My sneaky plan to extend engine life for Series I
 

After reading a bizillion posts and implementing some of the suggestions, here's my summary:

(0) Cooling is critical. Make sure your plastic undertray on front of the radiator is intact, without it, air will exit around the radiator rather than through it. Some foam sealing around the edges of the radiator may help as well. The stock radiator is pretty good, the inexpensive aftermarket alternatives aren't better and may be worse. It's a significant advantage to lower the temperature at which the fans turn on. You can find a DIY to set up a manual switch (cheap), or buy a kit from RX8Performance (modest), or reprogram the PCM with a Cobb Accessport (expensive). Automatic transmission cars are more prone to overheating since they have only a single oil cooler. (The second one is for the tranny). Airflow through the radiator is restricted by the stock battery and airbox. Relocating the battery and/or using an aftermarket intake may help cooling, but also may cause other issues. When draining the radiator, be gentle with the little plastic drain plug; it's easily broken. Very little torque is required to get a good seal.

(1) Make sure you have the MSP-16 factory reflash done. It ups the oil injection rates. Simple and free at the dealer. [The dealer should also be able to tell you from Mazda's database if it's already been done on your car; my dealer didn't bother to add the door sticker.]

[1b] [Avoid the flooding issue by not shutting off a cold engine. Some report that the MSP-16 fixes this issue, but better safe than sorry. I've had no problems with trips as short as a mile, but I don't start a cold engine to just move it 20 ft in the driveway.]

(2) Add 4-6 oz of a good, non-marine, 2-stroke premix [like for snowmobiles, motorcycles, or lawn equipment] to the gas tank at each fill up to give some extra apex seal oiling. [The whole synthetic vs. non-synthetic discussion is full of unresolvable controversy. It was pointed out that marine-use premix chemistry is constrained by what is acceptable to the EPA wrt lake water contamination. There is general consensus though that a little oil in the gas is a good idea.] I'm playing it safe by using the Idemitsu premix designed specifically for rotaries

(3) Restrict rpm to below [~4k] until the oil is fully warmed. Gauges are a help here. [I was trying to keep costs in mind, but having at least a real water temperature gauge is almost mandatory. It allows one to see trouble coming. A single excursion into the 235-250F water temp range may cause water seal failure and an engine rebuild. Oil temps will generally stabilize to within +-10 deg F of the water temp during street. A way around the installation hassle of a "real gauge" is to use the OBD readout of water temps that every modern car has. I've had good luck with this $170 unit - http://www.scangauge.com/products/ - but there are others. The ScanGauge also has features like real-time MPG, trip meter, miles left to empty, and so on, plus of course lets you diagnose and reset (but not block) any check-engine-light conditions.]

(13) Keep the ignition coils and plugs "fresh". The non-stealth solution is something like the BHR coils ... potentially doing a swap back to stock if needed. [Add ignition wires to the list. Quite a few problems reported here relate to the ignition system. Ignition problems can also create other problems such as flooding, cat failure, detonation, and in worse cases, apex seal failure. It's hard to define exactly what "fresh" means and it depends on your highway/city driving ratio, but several have suggested 30k miles as a good change interval.] It's been suggested in another thread that adding a few washers underneath the stock coils where they mount to the plate may allow them to run cooler. Also, RX-8 plugs are very old school, using smooth round head to connect to the plug wires (think Briggs & Stratton) vs. the screw-thread like kind all other modern cars use. This can create higher resistances and sparking to unwanted places which may also effect coil life. Keep the connections clean and secure.

(4) Use a magnetic oil pan drain plug; just makes sense.

(5) Install Mazmart's oil pressure modification ($55). If you're cautious, wait until after this summer and see what the early adapters report. It's unlikely the dealer will notice in the event of a warranty claim. I've had no problems to date with this mod, even with oil pressures reaching 110 psi, there have been no leaks. Racing Beat sells a less-aggressive increase version for ~$100.

