Was running my FD3S around yesterday, beating the **** out of it, 20 to 100 pulls, 60 to 100 pulls. Everything was fine. Temps were all where they were supposed to be. Stopped and ate for about half an hour, went back at it and everything was still good to go. Until i got back into town filled up my gas (and 2 stroke oil) and turned the car back on. Immediately there was something wrong, but im figuring fouled plugs. The idle would hunt, and was lower than normal, i had to check to make sure i actually turned the car on. After pulling out of the gas station i stopped at a red light an noticed steam coming from the engine bay and thought **** im overheating, but the gauge was only just now starting to go up. I was able to limp in home with a couple stops to cool down. I dont know exact temps but the gauge never hit the white line on the upper part of the gauge. it was always at least 1/4in away. I was told when i bought the car from the PO that my adaptronic ECU will automatically shut the car off if it gets way hotter than it should be, if that was working it never got that hot. My guess is my thermo-switch is bad or the relay the kicks that fans on after the temps get too high is bad, i need to do more reading on that. But the fans do come on when i turn the ignition to ACC. This morning i started the car it ran fine except the weird idling to where it would die. I removed the old plugs and put new ones in and now its better but not perfect, the car still hunts for idle by like 100 rpm but other than that is fine. I had to add about a gallon of coolant, i guess when it over heated it tripped the thermostat and puked into the overflow tank but since it was so hot evaporated. I only got a lot of smoke at first but slowly came back to normal. It smelled like it normally does, maybe a bit more rich, but nothing seems out of the ordinary.

If i did hurt the engine from overheating it would i notice it right away?

 

I think I found part of the problem.
If you’re referencing the stock temperature gauge, it isn’t linear. It goes to about the 8:00 o’clock position almost before the t-stat even opens and stays there, essentially, until it overheats. This is mentioned in many threads and sticky’s and why one of the first things recommended is an aftermarket gauge. Losing coolant out of the overflow and white smoke (steam) on cold start together with a lumpy idle that clears up after a few moments are two classic symptoms of a blown coolant seal.

 

The white smoke on start up doesn't smell sweet. It smells like its running rich and has been that way since i bought it. I bought it with a new engine from turblown maybe 700 miles on it. The lumpy idle only happens after its warmed up. The idle when its cold is just super low, like 500 600 rpm.

I was checking to see what was up last night, started it up, got it warm and it held a normal temp for a good 20 minutes after that the temp gauge started going up, i looked and the fans didnt kick on so thats a problem there.

 

This doesn't work very well if the coolant system is low on coolant, due to a leak (steam is a leak). An air pocket can form on the coolant temperature sensor for the ECU, thus it never sees it is overheating.

I'd start with a coolant pressure test, you can rent the testers at any auto parts store. Although it is not foolproof, it helps rule out any damage due to overheating.

 

Didn't think of that, ill check the local places and see if they have what i need to test it. Thanks.

 

Running rich = black smoke.
And you might want to search/research Turblown here on the forum.
Regardless you want the ability to monitor you temperature. The stock gauge doesn’t do that. You overheated, maybe more than once and significantly.

 

Anything i should be concerned about with turblown? I thought they were pretty reputable. Ill get a digital gauge, and do the leak down test. Hopefully it looks good. If not looks like ill need new seals, at least its almost winter when i wouldnt be driving it anyway.

 

You should just connect a labtop to the ECU to confirm what is going on. Yes the ECU will limit RPM if coolant temps get too warm, but the ecu has to be configured for that. Jumpy idle, idle too low etc, could just be tune related, or a sensor going bad etc. Posting a datalog/ecu file would be most beneficial if you want forum help. OEM temp gauge is not very accurate FYI.

 

Sounds good. After the leak down test I'll get my laptop hooked up and get a data log and ecu file for it.