Audiofight

Here's the deal:

I bought my car a year ago. This past March I shelled out $1400 for a new paint job, windshield, tires, & floormats.

I just resoldered the idiot lights a week ago and finished changing my tranny oil 10 minutes ago with Royal Purple 75W90.

I took my FC out for a little drive to see how it reacts. I hit 5k in first gear and then took it nice an easy through the rest of the gears until 4th. While in 4th, I hit around 2800 and felt something give loose. My first thought was clutch and hit the clutch pedal and the motor idles down to 500 rpm and then stalls while I am coasting at 55 mph

I get it restarted and it has no power and when I got home, it would barely hold an idle at 500 rpm and has no power when giving it gas. It sounds like it is missing and sputters on its way back down to idle from 2500 or so.

I think I am going to cry.........

Tell me I am right in thinking that I just blew a rotor.

I checked and both coils are firing. The only other thing I can think is that somehow I am not getting gas to one chamber, but that isn't good either.

Aaron Cake

iTrader: (1)

Try a compression test. Or, pull one plug out of the front rotor, crank, and listen for even "psst" sounds...Now do the rear. It will be obvious if one rotor has lost a seal.

Sorry to hear it...But look at it this way, new engine means rebuild with all the good stuff (porting, '89 rotors and counterweight, oil mods, etc.).

E6KT2

You are upset by a blown apex seal? I couldn't wait for my car to go down so I could have it rebuilt! It's hard to justify tearing apart a good engine. It's a happy day when your engine decides it wants to be rebuilt with more vitamin HP!

Audiofight

I thank you guys for the ideas of confidence, but I am have less money than those kids on the "Save the World" commercials.

Hey, maybe if I do an infomercial............

I am just hoping to be able to get it running long enough to save some money to rebuild the thing and do the proper porting and stuff.

Oh, and today I bought the washers to shim that damn Oil pellet or whatever it is in the front of my motor that has caused my oil pressure to be slightly low (45-50 psi instead of a constant 60-65 like it used to)

Sniper_X

you should never drive it again until you rebuild.

Each second it runs with a blown rotor increases your rebuild costs.

it will slowly eat itself.
And if the motor were to lock, then you could strip the tranny.

Aaron Cake

iTrader: (1)

Well, if a seal has cracked/blown, then there's nothing really you can do. Perhaps you can find an engine cheaply in a junkyard?

Audiofight

Junkyards around here only look at you funny when you ask them for an RX-7. If you don't put Mazda in front of it....

They just say:

"Oh, you mean a Mercury Cougar XR-7"

Stupids yokals around where I live don't understand what good engineering is.

I am beginning my search for engine parts tonight, for an estimate. My parents are willing to loan me the money to rebuild it. My gf is going to be quite disappointed that we can't go on our trip to Canada now, but oh well.

I am thinking 2 piece 2mm Apex seals from Atkins and a rebuild kit that I see on Ebay. Anything else that I will need?

Manolis_D

iTrader: (2)

you'll need a rotor and at least one rotor housing almost definitely. While the motor is apart, check the other housing as well, as it may well need replacing (due to normal wear and tear).

Try checking your OMP before you put the new motor back together -- I believe that is what caused my 1stmotor to fail.

Audiofight

Is there any chance, being that it can move itself around, that my current rotor and housing can be used? I can't afford to sink nearly a $1000 into motor parts.

It would be more affordable for me to buy a 327 that is in my local paper and drop that into it. I will do whatever is cheapest, a V8 conversion or rebuild my rotary. At this point, I don't care which motor is in my car as long as I can get around again.

VetteKiller

talk to Kevin Landers at Rotary Resurrection, I hear he does very good rebuilds for cheap:

http://hypntyz.rx7life.com/rebuildpage.htm

FPrep2ndGenRX7

Don't assume you need an engine rebuilt till you check it out first. I've had a spark plug work loose before and it obviously ran bad. I didn't know enough then and thought the noise I was hearing was from the engine dying. I finally found the loose plug, tightened it and "Viola" Instant rebuild. You might also want to check the injectors. If for some reason the primary injector on one of the rotors quit working I can only imagine the engine would run bad.

Audiofight

That is my plans for the morning exactly.

Here is what I tried so far:

I pulled the trailing wires off, it didn't make any difference. I pull off either of the leading plug wires, it ran shittier and stalled. All four wires have good spark from the coil packs, so they are working. The plugs are only 4k miles old, they should still be within acceptable limits.

I am going to let it sit overnight and then do a compression test tomorrow morning. I am just hoping it is fuel related and not a blown motor. I am crossing my fingers and toes (kinda hard to type )

If it miraculously has good compression on both rotors, then I am going to have to assume fuel related problems. I did dump a can of Sea Foam fuel system cleaner in it today to try and get the injectors cleaned. This thing has been idling bad for about a week now and I finally decided to try something quick to get it idling good again.

It used to idle at 750 with no problems, even with the AC on, it would only drop a little but stay smooth. Lately, however, it has been idling around 600 and sounding kinda rough.

Ryde _Or_Die

Man that sucks if its your engine. Look on www.thepartstrader.com www.mazdarecycling.com and the for sale section on here. Might want to post a "wanted" ad as well for a used engine. I am sure something will pop up.

