St. Louis mechanic needed

Well, I gotta get my 318ti to a mechanic sooner or later.

It has started overheating after idling for 10 minutes. My coolant overflow tank is also getting extremely pressurized to the point that no coolant registers when it is running. Throughout all of this, coolant is disappearing but isn't dropping onto the ground. The oil also shows no milky substance and the heat blows hot. It cools down right away as I start moving.

I'm in college out in St. Louis but I'm from NJ. Therefore, I have no tools or any ability to diagnose my car. Can you guys suggest a trusted St. Louis city mechanic that will look at my car? I prefer a small shop that will charge less.

I'm too far away to help with this but hit up Sperlo. Also see if there are any diy auto repair shops in town.

The only guy I trust my cars with is in Florissant. I don't have a problem troubleshooting, though.

N Sperlo wrote: The only guy I trust my cars with is in Florissant. I don't have a problem troubleshooting, though.

Who is this guy in Florissant?

Right now, I just want to do a radiator leak test and another test to see if exhaust gases are leaking into the coolant. I suspect some type of head gasket or profile gasket going bad after 168k miles, but I'm not sure. Do you have/know where to get these testing tools?

Not sure about the tools, but you can give MAG Automotive a call. The owner is a friend and does whatever I don't have the resources to handle myself. (314) 839-5353. They are at North New Florissant Rd and Lindbergh.

Sounds like a headgasket or maybe just a bad radiator cap.

You can check for coolant leaking into the combustion chamber by pulling the plugs, the offending cylinder(s) will have a plug that looks new and a peek down the plug hole will show a steam cleaned piston.

I'm pretty sure O'Reilly rents out pressure testers and coolant analysis kits.

Ok, I'll give those guys a call when I have free time.

In the meantime, I'll try out the rental tools to see first. I gotta get some more coolant anyway.

The spark plug tip is great. I'll check it out after classes tomorrow. Thankfully BMW still included the spark plug wrench in my car.

Only able to get 3 out of 4 spark plugs out with my given tools. All of them look like this. The tip has a white carbon buildup, almost as if it was running lean. It doesn't look new, and I didn't see a clean piston.

Head gasket most likely with a pressurized coolant bottle and overheating. Avoid driving it where it could overheat if you can.

Well, I went to O'Reillys to get more coolant and rent a block tester. It's the thing that attaches to my coolant tank and checks for HC from the exhaust getting into the coolant. No issues at all as the fluid didn't turn yellow after 15 minutes. I also couldn't get the car to overheat after idling for 15-20 minutes either. It was only 45 degrees instead of 65 degrees though.

I also can't get the low speed function of the aux fan to work. Without it, temp will creep slowly to 100C but never hit it. If I turn on the A/C, it puts the fan on high speed and the temperature drops right down to 88C, which is operating temp. Maybe I just have a faulty fan switch or fan and that is why it won't cool the car.