[AirbusPilot]

2012 335i, AT coupe. 32k miles, warranty expires this June.

Mods: JB4. VSRF 7" intercooler.

Yellow caution overheat, followed by red warning and limp mode.

Symptoms:

1. So far, ONLY happens after about 25 minutes of driving. In fact, it's happened twice at the same point along the highway as a I drive home from the airport.

2. Once I pull over, I shut off the engine, wait a few seconds and restart it, all is well, no overheat messages.

3. So far, happens only during normal highway driving.

3. It's using some coolant. Not much, but some and I replace what's lost.

4. Tonight, after this happened and it was running normal again, I stopped at the mailbox, turned it off, returned and started it and heard a brief "shhhhh" noise. I pull into my garage, pop the hood and see my coolant recovery tank is somewhat wet with coolant. Cap is tight.

5. I took it to the dealer a couple of weeks ago, and all they found wrong was a weak battery, which they replaced. It's going back to the dealer Tuesday.

Any ideas? Thanks.

[Supermoon]

Did you replace your water pump?
Water pump failure seems to happen to almost every n55.

[AirbusPilot]

Originally Posted by Supermoon

Did you replace your water pump?
Water pump failure seems to happen to almost every n55.

No, it wasn't replaced.

The SA stated it would be unusual to have a WP failure at the lower mileage of my car. If not for the coolant sprayed on my recovery tank, I'm wasn't sure it was really overheating since it doesn't show an overheat once I turn it off, and turn it back on.

[Dhillon92]

When my water pump died, it was an intermittent problem, it would come and go, until it finally completely died. Better to have it fixed beforenit leaves you stranded. Dealer replaced water pump no problem just from the yellow and red overheat. They find it in the history of codes.

I had about 55k km.

[kamfa39]

BS- my water pump died at 30k

[Cory S]

Only three things needed to keep the engine at operating temperatures.

1. Coolant
2. Circulation of coolant
3. Radiator

When going less than 10-15mph, usually a cooling fan will also be required. (not enough natural airflow through radiator)

Sounds like your water pump is on its way out.

[jseide36]

my car was the same and it was the water pump.. don't wait too long so you don't get stuck on the side of the road!!

[AirbusPilot]

Dropping it off tomorrow.

I hope at least they find a code this time (couldn't find a wp failure code a couple of weeks ago..not sure if the jb4 wiped it clean).

[AirbusPilot]

Water pump! So, I at least got a new battery (took it in a couple of weeks ago and they first thought a bad batt was the cause), and a new water pump all before the warranty expires in July.