Hi,

I've just completed a 2 week course to drive CVRT (Combat Vehicle Reconnaissance tracked) - Spartan, Scimitar, Sultan, Samaritan. Next course is Warrior and then Challenger 2!

It was the turbo-diesel model, one of the points raised was before turning the engine off to let it idle for 3-4 minutes for the turbo-charger to spool down and to prevent after-boil of the engine coolant. By turning the engine off, the coolant and oil pump will turn off so the turbo will still be spinning with no new oil, same for coolant.

Is this applicable to other turbo-diesel engines - i.e. Fabia VRs?? What keeps the turbo oiled up after engine turn off? I also know that diesels don't like to idle either.

Also, it was fitted with a 'charge-air cooler' - cooling the compressed air from the turbo-charger. How does this compare to an intercooler?

One last thing, if your ever stuck behind a tank - be advised; the driver will have near-no rear visibility. The driver is also limited to 40 mph, so try to be patient.

Thanks,

Matt

I always let the engine idle for a little while before turning it off, more so atfre a motorway run or a blat where it will be at it's hottest. It allows fresh cool oil to circulate and helps prevent premature turbo failure. Not sure that it's the same for coolant as without air passing over the rad there's no real cooling effect to it.

It's mainly for the turbo IMO. This is why manufacturers offer turbo timers.....you can get out and leave it running to cool the blower with the doors locked etc.

In terms of charge cooling, I belive that's done with a water based radiator rather than just air passing through an IC. The benefits are much debated TBH.

A well located, well designed IC would do the job just as well and not require it's own radiator to cool the charge coolant with all the associated extra pipes etc.

i always let my tdi run for a couple of mins let turbo cool down after a blast..

remember if your driving the 4tonners let them cool down couple of mins too..

I generally cane it around a bit but when I get near where I live there are potentially children outside so I slow right down.

A charge cooler is an intercooler with a permanently running fan or compressor pushing air through it. Wheras an ic will soon get hot in traffic due to lack of air flow, a cc will not.

Presumably, then, you were driving an LEP version, with the 5.9 Cummins diesel? (A mighty 190bhp IIRC! ) I don't know whether the turbo will have been oil-cooled or water-cooled, however hopefully this should shed some light on the matter:

Personally, I usually let the engine tick over for as long as it takes for me to get all my stuff from inside the car and put the steering lock on (20-30 seconds). I believe the manual suggests longer than this, but I've not had any probs in 50k-odd miles!

yup, driving the (deep-breath)...

Cummins

5.9 L Diesel

6 cylinder inline

4 stroke

Turbo-charged + charge-air cooler

190 bhp

Top-speed is 50mph or 80 kph, although we're told not to drive above 40mph/64kph. Although my instructor got bored of doing 40, and told me to put my foot down. So if you around Dorchester and we're over-taken by a Spartan doing 55 then thats me!

Think turbo is air-cooled, with oil pumped around it. Charge-air cooler supposedly sucks air in from the front.

In future i'll do a crossword before turning Fabia off, unfortunately i'm no good at So-Duku (can't spell it either)...

Matt

charge coolers are basicly a heat exchanger sort of thing!!!

meaning you have a radiator filled with water at the front of the car, the water gets cooled by that runs through the pipes to the actual charge cooler unit, which is like another radiator sort of thing but in a box, boost passes through the fins that are cooled by the water!!! then to the inlet manifold.

Air to Air (Intercoolers) will all wase be better and more efficiant, but for some aplications such as mid engined turbo cars it is easer to have pipes going to a radiator at the front, rather than having a very long boost run to a intercooler!!!!

hope that explains it

A bit OT, sorry, I used to be a Warrior Commander and then ......... have fun, they are wicked bit's of kit (well they were when they were new)