(6) Run a heavier weight oil. Personally, I wouldn't use over a 30 weight without the oil pressure mod. (A higher viscosity will cause the stock 70 psi oil bypass valve to open sooner in the rpm range, reducing oil flow above ~4k-5k rpm). [Synthetic vs. non or the particular brand is less important than going to a heavier weight.] The Valvoline Blue (diesel) oil should not be used with a cat in place. The ZDDP antiwear agents are not Cat-safe!

((7)) Stealth mode: Let the dealer do the oil change at 7k miles with the 5W-20. Since only about 55% of the oil volume is really exchanged, consider it a "flush" and change the oil yourself soon after, using a pump or a 'rocking technique' to get more oil out. Then change again on your own half-way between the official 7k interval.

(8) Run above 7500 rpm on occasion to make sure the intake manifold valves get exercised and the intake ports see flow. [It was suggested that putting a ~8k - 8.5k rev limit on yourself is good for engine life. I'd add, especially so without the oil pressure mod.]

(9) Install the Mazmart modded water pump (~$300). It's gonna move more water, especially at high rpm. Again, in the event of problems, the dealer will never notice.

(11) If you're driving in winter, particularly a lot of short trips, consider blocking off one or maybe both oil coolers with a piece of cardboard or foam to reduce water buildup in the oil. Monitor temps!

(10) Open up the cooling outlets in the front wheel wells to improve air flow. I'd now suggest doing this only if you're in a warm climate. Here in Michigan, cold oil seems to be a bigger problem than too-hot oil.

(12) Mazmart 170 deg thermostat for the hotter climates. [Remains somewhat controversial. Benefits and drawbacks likely vary depending on your climate and driving profile.]I tried this and then removed it, because it had a negative effect on my gas mileage. Also, unlike the 3 year-old stock thermostat, the Mazmart one had a rusty valve plate after only a few months of use.

[x1] [Install an oil catch-can in the line between the crankcase vent and the intake manifold. Oil gunk has been reported as coming along this line and gumming up the intake system I understand this problem only applies to 2004-5 models. 2006 and later have the breather lines routed to a point past the throttle body/MAF where it's not as big a deal If one chooses to do this, do not vent the can or line to air; use a sealed can for trapping oil vapor, but continue the line to the manifold. For some reason, blocking the manifold line and venting the can to atmoshpere causes unstable a/f. See: https://www.rx8club.com/showthread.p...72#post3968972 ] [Venting to air for the 04/05 models is apparantly ok, 06+, not. Adding to confusion is a few cars have had the "Milky Oil" TSB done which reroutes the 04/05 hoses into a more 06+ configuration. https://www.rx8club.com/showpost.php...98&postcount=8 ]

[x2] [Do the e-pellet mod to eliminate that bypass in the oil system. (This requires a little more "mechanic-ing" than the other mods mentioned above.)]

[x3] [Early replacement of transmission and differential fluids. In the group experience, Redline MT-90 gives good results. In my experience with another brand, gear shifts at high rpm become a problem. It may take some time after changing to MT-90 to see the improvement since the old stuff takes a while to come off the moving surfaces, especially if the tranny doesn't get fully warm in your normal driving cycles.]

[x4] [If you decide to eliminate the connection of the coolant lines to the throttle body, do *not* use the screw in the line trick to simply block coolant flow. That line goes on to the rear iron where it adds cooling to a critical area. Do a full bypass so that flow to the iron continues.

[x5] [I've read a couple of comments that overheating with heavy high-rpm operation can occur when a radiator hose collapses under suction. Perhaps heavier-duty hoses would help, or old-style "springs" inside the longer straight runs. I don't know if it's happening, but am recording the possibility for consideration].

