i purchased a 1991 mazda cosmo a couple months ago, and i have a few questions

when i first drove the car when it was shipped from japan, it burned oil for about the first 5 mins of driving, after that it didnt seem to burn any

but but if i let it sit for a couple weeks without starting it it seems to burn a tiny bit for about 10 seconds

is this a problem, could there be a wrecked seal

the car has approx 40,000 miles, and it came with a boost controller and the boost was set at 12psi when it arrived

would this cause problems having a stock intercooler and exhaust

i would like to upgrade to a single turbo, so i can run around 450hp butwould this be a bad idea with what ive mentioned above

i dont know too much about rotory engines, so forgive me if a have to ask more questions

much thanks

 

considering that you mentioned this happens only when the car sits, i'm inclined to not yet condemn the engine.

all i can think of for now is to change the oil (and filter) and use a quart of MMO in lieu of one of the quarts of oil. also, run some MMO in your fuel for a while - and take it easy with the boost until you change the oil again. run the oil for 2000 to 2500 miles and change, then see if it does the same thing.

hope it works.

 

would 5-50 mobil1 synthetic be ok?

i should also mention that the ammount it burns now when you start it up is almost non noticable, its not like a big puff of oil smoke

whats mmo?

thanks

 

Sounds like turbos...
Those turbos are notorious for failing.


-Ted

 

thanks for the replies

would the turbos doing that hurt the motor if i dont replace them soon?

is there any way to check the condition of the rotor seals and internal parts without tearing the motor apart?

also is 5-50 mobil1 synthetic a proper choice oil for my car


sorry about all the newb questions :0

 

NO............. Do not use a full synthetic oil on rotary engines

If you can get it. PENRITE HPR-10

Or the best quality semi-synthetic you can find

As for the smoking, its just a sign of the turbo's starting to leak. They all do it at some stage. I have known FD RX-7s (92+) to start smoking at 10,000km. Dont sweat it, there just lubricating the engine internals more than usual. Make sure you change the plugs to the following.......

Leading................. NGK BUR6EQ . . . . . . (lower)
Trailing.................. NGK BUR8EQ . . . . . . (top)

Change them every 5000km along with the oil & filter.

The boost setting at 12-psi is right on the factory boost cut limit. You may want to set it to 11-psi as boost cut on a cold night can lean out the rear rotor doing a fuel cut & pop the engine.

Post the VIN of your Cosmo please. (EG, JCESE-100375)

REgards

 

thank you very much

the plugs in my car right now are bur9eq and bur7eq, should i change those out right away?

there new, but i guess my local lordco does not know **** because they also reccomended me the 5-50 mobil1

i have drive the car about 2000km with the above listed

i hope i didnt **** anything up

from now on im only asking you guys for advice


i will take some pics today and post them, as well as post the #'s

 

6's and 8's not 7's and 9's for spark plugs?

 

YES. Having played with the JC Cosmo since 97, experience has taught me that the 7+9 combo will foul over a few thousand km where the 6+8 combo burn perfectly.

The reasons are quite logical. The 20B + auto trans means the engine is reving a lot lower compared to a 13B + Manual in an RX-7. The excellent torque characteristics of the 20B simply mean you rarely require any more than 4000rpm to get into balistic speed territory & that rare 4000rpm rev out isn't enough to keep the 7+9 combo unfouled over the long term.

Mate, if you order the plugs as a complete box (like I do) then you get a better price. Here in Oz, they drop from $18ea to $12 ea when purchased this way.

Use the same oil filter as the FD RX-7 (92+). THe air filter is unique but if you get a pod filter, use the K&N RF-1003. Its offset perfectly for the Cosmo & has the correct dia pipe.

REgards

 

ah I see. makes sense to me dmrh

 

I've been using 5w-30 Mobil 1 synthetic. When I had the engine rebuilt, the mechanic said that the inside of the engine still looked new.