about 2 weeks ago i went through the auto car wash and the rx8 started gushing out coolant from the overflow or so i think...afterwards i checked the fuse for my fan and replaced that along with the relays for the fan. went to test it out to see if the problem is fixed...still overheating. when i looked at it the coolant seems to be boiling in the coolant reservoir. really dont know much but would like some help with an idea of what it could be

 

Hate to say this to you but i've just had the same problem. The boiling you are referring to is your coolant seals gone, This isn't a joke :-(

 

what am i looking at for replacing coolant seals

 

$252.95

You will need (minimum) O-ring set and the gasket set so suit. Is yours 6 port? AT?

04-08 Rx8 6 Port Manual Gasket Kit (N3Z3-10-S50)

If the car is cold, go and take the coolant tank lid off and turn / start the car see if it spits out, the bubbling is from the combustion chamber i believe. Has it started smoking yet?

 

Bonesy, thanks for trying to help him, but some mis-information here.

A) Coolant overflow / boiling can be more than just coolant seal failure. Coolant seal failure can certainly do it, but so can any blockage of the cooling system, including a stuck thermostat, sediment buildup, or a blocked restrictor in either the upper coolant bottle return line or the heater core. All of the other options are far cheaper than engine replacement, and worth checking.

B) If a coolant seal has failed inside the engine, it is highly unlikely that you will be able to re-use the irons and/or housings due to contamination and/or warping. A single housing can go for up to $2,000 at dealer retail, about half that if you can get it closer to dealer cost. An engine with a coolant seal failure is often cheaper to replace with a quality rebuilt engine (like from Mazmart in the $3,000-3,500 range) than it is to try to rebuild yours. You can rebuild it, but only expect another 5-10k out of the engine before you have to rebuild it again. If you do a rebuild, you need more than the gasket kit. You will need all the seals as well (12 corner seals, 6 apex seals 12 side seals, the oil control rings, coolant seals, etc...). PLUS you will need to re-surface any side irons that aren't within spec, usually means lapping, and re-chrome the housings. Any iron or housing that is warped (which is typical with coolant seal failures) needs to be replaced entirely, can not repair.


So check the rest of the cooling system first. Replace hoses, get a solid coolant flush to force out sediment, at least remove and test the thermostat for normal operation, pressure test the cap and coolant bottle, etc...

 

well i flushed out the radiator tonight and seems to beholding up strong for now didnt go for a drive but let it idle for 20 mins and the fans actually did their job so thats a plus guess the real test is tomorrow when i go for a test run...also when i went to my local autozone awhile back and hooked the computer up they said my pre cat o2 sensor went bad (Sensor 1 Bank 2) went go get a price and it was about as much as a car payment lol is there anyplace i can get one cheaper

 

Front O2 is going to be about $200 or so, usually a bit more. Rear O2 is a bit cheaper. Can't interchange them, and DON'T go universal. Universal sensors aren't always reporting correctly, and the penalty for a lean spike at the wrong spot is a blown engine.

And yeah, that sensor is kinda critical. Contact Mazmart for an OEM sensor at a fair price.

 

Update well still getting a lot of overflow from the reservoir and steam coming out as well trying the thermostat next then from there Im out of ideas

 

Here are some more:
- Pull an oil sample for a test (contact Blackstone Labs, $25 for the test, if you have coolant in the oil then it's going to show and you know it's the engine)
- test your radiator cap for proper holding pressure (if the cap can't hold pressure, it's going to overflow, most shops can do this)
-test your coolant bottle for proper holding pressure (if the bottle can't hold pressure, it's going to overflow, most shops can do this)
- power flush the system (a drain/refill won't always fix clogs, most shops can do this)
- Make sure the system is bled thoroughly (air in the system will expand, overpressurizing the system beyond cap/bottle design limits)
- Test your coolant for the presence of combustion gases (will confirm coolant seal failure if present, doesn't disprove if not present, most shops can do this)


If the coolant bottle is questionable in any way, order a new bottle and cap from Mazmart.

 

I just had a quick question relation to this topic.

How long will a mazmart rebuilt motor last?

 

Did you check the nipple on the Radiator?..it is right below the overflow bottle....and they tend to break off...

 

There is no given time as to how long a motor lasts. That's like asking how long you expect to live... Provided that you maintain it according to instructions, it should have a "regular" life.

If the motor is properly done, which MazMarts are, then it should last as long as a new motor.

 

That's dependent on many things...

It should last as long as an OEM engine...but it would depend on what new parts were used, the application and so many other variables

Phone and talk with Paul...he is a wealth of information

 

Yea thanks. I was asking regarding the reliability and not how many miles specifically. But that this answers my question.

 

Might be a bad or broken radiator cap.

 

problem was the fan relay went out along with the fuse...also had a misfire in rotor 1. plugs wires and 2 ignition coils $822 worth of work

 

Ouch.

$30 plug wires, $25 coils, $14 for the relay, that's $94 of it. I guess $728 in labor?

 

that would be about right...gotta love a certified mazda technician...but now the 8 is running like new again and no issues to report