11secEVO7--> Erratic reading happens on both....stand still and moving. NO signs of OIL on the Radiator.

Gunzo-->i just replaced the thermostat with a new one. Still the same

The temp reading i very irregular.....sometimes its just sits at normal level then shoots up high as soon as i turn on the Aircon.

Whats the normal operating temp of the engine? Im going to borrow DEFI water temp gauge to check if the temps are regulated.

Thanks again for the replies....

 

did u open up the rad cap and check inside...to see if u see any ..just any little signs of oil in the water?

reason i'm asking is because the same thing happened to me....i changed the thermostat,fan etc...and it was reading normal once in motion..but in traffic it would go up a little..

i ignored it for a while and then it started to go up when the car was in motion...checked inside the radiator and saw probably two little dots of oil for the most.

and well with the a/c on....it would make it worse and the temp would shoot up.


eventually it started going up while i was driving..regardless of a/c on or off....so i switched off and towed it to the mechanic.pulled off the head...and there it was..blown head gasket.

 

Could be with the settings in your Fc commander. Check settings and maybe do a post in the fc thread. Try to get yourself a pyrometer and just take readings during different periods the car goes into. Take radiator in temp and radiator exit temps for each period. Could be all sorts of things at this point but we all hope its not your headgasket bud...

Good luck.

 

11secEVO7-->Yup i did a detailed check on the radiator no signs of oil droplets.

FastEvoFL-->Ok im going to do the temp check tommorow. I got the defi gauge already. Any idea whatsthe normally operating water temp?

I started the car and let it run for a few minutes. As soon as i gt the engine warmed-up. I turned the A/C on and let it idle for 30mins.....all is normal. I drove it around the village for another 30mins and still the stays normal. Im really getting frustrated with this car and SAD part is there's no shop or auto dealer than services evo's here.

 

oh yah forgot 1 very important detail..
do you have trapped air in your radiator system??

open up the cap cold and start car till everything bubbles over.. then cover up the cap..

since you're already out of ideas

 

Well any competant place should be able to diagnose the problem but nothing gets things started then a trial and error approach. Im sure there are a dozen other ways to check for issues but we've covered important things.

I'm not even sure what would be ideal conditions but hey I or someone else could give you their values to compare with what values you get. Ill get my brother to bring home a meter and Ill let you know what I see.

Just let me know what conditions you want me to simulate and ill work out the values.

Correct me if I'm wrong 160C is ideal correct?

 

FastEVO7--> I forgot to mention to u that i reside at Philippines (asia) and i tell you i'd rather trust my little knowledge on cars and this board than to have someone experiment on the car

btw, do you have an idea how the engine fan is triggered??? is there a temp sensor that controls the engine fan. I think thats the only thing thats left out that i haven't checked yet

 

I do not know exactly but there must be something within the ECU I think that takes care of that. Id have to read some circuitry.

 

You can also hotwire the fan so that it comes on and stays on as soon as you switch on ignition.from the time u put on ignition you would hear it come on...you can always check to make sure that it is on. and well once it's on, it will stay on.
try it like that and if it still does it then you know the problem is deeper.

 

FastEvoFL--> Thanks..let me know if you come across the fan trigger.

11secEVO7--> I hotwired the fan of the evo7 via ignition. Drove the car for 2 hours...encountered some traffic...was a hot day. TEMP is ok and normal.
I guess engine fan trigger could be defective.

 

It really has to be something with the PFC. Do you still have the stock ecu?

 

no more stock ECU.....i'll try to borrow a stock ecu tomorrow.

 

was able to borrow a stock ecu....but is it ok to start the car and let it idle with no maf?...just to test if fans will operate normally... its has a power FC and its map already....no more maf and its very hard to convert it to stock intake....since the evo7 is fitted with a greddy 25g turbo...a lot of hassle just for testing.....

 

idle yeah but will that show your problem? cuz really... what is the problem? had no idea a fan could cause so much trouble.

 

trinydex,
-->Problem is...engine fan isn't turning on automatically when it reaches above normal temp. I've done and replaced almost everything related to the fan system and still doesnt operate normally.....suspect is the FC commander someone one on the other topic confirmed that FC commander has a glitch on the system. Thats why i want to run the stock ECU. Just to check whats the real deal.