buying a 89 s5 na gxl
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buying a 89 s5 na gxl
My friend wants to buy a gxl 89 s5 na, the only problem is, it blows a little bit of blue smoke during the initial start, after which the blue smoke goes away. I know I know, everyone is probably thinking its blown apexi's, but my friend does not think so, so i'm posting this to see what the rest of u think.
The car is in excellent shape on the inside, it looks just spanky new as if its been taken care of really well. (who knows maybe the engine was or wasnt on the "take care of" list) anyways, the car has 109000 miles on it and is going for a good price. Now, the car starts and all but does not idle, plus it seems to heat up really fast, but from my own experience with rx7's seeing the temp at half way was normal. (Current proud owner of an s4 t2 and "roommates" s5 t2,..,. big rotary fans....however still ametuers) Either way, I felt the exhaust coming out and it seems to sort of "studder" or backfire, (but theres no bang) The car was sitting for a while, so maybe this is just a sitting rotary thing, i know that atleast thats the way its been with my 1st and 2nd gen after a long sit, but not so much with the 2nd though, accually i think not at all with the 2nd.
Finally we havent test driven it yet, but i've reved up the rpm's and it seems strong, even though there is excesive exhaust pressure in my opinion. Maybe thats normal. Plus the air that was coming out seemed to me way too hot, i had to move my hand about 1 1/2 or 2 feet back. Does anyone has anything that they could possibly share or advise on, conserning the blue smoke the exhaust heat and backpressure. Please please reply and let me know. Thanking you in anticipation of your response, Sergei The Saint.
"Love going out to rotaries and rx7's all over the world, and anybody looking into and researching the supirior potential of the rotary"
Sergei.............
The car is in excellent shape on the inside, it looks just spanky new as if its been taken care of really well. (who knows maybe the engine was or wasnt on the "take care of" list) anyways, the car has 109000 miles on it and is going for a good price. Now, the car starts and all but does not idle, plus it seems to heat up really fast, but from my own experience with rx7's seeing the temp at half way was normal. (Current proud owner of an s4 t2 and "roommates" s5 t2,..,. big rotary fans....however still ametuers) Either way, I felt the exhaust coming out and it seems to sort of "studder" or backfire, (but theres no bang) The car was sitting for a while, so maybe this is just a sitting rotary thing, i know that atleast thats the way its been with my 1st and 2nd gen after a long sit, but not so much with the 2nd though, accually i think not at all with the 2nd.
Finally we havent test driven it yet, but i've reved up the rpm's and it seems strong, even though there is excesive exhaust pressure in my opinion. Maybe thats normal. Plus the air that was coming out seemed to me way too hot, i had to move my hand about 1 1/2 or 2 feet back. Does anyone has anything that they could possibly share or advise on, conserning the blue smoke the exhaust heat and backpressure. Please please reply and let me know. Thanking you in anticipation of your response, Sergei The Saint.
"Love going out to rotaries and rx7's all over the world, and anybody looking into and researching the supirior potential of the rotary"
Sergei.............
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The blue smoke is not caused by bad apex seals. It probably has oil getting past the oil control rings on the rotor. Its a normal thing on rotary engines. Oil in a piston engine has an easy time draining back to the pan. Not so on a rotary. If it goes away right after start up, then thats fine, nothing to be concerned about. If it starts happening at higher RPMs while driving, or when you shift gears, then that means the oil control rings are getting bad. Another bit of info:
Blue smoke= burning oil
White smoke = burning coolant
black smoke= burning fuel (running rich)
As far as the coolant temp, halfway, or slightly less than halfway on the gauge is normal. If it starts overheating, shut it off if it gets to the 3/4 portion of the gauge. Check coolant quanity, and oil quanity. Oil cools the rotors, and internal engine parts much more than on piston engines, so oil its very important to keep it full, and change it after no more than 3,000 miles. I would change the thermostat just in case the thermostat isn't opening fast enough. Also, if you take out the center bolt that holds the main crank pulley to the front of the e-shaft, there will be a thermostat type plug in their. What it does is it block oil from getting to the rotors until the oil is warm. What a stupid idea Mazda! If that thermo plug fails, it will fail to open. This may have happened since its been sitting. The rotors must get oil, as the oil cools the rotor. Go to www.atkinsrotary.com and look for the link to the "Thermal Pellet Instructions". They make a piece that you use to replace the thermal plug. The piece allows oil to get to the rotor 100% of the time. Its just a dummy plug, so there is no possibilty that it could fail. I've seen the rotors and housing from an engine where the thermal plug failed, and it isn't salvageable. Once the rotors heat up and get no lube, they get trashed.
