Sign in to follow this  
Followers 0
luckydog

Turbo care

23 posts in this topic

I was wondering if anyone idles their engine to cool down the turbo after a hard run (cools the lubricant, good for bearings)? I've heard it extends the turbo's life. I've also heard that if you allow the engine to idle a few mins. before driving off it allows the lubricant to circulate. Both are supposed to be good for the hair dryer.

Share this post


Link to post
Share on other sites

Yeah, I give it 30 seconds to a minute or two, depending on how long and hard a run I've had.In general if I switch off and still hear the intercooler fan running, that's my signal that "oh, I didn't let it idle long enough".-Iain

Share this post


Link to post
Share on other sites

Yeah you can generally hear when the cooler fan kicks in, German Smarties said the same thing 30-60 seconds in park then cut it

Share this post


Link to post
Share on other sites

When I stop at the top of a mountain pass after a hard belt uphill, I let it run for 5 minutes......keeps the heat soak down.

As for the turbo, well it spools up and down so fast due to it's thimble-like size that the only real advantage to a really long idle is to control temperature, not to prevent the turbine bearings from running dry when the engine is cut (i.e.turbine still spinning with zero oil pressure).

Share this post


Link to post
Share on other sites

is to control temperature, not to prevent the turbine bearings from running dry when the engine is cut (i.e.turbine still spinning with zero oil pressure).

You couldn't sensibly pull a smart to a standstill in the time it takes the turbo to spool down.

It's all to do with reducing the heat of the turbo by reducing the friction, this heat will boil standing oil causing it to lose its lubricational qualities and causing burnt oil deposits in the turbo oil pipe.

It is less necessary to do it on the petrol smart as the turbo is water cooled, the diesel has a standard air cooled turbo, another reason for the oil heat exchanger.

Share this post


Link to post
Share on other sites

I was thinking there would be a lot of conducted heat in the races of the turbo bearings. Cooling the turbo (minimal exhaust) would result in less potential heat energy to be present when you turn the key off. Evil, I can see you have a lot of knowlege of the design, I just ask for a more pedestrian explanation.

Share this post


Link to post
Share on other sites

Also just as important as idling a minute to warm up AND cool off is driving easy/slowly the first ten-fifeteen minutes, not flooring it to redline in each gear as soon as your out of your driveway. Stressing a cold turbo makes them noisy really fast, they don't necessarily die right away but you can hear them spool up, different sound and much noisier on cars that are beat hard. I would never by a turbo charged car off anyone who lives on a major highway with 80+km/h speed limits, people just don't think about the damage is causes their engine to accelerate hard when it is cold.I never shut off any of turbo charged vehicles after a long climb, I just lock, run to the restroom and get back on the road. A couple minutes after a hard run is not enough, I have aftermarket guages in some cars and the temperature spikes a couple minutes after shutdown, as much as 50-75 degrees farenheit (way hotter then I ever see it when running). I also open up the hood to let them cool off faster, not so easy in the Smart though. This also saves headgaskets, I have never blown a headgasket on any of my vehicles...Greg

Share this post


Link to post
Share on other sites

not for 250,000 or so with maintenance.

LOL, 260 000 km here and 4th turbo...-Iain

Share this post


Link to post
Share on other sites

Maybe running flat out all day is not the best way to keep a turbo turning. It's also hard on tires and other components.

Share this post


Link to post
Share on other sites

Maybe running flat out all day is not the best way to keep a turbo turning. It's also hard on tires and other components.

As long as the turbo is properly lubricated and cooled, no damaged should be caused by it running. I think this sight shows that the smarts that travel further tend to have fewer issues by a given mileage. More damage will be done by not letting the turbo properly cool down before turning the car off. which I have seen from several smart owners. With respect to Iain's turbo trouble, I think there must be some sort of internal issue starving his turbos of oil, that or just bad luck getting poorly constructed turbos.

Share this post


Link to post
Share on other sites

ya but that's what i'm saying, who is going to want to buy it from you 4 years old with a ticking time bomb. and if you sell it before that the next guy does it. how are we saving money or getting good value for a car? at least a 3 cyl car gets 60+ mpg for the life of it to outweigh the costs.

