Hey everyone-

Just want to confirm a few things before I go about repairing this.

I noticed that the radiator fans are not kicking on after my Laskey Engine swap, at least not kicking on with the thermostat... They work fine when the AC is turned on (as they should, as that is part of the AC dryer circuit, apparently).

The coolant temps have gotten all the way up to 212* before I shut the car down (no AC on, idling in the driveway, waiting for the thermostat to kick the fans on).

I have already corrected the coolant table values within the EMS, so the coolant temps are accurate.

I am going to drive it VERY conservatively until I get this sorted out, with coolant temp constantly displayed via 1 of my serial gauges. My drive to and from work is only about 10 minutes, and temps have not gotten above 205* on my way to and from work yet...

I also re-bled the coolant system yesterday. I noticed there was no coolant in the overflow tank yesterday, and when I filled it, I bled it to get any air bubbles out. A few came out, then I re-filled the radiator w/funnel and coolant until it "pee'd" out of the bleed nipple near the fuel rail. I closed the bleed nipple, and ran the car with the radiator cap open (funnel w/some coolant in it was inserted into the radiator fill port). The funnel filled up a bit with coolant as it was running (which was expected). No more bubbles coming out, I went ahead and capped the radiator. Idled it up, and still no fans.

So, I think it is either:

1) A REALLY pesky bubble in the coolant (I have read that bubbles near the thermstat switch are a PITA to get rid of).
2) Bad thermostat (but it was working fine pre-swap).
3) Bad connection / signal to the switch from the thermostat.

I think I can only really test for #2 and #3... I was going to put 12v through the thermstat relay, to see if that would kick the fans on (that would be testing my connections). If that works, I think the next thing is to test the thermostat... The only way I have read to do this is with a control liquid (such as boiling water).

Any input on this would be appreciated. My mechanic is out of town until this weekend, so I am getting a jump on it myself in the meantime.

Thanks again!

John

 

Do you mean fan switch? Near bottom driver side of radiator?

 

There is also a fan relay in the engine compartment that may have gone bad, check that as well...

 

Yeah, the switch. The thermostat puts a 12v signal through to the switch as soon as the coolant temps reach 192-203 (that is the full-open range of the thermostat, per the S2000 Repair Manual)... I think that is how it goes.

Original post modified to clarify.

I was going to test the voltage into the switch, from the thermostat, when the coolant temps read within the "full-open" range noted above on the serial gauge. This will tell me whether or not the thermostat is passing the signal on correctly. No signal = thermostat not working right (move on to testing that component with control liquid). If signal present, but no fans = bad relay.

Can someone confirm these steps will work (I am not a mechanic, but can follow instructions...).

John

 

Damn I've never seen my temps go over 195.

Hope you get it worked out!

 

That sounds about what I was running before the swap. I saw 200 occasionally in 5 o'clock traffic.

I kill it once it hits 212 (water boiling temp) just to be safe.

I have read 220+ can warp the head... or something like that.

John

 

in a closed system , pressurized cooling system, boiling temp goes way up. there is a little black nipple on fire wall, with engine running and heater turner on remove nipple, run engine until water comes out steady, close, then open the bleed valve near fule rail, again once steady flow close - top off radiator, close cap and let it get up to temp, some are a pain to bleed, your ame ems can control turn on off and that is easily to get setup wrong.