[x6] [Several have reported plugged (or cracked) MOP lines between the pump and intake manifold. A reported symptom is lower-than-normal oil use. For high-mileage or older cars, it may be worthwhile to pull the lines and make sure they are intact and open.] Here's a newer reference for cleaning techiques (well done 1.3_LitersOfFury!), https://www.rx8club.com/series-i-tech-garage-22/possible-mop-oil-line-cleaning-method-225321/

[x7] [The short overflow hose on the top of the coolent reservoir points right at an electrical connector under the bottom edge of the stock airbox. If the car overheats, coolant can spay into this connector and cause problems with the electric power steering. While not really an engine issue, extending this hose to a point below the connector is relatively easy and definately wise.]

Other remarks: I suspect that some reported issues may come from over-filling the oil. The marks on the dipstick are calibrated for measurement with a hot engine after waiting just a few minutes. (See owner's manual for details.) If one fills to the top mark with a cold engine, there's too much oil in the system. Don't fill above the 1/2 quart "low" mark with a cold engine. I also notice in the "new engine club" stories, that a remarkable number were members of the red-line-a-day club as well. I don't think it's a coincidence.

Comments?

I edited the above based on comments received so far, indicating the edits in [brackets]. I rearranged the order, but it's still somewhat of a guess, and is going to depend on your driving situation, cash flow, and the miles already on your engine. Also, if you're running forced induction or with other major mods ... all bets are off, but most of those in that game, know that already. New edit 1/18/11 adds [x6] and [x7]. Edit 5/6/11 revises comments on catch cans [x1] and transmission [x3]. Edit 6/1/12 revises [x6] and [x1] . Edit 7/13/12 adds section (0) on cooling.

Well done. I like the no. 7 "dealer oil flush" in particular.

Along those lines some also recommend a true oil flush:

http://www.mpt.org/motorweek/goss/2909.shtml

I would avoid 7k miles (or half) and stick to the 3k miles.

Oh the 7k is just for show to satisfy warranty requirements: (dealer change w/20W)+50 miles; (self-change with 40W) + 3000 miles; (self-change w/40W) + 3000 miles; (dealer change w/20W) and so on is fine too.

I watched that segment last weekend with some amazement. Either that 50k mile engine had no oil changes, or was never warmed up, or perhaps it was part of the Toyota engine series with sludging problems. Back in the 60's and early 70's, every car I worked on with ~70k miles had 1/4" of gray sludge inside the valve covers. However, after the revolution in lubricating oils from the late 70's on, plus unleaded fuels, every car engine I've looked at was clean inside. I wouldn't recommend that sort of chemical flushing be done unless there was a clear reason for doing so.

^ noted and concur.

btw: I don't care who sees my BHR ignition system. I'll do battle with a dealership on that one any day of the week. ;)

One to add. Don't shut the car off cold as it leads to flooding, which then usually leads to pre-mature CAT failure and other potential issues.

I think you could also expand on the coils and plugs one as well, as incorrect spark leads to not burning fuel off......leading to........you guessed it........CAT failure.

Personally, I don't let plugs go past about 10k miles, but that's just me.
In terms of coils........well, if I was stock I wouldn't go much over 25k without starting to check them often.

There are some older threads that were started and may contain this info along with other stuff.
It's kinda nice to see an updated one though! you might wanna search out those others to see if any more info that you may have missed.

In conjunction with #8 - most people shouldn't be running above 8400 rpms to clear the carbon, so you might want to set the upper range. I know that my AP says my latest valves to open are at 7250 rpm, so I bring it just to 8000 or so (given that my tachometer is off by 500 at that point). I usually don't bring it above that due to the water pump cavitating, and the increased stresses.

^^ what fun is that? The beep is FTW!

Old warriors never die.

Sounds pretty good to me but having pulled my engine I'm unconvinced that 5 is necessary and I've always thought 12 was a bad idea

...I have a '04 that I bring to redline on a nearly daily basis. Car made 210 hp last summer @45k miles.

