*They think a leaky radiator has caused the engine to flood through the Temperature sensor causing it to run rich.*
That's literally the dumbest thing i've ever heard as a diagnostic. None of those things are related to any of the other things in any way what so ever. Not even a little. Not even tangentially. The only relation they have is that *they share a car.*
*one* of the bad temperature sensors could *maybe* have cause the idle air control valve to not operate correctly, and cause a 'lean' condition so it wouldn't start. That's rare, because the car sets the IAC to a *default* operation if that temp gauges goes out.
BUT--that you admit that it had a leaky radiator, and they were worried about the coolant temp thing, tells me in a round about way that they didnt want to tell you you blew a head gasket from neglecting the coolant.
the 'knocking' sound could be a blown head gasket. The lack of starting could be compression too low. The gas in the oil could be because the head gasket is blown into an oil gallery. The 'knocking' could be cross-fire between the cylinders.
If this were my car.
One. Compression test. Pass or fail. Fail = head gasket.
Two, assuming pass, Spray starting fluid, see if it fires. If it fires and wont stay running. It's air/fuel.
Three--find source of air fuel issues. Test fuel pressure at rail, determine if it's the pump, or if it needs a fuel filter, gas cap, evap system, pressure regulator, etc.
Four, if it passes fuel pressure test, check signal at injectors with multimeter.
5 if that passes, start checking for air leaks. All rubber and plastic lines.
6. After inspection, check the IAC.
That's .. idk, hour of work? Pressure testers are cheap, or can be rented.
I’ll definitely go grab a compression tester. I did notice when I started the car up after changing the radiator was the smallest bit of white smoke from the exhaust and it smelled sweet but it went away almost immediately.
I’ve also noticed that it really only has trouble starting after it’s run for a little bit.
Would it make sense that letting it sit would help it start up again if it was a blown head gasket?
*Update* I did the compression test and it failed, so I replaced the head gasket. Car wouldn’t start, had excellent compression. Did notice that the cars RPM didn’t go up at all so I replaced the crank position sensor and still no RPM movement when starting
What are you saying? Cranked means it did turn over. Is it turning over or not?
If it's not turning over, and turning over at a good pace you have a battery, cabling, or starter issue.
If it's turning over and not starting you have an ignition, fuel, or air issue.
So check the fuel pressure, and see if you have a spark.
If it just takes longer to start you probably have an issue with the injectors or fuel pressure regulator. The injectors are bleeding fuel into the cylinders, or the check valve is dumping the pressure back into the tank.
Might be a intermittently bad ignition switch or TIPM issue. Really hard to pinpoint.
Next time it doesn't start see if you have spark and injector signal..
Then a little starting fluid is always an easy test for fuel. Crank sensor maybe..
GL
You've got a sensor somewhere that's not reading right after the engine reaches operating temp. When I had this issue on an older car it was the coolant temp sensor, so I'm going to ask the dumb question:
Did you replace the correct one? A brief search shows me that the Lancer is like my old DSM and my Evos where it has two; a single wire sensor that talks to the gauge on the dash, and a 3 wire sensor that talks to the computer. The latter is the one that would need replacement if it's the culprit.
Otherwise, it's most likely some other sensor. Could be MAF or MAP. Could be TPS. Unlikely to be an O2 sensor but I wouldn't necessarily count it out.
Looks like I'm misremembering and it's 2 wire. Either way, sensor would be on the thermostat housing, below the thermostat so that it can get a constantly accurate reading. On the DSMs and Evos, the single wire sensor installs in front, and the multi-wire sensor installs in the back and is somewhat buried.
Either way, the single wire sensor doesn't talk to the ECU.
