Heat / Over Heating Question
 

I have an 01 Civic EX - vtec - 5 spd

I just bought it used 90k miles on it. It runs great the only problem I am having with it is that when i am driving the heat (sometimes takes forever to get warm) will just get cold. A minute later the temperature will start to rise. It will get to to about 3/4 up the heat gague...then cool back down to about half. It normally runs a little over 1/4 on the heat gague. I took it back to where I just bought it, the Honda place flushed the radiator...and put new thermostat in it...but no go still same problem. Driving along, heat goes cold...temp goes up. Any suggestions. I have had it in the shop 3 days and thats the best they could come up with. Also when the heat starts to get warm...the car will cool back down to its normal position usually.

Re: Heat / Over Heating Question (odarkshineo)
 

my honest opinion is who cares if that's the best they can do. They sold you a car that should be working and it's not. you didn't buy it under the terms that your car will heat up and we can't fix it. they should fix it.

Anyways my gf car had a similar issue. we checked all the hoses, changed the thermo, changed the radiator, flushed and refilled.

the problem was that the previous owner took shit car of the car and the head was cracked from the heat why the heat kept rising.

Re: Heat / Over Heating Question (odarkshineo)
 

o they are taking care of it, I just picked it up this evening as they closed I gotta run it back out their tomorrow or monday...The car is in GREAT condition. I wouldn't think the head was blown. Everything under the hood looks good, and the car itself is in amazing condition.

Re: Heat / Over Heating Question (odarkshineo)
 

we thought everything under the hood looked good too. that was the last assumption - engine head being cracked - and it was right.

well hopefully if someone else has more data on this that they can spare would be good.

sounds like a head gasket.

It sounds a little fishy for a head gasket, but worth a compression and leakdown test. The fact that it waivers around make me think its that valve in the heater line on the firewall sticking though. I'm not sure why that would make the temperature gauge flutter around though. Get an OBD scanner with realtime readout, you can monitor what the engine temp sensor is actually reading, see if the engine temp is actually fluttering around. If it is... and its cooling while driving and heating while stopped, you need a headgasket. Its all too common on these cars.

nope its a head gasket the d17 is funky like that

Re: (DankasCivic)
 

Sounds like low coolant, aka air going through the line, mine does it when it runs low, I blew a small part of my headgasket so it ingest's it slowly, but when it gets low, air goes past the thermo sensor, kicking it way up, then it falls back down, the heat goes cold too.

Check for bubbles @ your radiator cap (with it off) when the car is running and even better park it going up a hill to drive the air forward.

Re: (RISRdotNet)
 

Well the dealer had about decided it was the head, but then decided to put in a new radiator...a larger one I believe he said. I went and picked it back up and drove it around town today it seems fine...again...Could the new larger radiator be just a way to get around the head being blown and ignore the overheating? Would it still run hot with a larger one. Also...their seems to be coolant dripping/blowing on the left side under the resevior but can't tell where its coming from. Also, at one point they said they looked at the spark plugs and one was cracked...supposedly when they replaced it the car started acting up even worse (this was before the new radiator). Any thoughts? Maybe it was the radiator...or maybe the larget radiator is just a cheap fix just to get me to take it off the lot.