Car is slow during warm weather or after motor warms up

[Deadly BlaZe]

Tried searching for this, but couldn't find an answer, probably because there are a lot of factors.

Anyway, when the weather outside is cold, the car will always pull strong, even just up to 3k rpm. This is even after driving around for an hour. During warmer weather, the car will feel fine while it warms up, but after about 30 minutes of driving, the car feels like it loses a lot of power and just feels like its bogging. I do notice that the car smokes a little under boost and the boost takes longer to build during the warmer weather. It looks like gray smoke to me, but I don't think the car is running rich because there is no black residue on the rear bumper. There is black stuff inside the muffler tip though (oil?). Not sure if that's related to the slowness during warm weather. Besides checking for boost leaks, are there any other possibilities?

 

[rossb]

As for the smoke and stuff I don't know but as for boosting quicker in the cold: Cold air is more dense than hot air and there for has a higher concentration of oxygen. This higher concentration of oxygen basically makes it easier on your intercooler which it's only function is to cool the air to get it more dense oxygen wise. And when it's hot outside, its the exact opposite. Less oxygen in the air, intercooler has to work harder due to its already out outside and your trying to boost which heating things up(aka heat soaking). All of that slows you down in the heat.

Edit: You may also have a boost leak somewhere that isn't very noticeable until you get pressure drop due to the heat. Which could explain the bogging down.

Solutions to this? Get a FMIC.

 

[97GSTAUTO]

As for the smoke and stuff I don't know but as for boosting quicker in the cold: Cold air is more dense than hot air and there for has a higher concentration of oxygen. This higher concentration of oxygen basically makes it easier on your intercooler which it's only function is to cool the air to get it more dense oxygen wise. And when it's hot outside, its the exact opposite. Less oxygen in the air, intercooler has to work harder due to its already out outside and your trying to boost which heating things up(aka heat soaking). All of that slows you down in the heat.

That is partially correct. Yes, cold air is more dense than hot air, thus it has a higher concentration of oxygen. But the oxygen content has nothing to do with intercooler function. You made a reference to the higher concentration of oxygen makes it easier on the intercooler but its actually the cooler air relative to the air comming into the intercooler. But otherwise the answer was correct.

 

[Deadly BlaZe]

So do you guys really think an fmic would help in this situation?

 

[the_mork]

There shouldn't be that much difference just based on temperature, try a boost leak test and consider that the warm weather may have nothing to do with it and the difference is in something else. I had a similar situation at one time that ended up being a cross-threaded spark plug. A FMIC is not a realistic fix to this problem, it will help your car be faster of course but if there is another problem the IC wont solve it and in fact may just keep it covered up long enough to cause you to have engine damage.

 

[bxxsted]

I agree with mork. FMIC is always helpful, but wont FIX whatever is wrong.

 

[97GSTAUTO]

I third that. Mine only does that when its like 90 degrees outside. But that was when I was bone stock. I'll see this summer what happens. It will proabably be worse. But you definately have something wrong. Do you have a logger? If so log it. If not buy one. But I suggest the usual catchall check for boost leaks.

 

[Deadly BlaZe]

Thanks for the replies guys.

I am very aware that an fmic will not fix whatever problem I may have right now. Don't get me wrong, the car runs good and strong, its just significantly slower during warm weather and I am POSITIVE it's the temperature that's affecting the power of the car. I thought it was just in my mind, but the power loss is always consistent with the temperature change.

 

[97GSTAUTO]

Whops. I didnt notice that you live in north ga just like I do. I havent noticed any difference with the weather that we are having. But then again. I dont drive mine as much as I used to because I have a company truck. Bu I would still check to make sure everything is OK. Unless you are making it seem to be a bigger problem than it really is. Keep in mind that our turbo'd cars are alittle more sensitive to air temp then n/a vehicles.