mikeferrell

I have used the search for this, so dont give me a hard time

I have seen everyone (including myself) make posts about loss of compression on our vehicles, though i haven't seen anything if there is a process that can be accomplished to prevent loss of compression happening.

So if anyone has any suggestions for everyone else and myself in preventing the compression from dropping and loss of horsepower would be nice.

I recently did a dyno run and it said i only had 156hp at the wheel. I took it to the dealer and they said that i haven't lost enough compression to warranty the engine out but they suggested i get a tune up, new spark plugs and they're going to put the seafoam stuff into the engine. Enough ranting, suggestions would be appreciated.

Oh, and i'm getting my mazdaspeed rear bumper today (authentic) is it a pain in the *** to install? should i be able to do it myself or have the dealership install it?

oltmann

What are your compression numbers? Run your engine to redline once it is thoroughly warmed up every time you drive it. That helps remove carbon and maintain compression. If your plugs/ coils are shot that could explain loss of power.

longpath

iTrader: (1)

In my own case, I had classic symptoms of compression loss (started fine when cold but was a real pain to restart when warmed up) which went away a week after my commute changed from 3 miles each way to 53 miles each way. Short trips where the engine coolant barely makes it to operating temperature before the engine shut down are not good for the engine.

Premix is a common favored strategy for engine longevity.

Also, lots of people recommend the AccessPort to allow the OMP to increase the oil injection.

mikeferrell

Not sure what the compression numbers are (it's still at the dealership) but i have never had issues with starting the car (warm or cold) I had the coils replaced about 10k miles ago.

What is premix?

I try to red line it every once in a while, but i will do it more often now.

bse50

Good synthetic oils, premix, change plugs every 20.000miles or sooner, change or upgrade coils etc. Use good fuels and buy an accessPORT.
That's a good synthesis.

Raptor75

The most likely cause of low compression is carbon build up in the compression chamber interfering with the seals. Carbon buildup is the enemy of the rotary and most likely the cause of most engine replacements. You need to get ride of it. Driving the car hard will help. I would also de-carbon the engine once a year with the Mazda de-carboning fluid and procedure, look in the DIY section.

The last idea is something I am looking at presently because I am worried my car could be heading to the dead engine club. I am looking at water injection systems, about $200 on e-bay. This could be the best way to keep your engine clear of carbon. The reason so many cars failed in the Southwest was because of the dry hot air. Humidity help remove carbon from the engine, less humidity more carbon and engine failures. A water injection system should be the best way to keep the engine free of carbon build up. IMHO

Beodude

iTrader: (3)

Low compression seems to happen because the side seals get stuck. Using an OMP adapter to pump fresh two stroke into the combustion chamber, premixing, and seafoam all seem to help. BHR ignition will ensure a clean burn with good coils.

hocknscary87

i was told by many people that you shouldn't use synthetic oil in a rotary engine, since its supposed to burn the oil. Speaking of oil, everytime i go to check it i only have about a pint burnt ever 1200 miles, and its got the milky stuff all over the stick. should i be concerned. it being my first rotary and people saying its normal makes me think no, but from what i am used to it makes me cringe a little.

RX8Soldier

iTrader: (24)

WTBRotary!

iTrader: (6)

disregard Hock

monchie

Don't believe the hype.

Beodude

iTrader: (3)

Synthetic burns just fine. It probably leaves less junk around than dino oils... Buuuuut that's a subject for a specific thread. People can get touchy with the oil talk around here. I'm running 10w40 synthetic in mine right now, but that's with the OMP adapter pumping synthetic 2 stroke into the chamber.

Gunk on the dipstick is normal. It means your oil does't get and stay hot enough to get rid of the condensation. 06 or 07 models fixed that.

AKzoom

Good suggestions everyone. When I was at the Lakewood dealer in CO the mechanic told me about the shut down procedure for the rx8. Maybe everyone already knows, but hold rpm's to 4,000 for 10 secs before every shut down. He said it'll burn off the excess fuel build up or somethin. But I usually just rev for a few seconds after short trips.

Also, keep your intake filter cleaned or renewed. Just changed my cai filter after 20,000 miles and the dif is night and day.
If you live in a wet or cold climate consider keeping the stock intake, short ram, or if you must get a cai buy a water bypass valve to keep out water and moisture.

scooter_dmi

Not necessary for every shut down. You only have to do that if the engine hasn't warmed up to the normal operating temperature, and you're trying to prevent flooding.

To the OP, oil and premix have been discussed soooooo many times so make sure that you search for the topics you have questions about first.

Supernaut6

Wow 4k on a cold motor? That doesn't seem right.

I've put some miles on my car since my last compression test and I'm still rock solid at around 120psi on all faces on my most recent one. I've premixed, made sure I didn't rev high until the water/oil was up to temp, rev to 3k on cold shutdown and floor the accelerator when ignition is off and more recently, I've had water injection and the Sohn premix adapter installed.

Bladecutter

And just more proof that not everything you hear from a Dealership Staff Member is to be fully believed.

BC.

200.mph

iTrader: (9)

only way to not loose compression is to never start/drive your car

usnidc

All good info so far, except possibly the don't use synth oil.

Loss of compression/carbon build-up is something that is unique to each engine. The most common problems are not driving the engine hard enough (after a proper warm-up) otherwise know as "babying it" (or early 4 port automatics), and degraded ignition performance. Our coils have a highly variable life span.

Must do:
use a good oil, pretty much everywhere else in the world but USA runs 5w30.
run good 91+ octane gas
keep up on routine maintenace (oil changes, filters, spark plugs, coils)
Let the car warm up (water AND oil) before driving hard.
"A redline a day keeps the carbon away"
Short trips kills the rotary... take her out for a nice long drive every week or 2.

Consider doing:
Pre-mix of some kind
Ignition upgrade
use synthetic Xw40
sohn adaptor

cujat

iTrader: (2)

I premixed, used good gas, kept it under 4k until it warmed up, changed the plugs and coils, and still had low compression at 62k miles. I'd say that it's just a matter of when your particular engine loses compression, and how pick you are about the issues it causes.

bse50

What year was your car? what maintenance did you do?

dannobre

iTrader: (3)

The only way to prevent wear to the engine is not to drive it

And that wouldn't even be for sure...cause sitting around is almost as bad for an engine as driving it LOL

cujat

iTrader: (2)

Mine was a 6MT Phantom Blue 2006 that I got when it had 15k miles in late 2008. I replaced the plugs and coils once at 30k miles, then replaced them and the wires around 50k miles with the BHR kit. I changed the oil and filter every 3k miles with castrol gtx 5w30. The car was never ran hard until it had time to warm up the coolant and oil. I premixed with TC-W3 2 stroke oil. The car began to feel slow and uninspiring; I drove a 2004 automatic RX-8 that was faster. I took it in for a compression test, then sold the car with a quickness afterwards while it still had some value.

Squidward

would a thicker oil improve compression? I've used 5W20 for the life of the car but now the engine is near the end of its life so I want to know if changing up my oil will give me some more miles on this thing before it's completely donefor.

bse50

Yours probably was a case of bad initial luck or bad first owner. A well built engine treated with your care will last definitely longer. Early models had improper Ecu flashes and that is what hurt them the most, in 2006 this problem had already been solved though.

AKzoom

Hey now, he was a highly qualified janitor who heard of a rotor engine!