flomulgator

While taking the RX-8 up to the ski hill (yes I did!) I had myself a scary mechanical moment that has left me confused.

Conditions:
Full car (400lbs flesh between 2 dudes + 2 sets ski gear + full tank gas)
ambient: 60 degrees
grade: stupid steep
elevation: ~3,500ft.
Speed: +80 somewhere
gear: 2nd
RPM: 9200
Fuel: premium
Oil: Royal Purple 5w-30

So w/ that steep grade and a bit less air, I was hammerin on the car to go up the straight, long, open grade. It was running out of power, so I wasn't accelerating fast. Didn't think anything of spinning the rotary fast, because of everything I've ever heard here. So it sat between 8500 and 9200 for a while before it got to the later number and then I shifted. WOT the whole time. As soon as I shift up to 3rd....engine light comes on, blinking.

Power then starts to go lower, engine is trying to stall. Hiccuping if you will. Slowing down doesn't help much, speeding up makes it worse (really wants to stall). After a bit the check engine light stops, and then later after that the hiccups dissapear. Limp up to the ski area, let 'er idle for a while to cool down.


I'm thinking it flooded while running or something. Is that possible? Why would this happen? Why poor old me?

Go48

Intermittent misfire. Do a search. Dozens of threads on this problem.

Also check out the latest service bulletins, particularly the Lack of Power and MSP-16 bulletins.

http://www.finishlineperformance.com....php?pageid=11

Flashwing

Yep, I'd be willing to bet it was a misfire situation. I had something similar happen on a mountain drive where I was hammering between 2nd and 3rd sitting at high RPMs the whole time. The misfire's were heat induced as my water temperature was pegged to the right. I had to have gotten the car to 240+ degrees.

This was prior to upgrading any cooling parts on the car.

staticlag

yeah, it sounds like you might have overheated it. What temp was it outside?

But more than likely you ran out of gas.

Or oil, if the oil isn't full it can have a tough time picking up on a steep grade since the pickup is on the front side of the oil pan.

staticlag

Lotsa stuff can go wrong if you take any car on a steep grade.

Make sure you're full of gas, oil, maybe some premix if you are going to be running it long and hard for a while, and watch your temps.

Mazurfer

240!

Yikes!

staticlag

Yeah, I'm pretty sure you ran out of gas. Cause keeping at WOT at 8-9K gets the rx8 roughly 6-7miles/gallon. And below 1/4 of a tank of gas it has trouble sucking up gas depending on how the car is positioned.

Macius8

iTrader: (3)

^^ he said full tank of gas

costello

Maybe full tank at the start of the trip, but what level was the gas at the time this happened? I get fuel starvation and have seen a mis-fire at the track at about 1/2 tank (depends on the corner). Plus the OP said he was running it at 8500-9200 RPMs for a while. I think this is really hard on the car. At least when you're doing track events, the RPMs drop down between corners and when you're shifting. Riding it at near red-line continuously will consume fuel fast and can overheat the motor. Water pump is probably cavitating the coolant and so it's not cooling as efficiently. Could be fuel starvation or overheating causing mis-fires.

alnielsen

iTrader: (4)

I haven't looked closely, but it seems to me that the fuel pump is near the front of the tank. This would make sense from a design stand point to prevent the car from running out of fuel during braking.
But, I think you may have a plugged cat converter.

staticlag

Ah, I forgot about cavitation. Yeah, thats a problem with the stock setup.

Mazmart Improved Water Pump FTW!

flomulgator

Hi all, thanks for the suggestions thus far.
At the time of the incident, the fuel was probably at 7/8ths, as I had filled up 40 highway miles ago. (call it 3/4 because of the pitch of the grade).

Engine flash up to most recent, loss of power recall done and passed.
Temp gauge never moved, never does.

Car just went into the dealer a month ago for bad flooding (2nd flood for this car). Got upgraded starter, new battery, and 4 new spark plugs as a result.

