03 mini s loses power when hot, does any one know what is the problem, over 100 deg. outside in las vegas ???!!!

 

Cars tend to have less performance when its hot outside. Hot air is less dense, which means less air is being inducted in your engine. The opposite happens when its cold outside.

 

Yup
Especially, force fed ala turbo or supercharger. It gets even hotter under bonnet than a normally aspirated car when force fed. Thats why alot of the SoCal folks are running the Meth kits like the rmw one.

 

it runs perfect for about 30 minutes and then when u hit the accelerator the engine bogs down and u cant even get it up to fifty miles per hour. it is not misbehaving at the start, even at 110 degrees outside temp. the car works perfect at the beginning.

( the thought of pushing it in lake mead has crossed my mind )

 

white,

[NOTE: I am not trying to help diagnose your particular problem, as I do realize we don't own the same car. Just trying to hear your thoughts on the situation.]

This sounds EXACTLY like the problem that I am having with my 01 Civic. In my case, it just started happening a couple months ago. Research (web) found that I STARTED to have the problem more than a year ago. I noticed that when I drove it to about the same time you are seeing, 20 minutes or so, on a really hot day, that if I stopped for a short stop, like at a convenience store or somethin, it wouldn't start right away when I turned the key. I thought it acted like the fuel that would normally be there to start it dried out or something. That happened a couple times. Folks say they notice that happening before the losing power problem crops up.

Then earlier this summer, exactly what you say. Fine for 20 minutes in the hottest part of the day, then MAJOR loss in power. Couldn't get the RPMs over 3,000 in ANY gear. Therefore, hard to get it over 30-40mph. Then check engine would turn on. It would throw an error code. Then if I let off the gas, it would occasionally just die on the spot. There would also be backfiring.

If I let it rest for 20-30 minutes, it would start right up and be fine. The CE light would reset itself, usually the next day (in the morning when it's cooler and I'm driving to work). It has only happened when the outside temp is currently over 98 degrees or so, which is alot of the time here since June, and similar to you in Vegas. So, I come STRAIGHT home (or stop off at the gym) at 5pm, because that's like 15 minutes, but became scared to run errands. I now just stay home in the afternoons on weekends, unless I can "borrow" my wife's car.

My car is a little older than yours, just about to hit 117k miles (not sure about your mileage), and yeah, is a totally different model, so I'm not too helpful, I get that.

I saw the folks that had a similar problem, some paid $1000 or more to diagnose it, maybe $1200. And I found 3 different (expensive) solutions folks had for the problem. So, there wasn't even a concensus for what went wrong.

For the Civic there was a bulletin about the deal. Others were able to cite the bulletin and got the dealership to fix it comp, or split the cost with them. But the ones I saw successful doing that were under 100,000 miles. I tried to investigate that at my dealer, and the manager I spoke to balked and said "well, if it were under warranty...." So, she really pissed me off. I paid big money for the extended to 100,000, and it really didn't run out that long ago, vs. the age of the car.

That's when I decided to get something new (and warranteed). The wife has always been in love with the Mini, and it's WAY more fun than a stock Civic (or a yellow bus). I know you can "customize" both, but I don't have the knowhow/money to do alot of that. It seemed to me like there was a great chance this would be a >$1000 problem. Which is a large chunk of my bluebook. And I had just dumped $600 to bandaid the A/C 6 months ago (and the blower is starting to make a new noise). I figure I'm close to having to deal with little/major things on the car. And this power thing has me no longer trusting it. I can't have my daughter (handicapped) with me and be afraid the car might just die on me. I'm not happy because I really wanted it to be a 200k car, and it worked like a charm until this year. Now I'm starting to doubt it's integrity in general, and mathwise think it didn't make sense to spend that kind of money to have a car that I feel has another problem coming around the corner.

Have you had this car long? I'm wondering if you just recently bought it used (no warranty?), so haven't even gotten to enjoy it the first 6 years of its life before it started doing this, and now are extra pissed (based on what you posted in the other thread) because of that.

Do you REALLY not have fun driving it (when it's not chugging in the heat, obv)?

You're in Vegas. You can't have a car that acts like that in intense heat any more than I can here in Texas. It's time to either suck it up and get it diagnosed/repaired (which may not be cheap) or get another ride.

 

OK I THINK I FOUND THE PROBLEM. it looks like carbon build up in combustion chambers. the s mini only has a 8.9:1 comp ratio. the lady that owns it drives it nice and slow, and uses premium gas. high performance car, low performance driver !!!!! for it to burn the slower gas she needs to make the charger sing!!

calls for carbon clean up ( lets see..... low cost alternative ??? ......... )
thanks falkon

ps schoolbus central... sorry asses, minis better

 

oh by the way hot temp has no bearing on performance, overall. the mini has super charger and intercooler

 

it has a inter cooler and it works just fine, when everithing is fine

 

So... help me understand....

Does your new diagnosis change your thought about the outdoor temp needing to be high?

And why do you think it doesn't happen until the car is at full temp (i.e. doesn't happen in the first 20 minutes)?

 

i believe that the carbon build up needs time and fuel burning to get to the glowing stage and then it is uncontrollably pre detonates the fuel charge coming into the chamber. then, the computer senses pinging and retards the advance until the car has no power. at first, i had to drive it pretty hard with ac on gunning it up hills ( 500 - 1000 ft elevations ) by starting at 50 mph and accelerating heavily to 110 mph up hill repeatedly. so after about 30 min. the car was toasty and it started bogging down when you stepped on the gas and it barely got up to 50 mph. then i started putting water in the intake and also carb cleaner ????!!! i guess it couldn't hurt, that to clean the chambers.
i then went back up hills and punished it some more and the result was that it took longer for the bogging to happen, AND it wasn't as intense, it would just sputter and if you took it to higher rpms (5-7 k) the sputtring was gone. the pinging at the bottom of the rpm range (2-3.5k) eased up and that was with 87 octane, which improved performance over all, believeit or not.
if i didnt use ac, the car was livelier and it didnt suffer as much.
the mini is quite impressive. it has 96k mi on the odo and it sings like a little kitten when u step on its tail, if everything works well, 120mph up hill with no strain.
ps. i dont punish cars to destroy, i have to take through its paces so the car works well when this lady gets it back

 

seafoam does good too.

 

what is seafoam, and how would one use this seafoam

 

Google it. Autozones, Advance Auto and other places like that carry it on their shelves.....

NAM search it in the forums section...some threads on it as well.

 

Engine treatment. Add to fuel or oil or both. Get it at any auto parts store, $8.00ish.

 

The choice of many Mini owners in a 1st mod is a Cold Air Intake (CAI) to minimize this problem. Muscle cars of the late 60's & early 70's had hood or cowl induction systems that reduced engine intake temps from typical 200+F underhood to ambient outside temp of say for example, 80F. The horse power gain/loss is 1% per 6 degrees F. therefore a 120F change = 20%. CAI is the cheapest source of maintaining power/performance.

 

So who actually owns the car?