Coolant is burning/disappearing. No leak

[Kyle_83]

Hi

I have a 2005 Honda civic SE Coupe 1.7 (280,000 km) with a new used lowish km engine installed almost a year ago. Im the original owner.

Anyways my Honda is burning coolant. I can smell it burning after a long drive. No leaks. I can drive about 140km distance on Hwy with no issues, but then when I get off the hwy the temp Gage will red line (red hot).

I turn the heater on or up full blast and it cools down and its fine. But sometimes the heater will turn from hot air to cold air and the temp will redline and not cool down unless I Rev up the engine to get the blowing cold air to turn back to hot air, then the temp Gage will cool down quickly and everything will be fine. Usually happens at red lights and once I start driving again and the heater kicks back to hot air then its all okay.

Then after driving that 140km, I will drive about another 25km on a 80km road trying to control the temp Gage from sky rocketing when I stop at red lights.

I will reach my destination, Coolant is not bubbling when I turn the car off and theres no white exhaust smoke. Then I will check the coolant levels and they will be low so after hours of cool down time ill have to fill up the reserve coolant tank and fill up the main coolant tank so I can drive back home.

I replaced the engine a year ago with a used engine with about 150,000km on it. I put in a new temp Gage, all new hoses, new radiator and water pump at that time. Also put in a new exhaust manifold.

I can drive around town locally with no problems, I dont need to refill the coolant every trip as it doesnt leak out. I would add coolant once a week or so when driving only locally.

I have no idea what the problem could be. My friend said the new used engine doesnt sound that great but this is the only problem I have. I only had a 3 month warrenty on this engine and had never went on a long drive so I never had a issue until after the warranty was up.

Any ideas what this problem could be and how I could fix it?

Thanks
Kyle

 

[jackdog1]

If you can smell it burning that probably means it is coming out of the system somewhere; when it gets that hot, is steam coming from any part of the engine? To me, it sounds like maybe your water pump isn't working properly.

 

[Kyle_83]

Nope, there is no steam at all. I looks up my past receipts and I dont see that I replaced the water pump. It was just the engine and radiator last year.

Do you think its the water pump, is there a test or way I could find out without spending all that money to replace it and find out thats not the problem??

Thanks
Kyle

 

[MotorMo]

Sounds like you got air in your cooling system ( heater blowing hot/cool, gauge temp spikes )-
Possibilities?- If not externally leaking,...
- Cooling fans might not be working, or the "ect/fan switch" may be faulty, causing "cool" driving at high way speeds with the increased air movement through your radiator, but stop and go leaves your radiator lacking air flow-- this can cause "boiling" of coolant, but that is normally seen around the resiviour and radiator ( coolant stains ).
-Head gasket failure, which can "eat" your coolant, cause temp spikes, and put air in your cooling system- ( used engine?)
-Thermostat not operating as designed- ( never say always, never say never, but ALWAYS use OEM thermostats- as aftermarket ones tend to be very problematic )
-Radiator cap not relieving pressure/ and, or vacuum properly- ( not allowing the coolant to expand and contract with temp changes )
---Double check all your connectors on your engine swap in case a connector is damaged, not connected, etc

 

[Kyle_83]

Ok thanks, I will look into that tomorrow.

 

[aRoKz89]

blown head gaskets are a common problem on 7th gens. if your not leaking coolant and its being burned there is only one logical answer, BLOWN Head gasket, coolant is seeping into the cylinders and burn out the tail pipe, thats why you smell sweetness in the air.

 

[Kyle_83]

I just noticed there is a small coolant leak. It was hard to notice. I can't see where its coming from. There is a dampness but you can tell coolant hasnt sprayed everywhere.

Do you think it might be the water pump? I havent replace that and the timing belt in a real long time. Theres no white smoke and coolant mixing in my oil for a head gasket symptom.

I hope its only the water pump.

 

[aRoKz89]

its the coolant leak then if there is one, fix the leak and run. if over heating persist then it still might be the head gasket, head gaskets don't always have symptoms of oil and coolant mixing, or white smoke. my car did neither and it still had a blown head gasket. you could take out the spark plugs and look at the inside of the cylinder, if the top of the piston is CLEAN meaning not dirty with carbon build up that is also a sign of a blown head gasket, or when at first startup the car shakes a bit and then goes away that always is cause of blown head gasket.

 

[Kyle_83]

Ok I will check the spark plug test. What about a combustion test, is tht a good idea?

Also how would I go about to fix the coolant leak?