yozsi

i all, i just got a 87 n/a rx7. it has 93000 miles and a perfect interior and exterior. the problem is that the car has been sitting for a while, probably more than a few months to a year. and the engine has absolutely no compression at all, when i crank it just rotates freely. i have read up that it could have the apex seals stuck or carbon build up. i do not think the engine is blown because all of the fluids look fine. if any one could help i would appreciate it. btw if it need another engine i wouldnt mind, because i bought it for only 400 bucks.

eage8

iTrader: (9)

if you don't have any compression it pobably has blown apex seals, and you'll need to rebuild the engine... but that is pretty low miles for an NA engine rebuild so I don't know, it might be something else... my friend has 186k on his original NA engine and it's still running strong. If you do get the engine rebiuld you deffinitly want to take it to a shop that specializes in rotary engines, I don't know what part of cali your in, but there are probably a bunch over there.

yozsi

if i need to rebuild it, i could always do that myself. any one ever heard of putting atf in the housings to free up the seals?

SOIA

use teh search fuction and type in atf trick or sumtin
ahh nevermind here ya go
https://www.rx7club.com/forum/showth...ight=atf+trick

Aaron Cake

iTrader: (1)

Follow the unflooding procedures (search). It's likely not flooded, just dry. The rotary can easily appear to have no compression if the engine has been sitting for long periods...

Oh, and I assume you changed all fluids, drained the old fuel and properly flushed the system before you attempted to start, right?

yozsi

its not flooded but has absolutly 0 compression. when i crank it does have oil pressure. and yes, i changed all vital fluids.

Jodoolin

Aaron's comment did not say it was flooded. He suggested that it may well be "dry". The oil necessary to complete a seal will dry over time. You will have no compression. Thus, when you try to start it you get a high pitched whine as the rotors rotate freely against zero compression.

I quess he was saying that doing the complex unflood procedure with ATF or MMO will restore the oil seal between the seals and rotor housing. Same cure different cause.

Aaron Cake

iTrader: (1)

Just use regular oil. Put a few ounces into each leading spark plug hole, crank over a few times, then repeat. Will start any engine, even thouse with "0" compression.

yozsi

well the problem is that there might also be carbon build up on the seals preventing them from moving. oil is not volitile enough to remove these deposits. thanks why i think i might do that atf trick.

hitmang11

How are u comming to the conclusion that there is 0 compression without doing a compression test.
Just because you hear it rotating freely doesnt mean it has 0 compression

Aaron Cake

iTrader: (1)

There also might be a mouse living in the exhaust manifold, but are you worried about that?

ATF is quite bad for all the rubber in the engine (oil o-rings, coolant o-rings) and should not be used randomly. Before you decide that your seals are stuck with carbon (which they probably arn't), start from the basics. If they are stuck, they will unstick as soon as the engine gets going...If they are truly stuck, then something nastier then oil can be used to free them...But an engine that bad is generally not going to be reliable in the long term...

yozsi

i know it is 0 because when i do the test it does not even regester a number on the tester. plus the car has been sitting so long, thats why i think the seals might be gummed up.