I have a bunch of cooling mods, and during the cold months, I see my temp guage drop from 3 bars to 2 pretty regularly. However, it is NOT cool here anymore. Last night I drove about 40 miles on the highway to my dad's house, then 40 miles back. I guess it was probably in the upper 70's, and I had the top down with the vent on cool (no A/C). The temp guage got up to 3 bars at the 1st stop light, but once I got on the highway, it dropped back to 2, then later down to 1, and I couldn't VTEC or go above 7K RPMs. It wouldn't stay at 1 bar for long before going back to 2, but it would drop back to 1 again about every 5 miles. It stayed at 2 bars the whole trip back home.

To my extreme surprise, it is still staying at 2 bars today, and it is in the upper 80's or lower 90's, and I didn't even get on the highway. I drove a 10 mile round trip to the post office, and it would go up to 3 bars at stop lights, then drop back to 2 bars once I got back up to speed.

My first guess is that my Mugen thermostat is sticking open, but I didn't think the cooling system was so efficient that it would be able to maintain 2 bars in such hot temps. My second guess is a defective temperature sensor, and my third guess is a defective ECU. Any suggestions? I know I can pull the thermostat out, but I suspect that it is closing when the car is off, since it does warm up quickly. How would I test it? Are there actually 2 temperature sensors (1 for the guage, and 1 for the ECU)? If so, I could borrow an OBDII scan tool to monitor the other sensor.

 

I only have the thermostat and radiator cap. I was on the dyno consistantly hitting 180-185 at a high. Everybody else was at ~195. This was only with the thermostat. The fan switch will possibly make it that much cooler.

Though it is interesting that you say this about Mugen equipment. That is because I have only heard of this 2 bar thing happening with Spoon cooling equipment. Do you have a mugen thermostat and a spoon fan switch?

Definitely get a scanner on there to check the temps.

 

I have all the Mugen cooling equipment and the vented hood, my engine temp always stays at 3 bars regardlessly

pinky is right, that 2 bar thing only happens to Spoon cooling mods

 

You can borrow my carchip for a couple of days and plot what is happening, but that will only tell you what the ECU is seeing from the sensor. If the temp reading looked normal before the thermostat change it seems reasonable that the first thing to do is pull it and test when it opens and closes.

 

try to switch back to oem Theormstat and fan switch and see what happenes

I dont think its normal to drop to 1 bar while driving

 

the helms manuel shows how you can test the termostat, check it out!

 

cool

smccurry has the Mugen thermostat, fan switch, and radiator cap alone with the hondata insulator piece...he claims his car runs at 2 bars sometimes as well.

 

I have had the Mugen thermostat, fan switch, and radiator cap for about a year (20K miles). As I said, during the winter, I could maintain 2 bars on the temp guage if my heater was on, and I was at a higher RPM. It never dropped back to 1 bar though.

I guess I should just go ahead and remove the thing and test it. I saw the test procedure in the Helm's manual. I was just hoping there would be some easier tests. Cdelena, thanks for offering the carchip. I would like to see how it works. However, I will probably just borrow TypeSH's Techtom, since it provides a real time display.

 

gernby when your driving your car in summer during a hot day...do you have 3 bars or 2?

 

Normally I would have 3 bars during a warm day. Last night was the 1st time I've ever seen it drop when it wasn't cold outside.

BTW, anyone know if there is any sort of warranty on the Mugen thermostat?