When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
Hey guys! Starting to get concerned about my 8, and i want to get some feedback before i start spending money on replacing things. It's been about 2 thousand miles now, and ive burned very little to no oil. Im fairly certain from what research i have done, that if the OMP has failed that its supposed to pop a CEL? Also oil consumption seems to have been slowly dropping over about 5k or so miles, but i cant be certain, due to having to replace my battery and do some other work, causing my trip odometer to reset several times.
So i don't think that is the issue, im thinking clogged lines, but from what ive seen, that requires taking then engine out in order to replace? Any other options or ideas? Ive also been premixing fairly heavily, so Im not too concerned about engine health as of right now, but i do know thats temporary.
Any thoughts or help would be greatly appreciated!+
Mine isn't consistent in falling oil consumption levels but on average the car consumes 0.6L of oil/1000 miles. Your results may vary - as shown in the model's distribution triangle (tip to tip represents 95% CI interval).
During periods of HEAVY premixing, I've seen my sump level increase.
.
Indeed,........Premixing for many years already with ratio 1 oz per gallon my engine oil level today keeps the same and does not lower.
A small part of the non burned 2 stroke oil mixes itself with the 4 stroke engine oil
This shows very clear that even during the gas burning proces the 2 stroke is present to lubricate the rotor parts and not burned fo 100 %.....
When I purchased my Rex new it had the regular engine oil consumption.
Some time ago I checked the OMP feed through the 4 oil lines..............they were fine........so oil level slightly lowerig / keeping the same / increasing slightly is influenced by the Premixing
BTW:...there is an excellent DIY on this forum to check the functioning of the OMP oil lines.......some work of course, but rather simple to do..........
Level increase? NO way if the oil metering system is working properly and if it were due to premix that would mean you were dumping fuel into your oil at a very high rate.
Level increase? NO way if the oil metering system is working properly and if it were due to premix that would mean you were dumping fuel into your oil at a very high rate.
"NO way.?"....Sorry.........this is not correct/true.............!
I did read about this fact already many times.........
For instance with Rotary 13B Plane Engines where mostly no OMP is running and the effect of 1 oz per gallon premixing causes to drain oil 1/4 oz per 50 hours flight time equal to approx. 3.500 mls........
11-21-04, 07:34 PM #1
13brv3
Senior Member
5 Year Member
Thread Starter
Join Date: Aug 2002
Location: Navarre, FL
Posts: 338
Does premix cause your oil level to increase?
Greetings,
I no longer have an RX-7, but I do fly an experimental plane with a 13B engine. In the airplane world, we almost all premix 1 oz per gallon, and one of the side effects is that it causes the level in the sump to increase over time. One person just reported that he drained a quart of "extra" oil after 50 hours of flight time, and I'd say that's probably about normal for all of us.
As I understand it, the premix oil gets past the side seals, and gets scavenged back to the sump. I searched the archives some, and can't find anyone mentioning this phenomenon in the car. Does it happen in the car, or just to us in the planes? We do operate much differently from the average street vehicle, so it's quite possible that you just won't see it in the car. Understand that we run wide open throttle at 70-100 % power (depending on altitude) for literally hours at a time. Not something you can do in a car :-)
Just curious.
Cheers,
Rusty
B ) Thanks Russ. I've heard from a couple car guys now, so I guess it happens to all of us that use premix. One guy speculated that more oil got past the side seals during low power operation, so it may even be worse for street cars.
C ) One more note when you heavily premix your crankcase oil level will rise over time. not all the oil is burnt and it eventually works its way into the crankcase oil. I am usually .74 quarts above where it was when i changes the oil after a 4k drive cycle.
NOTE: Long time ago when I was doubting that the oil level raise would not be due to premix but by fuel-leak into the sump (my RX-8 was a 15.000 mls car that time) i did my sump oil analyse......the conclusion was that no abnormal content of fuel was found......
"NO way.?"....Sorry.........this is not correct/true.............!
I did read about this fact already many times.........
For instance with Rotary 13B Plane Engines where mostly no OMP is running and the effect of 1 oz per gallon premixing causes to drain oil 1/4 oz per 50 hours flight time equal to approx. 3.500 mls........
11-21-04, 07:34 PM #1
13brv3
Senior Member
5 Year Member
Thread Starter
Join Date: Aug 2002
Location: Navarre, FL
Posts: 338
Does premix cause your oil level to increase?
Greetings,
I no longer have an RX-7, but I do fly an experimental plane with a 13B engine. In the airplane world, we almost all premix 1 oz per gallon, and one of the side effects is that it causes the level in the sump to increase over time. One person just reported that he drained a quart of "extra" oil after 50 hours of flight time, and I'd say that's probably about normal for all of us.
As I understand it, the premix oil gets past the side seals, and gets scavenged back to the sump. I searched the archives some, and can't find anyone mentioning this phenomenon in the car. Does it happen in the car, or just to us in the planes? We do operate much differently from the average street vehicle, so it's quite possible that you just won't see it in the car. Understand that we run wide open throttle at 70-100 % power (depending on altitude) for literally hours at a time. Not something you can do in a car :-)
Just curious.
