Blue smoke problem on new rebuild
Thread Starter
Full Member
Joined: Oct 2002
Posts: 79
Likes: 0
From: Clermont, GA
Blue smoke problem on new rebuild
History:
Got a mazda reman engine for my 3rd gen from Malloy Mazda to replace my 93k mi engine w/bad coolant seals and “medium” amount of blue smoke 1-1/2 yrs ago. Rebuilt turbos myself w/ turbo city kit. Car ran well after rebuild but smoked & had no secondary turbo boost, drove it about 300 mi to break it in, then put it in storage because I was moving from Chicago to Georgia and didn’t have time to troubleshoot the boost problem. Just got the car unpacked a year and a half later; I had missed 2 vac hoses that were preventing 2nd turbo operation (now reconnected), car runs great normal boost pattern, etc, but the car still smokes on startup and idling and at a stop light. Not huge billowing clouds but definitely way beyond what it should be. Will occasionally even run for a few seconds here and there (only when idling & cold) like the plugs in one of the rotors is fouling and not firing. Doesn’t smoke under load that I can notice while driving, but have not had anyone following me to look for this. I need to track down the cause of this smoking, would really hate to pull the motor if it is the turbos, or redo the turbos if it is the motor, so the questions become:
A: Is there another possible (easy fix) source of the smoke, such as accumulated oil in the muffler burning off, a crankcase ventilation problem (my first step will be to vent the crankcase) etc?
B: I pulled the plugs to check their condition to see if one rotor’s plugs color is different than the other- this would indicate an engine rather than turbo problem, because in this case there is no oil in the intercooler lines (which would indicate an issue with the seals in the compressor side of the turbos) whereas the old motor blew a bit of oil into the IC & lines. Plugs from both rotors were same black color but not wet at all. Also did a compression check- unfortunately my gauge is not the type where you can remove the Schrader valve but I did multiple tests and the rise for each of the three pulses looked good.
C: Next step would be to try idling the car w/ no muffler for a bit to see if maybe a build up of oil in the muffler from the previous engine was the issue. The more I think about it the more I doubt this because the exhaust runs so hot I would think the oil present would have burnt off by now.
D: If I still get smoke the only other 2 possibilities are turbo (turbine side) seal failure or a problem with the engine. Now the issue becomes how to determine which. Anybody have any idea how? The ways I can think of would be so much trouble that I might as well pull the engine and tear it down anyway- like idling the motor with the compressor side ducting removed, turbo shafts clamped to immobilize them and turbo oil lines disconnected and plugged- (if the engine would run at all that way). Or removing the turbos and fitting a 13b header to run the engine normally aspirated, which I’d probably have to make from scratch, not likely! I’d hate to think I got a bad engine from mazda but I am leaning that way. Anybody else ever have a problem like this? What could they have left out of the motor that would cause this problem and not tremendous billowing smoke, which I think would be the case if they left out a rotor seal or something like that. Maybe a stuck seal or something? Any suggestions how to troubleshoot this? will it heal?! In the back of my mind I’m thinking I should shitcan the whole thing and put in a hinson SB Chevy setup, but I really like the car how it is if I could clear this up.
mods added at rebuild time:
no ac, no ps, fluiddyne rad, block off plates on most emissions stuff, I still have double throttles and coolant to the TB., and run sequential twins.
Got a mazda reman engine for my 3rd gen from Malloy Mazda to replace my 93k mi engine w/bad coolant seals and “medium” amount of blue smoke 1-1/2 yrs ago. Rebuilt turbos myself w/ turbo city kit. Car ran well after rebuild but smoked & had no secondary turbo boost, drove it about 300 mi to break it in, then put it in storage because I was moving from Chicago to Georgia and didn’t have time to troubleshoot the boost problem. Just got the car unpacked a year and a half later; I had missed 2 vac hoses that were preventing 2nd turbo operation (now reconnected), car runs great normal boost pattern, etc, but the car still smokes on startup and idling and at a stop light. Not huge billowing clouds but definitely way beyond what it should be. Will occasionally even run for a few seconds here and there (only when idling & cold) like the plugs in one of the rotors is fouling and not firing. Doesn’t smoke under load that I can notice while driving, but have not had anyone following me to look for this. I need to track down the cause of this smoking, would really hate to pull the motor if it is the turbos, or redo the turbos if it is the motor, so the questions become:
A: Is there another possible (easy fix) source of the smoke, such as accumulated oil in the muffler burning off, a crankcase ventilation problem (my first step will be to vent the crankcase) etc?
