Hey guys,

I have a stock 05, and not too long ago I had a brief overheat. It was the super hot day here in so cal (115F); and my car on the drive home stayed at the 8 bars in ap2. It was only after I parked my car at home (front facing downward hill) and turned it off when coolant shot out from the reservoir cap. Most likely due to pressure, but there was no steam or signs of boiling. Since then I changed out the Tstat, cap, and did a coolant flush/fill/bleed (heat comes out hot hot hot, once drove it all the way to work with it on 20-30 minutes with no changes in the hot air temperature). However, one thing I now notice is that my car warms up unusually quick; even in cooler days (70-80F). It would reach the 8 bars in about 2-5 minutes.

I bought an ODB2 gauge to monitor the coolant temps and here is what I got. Even though it warms up fast, the car stays around 180-190 degrees regardless of temperature (its been between 70 to mid 90's here) and only when the car has been driven like 15-20 minutes and in street traffic that it will go up to 205 before fans kick on and lower it to 195, before it steadly rises up and cycles again.

My concern is that is this fast warmup and issue? or is it normal in 70 degree weather that it would reach 205 so my fans would kick on after a while in street traffic/idle? From what I can tell there's no leaks in the HG as I haven't seen loss of coolant from reservoir or rad; nor the milky color in oil or coolant. Could it just be because of the hot heat and the heat soak? My intake air temps run to like 150-160 degrees on the warmer days. Could it be that the condenser is blocking airflow to my rad while driving? I also have my license plate zip tied to the grill if that matters (I doubt it).

My main worry is that it can possibly be a water pump issue at this point or the stock rad isn't getting the good amount of airflow to cool properly. I'm at a lost now since the car never goes about the 205 but it seems unusually warm.

 

The quick warm up is pretty normal, that doesn't sound odd to me. I don't think you will overheat any time soon given the driving you've been doing lately. If it was going to overheat you would have seen it by now, these cars react very quickly to improper cooling system operation.

What sounds odd is why fluid was blowing out the reservoir, unless it was overfilled at some point. I don't have an ap2 so I don't know if 8 bars is where it needs to be, perhaps other ap2 owners can chime in on that and compare it to their rides.

The license plate mounted to your front grill will increase coolant temps in driving conditions, a few guys logging data at the Dragon event all noticed increased coolant temps when their license plate was mounted in the grill, as compared to not in the grill.

 

8 bars on an AP2 is perfectly normal. I live in Florida where I also hit 8 bars in a matter of minutes. Obviously coolant spraying out isn't good though lol.

 

Alright thanks guys, its making me feel more assured, cause when i was searching around on the forum, people were saying they were getting like 170-180 temps from driving around coolish ambient air, but I guess I'm ok; I'll keep monitoring it to be safe.

Thanks for telling me about the front plate, I'll probably throw it on a tow hook mount or just get rid of it all together.

As far as coolant spraying out of the reservoir, I don't believe it was overfilled; but it happened the moment I turned off the car. My old acura back in the day would use to run the fans until it cooled off enough even after I shut off the car, but it doesn't happen on my S. I'm assuming I shut it off on the wrong cycle and all the heat built up too much pressure and no flow since everything is off and the only way out is the reservoir cap.

 

The S2000 temperature gauge is a glorified idiot light that, on an AP2, will always stay at 8 bars unless the engine severely overheats. From the time the thermostat opens around 170°F the gauge will stay at 8 bars until the temperature reaches 225°F. Even the Modifry modification uses one bar with a wide range (180° to 205°) as normal.

The gauge should rarely show 9 bars and showing more is a sign of severe overheating -- which didn't happen in this case.

-- Chuck

 

Yeah after searching on here, I realized the gauge is pretty useless, hence my purchase of an obd2 gauge to watch the actual temps.
Just coming back from lunch on a 90 something degree day, my car never went past 190-192 on street traffic with ac on.

This morning though by the time I got to work and idled in my parking spot (20 or so minutes) it got to 205 and fans kicked on, but outside temps were probably high 70s.

My main concern now is should my car be hitting the fan switch limit in coolish weather? Or is the idle heatsoak in our cars that bad

 

It most likely sprayed out from either cracked reservoir top (threaded piece), an improperly seated radiator cap, or a bad radiator cap. Are you sure it came specifically from the overflow reservoir or were you just tracing the spray pattern? My bet is a cracked reservoir top piece. They can crack and you can't even see it unless you work it a little.

 

I agree on something being cracked. Your temps are perfectly in range for a S2000. Fan usually kicks on around 200-205. If you throw the AC on, the fan runs all the time and actually keeps temps a little cooler.

Good luck with it!

 

There are OBD2 devices that will record data like coolant temperatures. I used one once when towing my camper trailer across the Pennsylvania mountains in the summer and the graph was a flat line just under 200°F. No worries. Lost the device (probably was in another vehicle I sold) so I can't repeat with the S2000 unless my FlashPro will to this. Anyone know?

-- Chuck

 

I'm definitely sure it came from the overflow reservoir cause I opened the hood as it kept spraying out and watched it spray out from there. The actual reservoir was doing that thing when you hose water into a bucket and all the water is just flying out and almost no water is in the bucket.

Yesterday when I went home it was around 105-110 and the car was fine all the way home and when I shut it off, temps got to 205, fan kicks on drops down to 195 minute later go back to 205 and cycle.

As far as the cracked radiator top, wouldn't that introduce air into the system? I'm pretty confident I have no air in it, but I'll keep an eye out on the top as well. I have a new reservoir and cap for it on order so planning to replace that when it comes in.

Also planning on getting a new radiator as an upgrade, I figure a thicker one would help with the California heat. Not necessarily concerned with the over cooling issues I've read since it never really gets cold at all here.

Thankfully I purchased his ob2 gauge, it's been super helpful monitoring temps.

On a side note is it normal for our intake temps to be so hot? Like yesterday it got as hot as 170-180 while idling. Is our heatsoak issue that bad? And would that somehow affect our engine heat which would increase our coolant temps?