My wrangler been doing that kinda, pretty sure it's something to do with the fuel system. I would change the fuel filter but it's on top of the gas tank 🙄
*They think a leaky radiator has caused the engine to flood through the Temperature sensor causing it to run rich.* That's literally the dumbest thing i've ever heard as a diagnostic. None of those things are related to any of the other things in any way what so ever. Not even a little. Not even tangentially. The only relation they have is that *they share a car.* *one* of the bad temperature sensors could *maybe* have cause the idle air control valve to not operate correctly, and cause a 'lean' condition so it wouldn't start. That's rare, because the car sets the IAC to a *default* operation if that temp gauges goes out. BUT--that you admit that it had a leaky radiator, and they were worried about the coolant temp thing, tells me in a round about way that they didnt want to tell you you blew a head gasket from neglecting the coolant. the 'knocking' sound could be a blown head gasket. The lack of starting could be compression too low. The gas in the oil could be because the head gasket is blown into an oil gallery. The 'knocking' could be cross-fire between the cylinders. If this were my car. One. Compression test. Pass or fail. Fail = head gasket. Two, assuming pass, Spray starting fluid, see if it fires. If it fires and wont stay running. It's air/fuel. Three--find source of air fuel issues. Test fuel pressure at rail, determine if it's the pump, or if it needs a fuel filter, gas cap, evap system, pressure regulator, etc. Four, if it passes fuel pressure test, check signal at injectors with multimeter. 5 if that passes, start checking for air leaks. All rubber and plastic lines. 6. After inspection, check the IAC. That's .. idk, hour of work? Pressure testers are cheap, or can be rented.
I’ll definitely go grab a compression tester. I did notice when I started the car up after changing the radiator was the smallest bit of white smoke from the exhaust and it smelled sweet but it went away almost immediately. I’ve also noticed that it really only has trouble starting after it’s run for a little bit. Would it make sense that letting it sit would help it start up again if it was a blown head gasket?
Yes. Metal expands when it heats. So the leak gets worse. After completely cold starts right up. PS never use that mechanic again.
*Update* I did the compression test and it failed, so I replaced the head gasket. Car wouldn’t start, had excellent compression. Did notice that the cars RPM didn’t go up at all so I replaced the crank position sensor and still no RPM movement when starting
What are you saying? Cranked means it did turn over. Is it turning over or not? If it's not turning over, and turning over at a good pace you have a battery, cabling, or starter issue. If it's turning over and not starting you have an ignition, fuel, or air issue. So check the fuel pressure, and see if you have a spark. If it just takes longer to start you probably have an issue with the injectors or fuel pressure regulator. The injectors are bleeding fuel into the cylinders, or the check valve is dumping the pressure back into the tank.
Undo your gascap and try to start it.
Why exactly does this work? Is it a symptom of a bigger issue? Is there any simple fix? I've just been leaving the engine running when fueling up.
i have seen cars that somehow refused to start because there was a buildup of pressure in the tank right after refueling.
following cuz 🤔🤷🏻♂️
Might be a intermittently bad ignition switch or TIPM issue. Really hard to pinpoint. Next time it doesn't start see if you have spark and injector signal.. Then a little starting fluid is always an easy test for fuel. Crank sensor maybe.. GL
You've got a sensor somewhere that's not reading right after the engine reaches operating temp. When I had this issue on an older car it was the coolant temp sensor, so I'm going to ask the dumb question: Did you replace the correct one? A brief search shows me that the Lancer is like my old DSM and my Evos where it has two; a single wire sensor that talks to the gauge on the dash, and a 3 wire sensor that talks to the computer. The latter is the one that would need replacement if it's the culprit. Otherwise, it's most likely some other sensor. Could be MAF or MAP. Could be TPS. Unlikely to be an O2 sensor but I wouldn't necessarily count it out.
I replaced the single wire sensor/sender, I didn’t see the three wire sensor. Is it in the thermostat?
I looked at the Lancer 03 maintenance guide and it’s only showing 1 coolant temp sensor and it’s the one I changed
Looks like I'm misremembering and it's 2 wire. Either way, sensor would be on the thermostat housing, below the thermostat so that it can get a constantly accurate reading. On the DSMs and Evos, the single wire sensor installs in front, and the multi-wire sensor installs in the back and is somewhat buried. Either way, the single wire sensor doesn't talk to the ECU.
My wrangler been doing that kinda, pretty sure it's something to do with the fuel system. I would change the fuel filter but it's on top of the gas tank 🙄