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2008 Smart ForTwo 451 Passion
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Discussion Starter · #1 ·
When driving highway speeds and through mountains, my 2008 Smart ForTwo / 451 with 70K miles loses 1 quart of oil every 150 miles or so. When driving in less demanding situations, around town under 50 mph, there is no loss. After a hard drive there is oil in the throttle body. Valve guides are good. The engine runs smoothly with no noticeable loss of power. Exhaust is crystal clear on cold start, warm start, and revving the engine in neutral. The is no sign of oil on, near, or below the engine. I have not been able to get a compression test.

Here is the strange part. Prior to hitting and running over a fawn at 68K miles, the car had never lost a drop of oil. I was on a road trip. It was later that day, about 3/4 tank of gas later, when the oil light started flickering and I added 2 quarts. This started the oil loss which I later found only happens as described above.

A mechanic in my small, remote town fixed the front damage (radiator and AC condenser) and checked for damage to the engine. While evidence of hitting the deer was apparent, there was no apparent damage. He found the oil in the throttle body and convinced me let him drop the engine to check the PCV and other inaccessible parts. No sign of oil leakage there either. We replaced the PCV valve even though the old one was fine. The MAP sensor was fine. We also replaced the belts and changed the oil/filter going with Mobil 1 10w-40 high mileage.

I sure would be grateful for any ideas or guidance. It seems apparent that there is increased pressure in the crank case but the crystal clear exhaust ruins the conventional explanation.

Thanks for reading through this.
 

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Have you done a compression test?
Pull the hose that runs from the valve cover to the intake and put your hand over it and see if it's actually pressurized.
Could your intake be partially blocked and pulling more vacuum through the pcv
 

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Registered
2008 Smart ForTwo 451 Passion
Joined
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23 Posts
Discussion Starter · #3 ·
Have you done a compression test?
Pull the hose that runs from the valve cover to the intake and put your hand over it and see if it's actually pressurized.
Could your intake be partially blocked and pulling more vacuum through the pcv
Thanks. Cylinder 1 is down 30% compression. At idle there is a tiny bit of vacuum at the oil filler / valve cover. I posted it for sale at low KBB with full disclosure. It sold within 48 hours.
 
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