95 Civic VX Engine Cooling Issue

[wandering albatross]

Also, I will double check that the coolant system was properly "burped."

[WD40]

YES that's a huge issue I totally forgot about.

[me and my metro]

I had a Ford Escort years ago that would only overheat on the highway, it was perfect around town. It had a restricted flow radiator, new radiator solved the problem. It is possible that the three row radiator could be flowing too much water and not removing enough heat. In a stock car we set temp by changing to size of the restrictor we used in place of the thermostat. We ended up with a 5/8" hole to keep the temp where we liked it in Bakersfield. The 11/16" hole ran hotter due to the water moving too fast through the system.

[California98Civic]

Absolutely do the flush and tests before anything drastic. But...

Back in NYC and NJ driving cabs, we used to crack the hood open so that the summer heat and AC would stress the engine less. The latch of course holds the hood down from flying off. Sometimes I do that now (very rarely).

Do you use the internal air recirculation setting on the vent system? If you do, you'll find you can shut the AC off for 10 or 20 seconds and still be blowing quite cold air. That might be enough for some hills. You could cycle the AC on/off during longer climbs.

Also, easier than adding another radiator fan would be simply to wire a switch to bypass the ECU's control of the OEM radiator fan and turn it on whenever you wish.

[wandering albatross]

I added a Spal 11 inch pusher fan on the front of the triple core radiator and it helped dramatically. I am still using the 12 inch Mishimoto puller fan with the aluminum shroud. The two work fine together.

Also, I added the Spal relay kit and tapped into the Civic's existing fan sensor. Both fans come on at the same time. The Spal relay kit is well worth the money - the quality is top shelf.

The 11 inch fan fits perfectly on the front of the radiator. If a 12 inch is used, it will "fit," but will rub against the vertical center reinforcement beam that runs across the radiator intake duct.

The only down side so far is that the Spal fan has straight blades and is much louder than the Mishimoto. The Mishimoto also has straight blades, but does not spin at the same high rate as the Spal and appears to move less air despite the higher CFM rating (~950 cfm vs ~1,100).

In the winter, I might pull the fuse on the Spal and just run the Mishimoto to reduce the noise. In motion it is difficult to hear, but around town, it sounds like a hint of a leaf blower. The curved blade fans are supposed to be quieter, but slightly lower CFM. Spal did not have a pusher in that size with the curved blades.

Here are the Spal part numbers that were used.
11 inch Spal pusher fan: 30101502 11" Medium Profile Fan - Straight Blade - Push
Spal relay kit: FRH

The high performance Spal fan has a taller motor by one inch over the medium profile that I used and will rub against the AC line that crosses the front of the radiator. There are three different motor heights (low, medium, and high performance). If you don't have AC or are okay with significant bending (medium profile requires moderate bending) of the AC line, then go with the high performance version for additional CFM.

I have done a moderate amount of testing in the mountains at altitude in the heat with the AC and it has not broken 50% on the gauge. I have a desert trip coming up and it will be around 110F so that should be an exceptional test.

Let me know if there is any questions regarding sizing, wiring, performance, etc.

[wandering albatross]

I did more driving in 110F and in the mountains and the car generally runs below 50% on the gauge. In some extreme situations it will sit at 50%, but if the AC is turned off it quickly drops back down to its normal 40% gauge location.

Overall, the pusher fan has made a significant improvement. Highly recommend.