Lougibb

Hello. Looking for some help. I've replaced my waterpump, thermostat, hoses,sensors, and cap. I had the radiator flushed and inspected. Had a compression test done to check for bad head gasket. Everything checks out good. Car still gets scary hot when I have to stop after driving for even 30 minutes. No air in system. Got fan switch wired to run constantly. Still no difference. I'm stumped. Any suggestions?

ek9_beast

Is the car indeed overheating? Could be a faulty sensor. What sensors did you replace?

Lougibb

Fan sensor switch and both of the sensors in my cat that I just replaced. It's got 218k on it. New timing belt and east also

Lougibb

The coolant boils into the holding tank everytime

Lougibb

If there's anyone who might have some ideas I would be forever grateful. I'm a decent mechanic but haven't ever had this much trouble diagnosing the problem.

f15Civic

Which thermostat did you get? Some ppl have had issues with aftermarket oem replacement ones getting stuck close which is why they recommend getting the Honda OEM replacement from the dealer. Also you have you tried running the car with no thermostat?

NotARaCist

iTrader: (1)

"Everything checks out good" doesn't really tell us what we need to know. What were your compression test numbers? Did you do a block test?

Lougibb

Don't remember what the numbers were. Guy said they were good. What about the metal line that runs across the back side of the engine? Could that be clogged possibly?

tony_2018

The coolant shouldn't be boiling at all. you got other issues. Check for combustion in the coolant. Your local parts store can help with that.

NotARaCist

iTrader: (1)

Block test. Block test. Do. A. Block. Test.

Jimi Hondrix

+1. Rent (free) a block tester and purchase testing fluid (blue color) from Autozone, O'Reilly's or other major parts store. Many youtubes how to do the test..best to find a Civic specific one. Another way to suspect a head gasket leak is a loss of coolant in radiator with a subsequent gain of coolant in overflow tank... is this the case?

If. you confirm a blown head gasket with block tester then do a cylinders compression test. If, you're getting good compression then maybe it's worth doing a head gasket replacement. If, the compression is bad in one or more cylinders at the mileage on that engine..best to replace engine.

Lougibb

Thanks. I will test it later this week and report back. I appreciate all the advice from everyone. Just need it to get me to work a couple more days and then I can rip it apart if necessary

thehondalyfe

you'd be better off diagnosing the real problem before just driving it to work. you said there was no air in system, did you burp it? if your coolant isnt flowing properly and you are overheating you run the risk of blowing the head gasket. if you replaced anything that opened the cooling system (which you did) you need to burp it. also i would take out the thermostat and heat it in water and watch to see if it opens. lines could be clogged if some type of no-leak **** was used in the coolant, but other than that im not sure. also wiring the cooling fan to run constantly isnt good either and isnt going to make your coolant flow. and it wont cool down the car enough to keep your head gasket from blowing. i know because ive experienced that. guy i bought my civic off of had it wired to a toggle switch..... and i bought this before i really knew how to really do any maintenance, im still learning, but needless to say i ended up having to replace my head gasket. but now im rambling lol i apologize XD