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-   -   Goodbye, coolant seal :( (https://www.rx7club.com/3rd-generation-specific-1993-2002-16/goodbye-coolant-seal-846968/)

ArmitageGVR4 06-19-09 05:02 PM

Goodbye, coolant seal :(
 
Well it seems like it finally happened to me. After 3.5 years, 20k miles and 36 days on track, it appears my reman has let go. Earlier than I would have expected, especially considering the car has never overheated, never run more than stock boost, etc.

Symptoms were that coolant was disappearing, no leaks, no smoke. Rented pressure tester and put pressure on the cooling system for 3 days straight. Lost 6 psi over the course of 3 days, but lost maybe 10oz of water too. Knew before I even tried to start the engine where the water went. Yup, engine would barely fire, sputtered and stalled. Coolant smell out the tailpipe. Game over.

RX7 RAGE 06-19-09 05:05 PM

What's the plan now?

BC-FD3S 06-19-09 05:12 PM

ls1? :P

Integrals 06-19-09 05:38 PM

rebuild it! :)

evot23 06-19-09 05:43 PM


Originally Posted by aaron_bc (Post 9302129)
ls1? :P


heh heh heh...

GoodfellaFD3S 06-19-09 05:45 PM

Some of the past reman builds were shoddy.....I've seen some interesting stuff over the years from opening up remans to port them. Definitely not the best quality control.

Sucks to hear. If you'd been running one of the brand new motors Ray sells (that prolly weren't available 3 years ago) you'd probably still be rotoring.....

Btw, how often have you changed your coolant on that motor?

DigDug 06-19-09 06:11 PM

Sorry to hear that, Matt. Did you notice this just after you got home from VIR?

ArmitageGVR4 06-19-09 07:56 PM

Not sure what I'm going to do yet. 90k and already in need of a 3rd motor. All options are on the table at this point.

The motor was replaced by PFS in 6/04 at around 70k miles.

I have changed the coolant @75k (new t-stat), 77k (koyo radiator) and 88k miles (FC fan thermoswitch, AST delete, FC filler neck).

The problem first showed up on the way home after the 2nd track day of this year (3 months ago) which was in a downpour so I never even opened the car up or pushed the motor very hard. Since then, coolant has been vanishing to the tune of maybe 4-6oz per track session. I've been topping it off in between sessions. Still, no smoke out the back or anything yet so it's still on the way out, but I'm sure it'll get worse not better. On the way back from VIR I had to stop in C'ville for some dinner and then I topped off in order to make the second half of the trip home.

arghx 06-19-09 10:21 PM

I think the new dedicated reman facility in Richmond is doing the builds now, or they are about to take over. I expect high quality from those motors.

Speeder165 06-20-09 09:04 AM

Same problem here Matt. I feel your pain! Engine is out & putting another one in. Taking forever it seems. Hope you get it back on the road again soon! :)

GoodfellaFD3S 06-20-09 09:34 AM

You guys might want to consider the Pineapple heavy duty coolant o-ring kit if you're pulling the motor apart.

Fritz Flynn 06-20-09 10:13 AM

Matt sorry to hear about your engine :( Guys v8s break too and please remember that 35 track days is no joke.

Even at just 100 miles per day that's 3500 track miles and trust me any engine even in a spec miata would be hurting.

W/ stock twins you really have to worry about the manifold temps across the housings on that side because those coolant seals are like steak on the barbecue. With a single you move the manifold away from the block which really helps to prevent this from happening.

Please go V8 just so there's another chance that I'll get to evaluate how they perform on the track :icon_tup:

All these LSX cars and I've yet to see one. I know a buddy out in TX who's tracked one a bit and he is very happy w/ the results but I don't think he's driven a well setup rotary powered FD either so I :dunno:

My current track car has atleast 5k miles and I seriously believe if I was running a V8 it would also have some tired legs at this point. There's no majic engine and the rotary is about as magical as they come if you have it setup. Two times the same day I shifted by mistake from 5th to 2nd at around 90 to 100 mph, the clutch was in quick but even so in a v8 there could of been some rattling afterward.

Track miles are probably 20 times as hard on an engine. Most race cars need a new engine each year to compete because the compression is that much lower etc...etc...

Obviously there's a HUGE difference between pro race car drivers and HPDE drivers but in advanced and instructor groups the lap times are very close to race times because many of the drivers are in fact amatuer racers getting in some seat time.

Nat6c 06-20-09 10:22 AM

i concur with fritz on this one, the reman "may" not really have been the problem, just it's time with all the track days, that's alot actually. look at it this way, it got you home instead of leaving out in the middle of no where on your way home from a track day :) there's always a bright side :)

twinturborx7pete 06-20-09 11:42 PM

Same issue, lookin to rebuild probably.

Banzai-Racing 06-21-09 06:42 AM


Originally Posted by Fritz Flynn (Post 9303400)
Matt sorry to hear about your engine :( Guys v8s break too and please remember that 35 track days is no joke.

Even at just 100 miles per day that's 3500 track miles and trust me any engine even in a spec miata would be hurting.

W/ stock twins you really have to worry about the manifold temps across the housings on that side because those coolant seals are like steak on the barbecue. With a single you move the manifold away from the block which really helps to prevent this from happening.

