Hey guys , always wanted an s2000 and finally picked up a jdm model in Feb and got it on the road April after breaking my k20 ek civic

Done a full service on it and drove fine for the first week then it wouldn't get uo to temp and would only get to 2 bars.
ended up changing to a mishimoto rad and hoses, a new thermostat from local motor factors as the oem one I bought off a trader was wrong on their part sending the incorrect one out.

Fitted it all, bled it via intake manifold nipple and drove it for another week or so, including a long journey to honda day and back which was fine.

Next time I came to drive it, it started overheating, hit 5 bars so I slowed down and pulled over. Limped it to my mates and let it idle and it sat at 3 bars for a good 15 20 minutes. Drove home and it was totally fine.

A week later I drove to JapFest and it was fine. On the way back it done the same thing again, pulled over on hard shoulder and let it cool a.while then started her back uo and drove home and which it was stayed 3 bars.

A couple of days ago I went to drive it and had the heater on which was blowing hot, enough for you to barely be able to hold. You hand in front of the vent.
Driving round town and all of a sudden the heaters went cold without me turning the knob. Temperature stayed at 3 bars
After a while switched to hot again

Driving to mates on the motorway at 70 and it overheated again.
Got to his and decided to try bleed it out via billmans method, got some air out

Went to drive it and same symptoms.
Bled it again the next morning and air in it again.
done some reading and many have complained about the Mishimoto cap so borrowed a mates arc one
Bled it again via billmans and drove it and same again
Tried jacking the front right up to bleed it, drove it and again overheats

No signs of oil in overflow bottle, can't smell. Coolant in fumes
oil in sump looks fine

Any advice or opinions guys? Reallydont know what do with it now. ..

 

Sorry about the essay just wanted to go through everything that happened so it makes sense

 

Thermostat take it off and test it
Put everything back on bleed the system run the car, turn heating on on full blast(hot) . Before the engine goes hot bleeding again you might have air bubbles in heating matrix

 

I'd check the thermostat but sounds like air in the system to me because it's intermittent.

Cheers,

Dave

 

Not sure how the water pumps are constructed but sounds like the impeller could be spinning on its axle at higher rpm, or that the ancilliary belt is old/worn/loose and not getting the drive to the pump.

 

Are you sure the stat works?

Normally these things bleed out air themselves through a few cycles of hot and cold

When the heater blows cold carefully check the rad for heat

 

You can check the stat in a pan of water on the cooker top with a themometer. But my bet is just air in the system. I read somewhere on here the best way to bleed it out is with the front end raised on ramps or stands.

 

In my kit car installation the only way I could get around airlocks was to drill another air hole in the body of the stat. I tried everything else, including jacking the front of the car up etc.

 

My 10p worth, is swap the stat for a genuine Honda one ( just to eliminate a crap stat from the local factors) then do your bleed again, when I swapped my coolant last year it took 2/3 goes to get all the air out. Nothing complicated here just trapped air, swapping the stat is just a back up. Good luck

 

Could also be a small hole in the hoses somewhere letting air in after you bleed it. Just check the hose joints too, I had similar on one of my S's, just swapped the OEM hose clips for a jubilee, nice and tight, rebleed, no more air in the system - job done. If the in car heater is not responding to temperature changes on the dial at idle that spells out air in the system. As does if you have the dial on hot and it'll only blow out hot air when the engine is revved up / at cruising speed. Best of luck!