Do you let your 135 idle?

[RWD4Life]

What I mean by that is do you let it on idle before turning it off after driving at highway speed? While I'm a total n00b in mechanics, I heard on a podcast that one should let a turbo car idle for like 5 minutes before turning it off, after driving at highway speed to extend the life of the turbo. Is it accurate? If yes, why is that?

[mike the snake]

I think if you are driving normally, it's not a big deal. If you are driving spiritedly, using boost, then the turbos will be much hotter, and then, yes, you'll want to let the car idle for a bit before shutting off.

The super hot turbos can coke the oil in them, causing early turbo issues, but under mormal driving conditions (not using high boost levels) they don't get super hot, so no need to idle.

This is how I understand things on this issue.

You also want to warm the car up thoroughly before running at high boost levels. High boost and cold turbos and cold oil is bad.

I usually let my car idle for a couple minutes before driving, and then drive VERY easy until I see the oil temp guage move.

[L8*Apex]

I believe our turbos are water cooled and there is no advantage to letting it cool down for extended periods. Back in the day you would need to put turbo timers on your car for this reason. Unnecessary now. If you were tracking it hard and suddenly shut it off coking may be an issue. Normal or spirited driving no problem.
Turbo gurus can chime in if my info is incorrect.

[135IS]

i warm up my car when i turn it on in the morning. i cant drive it when its idling over 1k rpm and Forcing it into gear doesnt feel good either.

[rking117]

for the older M roadsters BMW recommended not to get the vehicle over 3000 RPMs until the engine warmed up. I am sure this applies to other models too since the same princle is in place. However, I dont generally warm up too much before i am romping through the gears.

[Stohlen]

Completely unnecessary as the car monitors temps after you shut it off and will cool your turbo for you.

[135Pats]

Originally Posted by Stohlen

Completely unnecessary as the car monitors temps after you shut it off and will cool your turbo for you.

This. If you were absolutely thrashing it on a hot track day, maybe youd want to let it sit at idle for a minute or coast around off boost to let things simmer down. But the car will cool the turbos on its own when you shut it down.

[Dackelone]

When I was with M3adjuster when he took his ED delivery of his 1M... the SA at the BMW Welt told us that one SHOULD let the engine cool down when you have been pushing it on the highway/autobahn. He said it only takes a couple of WOT runs before the exhaust is glowing red hot. Its best to let the engine idle for a min or two - to let the oil temps stabilize. I let my engine cool down running any time I been getting on the gas hard - before shutting things down.


And btw... the turbos are oil AND water cooled. Coolant flows via the electric water pump (electronically) when you switch off the engine and the under hood temps(at the turbos) are too high.

[mike the snake]

While the water continues to circulate after the car is shut off, the oil doesn't. If the turbos are super hot, then they'll do bad things to the oil when it stops circulating, maybe for not as long with the water cooling, but I'd still think idling to let the temps drop and stabilize after running hard would be the right thing to do.

[New21er]

It is my understanding that with new synthetic oil that there is no need to "cool down" modern day turbos.

[ejm3]

When I brought my car in for a 7500 mile oil change I was asking a lot of questions about the car the service manager couldn't answer. But he said there was a tech working there who had a 1-series that was pretty tricked-out.

So I talked to the tech (who said he posts here occasionally) and one of the questions I asked him was about idling the car before turning it off.

He said he drives his like he stole it and doesn't let it idle and said its unnecessary due to the electric water pump and synthetic oil.

I generally don't drive mine like I stole it but I take it easy the last couple miles before I'm going to be turning it off.

[631twentyeighteye]

if i had a turbo i would let it idle a bit after hard driving, i did that with my previous car which was a VMmotori 2.8 turbo diesel. But alas, the benefit of an NA engine.

[Bill B.]

See here:

http://www.1addicts.com/forums/showthread.php?t=748752

[1speedbike]

I never do. After you shut off the car, you should hear a soft humming noise. That humming is the noise of the electric motor pumping coolant over the turbo(s). The car does the job for you You think the yuppies who buy thousands of turbo BMW cars really know anything about letting a turbo cool? Done this for 4 1/2 years so far, and no turbo problems (yet... knocking on wood..). Only time I ever let it sit is if I really drove it HARD. Like.. burnouts in my driveway, etc.

[rking117]

Originally Posted by ejm3

I generally don't drive mine like I stole it...

You clearly need to address your driving habits...

[Bmwbreed]

Usually always let mine do for a min or so after highway driving. But it's a forced habit from when I had my turbo RSX back in the day, which I later installed a turbo timer on to do it for me.

[GeeRam]

Originally Posted by 135Pats

This. If you were absolutely thrashing it on a hot track day, maybe youd want to let it sit at idle for a minute or coast around off boost to let things simmer down. But the car will cool the turbos on its own when you shut it down.

Yup, in any sort of road driving even a spirted one, it's very unlikely that you'll be switching the engine off without some sort of natural run-down period, so it's not really neccessary to let the engine idle for any significant time.

However, I would recommend some sort of run-down/cool down period after any sort of track session. I also try and do at least one cool down/run-down lap before come into the paddock to let the engine settle and temps reduce a bit (and brakes cool) and then pop the bonnet as soon as I'm parked to let all that heat straight up and out.

[ejm3]

Originally Posted by rking117

You clearly need to address your driving habits...

Well this afternoon I had it up to 130 for the first time. Does that count?

[lastMleft]

Originally Posted by ejm3

Well this afternoon I had it up to 130 for the first time. Does that count?

That's movin

[LeifW]

Originally Posted by Dackelone

When I was with M3adjuster when he took his ED delivery of his 1M... the SA at the BMW Welt told us that one SHOULD let the engine cool down when you have been pushing it on the highway/autobahn. He said it only takes a couple of WOT runs before the exhaust is glowing red hot. Its best to let the engine idle for a min or two - to let the oil temps stabilize. I let my engine cool down running any time I been getting on the gas hard - before shutting things down.

Well that's good enough for me. Also, Mike Miller (Bimmer magazine and Roundel) also recommends letting a turbo engined BMW idle.

Leif W.

[Bob Z.]

Originally Posted by ejm3

Well this afternoon I had it up to 130 for the first time. Does that count?

With the top up or down?

[euro2fast4u]

Have you ever watched oil temps at idle before? i have and thats when mine get the hottest. before parking dont be pulliing wot into your driveway