Ok so a few months ago my car started overheating. I replaced the thermostat & the rad fan switch. All was fine until a week or so ago. Now it’s having the same problem. After you drive for a while, then come to a stop, the temp gauge rises over the half way point; drops when you move again. The needle is still high for a bit, then drops to a bit over/under the middle. If you sit too long it’ll happen again.
This is a 93 LS w/ the stock B18A1
I’ve gone through everything I can think of:
replaced thermostat again (not sticking)
flushed radiator. (not clogged/ no bubbles)
replaced coolant temperature sensor (manual says its for the fuel injection system, so I don’t know)
replaced temperature gauge sending unit (no false positive signals)
check condensor & radiator fan relays (used jumper wire on plugs, still kick over)
hot-wired fans to battery (fans not dead)
can’t find any leaks or squeeks @ the water pump. Coolant wouldn’t flow properly if this was bad, right? My thermostat still opens.
Could the rad fan switch I replaced a few months ago be failing? Replacing that switch did the trick last time. My only other option is to wire the fan to run constant when the engines on, but I don’t wanna “ghetto up” my system like that.
The manual says bad ignition timing can cause overheating, but what are the other symptoms of that?
For some reason I think it’s the fans.
If I warm up the car & wait for the fans, it takes about 15 mins; then BOTH rad & condensor fans come on simultaneously for about 15-30 seconds. I don’t notice them when I’m on the road. When the car overheats, they don’t kick in to decrease rad temp. Last night the condensor fan did come on & stay on for about 10-15 mins after the car was shut off, but its done that always. Not really hearing it that much lately though.
Any help is appreciated. Thanks in advance.
BTW- I know this thread is about overheating, but I think the root problem is electrical, that’s why I chose this section instead of Stock Engine Components.
:getsome::manual:
Corniest quote ever: “Get yours today! JDM is IN!”
If the rad fan is not comming on when engine coolant temp., [engine temp.] goes above around 194 degrees F it will be electrical.
The problem can be at any number of points in the circuit, you will need to find where the problem is, I would start with the “Engine Coolant Temperature Switch”, test for a ground on the yellow/green at the “Radiator Fan Relay” when driving and engine temp goes up.
It will mean jumping out and popping hood and testing, or make yourself a “telltale”, run a lead from the “RFR”, [connected to the yellow/green] into the car, connect a test light to the lead, [or you can use any 12V light bulb] drive car until engine temp. goes up, if “ECTS” is working and wiring/connections between “ECTS” and “RFR” are good, the telltale, [test light/light bulb] will turn on, if not move lead from “RFR” the “ECTS” and try again, if still nothing replace the “ECTS”.
If on the other hand the test light/light bulb does turn on, the “ECTS” and wiring to relay is good, move wire to the blue lead at the “RFR” and check for power, [12V+] on that lead when engine temp. is up, if no power check for power on the black/yellow at the “RFR” when ign. is on, [while driving] if there is no power on the blue lead when engine temp is up but there is power on the black/yellow, replace the “RFR”.
If all is good to that point, move telltale lead to the blue at the “Radiator Fan Motor” and test again ti check wiring between relay and “RFM”.
Let me know what you find.94
Well I had a chance to test the things mentioned, & when I tested the wires @ the relay, all lit up. (except the black ground of course)
I tested later & couldn’t get a light on the blue wire. Think maybe the relay is going bad, & working intermittently? The fans did kick on when I cold started & let it warm up. They also kicked on yesterday @ least once that I noticed. But once again, when she runs hot & I stop, no fans.
Just to give a thorough overview:
Today I had to replace the radiator 'cause I found out the lower hose port broke. I also replaced the lower hose, as I didn’t replace it last time. The cap was steaming so I got a new one, but haven’t found out yet if that’s the culprit. She started getting hot as I was driving tonight, after I stopped @ a light. It never goes higher than 3/4 on the gauge, & will drop down to 1/2 as I drive.
Thanks for all your help BTW.
:getsome::manual:
Corniest quote ever: “Get yours today! JDM is IN!”
You mentioned a condenser fan so I assume you have A/C. Have you checked the condenser for blockage?
As for the rad fan relay it should have power on the black/yellow when ign. switch is on. [one side of relays coil] the yellow/green will test as 12V+ if the “Engine Coolant Temperature Switch” is off, [coolant below 194 degrees F] but should test as a ground when engine temp up. [other side of relays coil], the above leads control the relay, [on/off].
The blue lead will test as 12V+ if relay is off, [rad fan not running] and ground when relay is on, it supplies the rad fan with a ground, [from black lead] when relay is on.
Engine temp. should stay “1/2” way at all times, once engine has warmed up.
It does but it’s not hooked up. The belt tensioner is missing.
You say the yellow/green should light up if the temperature switch is off/ below 194 F? Whether it’s @ decent temp or overheating, it always lights up. I haven’t tested it when the fans are running, but I’ll take your word for it.
If testing the yellow/green right behind the temperature switch, I should get a light if it’s off/below 194F correct? No light if it’s on/ above 194F? I’ll test it later if she starts overheating again.
