Engine not warming up

[Félix]

Hi.

It is currently -33 degrees celsius (-31 fahrenheit) in Montreal, Quebec. My Honda Civic 1990 is having alot of trouble warming up. Yes this is very cold, but keep in mind I’ve had many different cars that have not behaved quite as bad in the cold. Whenever it is at least -15, the engine will take a while to get to normal temperature, especially if I turn the heater on to defrost the windshield. The temp. gauge can also drop if the heater is on high. Also, there are surging noises coming from the engine and alot of rattling coming from the body, suspension, etc. Last thing, the clutch pedal feels normal halfway, then theres kind of a notch and normal again.

I flushed the radiator a month ago. I am pretty sure that I got all of the air out, I let it run without the cap for at least 15 min, plus I pinched the hoses lightly until no bubbles came out. I also changed the thermostat and gasket (I bought a Prestone one, wasn’t cheap, plus the best gasket).

I love this car (when it isn’t cold), it has 65k miles, no leaks at all. What do I do?

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[Its me]

Normally I would think your thermostat is stuck open, but since you replaced it lets rule that out (unless the temp range for it is much lower than OEM or installed it backwards/improperly (some have vents that need to be mounted at the 12 o’clock position)). Are you absolutely sure the vehicle is topped off with coolant? Do the surging noises sound like liquid moving? Air in the system is a concern as well (did you run the heat on high when you did this?) The Lisle spill free funnel does a great job of ensuring that you truly have bled the system… Eric has a great video on this…

-Karl

[Félix]

Hi and thanks for the reply.

Is it possible that I absolutely need an OEM thermostat?
And yes, I am quite sure I bled the coolant properly. I do not have a spill free funnel, but the one I have still stands there without me holding it. I filled it and could watch the bubbles coming out of the funnel. I took it out 5 minutes after the coolant stopped draining and the bubbles stopped coming out.

[Its me]

I would not say you need an OEM thermostat, just one that opens at the OEM recommended temperature for your vehicle… Also, some thermostats have a vent/bleed hole that must be placed at the 12 o’clock position… I don’t know if yours has one, but if it does, I hope you put it at the right position, this helps the bleeding process…

I highly advise you to re-check your coolant levels… Many times in cold weather if a car does not come up to a good working temperature it is either the thermostat or the coolant level…

-Karl

[Félix]

My thermostat had that bleed hole and I did put it at 12 o’clock.
I will check the levels again, but seeing as the overflow reservoir is at the right reading, I doubt it needs more coolant. Plus with low coolant, wouldn’t the engine overheat?

I’m trying to learn car mechanics but it seems like the problems I get are always the worst case scenario, or the part that can’t be found, stuck bolts, but never ever the simpler solution.

[Lorrin Barth]

Did you own the car last winter? If so, did it warm up better then?

[Félix]

No, I just bought it in november. The reason I bought this car is to learn the basics of car maintenance and repairs. I figured an old Honda would be the easiest and cheapest to learn on.

[Its me]

[quote=”Boisclair” post=8615] I doubt it needs more coolant. Plus with low coolant, wouldn’t the engine overheat?[/quote]

Nope, In cold weather, the inability to provide heat and heat properly can be due to low coolant…

-Karl

[valde]

Many times non oem thermostats have bigger “leakage” (amount of coolant that goes through it when its closed) than oem. This could be problem with yours. I have seen it on old Toyotas a lot. You normally notice it only when its colder than -18c/0f.

[Lorrin Barth]

^^^ I agree. Aftermarket thermostat quality went to pot more than a decade ago and it has never come back. Try OEM.

[EricTheCarGuy]

First, I’m not convinced you bled the air out properly. Civics are a pain about this. I would recommend you follow the procedure in the video Toyota Karl posted to the letter. This means running it at 2500 rpm with the heat on hot, the blower fan off, until the cooling fan cycles. Failure to follow this procedure can result in air still left in the system.

Second, it just so happens that the thermostats in this video are out of a Civic. That said, you can see that the aftermarket is much quicker to open and close over the OE. Meaning that it would likely run cooler with an aftermarket t-stat.

[Félix]

Thanks everyone. It seems like you’re all on the same page that it can only be either the thermostat or air in the system.
Although I could only run it at idle because I was in an indoor parking and I couldn’t make too much noise or emissions, I did let it run for at least 10-15 minutes, I did have the heat on hot with the blower fan off and I pinched the heater and radiator hoses gently until no air came out. I’m pretty sure this also solved my problem where I couldn’t get any heat in the cabin.
I tested my thermostat as per your video and everything seemed fine.

I started it after only a few minutes instead of the 10-15 I used to wait before and the problem might just be that I’m worrying for no reason, and -30 weather will do this to a car.

And again, thank you everyone, it is great and empowering to learn how to do all these things myself.

Also, does anyone know the cheapest way to get Honda parts in eastern Canada?

[Author]

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