Mercedes 300CE rough idle

Isn’t that known as an “Italian tune-up?”

Right – “Italian tune-ups” can legally be done over here.

But you would find a downside of this area – latest when you drive to a gas station for the first time and you find out, that you have to pay $ 8,50 per gallon of fuel.

later

When I bought my Fiat years ago, it had a manual throttle that you pulled out and twisted to lock in position, kind of a poor man’s cruise control. The joke was that the way Italians used it was to pull in out and bend it down!

Fiat – that brings back memories!

When I was 14 years old, my aunt wanted to get rid of an older Fiat 500 ( 2 cyl, 500 cc, 18 hp), that she had used as a motorized shopping cart for several years. I asked her whether I could have it and she gave it to me (for free!). I spent more time working on it than driving with it (on our private grounds). I found that very interesting.

At that time I also had an older motorcycle (250 cc Triumph), which I had bought from someone in a neighbouring village (converted for about $15). I rode around with it on side roads in the countryside where I grew up.

I was very bad at school at that time!
Very often I was sitting in the classroom and wondering how I could repair or improve things on the motorcycle or the car.

At 14, my twin brother and I (with Dad’s welding help) mounted a mail-order 55cc Hodaka 4-speed engine in a Whizzer motorbike frame. Here’s a (bad) old photo of us on that and a 125cc Ducati (right). Luckily, we had a farm behind us where we could ride.

@ insightful

Hey! – you and your brother looked like you were very good at school at that time, in contrast to me!
Hahahaha…

If you would have lived in the area where I lived we would certainly have known each other at that time. All teenage gearheads knew each other – and we were many. Something I always enjoy remembering.

My first motorbike that I could legally ride (up from the age of 16) was a second hand 50 cc, 2-stroke, 3-speed Zündapp.
But then again it was only legal for 2 or 3 weeks. It had only 3-point-something hp and an offical top speed of 25 mph. The insurance of that kind of motorbikes was quite cheep and all I could afford at that time.
The performance of course was something I couldn’t accept. Among other things it was clear that it needed more compression.
So I clamped the cylinder head in a vice and ground off 1/10 of an inch of the combustion side with a hand grinder. I gave it the final touches with sandpaper (first rough, then fine and wet). I put the sandpaper on top of a thick glas plate, took the cylinder head in my right hand and moved it in circles over the sandpaper. It took me more than 2 hours until the surface was as plane and smooth as I wanted it.
I installed it back on top of the engine and tried to kick-start it – but the kick-starter could only be pushed down a short way until it was stopped with a “click” sound.
Right - the piston hit the combustion chamber wall in the cylinder head.

So the next day I brought some chalk from school back home, took the cylinder head off, coated the top of the piston with it, put the head back on, marked the combustion chamber wall in the head by pushing the piston against it and ground off some material at those spots. After 3 or 4 repeats the piston could move freely.
Luckily the engine was equipped with the same crankshaft, conrod and piston as the stronger version of the 50 cc model - that way it sustained the higher compression.

Together with several other modifications (exhaust pipe, carburator, output and transfer ports in the cylinder, bigger sprocket at the gearbox, smaller sprocket at the rear wheel) finally I had it the way I wanted it – on a flat route with a little tailwind and the chin on top of the fuel tank cap it had a top speed of almost 75 mph.

Times have certainly changed:
Today I have a problem with a slightly shaky idle.
When the performance of that 50 cc motorbike was satisfactory to me, it didn’t even have any idle anymore – I had to keep it alive with the accelerator throttle. But that was a price I payed with pleasure.

you and my son would like each other very much. ever since he was a boy and I came home to find him riding a bike with 2 frames and 3 wheels around he has been modifying things to suit himself. next I came home and found a huge compressor motor bristling from his go kart . the thing was so scarv fast I had to ban it. luckily it blew up when he was demonstrating it in an effort to change my mind. it has continued til now. last week he traded his 883 Harley Davidson for a 1980 trans am with a 406 cu in motor. I was happy to see the bike go. even tho he drives conservatively, a bike, to me, leaves you too vulnerable to bad luck. he hit a deer with the bike a couple months ago, and even tho he managed not to wreck, I think it scared him, thank god

he is a true gear head

@ wesw

Yes, I sympathize with the young gear heads. The son of one of my friends is also one. Everytime I come to their home, the first thing he wants me to do is go to the garage with him where he shows me the newest modification to the go kart which he has built together with his friends. Sometimes his friends are there too – than it’s shop talk time!

20 years ago I once went to watch the professionals race on Michael Schuhmacher’s father’s go kart race track, which is less than 30 miles away from my home town. The acceleration and the cornering speed of these karts were really impressive!

You’re right to be glad that your son’s bike is gone. I also suffered several injuries during my motorcycle time, but I guess I was lucky compared to others in my environment who got severely injured or even died.

A 1980 trans am – isn’t that the model which Burt Reynolds used in his cannonball movie?
I hope it’s still in good condition after 34 years!
A 406 cubic inch engine - probably one of the last trans ams with that big engine, right?

My feeling is that connecting a vacuum gauge to that Benz is still the way to go.

I think the Trans Am in the first movie was a 1976 or 1977 model and a 1980 model in the later movie.
The first engine was a 403 and it’s actually an Oldsmobile engine; low on horsepower but did have some low end torque. GM was mixing engines up a bit back then and my parents even had a Chevrolet station wagon that had an Olds engine in it.

The 3.8 six cylinder in the 1996 Camaro that belongs to my oldest son is a Buick engine actually.

