sergiothegolfer

This is my first post... I've been checking out the site for about a month now, and gained a lot of information before purchasing a 2004 GT trim RX-8. The test drive for the car was fine, I saw a large number of service records from the previous owner, showing he used 5w-30 oil and had all oil changes and routine maintenance done by the Mazda dealer where he bought the car. I felt confident that the car was well maintained. It had 81,050 miles on it when I bought it and I knew the engine core was under warranty to 100,000 miles. I thought I got a decent deal at $11,325 after a few days of negotiating (its black, black/red leather, nav, and everything in great condition).

I bought a few quarts of Amsoil Saber Pro and added 4oz to the tank before each fillup of 93 octane gas. There was a noticeable difference in the "smoothness" of the engine as soon as I filled up for the first time using the saber pro. I drive it as it should be driven... i.e. let it warm up for a few minutes in the cold until the idling rpm's are under 1,500, then wait until the engine is at normal operating temp before revving above 5k rpm. I redline it every other day or so, and keep my cruising rpm range around 3500.

I noticed about a week after buying it, when I filled up the tank for the first time, that it was having problems with warm starts. After the car had already been running for 10-15 mins and the engine was shut off, I would have to wait at least 15-20 minutes for the engine to cool before it would start. Even after waiting, it would take at least 12-15 seconds of cranking before starting. There were no other issues besides this... no misfiring, stalling, no issues with cold starts, etc. I thought it was running fine, but I also had no basis for comparison because I've never driven another RX-8. I finally decided after owning it for 3 weeks to take it to the Mazda dealership to have it checked out. I had this gut feeling after reading many, many posts on here that my engine was losing compression.

I printed the TSB "Engine cranks, won't start" and brought a copy to the Mazda dealership. They looked at me kind of funny, saying that I shouldn't count on that to be the issue and that if it was just the starter, ignition coils, etc. it would be a few hundred bucks for the repair. They looked up the VIN and saw it had the 4206 recall and starter replaced in late 2006, then they started running through tests (I had left the engine idling to keep it warm while I was talking to them). Sure enough, they ended up playing around with it for about an hour before deciding to do a compression test, and it failed. The engine will be replaced in about a week, as soon as they get the rebuilt one from Mazda. I'll pay nothing.

I thought this was a relevant post because the car has been using 5w-30 oil for its entire life (first documented change at 6,000 miles, and has been serviced regularly by a Mazda dealership. The recalls were performed relatively quickly after they were issued. The engine has 81,500 miles on it (I drove it less than 500 miles). I'm kind of shocked that the dealer (not the same one I took it to) sold me the car and said it passed a thorough inspection... and it passed my inspection too, though I never thought to do a warm start in the few days I was thinking about buying it. I'm kind of glad I'm getting a new (or rather, rebuilt) engine... hopefully premixing and using 5w-30 in combination will extend the life longer. I love the car. Any suggestions/comments/thoughts? Thanks

Chris

Jedi54

iTrader: (7)

First off Sergio, thanks for sharing your story.
Compression is a strange thing, it can gradually diminish and then one day it starts to have unwanted side effects on the vehicle's performance (idling, hot starts, shutting off, etc)

Most of us here agree that 5w-30 and up is the way to go with our vehicles but one issue that Mazda still has with the earlier engines is lack of proper lubrication via the OMP. As you might now know, the rotary needs oil to lubricate the seals but the problem with the setup in our cars (Series I) is that the center of the apex seal never sees enough oil.
In your case, you pre-mixed at every fill up but I fear your engine was already doomed by the lack of oil and miles driven by the previous owner.

I'm glad you're taking the proper attitude here and seeing the bright side of things. One thing we have noticed is that the Reman engines coming from Mazda lately are exceptionally well put together and very few people have reported issues.
I highly recommend you stick to your plan of pre-mixing at fill ups and running 5w-30. I think you'll have plenty of happy Zoom-Zoomin' miles ahead of you if you do just that.

Good luck with the repairs, hopefully you're back on the road soon.

Lorrie Robinson

Learned this morning that my engine needs to be replaced. Thankful for the extended warranty but pretty bummed in general. I had no problems until Monday when the car started stalling at traffic lights in low idle. I had noticed for a few months that it occasionally idled roughly and made me nervous that it would stall though it never did. This was during the summer and when it seemed to be especially hot(here in Fla.) I was pretty good about service-went to Jiffy Lube close to every 3k and they followed mf recs. Mazda dealer asked me if I used high test-which of course I did...he said the engine was really carboned up...

