Alright.

Im getting a little POed at Mazda ATM. I just brought my car into Mazda for the 2nd time for a compression test and was once again dissapointed with the results.

The first time (and i dont have the numbers on me atm cause im at work) I had idemitsu 10w30 oil in the car, and it failed the compression test. they zoompower cleaned it and it BARELY passed the test. They sent me on my way and told me to beat the s*** out of it to get it failing. While I dont really like the idea of that because I love my car, I did drive it a lot harder. I replaced the idemitsu oil with 5w-20 because Mazda told me they would refuse to do an engine replacement if i had synthetic oil in the car. I went back for another compression test this week and they said it passed with flying colors this time. it improved greatly. I dont have the numbers yet but wow what a difference a certain type of oil can make.

Anyways, I asked them why my car was slowing down so much recently. They said that their tech test drove it and they said it is twice as fast as any other RX8 they have driven. What kind of herb are these people smoking. My RX8 may be the only 8 that now has higher low RPM pull than higher RPM pull, because thats exactly what I have. When I replaced the coils (with cheap intermotor coils) I ended up with a lot more low RPM pull but through the past 2 months I lost a LOT of high RPM pull. I have been spending a LOT of time reading stickies and trying to get some skills under my hood with basic ignition part replacement. But what gets me is, The mazda dealer had so many different ways they could have gone from here to get my money. They could have said "We think you cat might be clogged" (which it probably is), and when I mentioned the motor mounts due to the bad idle they just said "It felt ok to us". Why would they not jump all over these things to replace them to get my money? It's like they didnt want anything to do with my car. And it is for 100% certain not as fast as other 8s I tried driving.

The only thing they recommended outside of engine tuning was putting in better aftermarket coils. So I guess that would be my main question; Like the mazda rep said; Could more expensive after market coils improve power a SIGNIFICANT amount comparedto like $30.00 coils? I just really felt shady about what Mazda was telling me. Not that I dont appreciate them not taking my $$, but I just didnt feel like I got the answers I wanted.

 

Sounds like you need to have a second opinion (dealer). BTW, any dealer that says "your car is twice as fast as any RX8 they have driven" is a clue to the idocrisy therein. If your car really is twice as fast, and can claim 0-60 times in the low 3's, I will gladly trade you, straight up.

 

This is more common that might be expected, if carbon is just unseating the seats, de-carbing can help get them to reseat correctly. I had the same experience with my first 3 compression tests, it gained compression.

I think you are missing something key here. The ENGINE needs to be driven hard periodically to help keep carbon down. This is not harmful to the engine as long as you don't spend too much time there and overheat it. You say you love your car and don't like pushing the engine hard, well, you are hurting it by NOT doing that periodically.


This is complete crap. Just don't tell them what is in the car. They can't prove it is one viscosity or another unless an oil sample is taken and tested within the first few hundred miles of ownership, and they won't take that trouble. They CERTAINLY can't tell what typo (dino vs syn) is in it, even with testing. They also can't legally refuse warranty on the basis of oil type and weight because no where does Mazda say not to use it. They just can't provide an active recommendation FOR synthetic.

The difference is NOT the oil. Think about how a rotary works. How could the weight and type of the oil in the bearings, that gets injected in miniscule amounts affect compression of the side and apex seals. It can't. What you are seeing is how the decarb and the harder driving that is improving compression.

Yes, they are blowing smoke your way.

No, your 8 would be in the same boat with any other 8 that has a clogged cat.

Because they are lazy and have no idea what they are talking about.

Take a look at my modding thread (in my sig) and look at the section on ignition. But no, they won't make a severe difference.

 

Yeah that dealer is full of BS. The dealer that just replaced my motor practically went out of their way to replace my engine. They didn't feed me any crap about synthetic oil vs dino, just ran their tests and my engine didn't pass. You definitely need to go to another dealer, and always ask for your compression numbers... Even if it "passed with flying colors", that sounds extremely fishy...

 

Thanks guys for all of the advice. I appreciate it. I think you're right about them not knowing what they are talking about. They actually told they have never had to do an engine replacement on an 8 before so they are new to the process. I understand that and can sympathize a bit. The reason I decided to go to this dealer is because they seemed a bit more personal than the big dealership where I got my car. And that was a horrible experience, and I did not want to go back to that kind of place. There is however another dealer near me, a Mazda/Ford dealer that is a bit larger than the VW/Mazda dealer where I brought it this time. I have spoke to a service tech there and they say they have to replace the engines all the time, so maybe they will have a better time working with me than this place. Ugh 2 hours of service $180.00 for a dead end. Boo!

But, none the less. Still love my 8 and I cant wait to get it back.

 

I hope you find someone who knnows what they are doing and can get you back on the road. Good luck!

 

The harder you drive it the better its able to get rid of carbon deposits. My car always runs the best and pulls harder right after I beat the **** out of it at a track day.

 

The bigger dealerships will be your friend here. Even though you may have had a terrible experience, they have at least done an engine swap a few times so they may be more inclined to handle your situation. Especially if you explain to them you current situation and how the other dealer handled it. I would give it a try.

 

Must be my RB revi intake lol. And no, I have only done about 7 seconds

 

The giant sucking sound is producing Porsche RSR quickness, that has to be the explanation.

 

*sigh* twice as fast

*facepalm*

They seriously should hire me instead.

 

Seriously...if you drive it like you stole it (but not all the time, and don't get caught speeding) lol, it will get better. Rev it once a day to get the carbon buildup away.

 

Sorry, I guess I kind of misrepresented what they meant to say. They were advising me to drive it hard right after start up while the engine is still cold to destroy compression and be eligible for the warranty.

 

Driving it hard cold doesn't mess with compression. It messes with your bearings, which only after long wear periods will bear wear start messing with compression.