I think you have some good items in the list, but I don't understand the new fear of revving these motors. They were designed for that. Doing so on cold fluids is unwise, and it may indeed be true that the last 2-300 rpm are not worthwhile from a performance standpoint, but other than that, I really don't see the problem, assuming you have good oil.

I also think some prioritization is in order, to help folks who are a little nervous about some of the mods.

I'd say your items 1 thru 3 are pretty good. Although, I'd make the #2 priority, right after the reflash, that of running at least 5w30.

#3 would be 3,000 mile oil changes.

#4, premix.

After that, I don't have anything specific to add in terms of prioritization, other than my comments that I think the engine should explore the +8,000 range on a daily basis, if possible.

Questions from a prospective RX-8 owner:

(2)- Like the same stuff for leaf blowers?

What kind of oil? Synthetic or non-synthetic? I've heard both, I need a definitive answer.

Lastly, some people say they rev the engine high before shutting it off? Is this true?

Thanks,
Jeremy

There is a thread devoted to the subject - if you have a day free you could read it and get totally confused .
Personally i use cheap non-synthetic ........ not because it is better , because it is cheaper by $15/litre (here in nz) and it works just fine . Just don't use marine grade or it will clog your cat - apparently .

+1. Even Kevin Landers (Rotary Resurrection) has made suggestions of running our motors hard every now and then.

Let's stop this right here, because this is not what this thread is for!

1. "yes", any 4-6 oz of a good, non-marine, 2-stroke.

2. No definitive answer, and has been beat to death. Please use search.

3. If not shut off cold(that is the danger) being not at opertaing temp, then no need to rev at all, but if you feel like it......rev to 3k and then turn the key off.

Sorry Brettus, didn't see you typing!

Totally agree with Dave on the Spark Plugs (Checked mine out ofter 20K KMS, 12K Miles) and while still working OK, did not look too bad, but with New Plugs it brings back that "Spark" in the engine, just feels better.

I think I will do my Coils at 20K miles, even though I have Mazda's latest, you have to remember these coils work 3 times harder than "normal" ones, just like your plugs.

Glad you guys are doing many of my recommendations, using the FD RX-7 sorry Mazmart's Rear By Pass Valve, oil cooler rear vents, magnets.

It is all good, and your car will thank ya for it...

At what temp does the fan start with MSP-16? Even though my Mazda Warranty History says mine was done, I can watch my water temp cycle up to 210 then down to 180. I also use hardly any oil.

What does this mean?

I think my plugs are shot aftr 7,000 - its misfiring at idle when warm. I pulled two and one had these little balls of carbon stuck to the outer edge. (I am using 4 oz of Amsoil Saber Pro and 1 oz of FP Plus with 10 gal of gas. I run it up to 8k after I have driven 10 miles every day.

Basically yes; "pre-mix" is a 2-cycle oil.

I use Idemitsu synth as it is pretty much the de facto standard 'round here. 4-8 oz per tankful is the norm.

If I have to shut down cold, which is very rare, I rev to 3k and hold for 10 seconds, but that's the only time.

Good list.
I would add one ?
Install real water temp/oil temp gauges.

Brettus---Im just curious ---why dont you agree with # 5 and the lower temp thermostat?

Because my own engine (and others i've heard of here) show nil evidence of the bearing wear you guys talk about @ 77000 miles . Did not even bother replacing them at recent rebuild - even though just about everything else got replaced .

The thermostat : how do we know that the lowered temp is not too low and causing additional wear . It is not a mod that increases cooling capacity so what good is it ?

Dude I must have missed something--the bypass mod isnt about the bearing wear--although i am sure it will not hurt.
OD

That's also a question for me. According to Mazda USA, I have MSP-16; but the door jam sticker says I never got MSP-16, so I don't know which is true. I believe I have seen my fan hold off on engaging on coolant temperatures as high as 210-212F (according to my Scangauge II), though the ambient temperatures were well below freezing, in case that is part of how it determines when to engage the fan.