Wow...but hopefully the new engine will be great and I will extend the useful life of my favorite car ever...glad to see a post that suggests the new engines are good...but this whole experience can't be good for Mazda or the rotary which pains me as I have been a fan since my first 1988 RX7.

shaunv74

Premix is the only band aid for the lack of lubrication we have on the series I cars. I've been doing it since my motor was replaced at 55K miles under warranty. I think anyone with an 04-08 should be consistently pre-mixing to ensure a long and healthy engine life.

sergiothegolfer

Thanks, good to know there's some faith in the rebuilt engines and that the premixing and 5w-30 should help

BigMikeATL

I spoke with a local Mazda performance shop which specializes in rotaries. They recommend 10w40 or 20w50 dino with Idemitsu premix. I switched to 10w40 and premix at 52000 miles (purchased my 8 with 51000 miles on it).

For those with newly rebuilt engines, break them in and switch to a higher viscosity oil and start premixing. As your mileage goes up, you may want to consider using slightly higher amounts of premix.

I am also adding some FP Plus to each tank.

madcows

Chris,

Sorry to hear about your misfortune, but on the bright side, you will have a nice new engine to take care of the way you want! There has been plenty of discussion lately about the oiling system.

I personally wouldn't go below 5W-30. If you're using dino oil, I would also suggest that you go no more than 3k miles between changes. One of the poor aspects about the oil cooling system is that around 40% of the entire system's capacity doesn't get drained out - can't even call it an "oil change", but rather an "oil mix". A good synthetic is preferred.

There's so much info and speculation on this forum that it'll make your head explode. But stick around, and we'll eventually find out what's best for our quirky car.

heyarnold69

iTrader: (1)

I've switched to 5-30 ... solved the hot start issue for me... i don't know how it technically did anything... but results are results....


FYI there are new plugs... i hope you have them!

madcows

Switched over from 5W-20? Sounds like blow-by all the way to the oil control rings then?

quikchong

i have a 2004 rx8 gt velocity red with 51,000 miles, never premixed, just regular oil changes, had my spark plugs replaced about 1 year ago at 35000 miles, dealer said it was fried, he also said he gave my car a fresh computer retune and that i should rev my engine to about 5 k rpm before shut down, n give it a good 5 k rev right after i start to car, does anybody else no anything about this? Is premix good for the car? would love to know more about it, thnx

ken-x8

Not to be a smartass, but a summary of the first post seems to be:

1. Bought an RX-8 that was running well
2. Warmed it up by idling, not driving
3. Added premix oil to the fuel
4. Engine loses compression and has to be replaced.

I wonder how much 2 and 3 have to do with 4.

Ken

ken-x8

Don't do that. Rev before shutting down is not necessary, accomplishes nothing if you've just driven the car, but should not hurt anything. Rev to 5k when cold is a very bad idea. Find another dealer.

I'll let others answer the premix question.

Ken

shazy

I use Premix. Amsoil is really good imo, like Interceptor and Saber Pro. I usually add about 4oz and the engine runs very smooth.
Anyway, good luck on the car.

shaunv74

Fixed. Most of our cars feel fine up until they need to be replaced. Especially if it's apex seal wearing out. It's a gradual degradation.

I'm curious though, why do you think premix causes problems? Care to share?

kersh4w

iTrader: (3)

i'd say you are very lucky! buying a used car and getting a new engine!

if my engine goes at 80k miles and mazda replaces it for free, i'll be really happy.

ken-x8

Well...maybe I was being a little bit of a smartass. But I do see enough posts from people who premix and have blown engines to wonder if it's really a cure-all. One respected member here is on his third engine, premixes, and reguarly assures us that you need to premix to ensure long engine life. Seems to be a bit of a disconnect. There have also been a few posts from premixers whose fuel pump socks got clogged.

When Mazda ran rotaries at LeMans, did they premix?

Ken

nycgps

iTrader: (1)

Do you think race engies have omp?

No they dont. And the nozzle is plugged or using houings that has not been drilled.

Premix is about 50 to 1

It seems that almost every new geeration has its own set of early problems. Happened to sa22c, fb, fc, fd, and yea, the fe. And these problems all corrected by mazda after maybe 2 revisions.

These engine have to be build by hand, and the build quality depends heavily on the builder's experience(feeling). For example, the seal's clearance. This is probably the reason why some engine last a lot longer thn some others.