Cheers,
Rusty
B ) Thanks Russ. I've heard from a couple car guys now, so I guess it happens to all of us that use premix. One guy speculated that more oil got past the side seals during low power operation, so it may even be worse for street cars.
C ) One more note when you heavily premix your crankcase oil level will rise over time. not all the oil is burnt and it eventually works its way into the crankcase oil. I am usually .74 quarts above where it was when i changes the oil after a 4k drive cycle.
NOTE: Long time ago when I was doubting that the oil level raise would not be due to premix but by fuel-leak into the sump (my RX-8 was a 15.000 mls car that time) i did my sump oil analyse......the conclusion was that no abnormal content of fuel was found......
Thanks for your posts/information..
It is a good thing to share this unexpexted phenomenon of heavy premixing with our rotaries......to avoid notorious doubts.
It is not just mileage, but how hard you drive the engine (load) that accounts for the amount of oil injected. If your oil was overfilled and you drove the car at steady light load, yes you could go many miles without seeming to consume any oil. This has happened with dealer overfilling an oil change, and all injectors and lines checking out fine.
Not likely 2000 miles though, but I have seen rotary engines that seemed to go a thousand miles with no apparent drop in oil (really they were overfilled in combination with light engine load driving). Steady speed highway driving can use less oil than lower speed stop-and-go city driving with more accelerations (more engine load) . Not making this up, this is from my own million rotary miles driven ,and real experiences of other fellow rotary drivers.
Check out your injectors and lines for sure.
Last edited by gwilliams6; 03-02-2017 at 02:06 PM.
gw6 is correct - always base line your oil level after an oil change and let out oil that over the top mark when it's done at a oil change place or stealer. I check mine at home in my level garage after 5 min of rest after driving home 25 mi from work (in other words check it consistently and with the same method. I also check it at gas stations that I know are level (like my garage - I've checked for levelness).
Mine isn't consistent in falling oil consumption levels but on average the car consumes 0.6L of oil/1000 miles. Your results may vary - as shown in the model's distribution triangle (tip to tip represents 95% CI interval).
Getting fuel into your oil and raising the oil level (aka "making oil") is not such an impossible issue (I have it on outboard marine engines, when the thermostat is stuck open and does not let the engine heat up properly causing some blow-by the piston rings, block is aluminum and engines are designed to run mostly at full throttle)....but why that would be increased by pre-mix would seem strange. So, I would lean towards checking for issues.
Alright thanks for the tips guys! I used to Premix about 4-6oz per tank awhile ago, when i was still using TCW-3 from autozone, but recently about a couple months ago, swapped to Lucas oil JASO FD 2 stroke, and since then been doing about double that, between .5-.75 oz per gallon. So the timeline does make sense from when i started to notice the oil consumption drop.
From what ive read so far, im gonna test by oil injectors to make sure they are working properly this weekend. I took a look yesterday at the oil lines, before and after i started my engine, and it looked like i could see oil going through them after i started my engine, although it was a little hard to tell. If they are working properly, anything else that could be the issue? Or pretty much in the clear in going with its just the premix?
Also gonna add that my driving commute is mostly highway miles about 18 or so highway with 4 or 5 city, however i do go about 80-85 on the freeway, and do a 0-90 pull almost daily on the onramp. As well as occasionally cruising through town for 'fun'
Last edited by Hydralisk19; 03-02-2017 at 09:25 PM.
Indeed,........Premixing for many years already with ratio 1 oz per gallon my engine oil level today keeps the same and does not lower.
A small part of the non burned 2 stroke oil mixes itself with the 4 stroke engine oil
This shows very clear that even during the gas burning proces the 2 stroke is present to lubricate the rotor parts and not burned fo 100 %.....
When I purchased my Rex new it had the regular engine oil consumption.
Some time ago I checked the OMP feed through the 4 oil lines..............they were fine........so oil level slightly lowerig / keeping the same / increasing slightly is influenced by the Premixing
BTW:...there is an excellent DIY on this forum to check the functioning of the OMP oil lines.......some work of course, but rather simple to do..........
Referring to the thread started on rx8club com by 1.3_LittersOfFurry.........
My first personal pot after cleaning my own OMP lines
Cleaned my OMP lines from top of the engine bay by removing battery plus battery tray.
Seems to be much easier as by removing the passengers wheel and access from the underside of the car, since handling of the lines and the cleaner from top is clearly visible with sufficient available space.
This first method is in detail showed in the UK-forum as per topic:
The access to the OMP lines is really perfect from top.
My 2005 231 hp had 25.600 miles on the odometer and I wanted to be sure that the OMP lines were free.
Immediately I saw that the lines were rather clean and actually a cleaning seemed to be overdone.
Nevertheless since the battery plus tray were removed at that point I cleaned the detached lines by soaking them in injection nozzle cleaner (so called "Petrol Injection Cleaner") since we have hardly seafoam available in continental Europe.
