hey guys, just wondering whenever i service my car for oil + filter change, i notice the oil goes black fairly quickly. less than 1000kms. my car runs fairly rich as at WOT a lot of smoke comes out the exhaust. i also notice on cold starts after idling for a minute or two, i get excessive amounts of smoke out of the exhuast. lastly i service my car every 5000kms, and notice throughout the service i need to top it up maybe 2 litres/quarts

is this an oil problem or something else? car just has bolt ons , tune etc, 98 oct (live in AUS), car is EVO8 JDM, the previous owner used ELF 5w-40 i think. i currently use motul 300V 10w-40.

any advice or personal experience would be much appreciated ! thanks guys !

 

What color is the smoke.

Black = Rich
Blue = Oil
White = condensation or coolant depending on the amount

If you are using 2 qts of oil between changes on a factory engine you def have a problem. Could be rings, valve seals, etc...

 

2 quarts is a lot...as stated above sounds like valve seals or rings

Check your coolant for white foam also...

 

Bummer

 

i know at WOT it blows out black smoke.. cold start idle after a minute or two smoke seems to look like white ? ?
i checked LICP for oil and build up but it was fairly clean , my car doesnt leak oil that i know of as i cant seem to see any in engine bay/on the floor when i park. i wouldnt say 2 qrts exactly but definately over 1qrt.

** edit : anyway to tell if its the valve seals or rings or just replacing them ? if its either of the two im looking at an expensive repair :S

anyone know why the oil goes black so quickly ?

 

your oil is going bad so quickly because of blow by. combustion gases are going past your rings and making your oil nasty. It's either messed up pcv valve thats letting your crank case pressurize and forcing blow by, or your piston rings are shot. I would do a compression test to check the rings. If they have low numbers squirt some oil in the cylinder and if the numbers go up then your rings are shot. Also check to make sure your pcv valve is clean and thers no oil gunged up in the lines. good luck!

 

so should i just take the pcv valve off and have a look ? if it is gunked up anything i can do ? will a catch can help ?
... also i did a compression test a couple months ago and the car was in the 150-160s from what i remember, i cant find the figures atm but im sure it was around there.
thanks again !

 

was it smoking when you did the compression test too?
Here's some info i just found by googling cleaning PCV valve real quick. They have good advice.

http://www.dummies.com/how-to/conten...pcv-valve.html (I'm not saying you're a dummy, it's a good how to)
http://www.ehow.com/how_5184165_check-pcv-valve.html

the second link is for testing on the car, but the "shake test" is basically how you determine if it's bad or good. I had your same problem on my 240sx. And it turned out that i was boosting past my pcv valve into my crankcase. i hope you get everything fixed! let me know if you need anymore help.

*Edit* You can tell if it's your valve seals if it puffs smoke after sitting for awhile. Like when you sit at a red light or when you first turn the car on. It's kind of a pain to change them out so hopefully it's not them.

 

yeah its been smoking as early as when i purchased the car (about 5months ago, when the compression test was done). also i dont notice any smoke from the engine bay at idle anytime while driving..
Thanks !! i will clean/inspect my pcv valve today and post an update !

 

i just took the pcv valve off and inspected it . the hose looked fairly clean, the pcv valve besides having some oil on it seemed fairly clean too.. i gave it a clean anyway, and yes it was still rattling when i shook it. . :S