[AGold1988]

Hello everyone! I've heard great things about these forums and hope I am in the right place.

I'm a relative novice when it comes to the inner workings of cars (unfortunately) but I wanted to post here and see if anyone has any ideas on my 2012 BMW 335i that just recently hit 100K miles. The vehicle is very well maintained and the mileage is mainly highway miles that were put on during a long distance relationship at time of purchase. Now I drive it less than the average 12K miles per year, and probably sit at 6k to 9k. I live in Atlanta and the temperature for the summer is usually 90-95 with high humidity.

Several months ago my car received an oil change. Shortly after that one of the hoses for the coolant blew. The coolant blew somewhat onto the engine and I could easily see the hose issue. My car only reached temperature right above operating for a minute or so (not much above 250) and was stopped and towed. The hose was repaired.

The Symptoms

About three weeks ago my car starting making slight squeaking noises when driving at low speeds through residential neighborhoods with the widened speed bumps you can go about 20mph over. The sound is similar to the sound you get when your brakes are wet. It would not occur on the highway and oddly only seemed to occur as I approached home in this residential neighborhood.

About 10 days ago (or so) when driving I got a short smell of burning rubber while surrounded by other cars. I checked my temp gauge and it was fine and figured it was someone else as the smell dissipated and didn't return. A few days later I smelled the same smell when I parked and walked past my exhaust but saw no smoke and the car behaved fine.

Yesterday while driving a friend back from lunch I pulled up to the building and stopped the car and noticed light smoke was coming from the hood. The temperature gauge was not reading higher than normal. I popped the hood and saw smoke coming from toward the bottom left of the engine at random but it was very light, white smoke and not black. Importantly the white-ish stains from the coolant hose blowing from quite some time ago are still on the manifold so at first I thought it blew again but the coolant levels look fine. On a whim I checked the oil level and it was "At Minimum"! The car never alerted me to low oil at all. I ended up going to Home Depot via Uber and putting enough in to keep it where it needs to be. I drove 2 minutes down the road with the car and parked at my job. When I drove home during a 15 minute commute the engine temperature was fine but now that I'm so focused on it, I noticed this morning that it seemed to heat up much faster than it normally would during a 70 degree morning, but I think there's a possibility that's just me focusing on it too much.

Importantly, I've checked all my parking spots and there has been no oil leak anywhere and the car has issues no warnings to me at all.

Conclusion

I have to bring this thing in, that's obvious but does anyone have any thoughts on this? Mine are quite simple:

• Low oil was leading to issues
• Thermostat may be malfunctioning and not allowing coolant to flow through system
• Maybe another hose did rot and the coolant is unable to be used

If there's anymore information you need please feel free to ask but I may be delayed or unable to provide info. I just went through a separation a few months ago and all of my paperwork on my car may be hard to locate. Thank you so much!

[AGold1988]

Hello everyone! I went down and took a look at the count the day I posted this with a buddy who is a mechanic (not with BMWs though) and we spotted a very very small leak on the valve cover, which is then dripping tiny drops of oil that causes the random smoke. My F30 is currently at 100,731 miles.

I brought the car over to my trusted mechanic and they took a look and confirmed writing the following:

1 - Valve cover is leaking. (The valve cover and gasket should be replaced at same time)
2 - Tires are worn. But okay at this time. Need to check at next oil service.

I spoke with them and they said that when you replace the valve cover you should also replace the spark plugs at that point as well and quoted me around $1100 for all of the work. What does everyone think?

[John in VA]

Originally Posted by AGold1988

I spoke with them and they said that when you replace the valve cover you should also replace the spark plugs at that point as well and quoted me around $1100 for all of the work. What does everyone think?

That quote sounds higher than I would anticipate or be willing to pay! Your buddy doesn't need to be a certified BMW mechanic to help you with this job, if he's willing - you just need the correct replacement parts.
You could also get an estimate from https://www.yourmechanic.com/

[cfm56d7b]

The spark plugs may or may not need to be replaced depending on what was included in the last major service. Simple inspection of the spark plug condition will suggest the next steps.

With over 100K miles, hoses and belts should be thoroughly inspected and replaced.

[cfm56d7b]

Also - the charge pipe on N55 engines is made of plastic. Please add it to the inspection list.