Please go V8 just so there's another chance that I'll get to evaluate how they perform on the track :icon_tup:

All these LSX cars and I've yet to see one. I know a buddy out in TX who's tracked one a bit and he is very happy w/ the results but I don't think he's driven a well setup rotary powered FD either so I :dunno:

My current track car has atleast 5k miles and I seriously believe if I was running a V8 it would also have some tired legs at this point. There's no majic engine and the rotary is about as magical as they come if you have it setup. Two times the same day I shifted by mistake from 5th to 2nd at around 90 to 100 mph, the clutch was in quick but even so in a v8 there could of been some rattling afterward.

Track miles are probably 20 times as hard on an engine. Most race cars need a new engine each year to compete because the compression is that much lower etc...etc...

Obviously there's a HUGE difference between pro race car drivers and HPDE drivers but in advanced and instructor groups the lap times are very close to race times because many of the drivers are in fact amatuer racers getting in some seat time.

Could not have said it any better.

We have customers with track-only cars that rotate their engines out every 1-2 years, depending on the amount of time they see. They always have a fresh engine we rebuilt ready to go in, then send us the previous years engine to be refreshed.

ArmitageGVR4 06-21-09 09:43 AM

Thanks for the comments guys. Sorry to hear Speeder165 and twinturborx7pete are in the same boat :( I am thankful the car made it home in one piece for sure. Also since it's still a pretty slow leak I may get a few more months out of her before I really need to pull the motor. I removed the plugs, disabled the fuel pump/egi and cranked all the moisture out of the motor before firing it up again. It blew clouds of smoke for a few minutes then cleared up. At least it'll give me some time to decide what to do next.

twinturborx7pete 06-21-09 09:53 AM

Yea, mine is still driveable, it just wants me to put water in it every time before I drive it. I still see 83C on my PFC. Car only has the problem when it is cold, after that, I'm assuming the coolant seal expands to plug the leak.

93rx74lyfe 06-21-09 11:23 AM

Sorry to hear the bad news bud. :(

ArmitageGVR4 06-24-09 08:17 PM


Originally Posted by Fritz Flynn (Post 9303400)
W/ stock twins you really have to worry about the manifold temps across the housings on that side because those coolant seals are like steak on the barbecue. With a single you move the manifold away from the block which really helps to prevent this from happening.

So I'm thinking if I do just rebuild my existing engine, it seems wise to replace the turbos at the same time since they do have 90k miles on them and are bound to go bad sooner or later. Based on what Fritz mentioned above, I'm wondering is there a suitable replacement single turbo that provides similar or better spool time/throttle response/power as the stock twins? I'm not looking to make any additional HP. Using my existing non-tunable M2 ECU would be ideal. I would have hoped in the last 17+ years since the car was engineered and with the advent of ball bearing turbos and such we might have something like this but every turbo kit I've seen online for the car advertises 400 or more horsepower and of course requires a whole new fuel system and standalone ECU which isn't my goal here.

Banzai-Racing 06-25-09 05:04 AM

If you want to stay with the stock fuel and engine management, then just buy the 99 spec twins, they are far less expensive and make more pore than the S6 twins. Honestly you should seriously consider pitching the M2 ecu and installing an Apexi Power FC, which would give you full tunability and plugs directly into the stock harness. We get cars in all the time with blown engines due to reflashed stock ecus, such as the M2.

Fritz Flynn 06-25-09 10:58 AM


Originally Posted by ArmitageGVR4 (Post 9312935)
So I'm thinking if I do just rebuild my existing engine, it seems wise to replace the turbos at the same time since they do have 90k miles on them and are bound to go bad sooner or later. Based on what Fritz mentioned above, I'm wondering is there a suitable replacement single turbo that provides similar or better spool time/throttle response/power as the stock twins? I'm not looking to make any additional HP. Using my existing non-tunable M2 ECU would be ideal. I would have hoped in the last 17+ years since the car was engineered and with the advent of ball bearing turbos and such we might have something like this but every turbo kit I've seen online for the car advertises 400 or more horsepower and of course requires a whole new fuel system and standalone ECU which isn't my goal here.

As much as you track your car I'd go single w/ 1200 cc secondaries and a PFC tuned by PFS. I'm running a small t04e (about 13psi) w/ a 1.06 or so on the hot side that's perfect for track use. It makes about 350 rwhp but I also use a v-mount which makes a huge difference. If after two laps your charge temps are 60c and climbing you're loosing lots of power and risking predetonation from the high intake temps.

This setup isn't cheap but you'll have less worries and the car will run cooler and stronger lap after lap. I don't know about you but I drop atleast 1k per weekend so all things considered spending 6k or so to properly set things up is only like 6 track weekends :)

Actually the best advice is to buy my black 94 that's ready to rock and roll right now :icon16:

sp_amend 06-25-09 11:43 AM

I'm sorry to hear about your car.

Hope you can rebuild it right and get back to the track soon!

gracer7-rx7 06-25-09 11:48 AM

NA 3 rotor?

sp_amend 06-25-09 11:55 AM

20b would be nasty, although it's $$$$$$

ArmitageGVR4 06-25-09 11:59 AM

One of the reasons I'm not keen on a big single turbo setup is because when I'm not tracking the car, I'm autoxing it and big turbo lag would ruin the throttle response and instant-on power at any RPM of the stock sequentials.


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