If i do replace the temp switch w/ a new one, would a 180F opening Mishimoto switch be a good replacement? it opens earlier, so would this be overcooling or OK? If I use it, should I use a lower opening thermostat too? Or should I just get the OEM Acura parts & keep it @ stock opening temps?
:getsome::manual:
Corniest quote ever: “Get yours today! JDM is IN!”
Depending on the test light you have, the yellow/green will test as 12V+ when “ECTS” is off, [coolant below 194F] if tested at the switch or at the relay and as a ground when “ECTS” is on, [assuming it works].
With that said, the problem with a test light is it can supply the low current ground the relay needs to energize, [turn it on], which in turn will, [should] turn on the rad fan.
Grounding the yellow/green at the “ECTS” is a good way to test the rest of the rad fan circuit, turn ign. switch on then ground the yellow/green, rad fan should turn on, no matter what the engine temp.
I would use a stock “ECTS” although 180 degrees F would probably also be OK, the stock switch is “around” 194 F.
The Mishimoto is $37.00 + shipping from Tru Power Motorsports (sponsor on here) or…
$33.00 shipped from ebay.
I can’t get the site to come up now to give you the sellers info. That’s what you get from a 2001 Dell. :tapfing::bang:
I’ll try to get it for you later.
I tested the wires @ the plug & the fans kicked on as you just said. Might not be them. I may still get the low temp switch anyway. Good insurance.
I do have an unfortunate devlopment:
the water pump may be going out. I’m not 100% on it, but there may be coolnat leaking from the lower weep hole. It’s hard to see w/o a mirror, & I don’t have one small enough as of yet. Keep you updated either way.
:getsome::manual:
Corniest quote ever: “get yours today! JDM is IN!”
Well, good news! I went down to Acura yesterday & talked to one of the techs. When I asked about the water pump, he said if I’ve been driving it for days now w/o a good amount of coolant loss or whining, it’s not the pump.
So I bought an OEM thermostat while I was there, & changed the thermo ONE more time. It seems to have fixed it. I drove around yesterday afternoon, all last night, & some this morning. No problems. Even left her sitting @ idle a few times.
Just goes to show you, get an OEM thermostat or you may end up paying for it.
Thanks for your help FCM. It may not have solved the problem, but it sure did come in handy when I needed it!
BTW- I was thinking of wiring a switch to the fan so I could turn it on if I wanted to, like after a long drive or a lot of stop & go rush hour type stuff.
I was thinking of using line t-taps, like these:
Would it work/ be OK If I:
hook these on @ the fan wires between the relay (after it) & the fan itself. (before it)
hook a fuse inline between the fan & the switch (on pos. wire)
run the switch to a free pin for power source
hook up neg. wire to chassis, or maybe tranny ground point?
Am I correct to assume this would allow me to turn on the fan optionally, while still allowing it’s normal functions?
Best way is to use a relay, run a fused lead, [1A fuse] from the 2nd ign. free pin, on the under dash fuse box, to a SPST, [on/off] toggle switch, then run a lead from the toggle switch to where the “Rad Fan Relay” is, install a SPST, [or SPDT] relay next to the “RFR”, connect the lead from the switch to #85 of relay, ground #86 and #30 of the relay, then run a lead from #87 of relay to the blue lead in the “RFR” plug, flick the switch and the relay will energize, [turn on] and supply the rad fan with the ground it needs, the rad fan already has 12V+ constant going to it.
Now with all that said, if the engine “cooling” system is working properly a switch to keep the fan running is not needed, if engine temp is high the stock system will keep the rad fan on, even if ign. is off the “Engine Oil Temperature Switch” will keep the rad fan on if oil temp is high, that is of coarse unless you have a CDM, [Canadian Domestic Market] G2, our G2s do not have a “EOTS” or a “Radiator Fan Control Module” for that matter.:shrug:94
Better to just leave it alone, & get the Mishimoto switch if anything, huh? I also got some Redline Water Wetter , so w/ that & the low temp switch, all should be fine, w/ just a bit more protection.
It can get pretty hot down here in FLA, so a bit more protection is warranted. At least I think so. Plus I drive a lot.
:getsome::manual:
Corniest quote ever: “Get yours today! JDM is IN!”
As long as all systems are working properly overheating should not be a problem, in very hot climates and under hard driving conditions the cooling system will be stretched to it’s limit, if you find the rad fan coming on when your driving at constant highway speed limits, then the system is “overloaded” and assuming all parts of the system are working as they should, you may want to think about replacing the rad with a better one.
I found that when I autocross my 94LS, and it was hot out, my engine temp would go up and although all systems where working as they should over-heating was an issue, I replaced the stock rad with a triple core one, no problems since. 94
Yeah, I’m doing a B20 swap in a few months. After that I want to get a better rad. Probably the Mishimoto w/ 2 slim fans.
Thanks again for all your help. I think I’ve called on you a few other times too, & you always lend your advice. If I ever get up to Canada, we’ll have to meet up & knock back a few. I owe you a couple 12packs @ least!
:getsome::manual:
Corniest quote ever: “Get yours today! JDM is IN!”
94
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