Sniper_X

to see if its blown is simple.

Remove the trailing plugs and the EGI fuse.

Turn it over.

If it hisses like a galloping horse, its dorpped an apex seal.

If it hisses constantly its okay.

NO need to over complicate.. a "galloping" rotary is a blown rotary.

RexRyder

iTrader: (10)

nippin-motors.com has some really good j-specs, complete w/ everthing too, or go to fc3s.org, dey got j-specs, too

hypntyz7

Do the compression test.

IN my opinion having taken apart about 30 blown core motors, whatever damage has been done internally has already been done, adn nothing further can be damaged. The instant it broke that seal is when the damage occured, adn it is irreversible. Plan on needing the rotor and housing. 5% of all teh motors that lost an apex seal had useable rotor/housings front and rear. The other 95% needed a spare set. I have plenty of s4 NA p[arts if need be.

I also have a running, good compression s4 NA motor I pulled used. The kid wanted a full rebuild with heavey SP and AT-5sp coversion, is the only reason it was pulled out. I will sell this engine cheap and guarantee it to have compression upon installation, and not to smoke excessively or use water.

OR, I could build you a engine from scratch, ported, whatever. IF youre interested in any of this let me know. hypntyz@charter.net

Silkworm

No offense, but that's the craziest thing I've ever heard... Any idea what a broken piece of apex seal can do to the housing itself?

PaulC

peejay

Doesn't matter. The housing will already have been damaged, most likely the rotor as well. You can't make it any worse off than it already is.

Sure it is. It's much cheaper to rebuild the engine when it's still running than it is to rebuild it after it's already hosed a housing or two and one of the rotors. Or you could take the motor apart, find out that everything is still well within spec, and port the engine, and all you're out is the price of a Mazda gasket/O-ring set

jspecracer7

WTF? If you blow an engine, you can only break so many things. Most of the engine's that I've taken apart have blown a apex/corner seal, which in turn took out the rotor housing. Most of them don't hurt the end plates or the intermediate.

If it slowly eats itself, then what? You'll still have to rebuild with good seals and rotor housings...something you would HAVE to do anyways.

That's what he'll have to replace. I've seen engines go together for about $100 in parts. Maybe he'll get lucky and only have cracked a corner or apex w/o damaging a housing. If that's the case...$100 rebuild is in place

Audiofight

Well, if I am going to have a good housing it is because the car was driven only .5 miles on the "blown" motor.

It dropped a 1/4 mile from my house and I am being very generous in saying the mileage that it used while we quickly diagnosed it and then drove an addition 10 feet into the garage and onto the floor hoist.

peejay

Here's the problem. When the seal breaks, it generally takes only one engine revolution or two for damage to be done as the seal chunks get lodged between the rotor and housing with the usual gorey results. In other words, as soon as you realize something is wrong, the damage is done. 1/4mi might as well be 25 miles, or 250 miles.

go here - http://my7.rx-7.org/PJ - and look at the pics - you can see how the seal chunks got stuck between the rotor and housing and got "smeared", except the seal is hardest and it's the rotor and housing themselves that get smeared. The rotor even had a hole punched through it. There were no traces of the seal in the engine - they just blew right out the exhaust. The other two seals were hammered into their grooves from being beaten by the rough housing surface, one to the point that it can't be removed at all.

Interestingly, the rotor got beaten near one of the sides, causing the rotor to mushroom outwards. It was actually rubbing HARD against the side housing. The rotor has a big shiny spot where it was widened. I drove the car 25 or so miles home (how far away is Marysville from Columbus, Ohio?) and then drove it 3-5 miles to work the next day. Still started right up and held a smooth one-rotor idle, but acceleration was similar to a Rabbit Diesel with four large passengers.

Sniper_X

Its amazing that many of you seem to think i just "made that up", when i said that it could continue to eat itself.

It will.

I have done it by driving a car with a blown apex almost 30 miles because I HAD TO.

It started to eat the other apex seals about 10 minutes into the trip because the surface of the housing was mangled.

this led to the eventual SEIZING of the engine momentarilly.

(The rear wheels started to drag at 20 MPH.)

This destroyed the clutch.

So, say "WTF" all you want...

I mean even when people say:
"In other words, as soon as you realize something is wrong, the damage is done. "

they contradict themselves a bit later like in the previous post...

The other two seals were hammered into their grooves from being beaten by the rough housing surface, one to the point that it can't be removed at all.

"Interestingly, the rotor got beaten near one of the sides, causing the rotor to mushroom outwards. It was actually rubbing HARD against the side housing. The rotor has a big shiny spot where it was widened."

This didnt all happen at once..

All im saying is that its not smart to drive a blown engine.
anyone that defends driving one is NUTS!

This whole thread is getting nuts.

He just needs a new engine.
why make this into a debate?!

Gefunk

VetteKiller is that a fair-lady Z in your pic? Those things are goers but extreme boats. Hey but if you have a boat like that than you must have a honda boat anchor to accomidate it. Anyway...change out the plugs. Immediatly and see what happens.

banzaitoyota

Basics people, there are no miracle fixes!

VetteKiller

its a S4 TII (look at the tail lights), Fair Lady Z