Well I took my RX8 in to the service department on Monday. We have had a few inches of snow here in the last few days. My car was covered in salt. I did not take the advice of many forum members. On the way in I stopped at an auto car wash two blocks from the Dealership, As I pulled in to the wash I told the attendant that I hard a unusual noise. He said it was just the sound of rubbing against the Teflon rail and was normal. When I pulled out of the car wash I noticed my tire indicator light was on. I got out and checked and nothing looked unusual. After pulling into traffic I immediately felt pulling to the left. The dealership was only two blocks away from the car wash. By the time I got there the tire was flat. My wife noticed the valve stem was broke. The cost of a valve stem which is attached to the sending unit was $150.00 plus $80.00 installation. We called the car wash and they sent someone down. They tried to say it was Mazda’s fault as the stems are not flexible as on other cars. In the end they agreed to pay for the damage. The next day the service manager called to tell me the tire seemed ok. Boy was I relieved. No more auto wash for me. The service manager said in addition to driving the car they would be doing about a dozen tests. Most of these meant nothing to mean as the terminology was foreign and the service manager said he did not know what it meant either. The test had been ordered by Mazda. He also said they would be checking the mileage. He said they rejected the possibility of a bad Catalectic Converter as the tests would have found that and that they would not be dropping the exhaust. They said I would have low power if it were bad. Today, Wednesday they called me again. They said they filled the gas and the Engine light came on. This had never happened before. They did not check the mileage as they were going to for some reason. They did drive it 20 miles and said it used more then a quarter tank of gas. That is what I have been telling them all along. They were shocked. They said tomorrow they would hook up a computer and drive it with the computer attached. They said the tech thought it might a sending unit from the radiator that tells the computer the temp and that the unit was bad. They said I could pick up my car on Thursday as agreed. They are closed of course on Friday. They said they did not know if they would have an answer for me by then. If not I would bring the car back on Monday. He said eventually they would determine the problem. I told him I was doubtful. I am sol glad they experienced the horrible mileage. Now they will stop thinking I am crazy and Mazda may stop saying it just can’t be. So after more then two months and five visits to the Service department this is where I am at. I STILL LOVE MY RX8. I don’t want my money back I just want it fixed so maybe I can get 14-15mpg instead of the 9-10 I get. Or give me another one just like it. I don’t want any other car. I think the mileage problem is related to a small percentage of these cars and that eventually Mazda will fix the problem. Thank you all for your support to date and a Merry Christmas to all.

 

Howard,

Given your latest experiences, the possibility that either you or your car is either cursed or possessed should perhaps be considered. Have you thought about an exorcism?

In any event, you deserve an award for maintaining a sunny attitude. Merry Christmas to you, as well. And good luck.

 

Damn...I'm definitely never going to an auto car wash, aside from the fact that i think they're a waste of money. Good luck with the car.

btw...next time for a long post...paragraphs.

people like me get distracted and can't find their place again

 

you should try to get mazda to reimburse you for all of that money you wasted on gas........I'm averging 16.8 mpg and I thought that was bad...........and it is compared to the 30+ mpg I was getting in my miata!!!

 

Did they ever say what the cause of the bad mileage was?

 

I guess my message was unclear. That was the whole point. They have no idea.
I probably could use a good exorcism on the car and everything else.

 

Oh, my bad.. was just difficult reading your first post but I get the point now

 

I just got another call from the service manager. He said "The thermosstat was stuck wide open." He said "this will fix my gas mileage when they replace it." He said that "any problems caused by the fact that it was running constantly rich would be picked up by the computer such as damage to the CAT etc. Of course this has been going on for months. I get back my car this afternoon and soon I should find out. Where are all the experts on the forum. I need your imput on this. Shouldn't the computer have caught this condition in the first place. How can I know it will find any damage to components as a result. I doubt they are willing to re-inburse me for all the extra gas I used in the last three months. I just hope this actually fixes the problem. So those of you out there with the same problem, have your thermostat checked.

 

Zoom 44 where are you?

