Not common. Your car is weird.

8500 or 85000? I put 80k miles on a company truck in a year, so no, it's not a stupid question. When your job has you running all over the desert, miles add up.

Once you remove the under cover, look for any dark areas on the exhaust around the turbo, turbo oil pan, hoses and joints and then look upward from where you may find it to see the source.

The other question I have is are you changing the oil every 5k miles or something different?

Do you watch the temp when driving in the mountains?

Did the dealer look at a possible CVT leak?

 

Better, after you take the under cover off, take some pics and copy/paste them to a post here. That way I can give you a better idea.

 

8500 miles, dealer changing oil every 6 months. First one at 4000, second at 8500. Car is 1 year old this weekend. Yeah I watch temps, never out of range, always lower half of range, the trans got to 215 a few times briefly, I was towing my 1500 pound boat in the foothills in 91 degree temps…Dealer does their “inspection”, which I can best describe as some drunk guy with slurred speech walking under the car with a cell phone camera never pausing and moving all over the place…time to do my own inspection. I will open my safe, and unlock the inner box, and retrieve my 10 mm sockets and get going on it! 🤣🤣🤣

Its also lost about 10-15 oz of coolant between oil changes…so ever 4000 miles or so…I thought maybe it was just new car burping air pockets out….no antifreeze smells, no steamy exhaust…no puddles…

Is there something like a PCV valve grommet in a valve cover, or anything like that?

 

That's funny. It seems they are trained to go around the car fast so you can't catch their BS. I've seen quite a few videos from Austin Subaru and when I slow it down I can see they never even touched an inspection plug or anything related to what they are telling you the car needs.


PCV is in the block.

It is possible that what you smell is the coolant. When the pressure increase and the cap releases it to the reservoir it seems off. This is you low reservoir and possibly the smell. It's open to atmosphere.

 

If the oil was changed recently, check around the oil filter plate. I had a drop of oil left in there next to the filter that would give a burning oil smell after running the engine for a while. Worth a shot.

 

There is a strong petroleum smell due to materials off-gassing when temperatures reach the higher levels of the operating envelop for the first time, however this occurred during the first 200 miles for me. My salesman warned me about this, and he was right in that it did diminish over time. My Outback is the same age with similar miles.

Billowing smoke from the engine bay is not normal, and I’m assuming this has only happened once. I would continue monitoring and expect the orders to diminish over time.

edit: Also, my car does not leak. I've thoroughly inspected for leaks many times and have found none.

 

My 2025 OB Base with only 6000 miles on it occasionally has a burnt smell from under the hood, more like near the front wheels after driving. ( I feel this equates to CVT )

What I've noticed is driving in manual mode using paddles, nothing spirited just holding higher revs in the 2000-3000 range, can cause burnt smells.

Never smoke.. Its basically still new at 6000 miles so I figure this is normal in todays quality of vehicles.

Anecdote, family member with new VW Atlas, $50,000, check engine light on second week of ownership..

Don't worry be happy

 

So I jacked it up, took off the plastic underbody tray.. nothing, dry as a bone! I searched the entire engine bay, transaxle, all the way down the exhaust And driveshaft to rear axle…

I did find this crap, tech wrecked the underbody shield with the lift. A few screen captures from dealer inspection report…..and my photos….

link to inspection report..🤣 if it posts…

ASR Portal 8

/

 

So the question is, on an incline, with increased RPM, what could cause a raw oil, and oil burning smell? Maybe PCV? The smell have been throughout it’s 8500 miles, not right after oil changes, and yeah I had new car burn smell for a while, this is absolutely oil.

When it smoked, in the mountains, it was after a 5-10 mile run up a steep tight mountain road, to a National park. 4 adults over 60 in the car, no hot doggin it…

 

The variable you describe seems related to the flashpoint of oil. The oil pressure and suspected leak would be constant.

There could be oil or transmission fluid somewhere it shouldn’t be (like sound insulation), and that area gets hot under heavy loads.

My car came with a tablespoon of oil spilled on the passenger side cam carrier. I cleaned and inspected that area for months before I was satisfied it wasn’t leaking.

 

I saw it. Marble mouth?

 

Take the air box off the throttle and look to see if there's a lot of oil on the throttle and inside the air box. When the car is under a load for long periods the crankcase pressure can rise to a point that the PCV system works backward. The pressure finds the easy way out and that is opposite the PCV valve and into the intake air box. At this point the pressure is exiting and no fresh air is entering..

 

The failure mode described sounds like a design defect assuming he has the correct oil level and viscosity. All my eastbound routes are over mountain passes and I drive those all the time. What would be the remedy if he finds oil pooling inside the air box; replace the PCV valve and service the oil properly? Thanks

 

It's not a design defect. The PCV system is designed for engine vacuum to pull on the crankcase which in turn pulls air into the crankcase via the hoses on the air box. This insures air going into the engine has past through the air filter. The air circulation moves the crankcase gases and the gases get reburned in the combustion process. Any oil particulates that get sucked up also burn in combustion.

Any engine running at a higher load will create higher crankcase pressures. Generally because of the higher rpms and heat. It also lessens the relative pressure in the intake when accompanied with higher rpm or throttle opening which reduces how much vacuum is pulled on the crankcase. Reduced vacuum means reduced air circulation.

It could be possible that a PCV valve be restricted after break in at low miles. It depends on how the engine was driven during break in and whether the oil schedule was followed. During break in there is going to be some metal particulates in the oil and these particulates can be pulled to the valve.

The brand of oil is a contributor. Some oils create carbon and sludge, even synthetics. In my experience with a large variety of manufacture cars, Mobile1 is a sludge producing oil, especially in German cars designed for high output and has crap PCV systems. And the longer oil is in the engine the higher the carbon deposits left in the engine as the oil breaks down.

Now, on oil in the air box - check the PCV valve to make sure the valve is not sticking or has any build up. Make sure the hoses are supple and connected as they should be without cracks or looseness at the nipples they connect to. On low miles engines, it shouldn't be a problem, but the valve cover venting can also be an issue contributing to higher crankcase pressure.

If you are data driven, data from the ECM can also indicate a possible PCV issue. When knock correction is high it's generally due to carbon buildup or excess crankcase pressure. On boosted engines this is where quality catch cans help because they allow for high volumes of air to move through the crankcase while reducing oil particulate intake.

 

So I am new to Subaru, can you clarify a little bit when you said check the airbox I assume you mean over on the side where the air filter is but I don’t see anywhere a vacuum or PCV line connects to it. Or are you suggesting I disassemble the intercooler at the throttle blade assembly? Or somewhere else ? And where is the PCV valve? Thanks a bunch. I am familiar with cars just not flat four turbos.

 

 

Yeah, PCV system is under the intercooler. Cardoc wants you to check for oil residue at the throttle body opening, and intercooler interface hole as well (where they mate together.) Not an easy quick job but certainly doable. I've yet to remove the intercooler but there are plenty of YouTube videos showing how to do it.

 

Yeah, that.

I was thinking N/A when I posted referring to the air box that mounts to the throttle.

 

I took a look at the process to remove the intercooler, and decided to let it be for now..the MRS wanted yard work done….and I am having a conversation with one of the dealership managers next week…so I will see what they say..it’s a new car, 1 year old, 8600 miles, fully warranteed…so no reason yet for me to start pulling it apart yet…

One other thing that I remembered that might of contributed..l noticed the oil might of been overfilled by the dealer at 4500 miles, it was above the full mark a bit.. so going uphill, higher RPM, overfilled might of all come together to cause the issue. I will be up in the mountains in a few weeks and see if it repeats…