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Not having had a turbo before - can anyone tell me:
1. What does it mean?
2. Why do you have to do it?
3. How do you do it?
Many thanks!:confused:
 

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took this from another website about a blown turbo on a diesel nissan..


"The turbo is a hostile place, very hot. There is a chance the turbo bearings were cooked. This is caused by heat soak - Driver turns off engine imediately after turbo has been hot and spinning - oil feed stops - bearing cook and simmer in own oil which goes hard - turbo kippered"

Basically, if you have been revving the nuts off the car and the turbo gets hot and you don't let the turbo cool down (let the engine idle for a bit so the heat exchange/intercooler can do it's job and cool it down, then the oil that is in the turbo boils and then seals go,bearings sieze etc.

in short, you don't simmer the turbo, you let it cool down so it doesn't simmer.

Modern Diesel engines rarely suffer from this due to very effective heat exchangers. Hope my limited knowledge helps..
 

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Basically, if you have been revving the nuts off the car and the turbo gets hot and you don't let the turbo cool down (let the engine idle for a bit so the heat exchange/intercooler can do it's job and cool it down, then the oil that is in the turbo boils and then seals go,bearings sieze etc.
Just to clarify: The intercooler doesn't cool the turbo itself, it cools the air that was heated by the turbo. (A turbo compresses the air, and if air gets compressed, it heats up)

Turbo's are normally cooled and lubricated by oil, the same oil that lubricates and cools the rest of the engine as well.


There isn't much that you have to do to keep your turbo from blowing up, just don't go from 80Mph to full engine stop without letting it idle for a while (about a minute is enough)
In normal use (ie, go from the motorway into an urban area and then stop) you don't have to do anything.
 

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Looking after a turbo is paramount.

If you drive hard then it is a definate requirement to let the turbo 'spin down' prior to stopping the engine. As mentioned above, the turbo relies on the engine oil pump to deliver oil to the rotating bearings so it lubricates & cools the turbo. Failure to do so over time causes the turbo to cook and it'll fail.

Intercoolers do not cool the air heated by the turbo, thats what the exhaust is for ;). Air is sucked in via filter, this assists in the drop in temp of the air before it meets the fuel in the chamber charging the air thus giving an increase in power. Once the exhaust gases enter the manifold, they're passed across the exhaust vanes in the split turbo casing to keep the turbo spinning during gear change, this helps keep the turbo charging with air on the inlet side too.

Yes compressing air generates heat but the main heat in a turbo comes from the exhaust casing, the inlet casing is normally alloy. (see picture below)

I owned an Impreza for 4 yrs & having removed my engine/turbo during that time for various reasons, I can give a few personal hints.

My car had an aftermarket air diffuser (HKS Superpowerflow), this was just a piece of foam secured in place with a cage and changed every 12,000 miles. You had to be careful when changing the element to make sure you get 100% coverage, during one changeout, I didn't notice the element had caught on the cage and had left a gap (not a big one may I add). A few days later when horsing down the road to work my turbo started to make a loud whirring noise, different than the usual whoosh but it onlt happened when only ever on boost. I removed it to find a small dog-eared bend on one of the inlet vanes. This caused imbalance and ultimately would have wrecked the turbo over time. These bulky units are very very delicate. So NEVER EVER run without an air filter or an open air box to stop any contaminated air, yes it might sound great ( ie induction roar) but it could kill your car.

Here's a few helpful links to explain turbo's

Turbocharger
Intercooler
Dr Turbostein - Universal Turbo's hints & tips
Turbo Technics - How a turbo works
 

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http://en.wikipedia.org/wiki/Intercooler

http://en.wikipedia.org/wiki/Charge_air_coolerAn intercooler, or charge air cooler, is a device used on turbocharged and supercharged internal combustion engines to improve their volumetric efficiency by increasing the amount of charge in the engine and lowering charge air temperature thereby increasing power and reliability. It is also known as a charge air cooler, especially on larger engines that may easily self-destruct with high intake-air temperatures. The inter in the name refers to its location compared to the compressors; the coolers were typically installed between multiple stages of supercharging in aircraft engines. Modern automobile designs are technically aftercoolers because they appear most often at the very end of the chain, but this term is no longer used. Also the thicker and large the Intercooler, the more Turbo Lag it produces.
 

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caz1562, you're wrong. Air heats up mostly due to being pressurized, and only smaller part due to heat of turbo itself.

caz1562 said:
Intercoolers do not cool the air heated by the turbo, thats what the exhaust is for :wink:. Air is sucked in via filter, this assists in the drop in temp of the air before it meets the fuel in the chamber charging the air thus giving an increase in power. Once the exhaust gases enter the manifold, they're passed across the exhaust vanes in the split turbo casing to keep the turbo spinning during gear change, this helps keep the turbo charging with air on the inlet side too.
????

That's the silliest explanation I heard about how turbo works. You picture does explain though how system works (just add intercooler inbetween turbo and intake manifold).

