Delica Canada | Mitsubishi Van Club

Hey everyone,

Wondering if anyone is a 'Turbo Pro' and can offer some insights.

I am curious about my turbo charger. I am also not interested in installing a boost gauge or exhaust temp gauge. But I would like to know more about my turbo and how to keep it happy.

Some main points I am curious about:

Should I always hear my turbo 'whining' ? If not, are there specific conditions that I should hear it? Seems I hear mine at random times.

Should I always let my van idle after driving it, to keep things happy, or do I only need to do so after driving it hard and/or fast? In other words, if I drove home from my friend's house at 40km/hr and it took 5 minutes, do I need to idle?

Is there anything else I should know about my turbo, or how to keep it running well, or when to replace it?

Let's discuss. Any other turbo talk welcome!

Cheers
Nate

If you don't want an EGT gauge i would still highly recommend deleting your EGR valve. It recirculates unburnt exahust gas into your turbo, therefore gumming up the compressor wheel with black nastiness like what is in your exhaust pipe.


EGT gauges are super simple to install, i would recommend one, it gives you an idea of how hard your engine is working. Also your turbo is working if it is whining, much like a kid whining when he has to go mow the lawn

Yes you should always let it idle after driving, the hardness of the driving is not important. The issue is not one of heat, its about stopping oil feed to the turbo bearings while its still spinning at speed. So by stopping the car and letting it idle the turbo can spin down before the oil is shut off. Turbos can spin at some silly speed, over 100k rpm IIRC.

Yes, you will hear the turbo when you boost. A very addictive sound!

As was stated, it is advisable to let it idle down, but not very long.

People often ask so I will address this; as for a turbo timer, you don't need to let it idle to cool it. Even for oil cooled (non-water cooled) turbos, as long as you are using a good synthetic oil, it will not coke inside the turbo. Therefore, you don't need a turbo timer, unless it makes you feel better, or you just want to use it to idle it down so you can jump out of the car without having to wait.

Water cooled turbos help with the coking issue even with regular oil because the liquid is there to draw away the heat.

Yokohama wrote:Yes, you will hear the turbo when you boost. A very addictive sound!

When I boost? What am I doing to boost? Stepping on the pedal hard? Going up a hill? I hear my turbo sometimes, but it is not consistant

sub-arctic wrote:If you don't want an EGT gauge i would still highly recommend deleting your EGR valve.

Also your turbo is working if it is whining, much like a kid whining when he has to go mow the lawn

My EGR is essentially blanked, or, rather, I have blocked the little hose so that the EGR always remains shut.

Incidentally, I whine like a turbo as well, when I have to mow the lawn. Luckily my wife usually does it


Thanks everyone for the inputs!

naterade wrote: When I boost? What am I doing to boost? Stepping on the pedal hard? Going up a hill? I hear my turbo sometimes, but it is not consistant

My EGR is essentially blanked, or, rather, I have blocked the little hose so that the EGR always remains shut.

Yes, the only time the turbo will 'boost' is under load. If you are not accelerating/engine under load you will not hear it.
The only time a turbo will really sound, i.e. whine/whistle is under full acceleration.

Yes, you can block off the EGR tube or disconnect the vacuum line from the control solenoid, and then use a small screw to plug the vacuum line off (of the line not the solenoid port).

I would advise getting a boost gauge installed so you know the status of the turbo boost; this can help you detect problems.

My turbo makes the most noticeable noise between 5-10psi when the engine's below 3000rpm. The turbo's sound changes from a whine to a whoosh above 10psi, and once the engine gets above 3000rpm it drowns out whatever noise the turbo is making.

The only time I show no boost is when idling. At 50kph I have about 4psi of boost, At 100kph about 8psi with just a faint turbo whine. Accelerating hard I have the boost limited to 16psi (but it'll approach 30 if I remove the boost controller- that's FUN!!) .

Most recommendations regarding letting the turbo spool down are for petrol engines which have relatively clean oil and only boost when accelerating. Diesel engines carry a lot of carbon in their oil and are on boost most of the time and, while I have no references, I'm inclined to think that would make coking more likely. Letting the engine idle for 2 minutes after even a short run is cheap insurance and easy if you have a turbo timer.

Growlerbearnz wrote:
Most recommendations regarding letting the turbo spool down are for petrol engines which have relatively clean oil and only boost when accelerating. Diesel engines carry a lot of carbon in their oil and are on boost most of the time and, while I have no references, I'm inclined to think that would make coking more likely. Letting the engine idle for 2 minutes after even a short run is cheap insurance and easy if you have a turbo timer.

Coking comes from the oil literally boiling off and leaving deposits in the turbo. Synthetic oils have higher temperature range before breaking down than conventional oil.

Doing oil changes before the oil gets saturated with impurities will also help, especially for conventional, but also synthetic.

And, as stated before, if a turbo is water cooled, then it will further help prevent coking.

Of course, as mentioned by others, it is not a bad idea to let it idle down for a minute; this is more than enough time to let some fresh oil in and let the turbo spool down.

If your idling around , stop and go your turbo isn't working too hard. I just shut the motor off. If I'm coming off an 80 km or highway type of thing to the gas station I like to idle for a minute or two before shutting it down.