CarTalk.com Blogs Car Info Our Show Deals Mechanics Files Vehicle Donation

A non-starter

Our 98 Mercury Mystique starts right up when it is cold. But with a full tank and a new battery it now has to cool down for about 30 minutes after being run before it will start??

Have you tried a flood clear (gas pedal to the floor while cranking) when the problem appears. If you do get a start with a flood clear, look at the Coolant Temperature Sensor for the correct calibration and its wiring for a short.

Reply with response to flood clear and we can guide you further.

The Mystique did it again this morning. Drove to the clinic, went in for about 25 minutes, came out and, viola, another non starting episode. I tried flood clear four times with no result. Went shopping for about 20 mintues and when I returned, it started right up.

BTW: the radiator low water light - cute little icon on the dash - has been on for about a year. My mech at the dealer!) said it was a sensor that went haywire and was not worth the cost of replacement unless the little orange glow bothered me.

No comment yet on the no start,but you do want the sensor fixed,did he give you a price and let you decide? There should be little labor involved much more so the part,I don’t mean the part will be in the hundreds,but I have not priced it.

Did it again. Waited three hours. Tried at least six times - no stat. Just before tow truck arrived, the SOB stated on the first turn!!!

WTH?

mlaw66

a sensor that went haywire and was not worth the cost of replacement unless the little orange glow bothered me.

I guess he did not consider not knowing if your car was overheating was important. With that light on all the time, you have no warring of a problem until it is too late.

When you say it will not start, do you mean when you turn the key the starter is moving the engine, but it just does not start, or do you mean the starter does not seem to be doing anything?

Assuming the starter is turning the engine, I would look for an ignition problem, maybe the coil. They can become heat sensitive.

Has anyone checked the computer for any error codes (other than that light)… Hey could that be the CEL and not just a temperature light?

At a basic level, the engine needs three things to run: fuel, spark, and air.
For the air part, just make sure the air filter is clean.
For fuel, you have determined that it’s not a matter of too much fuel; so, let’s check for too little fuel. When the vehicle doesn’t start, spray a shot of STARTING FLUID into the large, black, plastic intake tube. You may disconnect a small tube connected to the large intake tube. If it starts, and runs a few seconds, it’s a fuel-into-the-engine based problem (fuel supply, or, fuel injection).
Spark. The engine can have all of the fuel and air, in the world, and still not run, if it doesn’t have that spark. Get a test spark plug (that clamps onto the engine block) from the auto parts store. When the engine does it’s, “Nope, not me! Unt uh!”, you can disconnect a spark plug wire, clip the wire to the test spark plug, clamp it to the engine block, and have someone crank the engine while you watch for spark across the gap of the test spark plug. There should be a spark every 2 or 3 seconds.
Whatever your findings, tell your mechanic. You could, also, tell s/him about this diagnostic tool: http://www.lenehanresearch.com/what_quits_first.htm

I’d be inclined to look first at the ignition system. This is a classic sign of a coil breaking down when hot.

Hi Researcher,

I’m excited to see that you link the starting problem with Coolant Temperature Sensor. My car also has this problem, and I did notice that the temperature gauge fluctuate a bit when I’m driving my car. How to calibrate coolant temperature sensor? May I just get a new one instead?

My car is a 96 Altima. Thank you.

Hey folks! I found the problem. The exectronic leads to and from the COIL were probably a little loose. I tightened the connector with my fingers and have not had a nonstart since!!

Hoooray, and thanks for the prompt response and good advice from all of you.