Car requires extra cranking after overheating incident

2000 Honda Civic LX sedan, manual trans, 161K miles and a fair amount of neglect, but this is my $1000 beater. Car is stock.

Yesterday (Friday night) I was driving around a parking lot and noticed that my coolant gauge was starting to climb. I pulled to a spot and let the car idle, thinking that would help it cool down, however the temps continued to climb on the gauge. I shut the car off, checked the coolant (it looks/smells fine and nearly new, as does the radiator, which was replaced recently), and felt that the lower radiator hose was fairly cool to the touch. It was a hot day, though this was maybe 9 PM, so it had cooled down. I drove home with the heater on (turning it off got the temps up quick) I had heard some air in the coolant system after shutting the car off previously, so I figured I’d burp it. The car never got over the 3/4 mark on the coolant gauge.

I burped the coolant first thing this morning before driving the car and a few bubbles came up. Topped it off after burping and drove to work with zero issues. On my way home from work, after the car had been sitting idle for a couple minutes at a stop light after a freeway drive, the temps started to climb, however it was 100 Fahrenheit outside and the A/C was on. The fan does come on for both the A/C and the coolant system normally. I turned the heat up, temps went down within seconds, turned the heat off a minute later, and the car refused to climb in temperature again. I sat at idle for several minutes when I got home and nothing came of it.

I did notice that, this morning and before I left work, the car required a couple extra cranks to start. It still does now that it’s cooled down, but I can get it started quickly by holding the throttle wide open. I’m worried that I may have cracked the head or damaged the head gasket despite the car not seeing temps all that close to the top of the coolant gauge. My guess is that the thermostat might need replacing, but given that the oil and coolant look and smell fine, are my concerns over the head necessary? Why would the car now suddenly have difficulty starting quickly? Thanks.

I think your head gasket might be on the way out. The overheating even though both fans work and the bubbles in the coolant is a hint. The head gasket may be the cause, not the result of the overheating.

I would suggest buying a test kit that detects the presence of combustion products in the coolant. $30 or so available at auto parts stores.

Couldn’t hurt to run a compression test as well. If one or 2 cylinders are low, that would explain the long crank times.


I suspect that the overheating incident may have led to a warped cylinder head and/or a breached head gasket, thus causing low compression.


The cool lower radiator hose would point to a thermostat that is sticking closed. Just my 2 cents, but I consider a thermostat a maintenance item that should be replaced every so often. It’s cheap don’t fry an engine insurance.

As for the starting, that may be coincidence. This could be caused by the main relay or ignition switch. Both parts are in the same circuit and both fail for the same reason; high electrical current draw due to the engine management and fuel pump in the circuit.

These cars are under a Recall for the ignition switch which can cause starting or stalling problems. Call the closest Honda dealer, provide them with the VIN, and they can tell you quickly if you can get the switch replaced free of charge.
IF this Recall has been performed in the past then you are out of luck as Recalls are a one-shot deal but that’s not to say the switch is not failing again.


Alrighty, I checked the head gasket with a NAPA kit and it checks out fine. No coolant in oil or vice versa still. Why does the car take so long to crank after this incident though? Bad coolant temp sensor?

I’ll be replacing the thermostat with OEM unless someone has a better/equivalent and cheaper alternative. Thanks for the help y’all.

^ This. Stuck thermostat, the rest could easily be coincidence. At a guess, possibly the throttle body needs to be cleaned or the fuel pump is on its way out.

The crankshaft position sensor may have been damaged when the engine overheated.


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Thanks for the reply. I cleaned the heck out of the throttle body and it didn’t seem to make a difference as it was already decently clean. Fuel pump makes zero noise at all.

However, after putting a new tank of gas in the car, the car no longer cranks like crazy on a hot start now. I’ll have to report back tomorrow AM to see if it still has issues in the cold.

Thanks for letting me know about this. I’ll look into it if the car still has cranking issues tomorrow morning.

The fuel pump is weak. And when the tank is filled, the pressure head that’s created from the level of gas in the gas tank assists the weak fuel pump.



I suppose it’s barely possible you just got hold of some bad gas. Just a guess though. As Tester says, more likely a fuel pump problem.

This is only the second week it’s been regularly driven as it sat in quarantine for several months. Possible the gas went bad from barely driven and it’s only just now being cycled. Hard to say. I will say that the car has been fine since it got new gas and that’s all I know for sure. I’ve done some digging and I found this thread interesting.

Guess I’ll find out tomorrow when I start my car on a hill (my driveway is very steep, as is most of SW Portland). My work parking lot is totally flat, so this might be why I had no starting issues there, but I did have a full tank.

Quick update: car has a full tank of gas still, only barely driven it today. Been teaching a friend how to drive a manual trans and he stalled the car aplenty, and each time he restarted it, it didn’t take a bunch of cranking. Didn’t take a bunch of cranking on my driveway either.

Car was low on gas both today and yesterday and required more cranking. Replaced both the thermostat and radiator cap and the car no longer overheats.

The car should not take a “bunch of cranking” or even a short period of cranking. It should start near instantly no matter the tank fuel level if things are correct.

Have you considered the fuel pump and the Recall suggestions that were made over 2 weeks ago?

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Another update: nope, car still overheats. Car starts fine with a fresh tank of gas. Guessing the fuel pump can lead to the engine overheating since the fuel isn’t cooling the engine?

It still makes no noise and the car has plenty of power.

Car’s recalls have all been taken care of according to Wilsonville Honda.


Thank you for this. I have almost all of these symptoms apart from the noises.

Ok y’all, yet again, even after replacing what appeared to be a crappy aftermarket fuel pump with an OEM one, the car still overheats a little bit. I did notice the car has quite a bit more gumption from my butt dyno and also doesn’t have any slight hesitation or anything, but the car, after letting it sit for 5 minutes at idle, had gotten the temp gauge up to the 3/4 mark yet again. Car has 3/4 of a tank of gas right now so I’ll have to see if it solved my cranking issue. The cooling fan does come on and help prevent the gauge from going into the dangerous temperature territory, but I’m wondering if it’s my next culprit.

The A/C compressor also went out on me the other day and slipped both its belt and the power steering belt off on the freeway, so that was nice. When it was working, running it while idling got it to overheat faster.