I've heard this term used to describe a procedure whereby the engine is cleared of all accumulated gunk by running it at high revs for a sustained period.
Is doing such a thing really beneficial and under what circumstances should it done?
How exactly should such a procedure be performed and for how long?
Or is it just a waste of fuel and a strain on the cambelt and what about all the gunge that ends up in the sump!
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Sounds like the motoring equivalent of a 'Croydon facelift'.
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Doesn't HJ himself often advocate the use of high revs in order to blow cobwebs away?
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Its not myth, and it does do some good, and I have employed it for years.
When the car is hot, I have a nice run down the slip road onto the motorway, hitting the rev limiter in every gear, then run it for 5 miles at 500 or 1000 revs belwo the red line. Do it once a week.
Its never done any harm, and all my cars have never used any oil. Done it to all my cars from brand new
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Yes it does work, few weeks ago came back from a friends house late at night, nothing on the road so gave the old MB the beans for 50 or so miles, runs noticeably better and has much more pep than before.
I don't do it as regularly as some, but when the engine seems a little 'lethargic'.
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I've tried a similar thing with my brakes. if I've ever had to hit them hard, the pedal travels less and feels firmer on subsequent presses. Presumably there is some kind of cleaning effect going on. Stands to reason sustained high revving of an engine will blast away debris.
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I would be suspicious it does a better job of clearing crap from the exhaust/cat converter than the engine itself, although high revs and hard acceleration will likely help clear any deposits on the injectors also. Both of these things obviously help smooth running.
I dont think modern cars are too bad for 'coking up' the pistons/valves/head but obviously any sooty guff that can lead to hot spots and pre-ignition may be blasted out with prolonged hard driving.
Can make a big difference to cars that have had their throttles tickled all their lives.
Shouldn't cause any excessive wear to a warm engine in good condition with decent oil.
Just watch the temp gauge if the cooling system has never been flushed and the car is 5 or 6 yrs old.
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How to perform an 'Italian tune-up?'
Forum search should find many previous threads on this subject.
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My car has had a blocked back box for a couple of months, getting worse and worse.
When the box was replaced, it failed the MoT on emissions. But it didn't need a new cat, just an Italian tune-up. It passed after that.
Mille grazie, wopperini...
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Or is it just a waste of fuel
It can be a help - I usu. do this at MOT time. Petrol's pretty good these days, ditto fuel systems, so unless there's something the matter, or you drive at inappropriate speeds for your forward ratio, or are forever doing cold starts and the thing doesn't reach operating temperature, you are unlikely to have any problem.
and a strain on the cambelt
The greatest "strain on the cambelt" is at start-up, not at high revs.
and what about all the gunge that ends up in the sump!
"Oil filter".
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What about the lip at the top of the bores on my 16-year-old that's never been past 2K RPM for it's 60K miles?
Every time I hit 6K RPM I wince as imagine the con-rods stretching and the rings hitting that lip.
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I think you are describing "delayed bedding-in" ;-)
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Perhaps we should do this to Mrs V's Mx5 - 54k, 6years old now & never raced or rallied, or gone over 60mph.
Well a couple of times, maybe!!
VB
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I have used frequently on rental cars which are a bit suggish. By the end of the holiday they are usually quicker and more economical for having had their necks rung (figuratively). I can vouch for the efficacy of the method, as long as the engine is fully up to working temperature. Of course, a car regularly driven at reasonable speed on the motorway should not need this.
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I remember a rental Uno many years ago that had no go whatsoever. I tried the 'Italian tune-up' but it just didn't want to rev. So I tried making it backfire by turning off the ignition briefly on the overrun and then back on again.
The first time it gave a little pfff.
The second time it gave a pop and an enormous cloud of crud.
The third time it gave an ear splitting crack and went much better.
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What Uno was that? Mine (999cc FIRE) seemd to rev for ever. I follow HJ's advice on the Italian tune up for my car Fabia 130 TDI. That is hitting 4500 rpm (once fully warm) a couple of times a week.
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What about the lip at the top of the bores on my 16-year-old that's never been past 2K RPM for it's 60K miles? Every time I hit 6K RPM I wince as imagine the con-rods stretching and the rings hitting that lip.
bathtub tom, I agree with you. All I can say to the OP is, on your own head be it.
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What about the lip at the top of the bores on my 16-year-old that's never been past 2K RPM for it's 60K miles? Every time I hit 6K RPM I wince as imagine the con-rods stretching and the rings hitting that lip.
Serves you right for driving like a nun! :-P
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I should've explained. I bought the car knowing the previous owners and their driving styles - somewhat more sedate than mine.
How do nuns drive? ;>)
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We hired a Citroen Relay van while at uni for a trip to Scotland. We only got decent performance out of it by revving the nuts off. In reality we only had a 500rpm rev range between 4000 and 4500rpm, but bejesus and begorrah it didn't half perk up after two days of this.
I save up the crud from my Passat to empty over shiny BMWs who tailgate me.
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Wife's car does around 2000 miles a year and seems a bit slow to pick up especially at low revs, so when the lovely weather allows will take it out for a good tune up.
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