[MrSteak]

Just got a yellow warning light (thermometer in liquid), which turns red soon thereafter, then into limp mode. On the side off he road now...

Can I make it the 8 miles back to my house?

Called my insurance, and they'll cover one tow, so I'd rather save that to get it to my local (trusted indie) repair shop.

[BlackBB6]

Tow it to the front of the shop and get a cab/ride home, is that an option?

[MrSteak]

Insurance won't cover that tow. My house is exactly in between where I'm stopped and my regular shop.

[RedLightVisions]

Let it cool off, drive it until the light comes back on.

Just did the same with mine and I was about the same distance from my house. Payed 800 installed for a new water pump/thermostat.

[9 amini]

I wouldn't do it.

Had the same problem and tried going about a mile to my buddies house. Car wouldn't let me drive and I had to crawl to a stop. Just tow it now.

[MrSteak]

Thanks for the advice... That's what I'm leaning towards right now. Just threw this up to help rationalize that decision.

[Higgs1]

Originally Posted by RedLightVisions

Let it cool off, drive it until the light comes back on.

I did this last year w/o issues. Had to stop every few miles but made it and didn't do any damage.....maybe I was lucky tho? Just don't push it and I think you'll be fine.

[MrSteak]

Originally Posted by Higgs1

I did this last year w/o issues. Had to stop every few miles but made it and didn't do any damage.....maybe I was lucky tho? Just don't push it and I think you'll be fine.

Awesome. Thanks for the input.

Used Google Maps to find the shortest route (6.3mi), then took it slow, trying to stay under 30. The fan was super loud the entire ride, but the temp gauge didn't rise much above 220, and the warning light didn't come on until the last 1/2 mile.

Now... the fun part, calling the shops in the morning and letting the repair cost sink in.

[Miller335]

Just do it yourself if you really feel that way about the repair bill.
That's usually the main motivator to get people to start turning wrenches.

There's plenty of info here on the web to guide you.

[Efthreeoh]

OP, it is nice to consider a DIY on the water pump, but if you do not have a really good tool set, and the proper lifting tools to get the car in the air to work on it, and a good skill set of working on cars, it is best to leave the water pump replacement to a professional shop. The E90 WP replacement is not a DIY task for a novice.

[Blackhawk36]

Originally Posted by RedLightVisions

Let it cool off, drive it until the light comes back on.

Just did the same with mine and I was about the same distance from my house. Payed 800 installed for a new water pump/thermostat.

That is the best price I have ever seen on the 335xi, by far.

[ucdbiendog]

Originally Posted by Miller335

Just do it yourself if you really feel that way about the repair bill.
That's usually the main motivator to get people to start turning wrenches.

There's plenty of info here on the web to guide you.

Google is definitely your friend. It will pull threads from all the forum boards, videos on youtube.

[Ikejones]

I just went through this a few weeks ago. Got the yellow temp indicator after just a few minutes of driving. Went to red like 1 min later. I let it cool and sit idling for a bit with the car on max cool. Seemed fine so i started to drive. In no time it was going back into limp mode. I got the tow. Free from insurance. Even if it wasnt, the 50 bucks for a tow is well worth not messing up the engine.

[MrZ]

Originally Posted by sappy13

I let it cool and sit idling for a bit with the car on max cool. Seemed fine so i started to drive.

Wait... to let the car cool down, you let the car idle without the working water pump?

[tc535i]

Yeah, Max cool doesn't do much if the pump's failed

[MrZ]

Originally Posted by MrSteak

Used Google Maps to find the shortest route (6.3mi), then took it slow, trying to stay under 30.

Correct me if I'm wrong, but I thought that speed is quite irrelevant to the engine temp. RPMs is what matters.

In fact, the car cools down better at higher speed (wind to the radiator), but not sure it will make a difference when the WP is not circulating the coolant.

[MrZ]

Originally Posted by tc535i

Yeah, Max cool doesn't do much if the pump's failed

Idling the car is an awesome way to bring the temp up, not down.
Max cool cools down the interior, not the engine.

[floydarogers]

Originally Posted by MrZ

Correct me if I'm wrong, but I thought that speed is quite irrelevant to the engine temp. RPMs is what matters.

In fact, the car cools down better at higher speed (wind to the radiator), but not sure it will make a difference when the WP is not circulating the coolant.

You're kind of wrong. Engine temp is modulated by the computer (via the water pump and thermostat), and is actually highest when cruising on the freeway at constant speed. That ekes a few tenths of mpg out of the car. It's lowest when driving slower speeds and stop-and-go.

[Titanium3Series]

Originally Posted by floydarogers

You're kind of wrong. Engine temp is modulated by the computer (via the water pump and thermostat), and is actually highest when cruising on the freeway at constant speed. That ekes a few tenths of mpg out of the car. It's lowest when driving slower speeds and stop-and-go.

this is true for our cars since it is controlled by computer, most cars on the other hand are the opposite.

[Blackhawk36]

This explains how the system work on the N54 engine. That is what is in the OP's car. See the attachment.

[smallseafishie]

Originally Posted by sappy13

I just went through this a few weeks ago. Got the yellow temp indicator after just a few minutes of driving. Went to red like 1 min later. I let it cool and sit idling for a bit with the car on max cool. Seemed fine so i started to drive. In no time it was going back into limp mode. I got the tow. Free from insurance. Even if it wasnt, the 50 bucks for a tow is well worth not messing up the engine.

That is the absolute worst you can do with you car overheating. You want to turn on the heater to max. Don't let it idle... with the car moving you get more cooling benefit with the aid of wind (at idle you are relying on just the fan).

Other things you can do is to try to be gentle on the throttle and keep RPMs as low as possible.

I personally would not drive the car if it was overheating. Especially if it went to thermal shutdown. It is not worth the potential of destroying the head gasket or warping of the head or block.

[MrZ]

Originally Posted by floydarogers

You're kind of wrong. Engine temp is modulated by the computer (via the water pump and thermostat), and is actually highest when cruising on the freeway at constant speed. That ekes a few tenths of mpg out of the car. It's lowest when driving slower speeds and stop-and-go.

Are you saying that given the same cooling circulation for a car @ 60mph at 2k rpm, engine generates more heat than a car @ 30mph at 2k rpm (same rpms, different gears)?


And I think you are wrong for "It's lowest when driving slower speeds and stop-and-go" for the very specific reason you mentioned: computer controlled. Car runs hotter when sitting in traffic, as with a hotter engine the fuel consumption decreases.