Here’s the deal:

JDM 1st gen B16A into 99 DX hatch
99 SI wire harness
99 SI distributor, replaced coil and igniter
PFR6L-13 spark plugs with used stock wires
99 SI fuel pump
Fluidyne radiator
99-00 CTR PCT ECU OBD2b
Toda flywheel with Exedy organic clutch
CTR N1 crank pulley
CTR standard bore piston with new rings with all new OEM seals for the bottom end
AEM fuel rail and fuel pressure regulator
Spoon Sports 70mm throttle body with Type R intake
Spoon Sports ventuli plate
Spoon Sports valve springs
Spoon Sports head bolts
Nothing was done to the head, no mill or valve job.
New head gasket and seals throughout, all OEM
Timing belt, oil pump, water pump, thermostat (99 SI), all new OEM parts

Everything else is stock that came with the engine. I had to switch injector plugs on the harness and I installed a Crank TDC sensor on the oil pump.

Problem:
It’s been overheating since I put the engine in the car. After the fluidyne install, it ran ok for one day. Then it was back to the same old thing. It’s pushing coolant into the overflow tank. Did a compression test and leak down test and everything seemed fine. I can drive it around all day as long as I keep it under 4000-5000rpms, as soon as I take it past 5000rpms at WOT the temp shoots up and it starts to push coolant out. It starts to miss and hesitate really bad. After that it doesn’t matter what RPM I’m at it misses and hesitates with a noise that sounds like plastic vibrating or being hit. What the hell could the problem be!?!

 

I know you said you have it, but, check the thermostat. Make sure that it actually works. Some people take it out, but it only makes it worse. Another problem could be your fan switch. It might be turning on the fan a little late. But most likely its your water pump. I know you said its new, but these are the only things that would cause your car to overheat.

 

I had Spoon cooling parts that I removed and replaced with OEM ones. I had the cap, thermostat and thermo switch. The water pump is new and has about 500 miles on it. I bleed the system, I even used the bleeder vavle.

 

need some help!!

 

I'm not 100% sure but i think its the thermostat.

Where did you by your thermo at?

I know plenty of people that have bought thermostats from autozone and them be defective.

goodluck

 

did you water pipe on the back of the engine? if not i bet thats your problem.....i've got a 91 dx hatch that once had a obd1 d16y8 in it and i replaced the blown y8 with a low mileage d16a6 and it was overheating.....but then i changed the waterpipe....problem solved, obd1-2 has a sensor on the thermastat housing

 

I figued out my problem today. My headgasket is leaking on the timg side. I took the upper timming cover off and it had coolant on it. I checked my headbolts and the end ones where a little loose, not sure how much cause I didn't ahve the proper adapter for my torque wrench. Any suggestions now. Thanks for your guys help