First off “DON’T RACE THE CAR UNTIL YOUR SURE THE COOLING SYSTEM IS 100%”. The amount of heat an engine generates is directly related to the amount of Horse Power it out puts. The coolant system needs to be at 100% to handle the stress of racing. Unless you are looking for a reason to buy a new engine? No visible leak in an engine that has run without or low on coolant is just the beginning. You need to pressure test the coolant system. Until you can pressure test it let it idle for ten minutes. Make sure the large radiator hose gets firm like it has pressure in it (it should be hard at the 20 min mark). If it does not get firm “DO NOT DRIVE THE CAR” until it is fixed. Driving a car that will not hold pressure kills more engines then all other issues combined.

As for your other issue that could any of a 100 things based on what you said. It could be anything from failing injector or cracked plug all the way up to a PCM issue and just about anything between. In the business we call this a drivability issue and it demands the highest grade mechanic with the right equipment to pin point a problem like this. You can throw parts at the car, meaning guess, and you will get a lot of people that will come on here and say I had that issue and this is what fixed mine. Many different issues can result in the same symptoms. Step one would be to make sure all the routine maintenance is up to date then I would check the fuel pressure while it is having the issue. It would be nice to see what the sensors where detecting while the car was smoking. It could be something reacting to the heat caused by racing. When you race a engine the engine is at its hottest about 8 minutes after the stress. It takes that long for the heat to spread and soak the whole motor. One of the worst things you can do to you motor is race it then shut it off. This would mean the engine is still getting hotter but has not coolant flow.

 

Thank you so much Gorn for your valuable information, let me tell you this, yesterday i had my ECT plug fixed(the one on the front side of the water pump) now i cant see any hesitation on Idle, engine starts nicely,but figured out that when the engine gets hot the rpm gets slightly lower and stay there, and when i brake hardly or suddenly i feel like the car is going to stall unless i will release the brake a bit the engine comes back to life.whats happening!!!!

I have done already what you mentioned earlier about the big hose coming from the radiator, and so far i can feel its firm, it feels like a balloon,is this a good sign or still i have to be worried.

For your kind information, i cant see any visible smoke from the exhaust so far.

Based on the above Gorn, do you think am safe i mean my baby is she safe,can i still drive it even to the mechanic or shall i get it towed....

 

It is not safe until you have the system prressure tested. The hose being firm just mean a light drive will most likely not hurt it.

The RPM issue could be a weak or dirty IAC motor.

 

so you mean to say i have to replace the IAC or is there anyway to clean it, i would like also to go through cleaning my TB, is there any special instructions on doing this and how , thank you for continuous support

 

the engine temp sensor being grounded would tell the computer the motor is really hot or there is a short or disconnect in the system. if it thinks its really hot a check gauge light will come on. if it thinks its a short or disconnect the computer will go to open loop and will run rich. this can cause a hard start and black smoke at first start as it burns off the excess fuel. if you have been running in a rich condition it will foul your plugs and 02 sensors. be a good idea to take a few spark plugs out and see if they are all black, same with the 02 sensors, take out and see if they are all black. replace plugs if fouled. can clean 02 sensors using a torch and heating till black is gone. do not get so hot as to melt the wires going into the sensor. if you are going to clean the tb do not use any abrasive tools like wire brush or steel wool. some tb will have a coating or rough spot where the butterflys come against the body. this is to keep them from sticking when closed. the iac can be cleaned again dont get to rough with it. carb cleaner will work most times.

 

Dears, am going insane, i dont know what happening with my car, without the ac on,everything looks perfect no leaks nothing, with the ac on after 5 minutes i will find the water boiling and coming out from the reservoir dripping from under the batter, what the hek is happening,please advise me with something as the mechanics here in dubai they suck, imagine i went yesterday to make a pressure test for the cooling system, they didnt understand what am saying, am so down to the ground and frustrated, cant lose it no matter what.

Second issue when i press on the brakes even soft press, the car is close enough to stall totally, directly i release my press then the car will come back to life.....please am seeking every advise, i know you experts and u would do your best to save my a**