A hybrid treated well may easily get 10 years or more out of it's battery pack, if it is abused much less. The same is the case with any ICE vehicle, treated well the engine will last for 100's of thousands of kilometers, treated poorly much less.

Share this post


Link to post
Share on other sites

As long as the turbo is properly lubricated and cooled, no damaged should be caused by it running. I think this sight shows that the smarts that travel further tend to have fewer issues by a given mileage. More damage will be done by not letting the turbo properly cool down before turning the car off. which I have seen from several smart owners. With respect to Iain's turbo trouble, I think there must be some sort of internal issue starving his turbos of oil, that or just bad luck getting poorly constructed turbos.

Crap, I never asked about this. Do diesel turbos need to be cooled down as well? Should I invest in a turbo timer?

Share this post


Link to post
Share on other sites

ALL turbos,of any kind ,need to be cooled off for a short period BEFORE shutting off the engine.Turbos run at a an extreemly high rpm,and can get red-hot during severe use. As soon as the engine shuts off,so does the turbo's lubricating oil supply.The turbo may still be spinning,and it's bearings will NOT be getting any oil to lubricate and cool them. You should always idle the engine for thirty seconds,or so, before shutting off the engine.More if you were just getting off the highway, or were raceing to get that parking spot!

Share this post


Link to post
Share on other sites

The tiny turbocharger in the cdi spins up and down very fast, so if you are driving gently before a shutdown, no idling period is needed. Just don't shut down immediately from a high speed uphill run, that would be bad.

Share this post


Link to post
Share on other sites

Posted (edited) · Report post

Because of the extreemly high heat that the turbos run at, if you don't idle the engine before you shut it off,to allow the turbo housing to cool, the oil 'Cokes' (burns) on to the hot turbo's bearings, shortening their life. Thus the premature turbo failures.

Edited by PrairieBoy

Share this post


Link to post
Share on other sites

The turbocharger will only be hot enough for that to happen if the engine was worked hard right before a shutdown. There's no need to do it all the time. It depends on how the car was driven immediately prior to the shutdown.160K km --> one turbocharger ;)

Share this post


Link to post
Share on other sites

Change the oil on time and that's it.

Share this post


Link to post
Share on other sites

At the risk of starting an arguement and/or opening old wounds, the other preventive measure you could take is to remove the crank case vent hose from the TIK pipe and fit an oil catch tank. Admittedly this is more of an intercooler preventive measure, however in my mind the intercooler and turbo are one unit. Can't have one without the other.

I know its been discussed many many times. But maybe its worth repeating in case any newcomers to the forums find this. Now or in the future. And it has pictures. :)

Posted Image

The stock way your turbo and intercooler are treated. The rubber seal where the TIK meets the turbo failed often. There is a newly redesigned seal (and clamp) that seems to correct the seal failure. Correction of the turbo seal just allows more burnt oil vapor into the turbo/intercooler system so why it is deemed a repair is a mystery to me. The left-most pipe coming into the top of the TIK is the pipe from the crank case vent. It dumps all of the burnt oil vapor into the TIK which then leaks out of the failed turbo seal.

Posted Image

Crank case vent and the inlet on the TIK where, by OEM design, the burnt oil vapor is sent into the turbo and then the intercooler.

Posted Image

The hose that connects the crank case vent to the inlet on the TIK. Mine was about 70% broken. I tore it the rest of the way when removing it to fit a new hose for the oil catch can. Which in hindsight means that the burnt oil vapor was just venting to the atmosphere and/or causing oil drips to stain the garage floor. Better (to me) than dumping it all into the turbo and intercooler.

Maybe the intercooler should be renamed the burnt oil vapor reservoir in the parts list from MB/Smart?

Edited by briand

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!


Register a new account

Sign in

Already have an account? Sign in here.


Sign In Now
Sign in to follow this  
Followers 0

    Chatbox
    You don't have permission to chat.
    Load More