so i just picked up an extremely clean 86 fc for 500 bucks and it has 57,xxx on it. but according to the old owner, it has a blown apex seal. now this is kinda hard to believe because when the car is on, it sounds really smooth and revs up normally and it doesn't stumble or have and weird smoke coming out of it. but on the other hand the car is really lacking power and will not idle on its own and has a major oil leak from what i think is one of the oil cooler lines.

i was jut curious if anybody has any good ways of figuring out if it actually has a blown seal. also the old owner says that the motor was rebuilt by Atkins about 7 years ago.

 

take out the trailing plugs and the egi fuse and try to crank the car. If all the pulses are there with no gaps in between all of your apex seals are intact. As for the side and corner seals someone else has to chime in.

 

yeah i was thinking about trying that. maybe a stuck seal??

 

my motor popped on me one night, and after limping it home that was the way I knew for sure it was a blown apex seal.

 

well anybody have any good running s4 motors for sale?

 

Getting no compression on one rotor?

 

Did you check it already? I would do that before I start trying to buy another motor. It may be a really easy fix. A gave a friend of mine a perfectly good motor and put it in the car for him. Then 2 weeks later he put atf in it to try and "raise compression", then he complained about not having power. It idled perfect and sounded good but it could outrun a school bus pulling a motor home. Well I took a look at it and the only problem was he put the spark plug wires on wrong . Just make sure you test things out before you jump to conclusions. It may be something really really simple . Good Luck!

 

well the old owner said he was on the freeway and out of know where it quit on him so idk i doubt its something that simple lol

 

im not really sure yet, ill check it tommorrow

 

this is literally exactly how my rx7 runs. im going to go ahead an assume its a chipped seal
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honestly fix the oil pressure issue and check for boost leaks (or a bad turbo). That car cant be a real 86 T2, as T2's came out in mid 87 IIRC. Check ALL wiring (especially to injectors) and get a friend to help compression test the motor.

 

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It should sound consistent like this, should be much faster in your case. Remember to pull the egi fuse, so no spark and it wont start up on you.

 

uh this car isnt turbo haha

 

Before you buy a motor, have you checked:

Trouble codes?
Closed loop operation?
Proper operation of the double throttle diaphragm?
Air cleaner?
AFM?
Air temp sensor?
Baro pressure sensor?
TPS?
Water thermo sensor?
BAC?

It almost sounds like a connector fell off a sensor while he was driving...

 

well its not throwing an codes so i dont think its that. but the old owner said the car started acting like this, the same time the major oil leak started

 

ok so i just did that 3 woosh test and in my opinion it passed with flying colors. every woosh sounded really healthy and almost made a whistle sound. now the question is, can you have a chipped apex seal and still pass the woosh test? is there any other seals that could cause my problem and still allow it to pass the woosh test?

 

It seems to me like the easiest way to know if an apex seal is having issues is a compression test.

 

I lost an apex seal in my rear rotor and I had no clue. The car ran perfectly fine, didn't smoke, and still had plenty of power. Sometimes I would have hot start problems so I did a compression test and only had 70 psi so now the motors out and I definetly had a broken seal-

 

well i don't have a rotary compression tester. and plus idk what psi it is supposed to be at. and if i use a piston compression tester, whats a good psi it should be at? because i know a rotary will register super low on a piston compression tester

 

I was unaware they made rotary specific compression testers. Air pressure is air pressure, no matter what's creating it. Do a search on compression numbers, shouldn't be difficult to find. Even if you don't know the numbers, you'll know if you have poor compression when the readings don't match.

 

I'm pretty sure you can buy any old compression tester at sears and it will work fine.(thats what i did) Anything over 100psi is great and over 90psi is good and i think 80psi is about the lowest you want to see.

 

OK so i compression tested it and the front rotor is just about 100 and the rear rotor barely even registers on the gauge. the first number on the gauge is 25 and it doesn't even make it to that
so my next question now is if im getting that low of compression on the rear rotor, doesn't that mean all 3 rear rotor apex seals are bad? like i said, when i did the whoosh test, it sounded really healthy

 

You only need 2 bad seals on a rotor to create that condition (it's a triangle). One seal probably broke, and then damaged the next as it was tumbling the broke one around. OR You might not have had the tester screwed in far enough to make a good seal?

You need a rebuild/replacement. You might consider doing a turbo swap to it, while you are at it.

 

i was considering a rebuild but i really do not know how to rebuild a rotary. i only know how to rebuild a normal engine

 

ok so ive decided to rebuild my motor. i wanna get my rebuild kit from atkins, should i get the overhaul kit or the rotor kit? the overhaul one costs 300 and the rotor one costs 700. but the overhaul one comes with all the same stuff as the rotor kit and it even comes with a gasket kit, which the rotor kit does not come with.