Clogged cat or misfires are, I think, the two best suggestions thus far. How can I diagnose a clogged cat? should the dealer have spotted this? Could this result from/be the cause of the flooding? Cheap *** spark plugs? terrorists?

staticlag

clogged cat = loss of power.

misfires shouldn't happen.

All signs point to overheating.

your cat can go bad from getting too hot, misfires can happen when your coils and plugs are too hot.

at 8-9K the stock water system can't keep up for extended periods of time because it doesn't push the water it just slaps it really hard which creates air bubbles and doesn't move the water through the radiator, for continious 8-9K use you need a new water pump and an underdrive system.

If you were going 80mph+ on a 45 degree gradient at redline then its def overheating.

No worries, nothing permanant probably done.

staticlag

PS, stock water gauge doesn't move from 180 degrees F to at least 240 degrees F.

Mazurfer

I rely on my Scanguage....so are you saying until you reach 240, you won't even see the stock needle move? Then what..........wham, it slams against the righthand stop.......indicating obvious overheat condition?

Thanks,

Dave

staticlag

Yup! exactly what happens! The epitome of an idiot gauge.

staticlag

At least 240. I have had it at 240 and it hasn't moved. But usually at that point I'm looking at my real gauges.

flomulgator

Awesome, thanks for the info. Sounds like heat soak was it. I really was sitting up there in the RPM's for a while....maybe upwards of 10 seconds in that range. Sounds like it's time for some cooling upgrades (and a turbo to run at lower RPM's w/ more power!)

As a scientist I am really irked to learn my "gauge" is not a "gauge". Sounds like it won't move until you're totally boned anyways. What's the point? If I wanted engineered instrumental comfort I would have a light, not a meter.

Nemesis8

iTrader: (3)

The RX8 is not a ski trip car for starters... Which pass was this BTW? I'm heading over Blewett Pass in May.

Idiot fake gauges are an insult to my intelligence. Why did they ever think we would happy with them? The other bone head move by Mazda was releasing an automatic with one oil cooler...

flomulgator

Sure it is! At least on the last weekend of the year when you are skiing in a T-shirt and the road is bare, dry, and warm. The passthrough is more than big enough!

It was Stevens Pass. Blewett would be way fun going North to South, because you would be going up the windy part. But I imagine you are going the other direction. Steep downhill turns = scary.

Nemesis8

iTrader: (3)

LOL - j/k. Spring skiing is a blast for sure. Yeah - downhill twisties! - I have new pads to go on this weekend to help....

costello

Eh, I think you were just driving it too hard. Did you need to keep up revved up so high for so long to make the hills or were you just having some fun?

I don't think I keep the RPMs high for very long even doing track events. It's usually accelerate hard to redline and then shift.

User24

iTrader: (1)

If you were 80+ and shifting to 2nd gear, I think it was the fuel cutoff causing you to loose power or something along those lines.

I have done 4 long distance trips across the US, at higher elevations, going uphill, in 3rd gear, 4th gear, loaded with 400 pounds of goods. High speeds. No misfires. At the highest elevation point in the interstate system, I certainly had problems accelerating. But this was all without MSP16. With the MSP16 I'm surprised how much acceleration I still have in hot 90 degree weather. That temperature used to kill my engine and make it wimpy as far as acceleration.

Mazurfer

And this 400 pounds of goods is.....................??????????
Just what you runnin?

flomulgator

Bring this thread back after a couple week hiatus.

Sooooo my car has been having a harder time starting ever since this event. Nothing bad, just.....more effort is necessary. This is especially true if then engine has been run at anything above a low-energy cruise. When I visit my parents I climb a hill then park. It is a particular problem then. And I am not bombing up the hill either (resedential), just getting up it.


Also I had been thinking about this. Everyone has thus far said that running it high and hard will "heat soak" the engine causing misfires, temporary cat issues, etc... But then I got to thinking about the Guiness World Record Mazda set (kinda cheesy record, but that's not the point) when the car first came around in 2004.

They ran a bone-stock RX-8 at ~149 mph for 24hrs straight. How do you make that statement fit with previous observations in this thread? I'm worried there is something else going on w/ my car. Any ideas?