4x4 diesel intercooler

Why I've thinking of this has got me buggered but it popped into my head so, did some googling but I'm none the wiser.
So here's the question:  do all 4x4 diesel motors with a turbo have an intercooler ?  from what I can see, they don't and it's an after market optional extra.

The answer is, no.
However most later models do. eg: Nissan Patrol 4.2 diesel had a factory fitted intercooler from 2003 onwards until the 4.2 was phased out due to not being able to meet environmental/emission standards and the 2.8 & 3.0L was introduced.

okey doke. so if you have an older diesel motored vehicle that doesn't have an intercooler, what are the benefits of having one fitted.
or would it be a waste of money seeing the vehicle has been running ok without one.

Cliff an intercooler can be compared to truckies driving at night when the ambient temperature is lower and the air is denser, so the oxygen content is greater, more power, fuel burns more efficiently.
An intercooler chills the air, increasing its density allowing for greater power to be generated.
Technical answers here;

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Cliff,
Nightjar has pretty well nailed the benefits of cooling the charge, I spent about 4 years reconditioning turbo's and fitting the kits up mid to late 90's, the kits we fitted varied, early days Schwitzer based turbo kits without a watercooled bearing housing, then Safari kits running watercooled Garrett's, the company I worked for then decided to make their own kits taking the best of both kits and used a Mitsubishi turbo because they were the importer and at the time the cost of the turbo was $80.
My time there was pre intercooler days, they were very expensive and not so widely available anyway, about the only thing we used to do is add an oil cooler if the customer was doing lots of towing.
The most important things with turbo's is to make sure it has clean air and clean oil so keep on top of the oil changes, every 5000km's, make sure the air filter is changed regulary and the air inlet is fully sealed because the damage that can be caused from sucking dust in can cause damage to the comp wheel.
The other very important thing is to idle the engine after a long run, need to avoid hot shut downs because the heatsoak from the exhaust wheel/housing travels up the shaft or into the bearing housing and basically can cook the oil and cause carbon build up which can block oil passages which eventually will cause bearing damage.

Darren

one good thing to know about the turbo diesel is that if the turbo fails you can get runaway where the oil feeding the turbo gets sucked passed the seals into the inlet and the motor just keeps running faster and faster on this oil until it blows up. had it happen to me once half way across australia but i managed to stall the motor by selecting 4th and dumping the clutch with the foot on the brake and replaced the turbo to get back on the road. if you have an auto the only way to stop it is to cut off the air supply by removing the inlet hose next to the throttle valve and shoving something in there like a big rag. worth researching how to stop it just in case..

Warning!!!! Do not use your hand across the inlet to try and stop it. Diesels create a fair suction and can cause damage.

I've read that if a turbo decides it's had enough and it lets go, it will throw broken metal into the motor.
but if you have an intercooler it doesn't as it throws back into the intercooler tubing.
Doesn't sound logical to me.
So what actually happens if you have or don't have an intercooler and the turbo packs it in.

Bits of turbo compressor end up trying to get into the combustion chambers... crunch crunch new motor! Cliff.

the intercooler is like a big heat exchange between the motor and the turbo so it will catch most of the bits but not all, if a turbo lets go its not the bits getting into the motor that is the real issue as most turbo's are bronze bush bearings there isnt much to spit out. the impella could hit the sides and chip off  bits but there isnt much to spit out realy. more the issue is as i mentioned b4, the oil feed line pumping hot oil directly into a red hot broken turbo, the smoke emitted is sucked back into the motor and off she goes revving harder and higher until it blows up.

here is a disco that has a small issue