So, easy explanation how turbo works:
First of all, turbo is dependant on ammount of exhaust gasses, which actually force blades to spin. At lower revs there isn't much exhaust gases and that's the 'turbo hole' many people talk of - on diesel engines this means car is 'not moving' under some 1700rpm, when it suddenly picks up.
Another effect of turbo being spooled by exhaust gases is 'turbo lag' which basically means when you're in gear on low, or not throttle and floor it - turbo needs time to spool up and build pressure (by filling pipes, intercooler, and finally have enough positive pressure in intame manifold).
But, back to how it works: exhaust gases spool turbo, and sucks air through intake filter and thru turbo. When air enters turbo it's being compressed (since engine can't take that amount of air) - but while compressing it heats up. Most heat is generated by compression itself, and one smaller part by turbo being hot also from exhaust gases. Due to this, many cars have intercooler through which that air goes and cools down (cooler air = more dense air = for same volume more mass).
By flooring your car, and turbo spinning it could continue to generate more and more pressure, but not to blow your engine there's a wastegate - it is actually an actuator which limits ammount of boost that will be generated. It works in simple way - actuator that moves after there is more than X pressure in intake. By moving, it actually diverts some part of exhaust gasses to bypass turbo - so it can maintain proper pressure on intake.
 

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All I know is... more (cold) air into the engine generally results in more poke (something to do with compression during ignition phase?)

Which is why a load of the old school yank cars have "shaker hoods" with the big ram air scoops....

But that would look rather silly on a Civ...;)

Civics also have some sort of gadgetry that will only allow the turbo to function at a proper temp too - well, thats what it says in the manual, you're not supposed to be able to drive the car till some little tell tale goes out?

And letting the turbo warm up and cool down, irrespective of distance and time travelling is always a wise move.
 

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Turbo functions as soon as your engine is running. There's no on-off switch for turbo ;)

As for cold air - colder air in same volume = more air mass = more oxygen per volume = in the end = more power.
Also, on petrol turbo engines colder air reduces chances of knocking (aka detonating) - actually on non-turbo aswell ;)
 

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So if I leave my key in position I for about 1 minute after a hard drive it should be fine?

Or should it be in position II and should the engine be running ?
 

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Ditmar, I'd make sure the engine was running for 1-2 minutes after a really hard thrash. Normally the last minute or two of a journey is pretty relaxed, so you're fine to just switch the engine off as normal (the engine must be running, as you're cooling it with oil pumped by the engine). This only really applies if you do something like a top speed test round a banked test track (or something similar). There's really no need to worry, which is why I think there's nothing in the manual about it.
 

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So if I leave my key in position I for about 1 minute after a hard drive it should be fine?

Or should it be in position II and should the engine be running ?

The engine should be running at idle as the oil pump is driven mechanically by the engine.

In the owners manual it says wait for 10 seconds.
 

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Cooling down the turbo

Hi guys,

Pick her up in 48hrs...................not that im counting them down:D
Just been reading a post on letting the turbo cool down before switching off the ignition.Im a little worried as i've always driven petrol cars untill now and was wondering how much of an issue this is with the turbo,as im worried i forget and just switch off once i come to a standstill.
Most of my driving is on B roads and even my runs to work are stop start 30mph jobs.But i do love to put my boot down when given the chance and cant wait to feel those 140 ponies and all that torque.But seen as this will be my newest car(only 9 month old) i do want to look after her,so advise would be great guys.
Also a guy from work who drives diesels all the time got on about dump valves:confused: what are they and does the civic have one.
My final point is ..................as im new to diesels.What is the best way to drive them? I.E isit good to give it a good thrash every now and then or are you supposed to be more responsable( i do hope not :))

sorry for the noob stuff guys

cheers:)
 

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Turbo's are not that much of an issue, just keep it in mind if you come screaming by at 100 MPH and then stop to fill up on diesel, THEN you would have to give the turbo some time to cool down.

Dump valves are a safety measure to keep the pressure build up by the turbo under a certain level. Because too high pressures might be harmfull.

Driving a diesel is just like a petrol, just keep in mind that:
- It won't rev that high, petrols go to 7000rpm or so, diesels won't go further than 5000 rpm
- Because you now will be driving a turbo, you probably have to get used to the sudden surge of power you get at around 2500 rpm.
- It'll keep going for EVER on a tank of fuel :D
- It'll warm up slower than a petrol, and you have to let it warm it up before you really thrash it.

That's about it
 

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2 rules:
1- and most important one: Let the engine heat up (check if the water temp gauge is up) before going over 2000rpm.
2- If you have been driving hard (often over 3000rpm) let the engine idle for 10secs before turning it off.
 

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I think People are getting confused between petrol and diesel turbochargers, there to differnt animals.

petrol turbos run at much higher egt's (exhaust gas temperature) then what diesel do, so the core of the turbo does not get as hot on a diesel(still bloody hot though) so it's not so susceptible to the oil sitting on the bearing after the engine is switched off and heating up and turning into carbon deposits(this is what kills them)


As potts has said the best thing to go is take the last mile nice and easy, i would not leave it to ideal to long as this is where a lot of engine wear can occur(low viscosity and low oil pressure)
 
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