dude stop trippin out. sounds like you u dont know much about engine performance. the hotter the air being sucked in by the intakes, the higher the power loss. for normal driving "on earth", your oils will be fine, as the car's systems were designed to operate within the parameters, temperatures, pressures, etc. that are found "on earth".

chill.

 

You guys are right, but his car is in limp mode, not just down on power.

 

No doubt about this, But the loss shouldn't be that much. I mean, the car should respond when i accelerate but that is not happening & it's a big difference compared to driving it in the morning .

Exactly & i have been driving it in hot weather before & never acted like that.

Despite the heat outside, what would make the car act like that?

Thanks,

 

See post #13. If you're going in Safe/Limp mode - the ECU thinks there is a problem and to prevent damage to the engine, it is restricting RPM/power. Get it diagnosed, that's the only way to tell.

 

I have a feeling he is NOT going into safemode. I think he is just experiencing what we all do on a day to day basis.

I live in Houston, and it has been HOT lately....well...always. I experience the same as you. In the morning going to work, car responds amazing. In the afternoon, car is sluggish and drives almost totally different.

What others have said is right.....Hence why ambient temp and miles above/below sea level is important factor to drag racers. The car will run quicker in cold, dense air and worse in hot, thin air.

If your temp gauge is reading that low always, however, id consider a stuck open thermostat in which your engine is not being allowed to heat up to proper operating temps.

 

He states back in post #1 that it won't rev over 3000 RPM. That's a good sign that it's being limited by the ECU via safemode/limpmode.

 

my personal thought on all this is, if the car is cutting out at 3k rpms, and its 120 degrees outside, i wouldnt continue to drive the car. its cutting fuel at 3k? like as if you were hitting rev limiter? if so, you can probably cause permanent damage... you have a decent car, bring it to nissan and get it fixed...

 

Limp mode, Candians car was doing the same on hot days. He could drive it to work in the morning , them in the afternoon here in the Vegas summer it would go into limp.

 

Apparently, "On Earth" is in UAE - a place a lot like Vegas.

OP - what kind of mods do you have on your Z?

 

If the thermostat is stuck open, i think the fans will start working once i start the car, Correct ? . But actually this is not the case. It will only work if the A/C is turned ON or when the temp goes high.

Looks like IP addresses show much . Yes man, I Live in Dubai, UAE & it's EXTREMELY HOT nowadays.

About my performance mods, I have aftermarket headers, test pipes & Greddy EVO II & I have the stock air intake.

 

The thermostat is a physical device that blocks the coolant water flow. The ECU has no connection to it and never knows what is going on there. It closes when cool and opens to allow the water to flow once it reaches ~170ºF.

In theory, if stuck open it would take a longer time for your car to heat up. Or if you are in a cold environment, it might never warm up properly.

The fans are controlled by the ECU based on a number of conditions: vehicle speed, coolant temperature, refrigerant pressure and the A/C on/off state. It sounds likek your are working correctly.


Have you ever cleaned or checked your Mass Air Flow sensor (right past the air box)?

 

Im going to go with this. OP will your rpms go up further than 3k just slowly, or does it act like it hits a rev limiter and WILL NOT go higher. Very important.

 

First of all this is normal in this time of the year .... 2nd, the fuel you are using is not 98 in USA count "PON" but rather "RON" which is equal to let say 93 PON.

Also, do you park your car out in the sun when at work? if yes, then the fuel your are using is at best became not that good

 

I never cleaned my MAF & i also think that it's not a part of the nissan scheduled check-up.

It's moving VERYYY slowly, But it will not go too much further & will not reach the 4x rpm despite how hard the gas pedal is pushed.

The fuel is 98 octane, It's called " Super Fuel " & i can not get any better fuel here.
The car is parked for at least 4 hours directly under the heat of the sun. Going inside the car by that time is like going inside a bowl of boiling water .

 

Here's some update,

So i went to a garage ( they are only working on 350z & infiniti G ), I cleaned the throttle body & MAF sensor. replaced my spark plugs also.

The car is Still acting like before & it's getting worst!!!. The car will accelerate ok once you push it from a stop, The rpm is moving OK & shifting OK, BUT once i will release the gas pedal & try to push it again, i will not be able to get the car to accelerate anymore. At the moment the car is not accelerating i will put it in the manumatic mode. ( The car is A/T ) & i will feel like a Turbo has been started & it's O.K .

I'm Realy worried about my transmisssion, Any ideas will be highly appreciated.
Thanks,

 

It seems more like an issue with the torque converter, as opposed to other things. So, chances are more likely you have transmission issues. What year and how many miles on your Z?

 

The car has 71.000 miles on it, It's 2005 by the way.

 

You say the car drives just fine when you're in manual mode and changing gears on your own, right?

 

Am I the only one who noticed that in post #4 he states he is using 10W-60 oil? why are you using such a thick oil

 

Here's what happens,

I will start a car from a stop & it will drive fine till i reduce the speed ( release the gas pedal & the car goes to lower gear ). After that the rpm is hesitating just under the 3000 rpm and not moving above even th speed will go a lil bit high.
In that moment i will push the car to the manumatic mode & it will go fine.

I didn't had a chance to test the manumatic mode in higher gears ( cops are everywhere ), So i cannot tell if it happens in manumatic mode at higher gears or no !

Thanks,