archaphil

iTrader: (1)

Car has some miles (155k) and I know its getting near its time to most likely rebuild, but it runs SOO good warmed up. However I have some questions about my rotary's health before I do unrebuildable damage to my engine.

couple question which I will follow up with a video of a cold start (my main fear is here)

1) My oil never seems to go black, ever. I have put close to 2k miles on this oil change, and Have owned the car for a year. Previous owner gave the car to me with a fresh oil change from the dealer. Is this strange? I have to add every so often (not much though) and the oil does not have a distinct smell to it other then oil. It just never gets "dirty".

2) And this I will follow up with a cold start video in the next day or so. When starting for the first time after a day or so, it cranks and fires like it should, runs up to 2k for a few seconds, and starts to drop down like it should, however if I just let the idle drop down to 1500-1000 like it should, every so often it will fall on its face unless I "lightly tap" the gas pedal. After the "light tap" it holds like it should, and runs through the initial warm up process.

The car seems to run like it should otherwise. This is my first rotary engine and through research on here I know I am getting due for a rebuild at some point, but I will be rebuilding my s5 turbo II engine before this ol N/A.

3) also on first start up, A bit of whiteish smoke, but I believe its just moisture because it goes away once I start driving and never comes back. No other smoke besides that.


Thanks in advance to you rotary wizards for any input on my engines health.

Drifted88

iTrader: (3)

Mine does the "Falls on its face" if I don't hit the gas as well. Guy I bought it from said there was about 10k on the rebuild. I always just figured whatever it must just be a perk of a 20+ year old car.

rotary_FD3S

Honestly if it runs and drives fine i really wouldn't worry that much about it.

archaphil

iTrader: (1)

To my knowledge, this engine has never been rebuilt, just dealer maintained.

We used a piston style compression checker awhile back and both housings were 75ish across the board. I am not 100% that my buddy did the check correctly though.

rotary_FD3S

I think both housings should be in the 90 range but i don't 100% remember

MrBotanical

I need to do compression test on my rotary as well, which has 140k miles. From what I read, you need a percentage average from all three rotor sides to get a good compression reading, which is what a rotary compression tester does . Luckily for me there is a guy out here who does it for $125.

On the other hand I have read too that you can use the bounce of the needle on a piston compression gauge to get an idea of whats going on inside. Im still reading up on that.

Drifted88

iTrader: (3)

Engine compression test. 4th paragraph Thanks aaron cake.

http://www.aaroncake.net/rx-7/blown.htm

Spinz DVP

do a compression test. and ive noticed rotary oil doesnt get as dirty as piston motor oil

Aaron Cake

iTrader: (1)

There's no reason why it would need to rebuilt soon.

It sounds like the engine is fairly solid inside and that the purge system is working correctly. That being the case the oil will stay clean for a while, but will eventually blacken as it picks up contaminates and such (as is its job to do). There's nothing unique about changing the oil so you don't necessarily need to go to the dealer. You can do it yourself or take it to an oil change shop, or a regular mechanic. As the rotary consumes oil to lubricate the rotor seals, you may find that it uses about 1 litre per 1000 miles, give or take depending on how you drive.

Sounds like the throttle body may be sticking such that the thermowax can't hold the throttle open slightly. Cleaning the area should help. You can spray on some lube, work in in, then clean the lub off. The assembly is designed to operate dry and leaving oil on there will just attract dirt. Also make sure the TPS is within adjustment.

Probably.

archaphil

iTrader: (1)

thanks all for the replies. TYVM Aaron for chiming in. This makes me feel a bit more relieved now. I do have to add oil every other fill up, but nothing drastic. Was previously owned by an older gal whom was the original owner and used it for a daily driver. I don't think she ever red lined the car, or very little.

I will check out the thermo wax and throttle body, That was my suspicion as well.

Thanks again!

ThtManSam

I Would LOOOVE My Engine To Do That. You, Sir, Have A Marvelous Engine.

archaphil

iTrader: (1)

So after Aaron's post, I still need to check my throttle body for hangups. but here is the start up video as promised. Pretty sure at this point though my motor is doing fine, or rather as fine as it can at 155k

Vid link:

http://www.youtube.com/watch?v=ts-dM...ature=youtu.be

Edit,

which code is normal to use for embed on here? neither seemed to work. Sorry

Whammo

iTrader: (1)

Rotaries blacken oil slower than piston engines if my source is right. And if you're dilluting it with clean oil every other fill up, then thats most likely why it looks like it stays clean longer. How much oil does it consume?

archaphil

iTrader: (1)

after 2 fill ups.... maybe a 1/4 quart. It is certainly not burning it as far as I can tell.

Whammo

iTrader: (1)

Assuming you get 22 mpg average, thats a quart of oil per 3400 miles. Sounds healthy to me. Rotaries are designed to burn just about as much as yours does. If it leaked any, you'd probably have to top it off irritatingly often.

archaphil

iTrader: (1)

good ****, well I see you are also in Bloomington, should take the ol cars out and grab a beer sometime.

Whammo

iTrader: (1)

Yeah, one of these days.. I work a lot, and im usually tired as sh*t when i get home haha.

misterstyx69

iTrader: (142)

huh?
if your engine is not burning oil then the OMP is not working!..think about it!
1/4 quart down on 2 fill ups?..ya that's about right .

archaphil

iTrader: (1)

You know, this morning when I got to work I popped the hood and checked oil and inspected around engine like I always do when I take it out.

I noticed the oil metering pump was a tad wet. I am not sure if its the lines from the oil squirters where they attach to it, or a seal. I need to get out my degreaser and pressure wash the pig down and go for a drive.

The car runs **** though is the boggling part. Would the OMP not "squirting" as much as it should do to a small leak damage anything internally? I mean, It does still consume. Previous owner never got into the higher revs as far as I know. I on the other hand get into redline frequently.

but 1/4 quart every 2 is normal?

misterstyx69

iTrader: (142)

the engine will consume about a quart?...per a couple thousand miles?
been a while for me on that aspect as I went Premix ages ago and haven't looked back at those stupid plastic lines!
Yes,seeking leaks at the OMP can Lead to internal damage If not attended to,so you'd be best off to look at that problem.You can Premix in the meantime but that just puts off the inevitable of fixing the leak at the OMP anyways..and if it is a S5 then something is gonna bite you soon enough.
Try to use a controlled spray,so you don't have an electrical stuff getting wet.
The engine doesn't like that..see threads in this section..

archaphil

iTrader: (1)

its an S4 NA. Ill get it cleaned up tonight and cruise around this weekend to track it down. I should look into blocking off the OMP permanently for my s4 NA and my S5 TII that's waiting for a rebuild.

Time for research. Thanks again guys.