I have a 2000 Mitsubishi Galant 4 cylinder with 160,000 miles on it. Been maintained pretty well over the last 7 years of ownership. Recently has started burning oil and I have been putting at LEAST 2 quarts of oil in everytime I refuel. No signs of leaking and the white smoke seems to indicate oil burn. I also commute daily about 80 miles. Is it worth fixing?
Already Tried:
Did a 100,000 mile tune up almost 2 years ago and was changning oil and fluids within 1000 miles of recommended change before oil started burning. (About 6-8 months ago it started) Have not taken it to the mechanic yet to see what they suggest.
Check the PCV valve first. That’s dirt cheap and easy to do. A stuck PCV will allow the crankcase to pressure up and may cause oil to enter the combustion chambers.
If the PCV is fine then a compression test should be performed with a dry test first and a follow up wet test. The readings should be in the 180 PSI range, give or take a bit and depending on engine wear.
(If a dry test shows 150 on a certain cylinder and the wet test shows that same cylinder jumping up to 175 then there’s a piston ring problem. Major engine work.)
A compression or leakdown test is not 100% definitive but it’s the only thing there is.
It’s possible to have an excellent 190 PSI reading on a cylinder and yet that cylinder will still consume oil.
Bad valve seals can also cause oil consumption problems but usually this only occurs if the engine has been overheated enough to fry the seals. There is no test for valve seals. They’re a replace and pray item. Hope that helps.
2 quarts of oil within 200-300 miles (typical range between fill-ups for most cars) is quite excessive. The oil is going somewhere in big doses. Are you sure there are no leaks, even with the engine under load? Look underneath the car for large wet areas and signs of leakage.
This much oil out of the tailpipe should be a very visible blue cloud all the time, especially when you hit the gas pedal from a dead stop. If the exhaust is quite visible when the car is warmed up, you’re burning it, and it is most likely through the rings. Check the PCV valve first, like ok4450 mentioned. If this doesn’t help, it’s most likely internal.
Well, for consistency sake, my '95 (same engine) started doing this at 150K miles and that was in 2006-so car was 5 yrs older but did this 5 yrs ago:)
It wasn’t the PCV in my case, kept failing emissions and kept going through oil faster than gasoline. Was using 20-50 weight oil for a while and sold it with full disclosure to a high school kid…
My 2002 Montero Sport started giving blue smoke and dripping oil from exhaust because of a bad PCV valve.
I had to replace that, clean up the throttle body and IAC. Then take it on a long highway drive to get my CAT nice and hot. After that no blue smoke, no oil.
However the consumption you state is excessive