Another problem is that mazda was too optimistic about the oil nozzle location. They hope that the oil will be squeezto the center(cuz rew has only 1 at center), the result was? No it didnt.

I will explain a bit more ater, i hate typing on my phone

shaunv74

Yes. They did premix at leMans. Speedsource also premixes. But that's because most of the racers ditch the OMP and just run premix. Also they premix at much higher ratios than we do for the street. As NYGPS stated ~50:1 where we are talking about 250-300:1 for the street alongside a working OMP.

Most of the folks I've seen that premix and blow motors also have turbos or some form of FI. I haven't seen anyone who premixed from day one/break-in and has lost an N/A or otherwise stock street motor.

what I do know is Racingbeat has seen increases in vacuum up to 180:1 premix ratio when they added premix to their motor on the test dyno. Specifically on the RX8. You can read up on it on their site. That tells me it does have a positive effect on the performance of the motor and is providing improved sealing and lubrication.

As far as the fuel filter I just replaced my pump and my fuel filter sock was fine. It was not clogged at all. I use Idemitsu premix so I can only speak to the performance with that brand but I haven't seen any ill effects. Of course I still have a long way to go before I have any meaningful data on whether or not premix is helping my engine. Hopefully when I have another 150K miles on the car and need to rebuild it I can take a look and let you know what I find.

Edit: As for whether or not it's a cure all I agree it only addresses the apex seal wear concern. I don't think it addresses the large side seal clearances or the potential for clashing with the side intake ports.

sergiothegolfer

I got the car back - Now it starts warm and cold both after turning over only 2-3 times. The engine light came on during my drive home from the dealer and stayed on for ~50 miles, but has been off now for about 200 miles. They replaced the spark plugs with the new engine but did not replace the ignition coils. I'm guessing it would be a good idea to replace those on my own sometime soon? The dealer put 5w-20 oil in the engine, but I bought a quart of 5w-30 to start adding when needed every 2-3 weeks or so. I figure the thinner oil won't allow as much harm in the winter anyway. I still plan to premix with Saber Pro. I've read enough about it on threads here, and don't see how using a low ratio (4oz/tank) will hurt anything, and it can potentially multiply the engine life 2-3x.

nycgps

iTrader: (1)

I think Mazda did a pretty amazing job on the Renesis, even with the lack of "support" from the o-mightly FORD. Sure the engine still has a lot of short comings, but it still amazed me. (just my opinion)

As soon as the weather gets WARMER (fuxking 21 degrees tonight!), I will take my pump out and do the Walbro 255 lph swap. god damn stock Arram pump SUCKS! Sure it works, but if the tank sits near 1/4 + doing high rpm = P0171. SUCKS, I have about 20K+ miles on this BRAND NEW PUMP. Last pump saw around 10-15 K premix ,sock came out clean, but still bad (chock at high rpm, no p0171 tho)

Stock fill is ALWAYS 5w20. There is no harm using "thicker" oil in Winter, if it does then before 5/10w oil exist all engines up north would've been all blown.

I use 8oz a tankful right now, well, I can't say it will increase your engine life by 2-3x, cuz like I said, this engine is build by hand, and the life of it depends heavily on the builder's experience. so you might still have a "booooogie" engine, but hey, at least you did your "job" to try to keep it spinning ~

Lorrie Robinson

If "all goes well" I should have my car back Wed. afternoon with new engine. I've kind of emersed myself in this forum since the surprising discovery that I needed a new engine. Kind of therapy...it seems pretty clear that significant numbers of these engines aren't likely to go the long haul...though I got nearly 80,000 miles so I have nothing to complain about relatively speaking...just hope I'm as lucky with the new engine...my oil change service was adequate but not perfect...I'll be sure it's perfect now though it's rather clear that this is a design issue not maintenance given the experiences of knowledgeable people on this forum who have maintained their cars perfectly...does anyone know whether there are improvements in the engine replacements? I'd like to believe the people with multiple engine replacements got a different engine than I will be getting...maybe awhile ago....'cause I do love this car!

nycgps

iTrader: (1)

Since 2003, Mazda made a lot of updates to this engine.

Material, Shape, Programming has been greatly improved.

and of course, Builder's skills has improved too (which is probably one of the most important thing for engine longevity)

So You shouldn't worry too much, Im sure your engine will last more than 80K (mind you, older 13B like the 13B-EGI, can go 200K+ miles without any problem)