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EG with B16A SiR2 swap, the radiator/fan are from the stock motor (d16..)

I was driving on the highway today for about an hour (at about 70-75 mpg, 4K rpm) and the temp gauge went up from the normal 'honda' position (about 1/3 up) to around 2/3 or 3/4, not into red tho. Is this okay and would getting a better radiator/fan fix this? If not what else could could it be, i really don't want to blow a head gasket or warp the head. Thanks
Originally posted by Calesta@Aug 9 2005, 10:57 PM
Not ok

Check to make sure your fan is working, that you don't have a leak, and that your coolant is topped off.
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You need to get your fan(s) working, but def check your fluid, as cal said u may have a leak, i did and mine started to rise, or if your in a jam, turn off a/c and put on the heater on full blast and put down the windows, the temp will drop.
Ok will do, I'm assuming if I have a leak there will be fluid under my car and if the fan turns on at all it's working..

The weird thing was it only happened on the highway with extended driving...around town it's fine, even reving up and doing pulls to redline every so often...On the highway if i coasted in neutral when it was rising or after it had risen and fallen..the temp would rise slightly then when I put it back into gear and accelerated slowly the temp went back down...

I have to make a 6 hour trip this weekend, should I just replace the fluid and replace the temp switch/thermostat to be safe? I will be replacing the radiator/fan/hoses next week for sure but i really don't want to screw up the engine this weekend...If it starts to rise and I pull over and let it cool off would that be safe enough to not cause any damage this weekend?

I'm also guess that the fan switch and a thermostat for a USDM B16 (99-00 Si) will work for the 92-95 JDM SirII? I know the 99-00 Si has two switches, does the 92-95 as well? Which one do I replace?

Sorry for the long post. Thanks!
You may also want to check your thermostat for your coolant, sometimes they have a dendency to jmp around like that when they start to wear out, mine jumped right into the red for like 5 minutes, then back to proper temp.... might as well change it while your in the neighbourhood.
Considering you are going on a road trip I'd change out the cooling, and thermostat.... if it's in your budget you might want to get a rad flush, usually they throw in a stat and fluid free if you do:/
Yea I know B series is B series, my hands were moving faster than my brain lol, happens when i'm nervous about blowing another motor <_< . Thanks for the feedback i'm going to replace the coolant and thermostat today and when i get back replace the radiator/fan
Well I replaced the thermostat and coolant (not the fan switch tho b/c they didn't have it in stock) and as far as distributing the coolant through the whole engine I let it run and warm up with the cap off to bubble out the air pockets then turned it off, refilled and closed the cap and re-warmed up the car. All the hoses are hot and there isn't any overheating (knock on wood).

My question now is through this process the fan didn't switch on at all. When the bottom tube to the radiator had not filled yet the temp gauge rose some above normal and the fan still didn't switch on...is this an indication of either a dead fan/switch? Thanks.
You would also be suprized at how many radiator caps fail and people start changing water pumps, radiators, thermostats, fluid, etc. and it is still overheating when it turned out to be a $10 cap, I've seen it all too many of times and the customer is out $300+ for their mistake. If you don't have a cap tester, I'm sure you could ask a guy at a small shop to test it for a nominal fee. Yeah, I know what your thinking "Well it is going to cost me the same to get it tested as a new cap, I might as well get a new cap" well, don't you want to verify that was your problem???
if your fan didnt come on id check the fuse...happend to me once i was all worried my car over heated once. i couldnt figure it out but the fan wasnt coming on so i pulled it out and wired it directly to the battery and it worked. i thhough that maybe it was just the plug. as it turns out it was a fuse.
K I'll get the cap tested and check the fuse on lunch.

Can anyone help me out and tell me which fuse is the one for the fan (Amps and location)? My car didn't come with one of those little cheat cards. Thanks.
K I'll get the cap tested and check the fuse on lunch.

Can anyone help me out and tell me which fuse is the one for the fan (Amps and location)? My car didn't come with one of those little cheat cards. Thanks.
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underneath steering column, believe she's a 15 amp, had same problem but was coolant temp. sensor, in block, not signalling fan
If the fuse is good and the fan motor isn't dead it's either the temp coolant sensor or the fan switch itself right? Is there any easy way to test the sensor and/or switch? Wouldn't the ECT sensor throw a code if it was bad?
Well I got to my destination without overheating...but the temp gauge did start to rise like before...I turned on the heat and rolled down the windows for the rest of the ride and it was fine...I'm not loosing coolant, just replaced the coolant/thermostat and had the cap pressure tested...I'm replacing the radiator cuz some of the fins are rusting off and it's a d series radiator.

The only thing i'm still trying to do is get the fan to turn on..any easy ways to troubleshoot what is wrong with the fan system (sensor, switch, fan itself)?
There is a real small coolant leak, I have to find our where it's coming from but over a 3 hour trip it lost maybe 2-3 ounces of coolant..

Update: I jacked the car up and ran it but i couldn't find where the leak was coming from...where ever it is it's real small, but i would still like to find it and fix it. If it's a leak it has to be from a hose or the thermostat housing right? Is there any thing major that would cause a coolant leak? Thanks..
Replaced the ECT sensor and now the fan clicks on so i think that's the overheating issue...still have a small small leak but oh well, i'll find it eventually
Yea I'm going to do that this weekend I just didn't have a chance...plus I got freaked out that my headgasket might be on it's last legs, but since the ECT was bad i can't imagine the leak is a HG..If it's not a hose what about water pumps do the seals on those ever wear out and leak?
I have a question on something too. I have a GSR (in 95 civic) and its turbo. i am having the same problem with the overheating. I have been driving with no bumper and no hood (for this reason) and its still getting hot. My fan is kicking on, I just dont know if its staying on long enough. I am going to try hardwiring it and see what that does but does anyone els have any ideas?