B: I pulled the plugs to check their condition to see if one rotor’s plugs color is different than the other- this would indicate an engine rather than turbo problem, because in this case there is no oil in the intercooler lines (which would indicate an issue with the seals in the compressor side of the turbos) whereas the old motor blew a bit of oil into the IC & lines. Plugs from both rotors were same black color but not wet at all. Also did a compression check- unfortunately my gauge is not the type where you can remove the Schrader valve but I did multiple tests and the rise for each of the three pulses looked good.
C: Next step would be to try idling the car w/ no muffler for a bit to see if maybe a build up of oil in the muffler from the previous engine was the issue. The more I think about it the more I doubt this because the exhaust runs so hot I would think the oil present would have burnt off by now.
D: If I still get smoke the only other 2 possibilities are turbo (turbine side) seal failure or a problem with the engine. Now the issue becomes how to determine which. Anybody have any idea how? The ways I can think of would be so much trouble that I might as well pull the engine and tear it down anyway- like idling the motor with the compressor side ducting removed, turbo shafts clamped to immobilize them and turbo oil lines disconnected and plugged- (if the engine would run at all that way). Or removing the turbos and fitting a 13b header to run the engine normally aspirated, which I’d probably have to make from scratch, not likely! I’d hate to think I got a bad engine from mazda but I am leaning that way. Anybody else ever have a problem like this? What could they have left out of the motor that would cause this problem and not tremendous billowing smoke, which I think would be the case if they left out a rotor seal or something like that. Maybe a stuck seal or something? Any suggestions how to troubleshoot this? will it heal?! In the back of my mind I’m thinking I should shitcan the whole thing and put in a hinson SB Chevy setup, but I really like the car how it is if I could clear this up.
mods added at rebuild time:
no ac, no ps, fluiddyne rad, block off plates on most emissions stuff, I still have double throttles and coolant to the TB., and run sequential twins.
Did not read your whole novelette on your problem, but it is normal for rebuilt engines to smoke for a few days untill all excess rebuild lube is burned out of the engine and exhaust system. Just go cruising at 60mph for a while and it will/should buren it off.
Thread Starter
Full Member
Joined: Oct 2002
Posts: 79
Likes: 0
From: Clermont, GA
doubt if it is their fault, they got it from Mazda. Nice guys @ Malloy. 1 thing tho, the plastic crate the motor came in allowed it to move around a lot; I think that may be why my oil pan leaks. Should have put on one of those cast aluminum ones with the O ring before putting the motor in.
if I knew then what I know now...
T
if I knew then what I know now...
T
Thread Starter
Full Member
Joined: Oct 2002
Posts: 79
Likes: 0
From: Clermont, GA
blue smoke on new rebuild follow up
tried to hook up small hose coming off oil fill tube to a low pressure guage and ran it inside the car , then also plugged the line I pulled. ran the car and the guage JUST barely came off of the zero stop, maybe 1psi max, but great gobs of smoke followed, and I do mean enormous. I figured I must be on to something so put it all back and ran the car with the oil filler cap off and a piece of fabric rubber banded on it as a filter. smoke was greatly reduced, almost to zero. I'm assuming I need a proper, conventional PCV setup or need to run with a vented (or maybe even scavenged) crankcase until the engine is broken in. Either the stock pcv valve is bad, or unable to cope with break in quantities of crancase pressurization, or I have it in bass ackwards.
more to follow
tom
more to follow
tom
Thread
Thread Starter
Forum
Replies
Last Post