The bolts were easy to unscrew and turned out to be without any debris
With the engine running at 3.500 rpm each line in turn perfectly slurped the cleaner out of a small container filled each time with 3 oz cleaner.
The operation was started with approx. 2 gallon gasoline left in my tank (reserve warning light in operation); I added synth. 2-stroke oil up to a mixture of 1:50 to eliminate the lack of OMP injection during the time that after the cleaning the lines will be completely filled by the OMP. (No problems with starting the engine with 1:50)
After attaching each line I noticed that the lines were starting to be filled by the OMP (incl. some small bubbles streaming) relatively quickly; however cpl. filling will take some time and therefore the 1:50 premix.
(By the way, I regularly premix since new with approx 1 oz per gallon.)
My second post.......
Hi 1.3 LittersOfFurry,
I want to thank you for starting this post in 2011, I became more or less aware for the first time about the importance of free-flowing OMP-lines.
Your report and pictures how you did it were very helpful and was a starting point for me to do the same. Later on I did read the UK DIY-report about this and choose for the latter because of some easier access.
Once again, thank you very much by taking the trouble (and critics/comments) to share your experience on this forum.
For your information: I use a 2mm restrictor in the OMP vac. line some time already.
After cleaning the OMP oil lines I also sprayed the OMP vac. line (restrictor temporarely removed) with WD-40 (advised by a German expert) as I did already once before in order to clean the 4 way splitter/injectors.
However when I did this the first time, removing the free flowing OMP vac. line immediately resulted in a high whistling sound..........this time after 20.000 mls with the oil restrictor it did not whistle, even since I just before cleaned the OMP-oillines/injectors.
However after 15-30 sec. injecting the WD-40 the screaming whistle came back as before. I can not find any reason for the initial lack of whistle except that evt. due to the higher OMP oilconsumption with the 2 mm restrictor may be somewhere in the "vacuumline-splitterblock" there was a stagnation etc?
Nevertheless the higher 4-stroke OMP oil consumption with 2 mm restrictor works perfectly (more oil consumption as desired); further I noticed that by complete blocking of the vac. line the oil consumption increases once again considerable (to much imo.)
After my latest "whistle-experience" I plan to monitor and evt. spray with WD-40 the OMP vac. line more frequently.
(for you information, I always premix with a ratio of little more than 1 oz per gallon)
Since we are accepting anecdotes as "data," here is mine:
On a typical track day, on which I am premixing at least 1 ounce per gallon, I burn 1/4 quart of crankcase oil per hour. Definitely no premix added to the sump.
.
Last edited by Steve Dallas; 03-03-2017 at 08:08 AM.
Since we are accepting anecdotes as "data," here is mine:
On a typical track day, on which I am premixing at least 1 ounce per gallon, I burn 1/4 quart of crankcase oil per hour. Definitely no premix added to the sump.
.
Hi Steve,
That's another "anecdote"; now from you .......
I am not surprised because track days are equivalent to a very high crank case consumption......even with high premixing...
Normal street driving + high premixing can cause raising of oil level...... a couple of posters confirm this phenomenon......search on RX-7 forums und you will find more affirmations about this phenomenon.....
No it can't. And RX-8's are not RX-7's. This is not a thing and if you are not burning oil then your oil metering system is not functioning properly. If that premix is making it into the sump, then so is the fuel it is mixed with. This is not normal, nor is it acceptable.
Hmm, in my autox club both RX8s see the oil level climb a bit over time. The other guy's more than mine.. Both with sohns, both premixing 1oz/gal, him with I think amsoil, me with idemitsu. His engine is original, mine recently rebuilt. Didn't think it had anything to do with the OMP though, and nothing abnormal through the catch cans. We're both kind of at a loss..
Hmm, in my autox club both RX8s see the oil level climb a bit over time. The other guy's more than mine.. Both with sohns, both premixing 1oz/gal, him with I think amsoil, me with idemitsu. His engine is original, mine recently rebuilt. Didn't think it had anything to do with the OMP though, and nothing abnormal through the catch cans. We're both kind of at a loss..
Hi ZIG,
Thanks for your contribution........
Another statement from a couple of users who experience the rising oil level due to havy premix.....
LOL..... 9krpmrx8 will persevere to call it "a truckload of BS".......
............and Steve Dallas will consider it another ëxample of "we are accepting anecdotes as "data,"......
If I was getting rising oil levels, I would seriously have a look at what is causing that. You may have a small coolant leak, try cracking your drain plug after the car sits for a day. See if there is any trace of water in the oil.
I have been running premix in my RX8 since I bought it mid last year even though the engine is shot. Never once have I seen my oil level increase...
Well, the oil has always looked fine coming out, and I haven't asked him but I certainly haven't had to add any water. At one point he went like 10 events or something without an oil change and we had to drain a bunch at the track because it was blowing into the intake. If it were a coolant leak you'd think being down like a litre would stand out..
02-28-2017, 11:34 PM
.......
