Hey guys, ive got an issue with my 7m. Ive finished building it up and it runs great and is extremely powerful except it consumes oil. somewhere in the order of 500-1000ml per 1000km. That seems like quite a bit imo.
The symptoms are puffs of oil smoke on start up and when taking off from a standstill at lights etc, as well as the obvious loss of oil when checking the dipstick from time to time. This along with the fact that the car has perfect compression of 160psi (9:1cr) on each cylinder within 5 winds of the engine would lead me to believe that i must have a poorly seated or faulty valve stem seal. After removing the spark plugs i found that the plug for pot 3 was blackened and a little wet as well as the top of the no 3 piston as best i could see it through the spark plug hole. all the other spark plugs looked like new albeit a little bit scorched and white.
I set upon the arduous task of replacing all the valve stem seals for pot 3 not easy without removing the cylinder head! One of the 4 seals for pot 3 was discolored compared to the other 3 so i assume it was the leaky one. Since completing this i have driven the car around for about 1500km and noted that it is still blowing smoke when being started in the morning and when taking off from lights etc. Although now that spark plug and inside of pot 3 looks nice and dry / non oiled just like the other 5 cylinders.
However the cars symptoms and oil consumption still persist. I am at a loss. What could be causing this?
Also of note is that im using an accusump and dont quite know what kind of pressure i should put into it before making sure the oil in the sump is at the full mark. A mechanic friend suggested that i might be overfilling the system and it is burning oil off the excess. is that even possible?
All your help is appreciated. Thanks guys.
Oh also something else. The engine has only done about 5000km and has no external leaks. of any kind.... ever
The symptoms are puffs of oil smoke on start up and when taking off from a standstill at lights etc, as well as the obvious loss of oil when checking the dipstick from time to time. This along with the fact that the car has perfect compression of 160psi (9:1cr) on each cylinder within 5 winds of the engine would lead me to believe that i must have a poorly seated or faulty valve stem seal. After removing the spark plugs i found that the plug for pot 3 was blackened and a little wet as well as the top of the no 3 piston as best i could see it through the spark plug hole. all the other spark plugs looked like new albeit a little bit scorched and white.
I set upon the arduous task of replacing all the valve stem seals for pot 3 not easy without removing the cylinder head! One of the 4 seals for pot 3 was discolored compared to the other 3 so i assume it was the leaky one. Since completing this i have driven the car around for about 1500km and noted that it is still blowing smoke when being started in the morning and when taking off from lights etc. Although now that spark plug and inside of pot 3 looks nice and dry / non oiled just like the other 5 cylinders.
However the cars symptoms and oil consumption still persist. I am at a loss. What could be causing this?
Also of note is that im using an accusump and dont quite know what kind of pressure i should put into it before making sure the oil in the sump is at the full mark. A mechanic friend suggested that i might be overfilling the system and it is burning oil off the excess. is that even possible?
All your help is appreciated. Thanks guys.
Oh also something else. The engine has only done about 5000km and has no external leaks. of any kind.... ever
Last edited: