Clearing of carbon-build up in 8
 

Hi,

Anyone here can enlighten me on how to clear carbon-build up in rotary engine?
I was about to run in the car. How often should we rev up to the redline? Mine is a 4AT.

Thanks.

you can read the sticky thread in the AT-Specific Performance Mods threads

in the 1st place if u use the correct oil, there will be no carbon deposit...

most of the people in the united states who had to get engine replacements were using mazda recommended oil and had automatics in hot climates.

Sorry to hijack the thread, but it's for a good reason. mysql101, are there cases of steering rack problems and replacements in US? I can't help but feel that Mazda is gonna have a class action lawsuit on their hands over there if you guys are having the steering rack problem that we are having here. But because we are a small tiny market here in Singapore, they are not doing anything for us other than replacing the steering racks under warranty. What I'm concerned about is road safety and who is ultimately gonna hafta foot the bill for a replacement steering rack after the warranty expires if Mazda doesn't have a proper fix for the damn steering rack.

I haven't heard anything about the steering. Are people losing control of the car or something?

A number of us here are having to replace our steering rack, some on warranty while others pay the bill themselves (about S$1.6K or US$1K). Do a search on 'steering rack' in the Far East/Asia for a description of the problem. At the worst stages, the steering may actually feel heavy (no power assisted steering) or even jerk by itself when turned in any direction. And the scary thing is it can act up while you are driving. I just cannot begin to imagine the consequences if it starts jerking out of control while cornering.

Best way to get rid of carbon in this car is to take it up to 150mph, or about 240k, that really gets rid of the carbon quick, my car ran like it was brand new for the next 2 weeks.

there have been a few.. most a harness... one or two a sensor in the rack... i think all have been warranty..

beers :beer:

im wondering wat oil u using?

idemitsu rotary oil 10W30

Hi Ivan,

Is it mineral of synthetic? Idemitsu also has synthetic. Where do you get idemitsu from? I thought there is only one exclusive dealer who bring it in. Does Monster supply idemitsu? Thanks.

IDEMITSU rotary oil, full synthetic 10W30. Local dealer does not have idemitsu rotary oil.

Monster has idemitsu oil and we also highly recommend them to customers.

so using this oil u no need to rev up to redline often to clear carbon built up issit

i wld suggest u read up the forum and use the search button.. has been said many many times....

I did a DIY on this very subject ........

https://www.rx8club.com/rx-8-discussion-3/rx8-essential-daily-maintenance-103468/

i was actually refering to u whether u do it..anyways nvm....

been reading up the forum and so many theories are said till u dunno which is right...so thats why im just sticking to normal mineral oil and change it very often :)

it doesnt matter wat engine oil i use, i redline my car at leat once, every tank of fuel.

1. The rotary is a high revving machine, so y not rev to hear the sweet high pitch sound?
2. U dun rev, if there is carbon, it will accumulate, so rev harder to clear deposit, if there is any.
3. revving high has more good than bad. The only bad i can tink of is it consumes fuel faster.

I'll tell you what my Mazda mechanic told me on the sly....ok....hit that REV limiter at least once, if not twice a week, drive it HARD all the time, i.e. drive it like you stole it. He said the main problems they are seeing with any of the rotary engines is the AT's. The owners dont know how to drive them, or are still thinking like they have piston engine, and are afraid too. The Renesis is a racing engine. They are meant to be 'rode hard and put up wet' if you understand that terminology.;) I have an 06, MT have over 9K miles on her, and have had her brand new not quite 5 months. NO problems what so ever, but I drive her the way he told me too. :)

I'm taking apart my first Renesis (HP), and here is how the rotor came out : full of carbon deposit.

The housing and side plates were OK. Some carbon deposit in the exhaust ports, that's all.

Comments welcome.

Was that before or after racing?

After last week's rounding - cleared my carbon and serviced my car, the car feels good now... Just realise there is ~2mm thick of carbon sludge/deposit around the edge of my muffler..lol

ITs time to clean and wash my muffler till it shines :cwm27:

we have taken apart 2 renesis...... the latest one was full of carbon deposits.. some seals were damaged bcs of carbon lock.

Engine oil used is most important to the renesis or rather, the rotary engine. And pls "LOOT" the engine to clear carbon. If not, prepare for major overhaul....

But having said that "LOOT" doesnt means speeding or drive dangerous. juz noe when to do the right things at the right time.

I got an idea. Lets turn this into another syn v. dino oil thread. :hahano: J/K.

Seriously, has anyone realy figured out how some people have the problem and others do not? I cannot seem to see a common thread. Could it be the gas, the oil, driving habits, the service interval? I just wonder.

This engine did not come out of the race car, but from a road car.

Oil could be a factor. Driving habits too. I beieve the second is the real culprit here. That said, the other engine I just started to tear down today has been replaced by Mazda out of warranty due to usage of wrong oil (synthetic). We'll see if I can see any clear sign of damage due to the use of synthetic oil.

Fabrice