"Italian Tune-Up"

[95E320cab]

I heard somewhere the idea of running a car at high RPMs to "blow it out" referred to as an "Italian tune up". Aside from being humorous, does anyone here advocate this method of stretching a cars legs to improve its idle, acceleration, etc? If so, how high the rev's and for how long?

[A. Rosich]

What Mercedes-Benz cars need is a fast run at highway speeds for a relatively long period, especially if they are only driven at town speeds or at constant stop and go situations.

If your local speed limit does not allow you to rev your engine into the high 3/4 of its limit, then speed up at position "3" so the engine will rev up higher at lower speeds. Drive like this for at least 30 minutes, varying rpms somewhat.

This does wonders for cleaning up the exhaust, the valves, the engine itself, and for some reason, it seems to cure all small electrical gremlims that appear from time to time.

A. Rosich
S320, 1998
E320T, 1995

[Vronsky]

Did that once with a turbo-powered car, and wrecked the crank shells. I would think twice to rev the engine without sufficient load, like in lower gear.
Just drive it hard for long stretches, in the right gear. The heat will clean out the internals.

Cheers!

My 107 loves it. When I bought the car in Texas and drove it home to Minn., I noticed quite a bit of greasy soot all over the back of the car. What I was actually doing was blowing all the carbon out. The PO had only driven around town.
I regulary run her at 80-85mph. If I don't feel like speeding, I just leave it in second gear and drive around between 4 or 5000 rpm. Have fun.......

sbr
'79 450SL
77,000 miles
'89 ASC/Mclaren Mustang #123
46,000 miles

I had the pleasure of running mine this past weekend for about 350 miles. About 150 miles of it was between 85 and 100. This morning, at a stop light, I thought the engine had stalled, when in fact, it was running so smooth I couldn't tell that it was running !

[Mike Richards]

Stu Ritter, a 30 yr. MB vet from the Ritter-Easley list has made mention of this approach more than once. He favors it over "snake oil" solutions.

The service mgr. at the independent facility I bought mine from used in '97 told me to not pamper the car or else it would require more service. I do not abuse my MB, but do "open it up" on the highway once fully warmed up periodically. Afterwards, I notice a smoother idle and generally improved performance.

Fortunately the state police haven't noticed. That's the down side to the "Italian Tune Up".

[daddiojiggy]

can someone of substance(larry bible,benzmac,mike tangas et al...) tell me if reving in third at slower speeds is the same as full throttle in drive?does driving in third of a four speed tranny do more harm than good when you are trying to do an italian tune-up?no offense to anybody else meant, i just wanted to hear from some mech's or senior members with experience in engine work

[David C Klasse]

The only difference doing it in 3rd gear is that you'll have a higher engine speed at a lower mph.....

(No offense, but you don't need a tech for that question...)

[Mike Richards]

Daddio:

The idea is to keep engine revvs out of the red line area. This can happen in any gear.

[speedybenz]

Find a twisty road and run the engine real hard. Use the shift lever on the tranny and keep it in 2d and 3rd mostly and before you go fill up the tank with lots of Techron injection cleaner.

Go out for about 100 miles and drive it like a race car. I think its OK to get it up to the Rev Limiter a few times.

Works for me.

Jeff

10 years of experince building motors that produce approx. 180hp to 200hp per liter, normally asperated.

[Vronsky]

Why not use 1e gear then, or even better in neutral? You can do that parked, and have a beer in the pub meanwhile.
There is a major difference in pushing a car under load in the right gear, compared to just revving. But maybe find out for yourself: only risk is an engine rebuild...

Cheers

[pentoman]

I hear it's bad for the torque converter to rev it lots in neutral - is this the same in Park?

I thing the main advantage of the Italian tune-up is to run it under load for a long time - I don't think it would be as effective running at high revs in '3' than in 'D' or 4th, as the engine would not be under very much load.

Maybe you need a big hill to run it under load without exceeding the speed limit too much..

[bobbyv]

just some points to consider:

* under load (i.e., in a higher gear, lower engine rpm), more heat is transferred from the combustion charge to the engine.

* a higher engine rpm (i.e, driving one gear lower than usual) sends more oil through the engine, fulfilling its lubrication, cooling and cleansing functions better. The coolant also flows faster.

* when you do your italian tuneup on the highway vs in neutral on your driveway, you get more efficient engine cooling

* prolonged driving at elevated rpms also clears the condensates in the exhaust system (which are acidic)

but the best point is that these engines were meant to be driven this way, and they can sustain those conditions indefinitely ...

Back in the middle '60s, when I was working my way through grad school doing tune-ups part time, it became clear that the then new Porsche 911 model had a propensity for plug fouling in traffic almost as bad as the Ferraris of the late '50s, and that "Polish" (to mention my Silesian ancestors) tune-ups were an excellent solution, if and only if they were done right. It seemed important not to go out and just put the pedal to the metal to run the engine suddenly under maximum load in a high gear, but rather, to warm up the carbon deposits gradually by easing up to and holding somewhere around 5000 rpm (red-line 6800 on those) for several miles in 3rd; otherwise the deposits would bake into a ceramic-like coating and the only solution would be new plugs, because even the standard Porsche sand blast machine wouldn't touch it.

I believe a bit farther north in Minnesota (up on the Iron Range) one of my colleagues with a Norwegian name called this a "Finnish" tune-up in those days.

Late addendum: Porsche was adamant that those motors should never be taken over 5000 revs when not under load, and then only when necessary to check the ignition timing (which was to be done at full advance).

The Italian Tune-Up
By Marshall Booth


The Italian tune-up - at least in a diesel [although it applies to a gas car too - Ed] consists of taking a SOUND car out and maximally accelerating from stop or slow speed to some high speed OR driving at near full rpm with a heavy load (up long hill) for minutes at a time. The idea is to get maximal air and fuel flowing through the engine to develop near maximum heat. This will burn and eject residual carbon that has collected in the engine. Following such a regimen the idle is usually smoother and the amount of black smoke at full throttle should be reduced. This occasionally does not happen the 1st time and the idle might get rougher or a pronounced knock could occur. This is usually because some carbon has been "rearranged" but the prechamber environment isn't appropriate for smooth combustion. Further TREATMENT will clear this up as more carbon is burned up, but it is a little scary the 1st time it happens to YOU and your car!
A few full throttle accelerations a week will usually keep most CLEAN engines cleaned out pretty well. More prolonged "treatment" is usually required for a car that has had a LOT of city driving. Just a long highway trip (50+ miles) with several two-three minute full throttle periods (long 6-8% grades are GREAT) will clean out an awful lot of carbon and crud that's build up, but with a really "city bound car" it may may take more than just a few sessions to really get it all out. My weekly 250 mile trips from Pittsburgh to Washington DC and back over the last 7 years have given me a chance to really examine the "Italian tune-up" and the concept of "flailing the heck out of the MB diesel engine" or at least running it at near full throttle/top speed for a long period of time.

I referred to a "SOUND" car. To me that means a car that NO serious mechanical problems. The chain stretch should be below 5 degrees or so, the valves should be properly adjusted, the air and fuel filters should be verifiably clean, and there should be clean and it would probably be best if the injection pump timing is known to be pretty close to correct (within a couple of degrees). The cars/engines I presently own, have THRIVED on this regimen. Idle smooths out, smoking diminishes, and fuel and oil consumption goes down. I can't promise that on an engine that's worn out, but nobody else can either ;-)