure cap is the first thing I check / replace when dealing with cooling / heater issues. Has fixed the problem in at least 85% of cases I’ve had. Sometimes when they go out it is an indication of another problem. I had a friend go through 4 rad caps, 2 thermostats, and a new radiator before eventually confirming my hypothesis – blown/leaking head gasket for ~6 months (exhaust/compression was leaking into the cooling system dumping hot air and extra stress on it). Regulating pressure and keeping air out are crucial to proper flow to the heater core & temp sensor.
[quote=”roywrench22″ post=46383]I recently was working on a 2002 Tauras that was losing it’s coolant out of the pressure cap. It would blow off at about 12psi instead of the 16 it was supposed to hold. If your system isn’t pressurized fully you will overheat sooner. (water boils at a higher temp. at a higher pressure)[/quote]
I agree, the pressure cap is the first thing I check / replace when dealing with cooling / heater issues. Has fixed the problem in at least 85% of cases I’ve had. Sometimes when they go out it is an indication of another problem. I had a friend go through 4 rad caps, 2 thermostats, and a new radiator before eventually confirming my hypothesis – blown/leaking head gasket for ~6 months (exhaust/compression was leaking into the cooling system dumping hot air and extra stress on it). Regulating pressure and keeping air out are crucial to proper flow to the heater core & temp sensor.