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Q: Car Won't start

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Our radiator blew out, we replaced it along with checking all hoses. Now the car Won't start. It tries but doesn't. We've checked the oil, and plugs for signs of cracks and leaks and found nothing. Checked the engine pulley to see if the motor was seized up, all working fine. Checked for loose connections, wires, hoses,etc. No diagnostic codes come up when scanned. I've read about a safety sensor that shuts the engine down to prevent damage but can't find anymore info about it. The car was not over heating before the radiator blew. The break in the radiator was located up by where you add coolant. The car was parked at the time it happened and idling with the ac on for approximately 5 minutes. We greatly appreciate any suggestions on what to check for next.

My car has 205000 miles.
My car has an automatic transmission.

Hey there.

First off, it looks like you’re doing a good job with the diagnosis part of trying to find the problem by tracing all the normal suspects. In some cases, this problem is caused by a malfunctioning Mass Air Flow Sensor or MAF sensor, a blown head gasket (but you didn’t find any water in the oil it appears). The safety sensor you’re referring to is actually a fail safe inside the ECU of your 2002 Jeep Grand Cherokee and is often tripped if you replace anything electrically powered - like unplugging the fan and thermostat without taking the negative battery terminal off prior. The issue could also be caused by excess water from the original leak getting inside distributor or ignition system components.

If it is the ECU, that’ll need to be reset by either the dealership or by an ASE certified mechanic that has that process down. I think your best bet is to contact a local mechanic and have them diagnose the starting fault and repair that issue for you. Thanks again for writing in, we hope you find the problem sooner rather than later.

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