overheating

[cheapscheisst]

so i just finished my swap a few days ago, and for some reason im having massive overheating issues. before i removed the thermostat, the car would overheat at idle within five minutes. without the thermostat, it stopped overheating at idle, but the coolant temps were definitely higher than they should be. after a few minutes of VERY VERY conservative driving, my gauge is reading H or higher and im knocking and bucking to no end. my radiator should be fine (it worked perfectly with my ka and i also flow tested it with a garden hose to make sure it wasn't clogged) and i have dual electric fans. the only other possible problem-causer i can think of is the water pump. when i look into the radiator cap hole when i first start up the car, i can see the water flowing, but barely. from what i've heard, it should be flowing pretty quick... this definitely isn't. apparently this is supposed to indicate a bad water pump. however, i replaced mine before the swap with one from enjuku (for the s14 motor, which is supposed to work with an s13 as well) and i tested it for slipping and it seems fine. any ideas?

[doridori23]

might have a foreign object in the motor (rag, dead mouse, socket, etc) restricting flow. When a motor sits on a pallet you never know what is going to happen.for poops and giggles pull the water pump and inspect it and all water passages that you can. After that call enjuku and double check on whether or not the water pumps are backwards compatible. I do not personally know, sry.

[cheapscheisst]

yeah i've checked and so far i haven't seen anything. the pumps are supposed to work but im going to put my stock one in anyway since it works.

[cheapscheisst]

alright so here's an update. that misfiring i mentioned in an earlier thread... wasn't misfiring... my engine was knocking b/c it was so damn hot. so after putting the stock pump back in, the heating issue is better, but it still overheats pretty easily. i noticed the other day when i moved the car 30 ft. into my garage the engine was already pretty warm to the touch. seeing as the car was on for like 15 seconds, i wouldn't think that the engine should already feel that hot. any ideas?

[doridori23]

Even if running crazy lean you shouldn't get so hot that you overheat like that. take the waterpump, hoses, and thermostat out and put a rag around a garden hose and shove it in the thermostat hole and turn it on. You should have flow going through the block. How are your lines plumbed on the back of the motor?

[cheapscheisst]

alright i'm an idiot. i didn't know i had to swap in the ka water temp sensors . that fixed things. but it still bogs and misfires occasionally. i'm thinking bad O2 sensor.

[sr20usmcswim]

it is almost a gurantee that it is your water pump i had the exact same problem with a honda i helped a guy with

[cheapscheisst]

sry that problem has been fixed for a while. i didn't realize you needed to swap out the sr s13 coolant temp sensors for the ka s14...

[schanne]

both temp sensors need to be replaced? I had overheating problems as well. havn't had it over heat, but i also havn't drove for over 45 mins in mid day. Do i need to replace both sensors??

[cheapscheisst]

i think you only need to replace if you are putting an s13 into an s14 chassis. if you aren't overheating within a few minutes at idle (with fans on), then chances are you have the correct sensors.

[Hijacker]

Make sure that the ECU temp sensor is for the motor's generation and the sensor that reports to the cluster is for your chassis' generation (ie get an S13 coolant sensor for teh ECU and an S14 gauge sensor if you drive an S14 car with an S13 motor)

KA and SR sensors are the same in this regard, so you can buy brand new ones at the dealer.

[cheapscheisst]

uhh which one is the gauge sensor?

[Hijacker]

It's the one with the black rubber connector (there's a spade connector in there)

The ECU sensor is the 2 pronged sensor with the annoying retaining clip in the harness plug.

[cheapscheisst]

alright thanks... wish i had known sooner. i spliced the ka plug onto those wires to fit the ka sensor... what a waste of time.

[dyfedd91w]

when you swap the motor you must bleed the air out of the coolant system. There is a bleed screw/vavle on the top of the coolant inlet in the head. unscrew that and and you should see air and some coolant purge from the lines then while you are doing that take off the radiator cap and add more coolant.

[footin616]

I am having a very similar problem. I did my swap (new radiator too) and my sr overheated in five to ten minutes.

1. I changed the thermostat, did not help. 2. Then I changed the water pump, did not help. 3. Then I re bled the system and had to add about 1 gallon of coolant. Still overheating.4. Also, when I am overheating I try to turn on the heater, some heat in the cabin but not as much as you would expect from a over heating motor.

My lower hose is getting hot and the passenger side of my radiator is getting hot but my upper hose is just getting pressurized but not hot.

Could the coolant lines from the head to the firewall be switched, which one goes where?

Could I have a massive clog in the coolant system, where do you think it might be?

Any help is greatly appreciated, I will keep you posted with any new news.

[Hijacker]

The heater hoses should be hooked up as such:the one coming from under the intake manifold goes to the bottom heater core outlet. the hose that comes from behind the block goes to the upper heater core outlet.

I can't see that being your problem though.

It sounds to me like you have a clog somewhere that's preventing flow. Normally I'd say check the radiator for a clog since one of your hoses is staying cool, but you've put a new radiator in. Was the radiator an aftermarket one (like a koyo) or was it just a new to the car radiator?