an overheating revelation???

ok so i thought it was all better, apparently i was wrong. this morning i drove about 200 miles of semi windy road and found that my temperature was all over the place, only setting back down when we got back on the motorway and sat on 60ish for about 60 miles.

now i'm going to check the bleeding again but i had plenty of time to think. ive done the thermostat, checked compression, had the radiator out and flushed, checked al the fans etc. had it bled and checked all at toyota, by the book.

aparenty the radiator is fine, but someone told me the air conditioning core is in front of the radiator, and mine looks pretty banged up, stones i guess. now i havent looked to confirm that the aircon core is in front of the radiator, but if any of you guys know, do you think that possibly the aircon core (because of bent fins) could be blocking flow to the radiator??? ultimately screwing with my cooling.

Do you know to turn your heat on FULL BLAST if you start to overheat? This (usually) will bring your temps down rather fast.

Have you checked to make sure your radiator fans are coming on? Usually in an MR2 the sensor fails and the fasn stay on ALL the time; however, it is quite possible to go the other way. I have this problem with Hyde right now, the sensor is not turning the fans on.

Very simple test for you to do: If you reach up from under neath the car (passenger side of the raditator) there is a sensor stuck into the side of it. Simply unplug the sensor. If your car is on, the fans should be ON when the sensor is unplugged.

This will first tell you if the fans are working.

If you go driving again, see if your temps stay steady now. That would be a good clue the sensor is bad (or the wiring).

Then, plug the sensor back in and go drive "fairly hard" and stop and let the car idle ... get out and see if the fans come on. If you got things all warm and cozy, the fans should come on.

WATCH your temps ... if they start to come up, jump in turn the heat on full blast, unplug that sensor and get the car moving to get air over the radiator again!

yeah ive used the heater before but they weren't steadiy going up they'd go up fast then come back down fast... stupid. had the fans checked out, but will try the sensor thing anyway just to see what it does.... may even pull it just to keep the fans on. have to drive back today. do you know about that air con position??

The AC condenser does sits behind the radiator I *think*.

hmmm gonna have to check it out when its not raining.

i have to regas my aircon to take the car to australia. JDM gas not allowed. so then woud be a good time to replace the aircon core.

just hoping it makes it home today. dont fee ike waiting hours for a tow truck in the rain in the middle of nz.

OK, I've just been to toyota to discuss it, turns out i already have good gas and don't need to regas the car. SO...

can anyone think of a good way to work out if the aircon core is blocking flow to the radiator?

well jeff i tried the pull the sensor fan check and they're working. what do you think would happen if i left them going all the time? would the car stuff up with the sensor pulled?

Pulling the sensor wil lonly tell you if the fans are working ... the next question is the the sensor itself working.

Have tried testing that?

You will not have any major side-affects from having the fans on all all the time, but they can get annoying to hear.

ok gonna try the sensor tonight...if its not raining. NZ summers suck.

on the other side, i went to the toyota wreckers last night to find out about a new (to me) aircon core, they said they usually have them in stock and will cost $125 (so about US$70)