I have a 96 civic with lsvtec swap. My problem is after the car warms up, it will over heat when i'm idling and goe down when i go, but then come back up again when i'm cruising (and thus slowing down) and in gear, and it is also very unpredictable some times and won't over heat and then do it. I have replaced the waterpump a couple months ago when it did this, and it stopped overheating until now, and is doing the same thing again, any suggestions?

 

Blown headgasket for sure 100%. Had this experience before with like 3 engines and a pt cruiser. If it were a thermostat it would completely overheat after a few minutes.

 

i've had the same exact problem before. and it wasn't due to the headgasket, since i changed it twice, and the same problem still occured. I believe this problem was either a faulty water pump, a bad sensor, insufficient radiator(depending on your setup), air in the system. worst comes to worst, if its none of those mentioned above or headgasket, then it can be a cracked head, block etc. good luck.

 

Do the fans work?

 

yes the fan is hooked to be on all the time

 

Intermittent overheating could be due to a thermostat operating erratically. Partial cooling system blockage could also create those symptoms.