Extended Engine Idling w/ Turbo

[Pitter]

I have always been given to understand that extended engine idling is bad for the engine. Of course police cruisers do it but they are generally big V-8s. And of course big diesel trucks do it regularly. So how acceptable (or not) is extended engine idling with the Mazda turbo version?

 

[Conrad 16.5]

How much time is involved in an 'extended idle'?

Generally speaking it's not good. Especially with a direct injection engine.

 

[markjenn]

It’s something to be avoided but engines seem to tolerate it pretty well. I’m not aware that turbo engines are have any special problems with extended idling. Many turbo diesel truck engines (admittedly, a different type of engine) often idle for hours at a time. And I haven’t heard of any special problems with modern turbo engines in high idle time service (I.e. Alaska).

I would change oil more often and religiously use a synthetic. Halving the spark plug change frequency perhaps.

- Mark

 

[pcardoza]

When idling, is the turbocharger even spinning????

 

[erhayes]

If the engine is running the turbo is spinning due to exhaust output. Since the turbo is water cooled and full oil pressure, I see no problems with a turbo engine idling for long periods compared to a non-turbo engine. Ed

 

[Mazdiod2]

The Cars Guys Clik'nClak said on their radio show that you could idle for days without harming the engine.
I've heard otherwise, plus low speed driving isn't particularly good either.
Lower oil pressure, air and coolant flow etc. Possibly plug or valve deposits.

Maybe modern computer control helps avoid this. Plus platinum plugs, thermostat controled cooling fans, etc.

I figure engines do best in moderate highway cruising. Maybe the problem with intake valve buildup is worse in low speed operation but thousands of people idle a lot and it doesn't ruin the engine.

 

[Conrad 16.5]

I don't understand why anyone would want to allow their cars to idle for an extended period of time anyway. To warm up before getting in so that one doesn't have to wear such a big coat?

I don't mean to tell anyone what to wear but you should be dressing for the weather outside, what if your car was disabled for whatever reason and you had to walk? A thin stylish leather jacket ain't gonna cut it and neither are those nice shoes.

YMMV

 

[Mazdiod2]

It takes some work for an engine to get fully up to operating temperature. Better not delay it too much for longest engine life.

 

[sm1ke]

I can't speak for everyone, but I do know that some prefer to have the engine idling if they are waiting to pick someone up from school, for example. Sometimes it gets too hot in the vehicle and the car needs to be on in order for the A/C to operate correctly, or they want to listen to a podcast or something without worrying about draining the battery in accessory mode.

 

[Mazdiod2]

I can't speak for everyone, but I do know that some prefer to have the engine idling if they are waiting to pick someone up from school, for example. Sometimes it gets too hot in the vehicle and the car needs to be on in order for the A/C to operate correctly, or they want to listen to a podcast or something without worrying about draining the battery in accessory mode.

True. And I think it's better to idle after pulling off the interstate in hot weather. The radiator fans might need to continue to run. It might be good to let the engine (and maybe the turbo) keep running to cool better, plus run the AC.

 

[markjenn]

I recall reading there are two issues associated with excessive engine idling: too-high under hood temperatures with localized overheating of things like alternators, power steering pumps, belts, etc., and engine deposits and spark plug fouling due to the too-low cylinder internal temperature/pressures. But modern engines are very tolerant of all sorts of abuse.

I recall reading about a guy who commuted to work in Duluth MN winters on an old Honda 125 motorcycle who would just let it idle all day during work rather than have it cold soak outside and be hard to start. (It burned something like a quart of fuel over 8-hrs.). He did this for years and the air-cooled, carb’ed engine had no issues.

- Mark

 

[Pitter]

The "Ice Road " truckers left their engines runing for weeks because those diesels wouldn't restart in those way below freezing temperatures. But regarding the question of why idle the answer is obvious if you live in a hot country. Who wants to sit in a car with the engine and AC off if waiting twenty minutes for somebody when the ambient temperature is 90 degrees?

 

[Conrad 16.5]

The "Ice Road " truckers left their engines runing for weeks because those diesels wouldn't restart in those way below freezing temperatures. But regarding the question of why idle the answer is obvious if you live in a hot country. Who wants to sit in a car with the engine and AC off if waiting twenty minutes for somebody when the ambient temperature is 90 degrees?

The answer for me is obvious.

I don't wait for anyone who makes me wait 20 minutes in the 90 degree weather. lol

 

[youri]

I don’t think the turbo makes any difference with regards to idling. Excessive idling is generally not the best operating conditions for any engines and the owner manual warns against it, but it depends what you consider excessive idling is. Is it 20 minutes once in a while with the engine at operating temperature, is it a remote start for 15 minute in cold weather, or is it letting it run all day ? These are all very different operating conditions.

Up north, they are going with what is the lesser evil. Idling for long period of tine is bad for the engine, but so is running the engine cold or worst not be able to start it at all (most of the time being in a condition where the engine would be too cold to restart is why they let the engines running). In those conditions idling is the lesser of two bad things.

It does take some work to get these engine warmed up, but at the same time driving on a cold engine is not good due to poor lubrication of engine moving parts.

everyone above made valid points, but all in very varied scenarios. (Prevent hot spot, engine warm up, etc.). All with very different idling second order effects. Let us know what type of idling you would do and we can be more specific.

 

[CX5_Driver]

Here is the wettest desert in the world the vehicle often idles in traffic for 20 minutes or 30 minutes or 45 minutes. Modern vehicles are designed to shed the heat soak while idle under even the most extreme 120 degree ambient temperatures. Remote start daily, daily traffic, all a non issue. Many of the antidotes of yesteryear are tales from a time when engines ran on leaded gas and there were no seat belts. If there were a severe problem with idling for extended times most cars in Los Angeles, New York, Boston, Chicago, Atlanta, or Houston would all be failing because traffic is often at a standstill for 30 or 40 minutes (or more) DAILY. And it is event worse because in bumper to bumper traffic air flow is minimal and the heat generated from other vehicles compounds the issue. Excessive engine wear --- pffft change your oil regularly. This discussion for a modern vehicle with regular maintenance is a non issue. My .002 worth.

 

[Conrad 16.5]

Here's a very good article on this very subject.

No, You Probably Don't Need to Warm Up Your Car Before Driving It

The long-held notion that you should let your car idle in the cold is only true for carbureted engines.

www.popularmechanics.com

 

[Pitter]

Good information thanks. Of course as mentioned in another thread my turbo runs at fast idle for about 45 seconds at first start up. I've noticed that if I back out of my driveway before the high idle has finished then get out of the car to close the gate it will continue at high idle until it has finished and returns to normal idle.

 

[sm1ke]

Good information thanks. Of course as mentioned in another thread my turbo runs at fast idle for about 45 seconds at first start up. I've noticed that if I back out of my driveway before the high idle has finished then get out of the car to close the gate it will continue at high idle until it has finished and returns to normal idle.

I think that's normal. My CX-9 does that too at first start, for about the same length of time. Same behaviour if I put it into gear before it returns to normal idle, then put it back into park or neutral. It's done that since I got the car, and seems common after seeing many videos of cold start CX-5s with freshly modified exhaust systems on YouTube. I think it's something to do with the thermostat sending a signal to the ECU to idle higher to get the temps to operating temps faster.

 

[Kedis82ZE8]

I had an '80's Mitsubishi with a turbo as a kid. Turbo didn't have water cooled bearings so you always had to let it idle a few minutes before shutdown as per the owner's manual.

 

[Pitter]

That was the same deal on a 1990 Plymouth Turbo I owned but only if you'd been driving it hard with turbo.