2001 Honda Civic Repair Question
01 Civic Overheats Only on Freeway
Asked by 01CivicLXSedanAnswer
I believe your problem is fan related. Does the cooling fan kick in. Check that out by turning on the A/C. Does the cooling fan kick in? When it starts to overheat on the roadway does the fan kick in? The heating system acts like another radiator only smaller.
I'm so sorry - I triple-checked my post and thought I had included all of the pertinent information. After installing a new thermostat and rubber seal (gasket), I idled the car in my garage on blocks at 1500 rpm to open the thermostat and purge air from the system in accordance with my Chilton's manual, and the fans kicked on twice in this process as described in the manual with the temperature at a normal fully warm setting (although without the A/C on). Original timing belt and water pump, but not req'd until 105000 miles according to service manual. I am thinking this might possibly be a plugged radiator somehow (?).
Personally I think 105,00 is too long for a rubber timing belt, im more of a 70-80,000 guy.Irealise the exhaust smells OK, but I would have it chemical tested to be sure. T-stat open in the garage, bring rpm's up and be sure one of your hoses isnt collapsing, ie- upper or lower rad hoses.
I tried a new radiator cap today after work and drove it on the highway again. No luck, same symptoms - the car will run very hot at high speed (70 mph, especially uphill) and it drops back to normal (2/5 of gage) as soon as the heater is turned on. I also tested the collapsing hose tip; after returning home I gunned the throttle body with my thumb and saw no sign of hose collapse. Starting to really think this is a bad radiator somehow, but not ready to jump to conclusions. Great site; great advice!
You've done about everything, the radiator is next. I just bought one on ebay for $5 and it is brand new. Paid $25 shipping and handling but it was very nice and was a perfect fit. Just checked and there aren't many on ebay to choose from for your model and year.
Good tip Bruce. Thats where I would go next
Yes, that was a good tip! I finally had a chance to swap radiators this weekend, used a Koyo model and got it done in one afternoon. Took it out for a test drive this evening and it runs like new, no overheating problems, even uphill accelerating on the highway w/ the AC on! Thank you all for the great website and advice.
Some advice of my own for other DIY mechanics - the engine drain plug is a bear to get at, had to use a 1/2" drive ratchet w/ 2" extension and universal joint to get it out. Sometimes the owner's manual is a good source too - I flipped through it after finishing and discovered I was supposed to put non-hardening sealant and a new washer on the plug; Chilton's never told me that! We'll see how long it holds for without leaking.