I just bought my rx7 about a month ago it didn't run, i changed the oil and a lot of other stuff, and i put 10w 30 in it. It had been sitting for about 3 years. I got it running, but after awhile it smoked a lot, but i called the previous owner and he said he always ran 20w 50, could this be the smoking problem? Also what material are the oil seals made out of? thankyou!

 

no habla when cant understand.....

what "other" stuff did you change?

when does it start smoking/ what color... ie: first start up (cold), after warmed up

 

just let it run for a while and the smoke should go away since that its been sitting around for that long...

 

I drained the tank, changed the plugs, the terminals, and the oil filter. It was a whiteish smoke smelled like a weed eater obviously burning oil, I was told my oil is to thin it needs to be thicker

 

According to Mazda:
In starting and operating temperatures below 20F, use 5W30
In starting and operating temperatures between 0F and 80F, use 10W30.
In starting and operating temperatures above 30F, use 20W50

Whoever told you it needs to be thicker is an idiot with no understanding of how a rotary (or piston engine for that matter) works. There are many reasons for a rotary to burn oil excessively, one of them is oil control rings failing which keeps oil from entering the combustion chambers. They can fail due to the oil thermo pellet in the front of the eccentric shaft sticking closed and preventing oil from getting to the front of the motor. The only way to fix this properly is to have the engine rebuilt.

 

Not necessarily. If the engine is worn down and burning oil, then thicker oil will help reduce the smoke. Motor honey works wonders too, but of course it's just a band-aid for an engine that needs a rebuild.

The stock seals are cast iron. Aftermarket performance seals can be made out of carbon, ceramic, or other materials.

 

the smoking problem can be that its been sitting for 3yrs...and 20/50 are usually used in turbo models...or depends on your area's weather...10/30 is fine in my rx7

 

i think tey are made of the same material as piston rings. i could be mistaken, im quite sure they are made of a ferros metal though.

 

i have always run 20-50 in my car year round. But in PA I would run 10-30 in the real cold months like jan-march and then 20-50 the rest of the year

 

I've never been happy with 10-30 except during breakins for the first few hundred miles. 10-30 is too think in my opinion for warm weather. Fine in the winter though.

For almost everyone I recommend 20-50.

This is all covered in the FSM though, which tells you the oil weights you should use depending on temperature.

 

I used to have a '79 RX-7 with worn seals that was letting coolant in-with 20W-50 thicker oil I got more smoke and oil consumption. Basically this occurred at start up and high RPM's only. Smoke was white.

I was told by Rotary Beat shop in CA(are they even around anymore?) to switch to 10W-40 thinner oil to minimize this problem. I ran the car like this for years and it helped the smoke and oil consumption greatly, even at high RPM's.

That was a 12A rotary.

 

correct me if im worng, but im almost positive in the owners maunal it actually says above 30 to use 10w-40

 

don't you mean too thin?

for the record, i use 20w50 year round with no problems (so far), even below freezing. Though, this is my first winter with the 7, so i'll see how it goes.

 

The k was a typo. He said thin. Don't bust on Aaron he knows more about 7's then you will ever know.

 

I use 20/50 year round, and my car is always started at below freezing temps during the winter. Its be been below 32 all last week and this week and my car has started fine except for an extra turn or 2 before it fired.

 

i use 10w30 mainly because it doesnt get that hot here except for in the summer, but even in the summer id only use it if it was going to be 80+ degrees daily in the summer.

I also think 20w50 gives more carbon deposits than 10w30 which is another reason i use it, and also because i run na not turbo.

 

I most definitely know that. I respect him a lot. I wasn't trying to bust on him. I wasn't reading closely enough and I thought it said thick, which confused me.

sorry, my bad.

 

i'm running 10w30 in my 89 t2.

 

really? I've never heard that before.

 

Well thicker oil is harder to burn so there will be more deposits from unburnt oil.

 

I thought about that, then I thought to myself, gee they should have prefaced their response with "The seals are worn therefore blow-by" but they didn't.

 

10 30 slices and dices in all of my rx7. that what the thred i put back a while ago came to. i kinda asked the same question.

 

V
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Yep, too thin.

20-50 is too thick for the cold weather. It's nearly solid below zero at startup, which is without a doubt not good for the bearings until it warms up.

 

ultrataco: pay attention to Aaron_Cake on this one. 20w50 in below freezing weather is definately a no-no. Your engine will wear a lot faster since it will hardly have any oil during startup. "Seeing how it goes" isn't a good policy, since your engine will be fine until it finally wears out early.

To anwer the original poster. No, I doubt the oil weight makes any difference at all here (nor does it do anything at all in the short term, for that matter). Thicker oil does flow slower and therefore leak slower, but even if that were the case you're only reducing the problem a little by using thicker oil. That won't fix it.

10w40 is slightly worse than other grades because it has more viscosity additives (and less of everything else). Ditto for other wide temperature range oils. Frankly, though, I wouldn't worry too much no matter what you use. Anything between 10w30 and 20w50 is good. I'm switching down to 10w30 myself because it gives slightly lower friction and it flows a little better during startup (to get your unoiled engine oiled up right away). 20w50, OTOH, seals a little better and it coats better after startup (to give a thicker layer of oil on all your parts).