Next, I would do a compression check on the vehicle. This is what will tell you if your apex and side seals are good. Those are the seals that form the compression cavity. If you don't know how to do a compression check, do a search in the 2nd gen forum. There is a good write up on it that takes you through it step by step. Lastly, if the car would hold an idle, without keeping your foot on the gas, its probably something on the throttle body. There is a peice that has coolant running to it, and the warmer the coolant gets, the lower the idle will come down. I think its called the thermal wax pellet. If you have a Haynes manual, or a factory service manual, you can check it for proper function. Smae for the Throttle Position Sensor (TPS), and the Bypass Air Control valve (BAC). They have to be set properly for the engine to maintain idle.
Lastly, the heat of the exhaust is hotter than a piston engine. I don't know how hot this cars exhaust is getting, and it isn't feasible to get an exhaust gas temp sensor, so I would bring it up to operation temp, but don't let it over heat, and look at the exhuast manifold, catalytic converter(s) an mufflers. If they are glowing, which is not uncommon, then you definetly have a problem. Either their is clogged cat or muffler, the engine is running lean, or the air pump isn't pumping cool air into the exhuast like it should. The air pump always pumps air, which goes to the Air Control valve ACV, not to be confused with the Bypass Air Control valve. (The BAC has a different function than the ACV)
Again, the factory service manual, (FSM) or Haynes manual will tell you how to check these components for proper function. The FSM is available online at www.iluvmyrx7.com Just look to the left under 2nd Gen and click on manuals.
Sorry if I got too much into detail and over explained stuff you already know. I know you said you have a T2. I rather you have too much info, instead of not enough. Overall, it shouldn't be too difficult to get the engine into perfect running condition. The only thing that would require a rebuild would be low compression. (below 90psi)
Good luck and hope this was helpful
Blue smoke= burning oil
White smoke = burning coolant
black smoke= burning fuel (running rich)
As far as the coolant temp, halfway, or slightly less than halfway on the gauge is normal. If it starts overheating, shut it off if it gets to the 3/4 portion of the gauge. Check coolant quanity, and oil quanity. Oil cools the rotors, and internal engine parts much more than on piston engines, so oil its very important to keep it full, and change it after no more than 3,000 miles. I would change the thermostat just in case the thermostat isn't opening fast enough. Also, if you take out the center bolt that holds the main crank pulley to the front of the e-shaft, there will be a thermostat type plug in their. What it does is it block oil from getting to the rotors until the oil is warm. What a stupid idea Mazda! If that thermo plug fails, it will fail to open. This may have happened since its been sitting. The rotors must get oil, as the oil cools the rotor. Go to www.atkinsrotary.com and look for the link to the "Thermal Pellet Instructions". They make a piece that you use to replace the thermal plug. The piece allows oil to get to the rotor 100% of the time. Its just a dummy plug, so there is no possibilty that it could fail. I've seen the rotors and housing from an engine where the thermal plug failed, and it isn't salvageable. Once the rotors heat up and get no lube, they get trashed.
Next, I would do a compression check on the vehicle. This is what will tell you if your apex and side seals are good. Those are the seals that form the compression cavity. If you don't know how to do a compression check, do a search in the 2nd gen forum. There is a good write up on it that takes you through it step by step. Lastly, if the car would hold an idle, without keeping your foot on the gas, its probably something on the throttle body. There is a peice that has coolant running to it, and the warmer the coolant gets, the lower the idle will come down. I think its called the thermal wax pellet. If you have a Haynes manual, or a factory service manual, you can check it for proper function. Smae for the Throttle Position Sensor (TPS), and the Bypass Air Control valve (BAC). They have to be set properly for the engine to maintain idle.
Lastly, the heat of the exhaust is hotter than a piston engine. I don't know how hot this cars exhaust is getting, and it isn't feasible to get an exhaust gas temp sensor, so I would bring it up to operation temp, but don't let it over heat, and look at the exhuast manifold, catalytic converter(s) an mufflers. If they are glowing, which is not uncommon, then you definetly have a problem. Either their is clogged cat or muffler, the engine is running lean, or the air pump isn't pumping cool air into the exhuast like it should. The air pump always pumps air, which goes to the Air Control valve ACV, not to be confused with the Bypass Air Control valve. (The BAC has a different function than the ACV)
Again, the factory service manual, (FSM) or Haynes manual will tell you how to check these components for proper function. The FSM is available online at www.iluvmyrx7.com Just look to the left under 2nd Gen and click on manuals.
Sorry if I got too much into detail and over explained stuff you already know. I know you said you have a T2. I rather you have too much info, instead of not enough. Overall, it shouldn't be too difficult to get the engine into perfect running condition. The only thing that would require a rebuild would be low compression. (below 90psi)
Good luck and hope this was helpful
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SakeBomb Garage
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10-09-15 10:05 PM
bypass, engine, opperating, overheat, pellet, rx7, s5, smoke, smokes, startup, temperature, thermo, thermostat