 

ok howard ive read it all. i dont know what to say at this point. i need to research and consult. ive never heard of a stuck open thermostat causing poor gas mileage. perhaps with it stuck open the car doesnt reach operating temp as quick as it should or always runs a little cool causing it to run in a rich map to keep the cat hot? no wait a rich map would cool the cat more. do you have any paperwork that says the tests they ran? maybe you can scan and post? and he thinks that the car constantly running rich for months didnt cause any damage/problems to the cat because his test didnt find anything? so he's not going to visually inspect it.

 

I don't have the car or the paperwork back yet. they are putting the thermostat in now. They said it had a sensor that was telling the computer the wrong info and that the computer was telling the ca to run rich. I don't know what to think either. I am certainly not knowageable in todays computerized vehicles.

 

do we have a fail open thermostat in our cars? most tstats fail closed but there have been new ones on the market for a few years that fail open. i wasnt aware any companies were using them from factory. it would make sense for one to be used in a rotary since heat is the bane of rotaries and fail closed t-stats make you over heat.

 

The PCM uses the ECT (coolant Temp) as an important variable for deciding which A/F map to use. Having said that....I can't see it running rich enough because its cold in the summer to cause that much of a problem. It would definitely do it now. The car stays in open loop til it gets to a preset ECT...then goes to closed loop.

I think the exorcism may be in order....... :D

 

yeah what he said- a quick google turned up this note-

and it appears that can keep the car in open loop. in open loop it doesnt use the feed back from other sensors that it does in closed loop. in closed loop mode it should hunt for stoich but in open loop with these maps it genenerally is much richer.

on this site which is about ways to maitain good gas mileage- no. 13 states:

so there you have it. its good to learn new things. hopefully this does help your gas mileage howard. unfortunate way to learn this lesson but its good for everyone to know. i still think they should look at your cat. i would have them put on your paper work that you are concerned about it so that if it does fail on you your previous concern is on record. the good news about the cat is as long as it fails within 110,000 miles its covered under warrenty. thats the federal standard

 

Thanks for this ifnformation. Isn't it true as they said that a failing Cat would reduce power. I can't afford to have them drop the exhaust at my cost as my wife lost her job recently and needs major surgery. In any case I will have them note my concern if it is not on the record. I am really hoping that it is true that it gets half the mileage when it is open as that would mean 20 instead of 10. :D
Wishful thinking.

 

loss of power can be gradual enough that you wont feel it. the catalyst slowly breaks off from the front and starts glogging the rear. you remember those photos i posted in the other thread? that car didnt throw a CEL. and its cat was screwed.

 

I picked up my car a while ago. They now tell me they did a milage test and it was around 16mpg. They said that what they said ealier was just them watching the gauge drop. Anyway they replaced the thermostat as far as I know. They did not have the paperwork done and said they would mail it to me when they did. I guess I'll just wait and see. They did drive it over a hundred miles. They filled up my tank which was great since I took it in empty like they asked. That was nice.

 

I checked my milage today and I do have an improvement 11mpg after them replacing the thermostat. I called the service department and they said they would get back with me. They did admit that there milage test that got 16.45mpg was 50/50 highway and in town and that they did baby the car all the time.

 

zoom, the P0126 code would show up with a stuck open thermostat.....

 

Howard, I second the call for paragraphs. I only breathe in between paragraphs and your first post had me seeing spots :D

I'd get an oil change if you've been running hyper-rich all this time your oil could be badly fuel diluted. Not only bad for the engine, but I'm guessing could affect compression; less power; lower mileage...

Your plugs may be fouled. A good long spirited run may help clean 'em up (after your oil change).

This may be the first post I've read where the deale fixed a MPG problem.

YAY!!!!

 

I'm not sure an improvement from 10mpg to 11 is really much of an improvement

 

So PLEASED to hear you're getting help with this problem:D Just shows posters with bad mileage have to be thick-skinned, determined, and go against the flow on this particular forum for that particular problem. Some here have given you a really hard time.

I get about 45-50 miles per quarter indicator mark. Fill light consistently comes on at 190-200 miles per tank. Averaging 16-17 mpg with 50% highway and 50% town.

 

Good luck Howard. Keep us posted on how this whole thing unfolds.

- Irish

 

same problem here buddy