So here's my question.
Is buying a low mileage Rx7 a bad thing? They sit around for so long that they begin to lose compression since the apex seal is being pushed against the housing for such a long time. If it isn't a bad thing, whats the advantage of buying a low mileage rx7 other than just to say you have or collect it? I have a 94 with 49k miles on it and it averaged about 86 front and 84 rear on the test but the vacuum is is strong 14-15 at idle. Lucky 7 Racing it's at the minimum for the test and they also said that vacuum is suppose to be 12 but as i mentioned its a solid 14-15 at idle. Anyways back on topic, what is the bad and good of owning a low mileage Rx7??

 

My car pulls 18in of vacuum at idle and has over 100psi compression everywhere. I have 83-ish k on my car.

The advantage I would see in a really low mileage car is the chassis itself is just plain in better shape which is considerably more expensive to bring back to "new" vs refreshing an engine.

Jason

 

agreed, other wear parts are just not as worn as a higher mileage car.

 

Ok, so does owning or buying a low mileage Rx7 come with the territory of low compression? The shop I took it to, said it was because its possible that the apex seal was pressed against the housing and made the spring lose tension causing it to have a lower compression. Does this sound right to you guys?

 

I'm far from an expert on rotaries currently, but inactivity i believe leads to the springs/seals getting stuck and not sealing correctly anymore.

Jason

 

anything that sits for a long period of time with out proper lubrication (run time) will corrode or dry and crack. in the rotary this could lead to lower compression. this can happen in a piston engine as well. I had a friend of mine with a low mileage never driven 2002 camoaro ss convertible (collector). He had it parked for almost two years without driving it, started it up and it leaked coolant and oil from numerous spots from just not being lubricated on a regular basis.

 

Had a 1993 CYM garage queen that outran both my other higher mileage FDs. CYM mileage was around 36k.

 

got a 11k mile FD with no issues. the owner used to start it up every so often. i do take it out every once in a while and have not noticed any issues with it, nothing is leaking and turbo's are strong. the major thing i love about it is that new car smell inside. haha

 

My car pulls nice and strong throughout all the gears and boosts just fine but now that the shop said that i need a rebuild makes me wonder if its even worth buying with low miles. Has anyone else done a comp test to their low mileage car??

 

Low mileage means you should have less:

Wear and tear on the interior

Wear and tear on suspension components, bushes and shocks

If it has been garaged and it is low mileage, less sun damage to paint and interior.

The transmission will be fresher.

The diff will be fresher.

The engine could be less abused, newer, or may need a rebuild from sitting still.

You are confusing "low mileage" with "left sitting and neglected"

Your car is low mileage, but that is not your issue. The last owner neglected it by not running it from time to time.
Theres no magic formula where low mileage X equals compression of Y. Thats plain stupid.

Neglect is neglect. You leave any car to sit for a long period without running it periodically or tending to it, and guess what? You're going to have issues.

My Chrysler had been sitting for 20 years in a garage when I found it. It was low mileage. But just left there to sit and never started.
5 out of 6 pistons had gummed or stuck rings. Causing low compression. The tires were dry rotted. The trans pan was leaking.
You accept that the car has had some degree of mechanical neglect, you take it on and you fix the faults.
You then get to enjoy an original, unmolested car in return.

 

Low mileage is definitely better unless the car has set unstarted for a decade. Suspension/ride quality is what I always notice with the lower mileage cars.

 

Low mileage is good no matter what way you look at it.
Even if the engine did sit for ages and lost a bit of compression - the core of the engine and all the main components will still have less wear on them than a higher mileage engine.
Change out the apex seal springs and you would have a good, low mileage engine with minimal wear..?

Most of the compression loss would be from the seals not being lubricated, not weak springs.

In theory the compression should build up a bit as the seals get re-lubricated if it hasent been run in ages.

If your car starts easily, runs strong and dosent leak/consume coolant there is no reason to have it rebuilt even is compression reads a little low.

 

I would rebuilt now rather than wait for something to break and mess up the low mileage part that's in the motor. Also, is higher vacuum the sign of loss compression or was it the other way around?

 

On my Older motor with 93 psi compression when I got the motor it pulled 18inches of vacume . it still pulled 17 inches when it spun a bearing


unknown millage since it was JDM motor . unless your motor is ported it seems on the low side

I now pull all of 12 inches of vacume at 850 rpms with a ported motor

 

I flew to Michigan to buy his low mileage clean CYM and it was properly maintained. I had ZERO problems on the 17 hour road trip back to Jersey or any other problems after the fact. By the way she still garage kept waiting for the snow to go away She currently has 43k miles on her.

 

Low vs high milage well of course low milage

Where the lines become blurred is low milage vs a total redone high milage car. What I mean by redone is engine, suspension, motor mounts, bushings, interior...

 

When I purchased my current 94 FD in 2006, it had 39K miles on it. The attached images show that I had strong compression for each rotor. Today, I have 45K miles on the car. She has always run strong.

 

Low mileage cars are generally better than high mileage cars.