Call me oldfashioned – but I still like the cars of the 70s and of course also of the 60s and some of the 50s. They had their own style (outside and inside). Today you have to look twice to find out whether a new car model is South Corean or Bavarian.

Take the sporty cars like Shelby Cobra or Corvette and also many of the comfortable big road cruisers.

In the mid 90s I was very close to buying a really very good Ford GT40 replica from an elder guy here in Germany. He knew everything about the GT40. When I told him that I have intense memories about being close around the GT40s and it’s drivers Phil Hill and Dan Gurney in the padocks and the pit lanes as a young boy in the 60s, he said he wants to see the car in my hands, emphasizing that by reducing the price without my negotiating.

My mind kept spinning around that idea for 2 weeks, finally I thought I shouldn’t because I knew that - not being a production car - it takes a lot of service time, which I didn’t have at that time.

I’ll never forget the test drive … very prominent nice V8 sound inside, impressive acceleration (350 hp), very light (2100 lb) … but a car with a hight of 40 inches really has it’s disadvantages in traffic, forget about looking through the windows of the car in front of you … and of course forget about comfort … but what a pleasure!

It was a real beauty, built with lots of love for details! From 20 feet away you couldn’t tell whether it’s an original or a replica.

I just took out the spark plugs. Here’s a picture of them. (First cylinder on the right)

I cleaned them 3 days ago.
Since then the engine has run for about 2 hours, mostly in stop and go traffic and at idle, never above 2500 rpm.

If you let the light reflect on the front surface, it looks a little more shiny then on the picture (like glazed).

Maybe you guys can read their appearance !?

It does look like you’re getting some oil on that #1 plug. If you put a new set of plugs in, do you get the shaky idle immediately? That black #1 could be the cause of a misfire or the result of a misfire. If the idle is shaky immediately after startup with new plugs, it’s more likely the misfire is causing the fouled plug. Note, I said NEW plugs. Cleaning plugs many times still leaves the ceramic somewhat conductive and likely to misfire.

Here are 2 more pictures I took inside the house with a flashlight before I installed them back. They may show more distinctness than the one I took outside before. I took them from both sides.

The spark plug of the first cylinder is at the end of the wood.

When I took them out, #1 was wetter than the others, but that wetness vaporized within 1 minute.

I want to get NEW plugs tomorrow, and I want to try NGK instead of Bosch.

Thanks for showing the other sides. There’s less variation than I thought. I hope the new set makes a noticeable improvement.

I can’t get that hydraulic lifter of the first cylinder’s intake valve out of my head – if that is the noisy one, which I think it is.
As I already mentioned: if that valve doesn’t open completely because of a (partly) collapsing lifter, maybe the intake gas can’t properly fill the combustion chamber and can’t be ignited properly.

The wetness of plug #1 vaporized like fuel. I forgot to smell at it.

That spark plug was already less clean before I installed the new injectors 3 days ago.

A local guy here used to own an original Ford GT40. He was out of town one weekend and some acquaintance borrowed it according to the paper. The car was then taken out about 10 o’clock one night on an arrow straight, 8 mile long deserted stretch of blacktop.

The car ended up traveling over a 1000 feet end over end; tearing out shrubs, small trees, and a lot of cattle fencing. The car was demolished, the driver was pretty much unscathed, and never prosecuted for anything; not even a speeding ticket, etc. The state patrol issued no tickets because they “estimated his speed at the time he lost control to be about 35 MPH…”. Ha.

That car was sold a few times and I think it has a home now in England after restoration.

Yeah – the mid 60s through the earlier 70s brought up some outstanding race cars, the GT40, Lola T70, Ferrari 512 and of course the unforgettable Porsche 917.

Many car guys may not know what I’m talking about, but I’ll never forget spring 1969. I was 12 years old. Porsche had announced to debut with the 917 at the 1000 km endurance race in Spa, Belgium that year (20 miles away from my home, at that time it was 8.7 miles long, for me the most beautiful race track ever, and I’ve seen many, the furthest from my home being Laguna Seca).
My father, my brother and I witnessed the first 917 race track roll out (it was the “long tail” version).
We were sitting on the grand stand opposite of the paddock from early morning on to watch the first practice – and then it happened: suddenly we heard an impressive sound coming from the paddock, a sound we had never heard before – a 4.5 liter flat 12 air cooled engine with 520 hp. Half an hour later it rolled out onto the track (in pure white). Remember what cars we were used to have around in 1969 – and then this “thing” came on! O boy - thousands of people were deeply impressed that morning.

Then in 1970 Porsche came up with the “short tail” version of the 917, this time with a 4.9 liter engine with 600 hp and it was bright blue and orange (the “Gulf” colors). At Spa, Belgium it took Joe Siffert & Brian Redman with their 917 less than 4 hours and 10 minutes to finish the 1000 km race (617 miles!, it was 1970! and the race was partly wet!).
That car - besides several girls at school – blew my mind! It was the most beautiful and phenominal thing on wheels I had ever seen.

Okay – time to snap out of that memory, I’ll go and get my new spark plugs now. I’ll report later.

sorry its a Z 28 not a trans am, and the 406 is some type of high performance engine, not sure if its original or not. it is beautiful though. the paint job has faded away but the interior is nice. I know burt Reynolds drove a trans am in smokey and the bandit, not sure about cannonball run.

and good thing you got the Mercedes and don t have to spend all that time servicing it :slight_smile:

my pet car is a 1975 ford f100 supercab. but my dream car is the 1966 442 Oldsmobile with 400cu in engine (w-30 package) of which only a few were made and that my dad had when I was a boy

Okay – I installed the new plugs (NGK “BP 6 EFS”).

The cold engine started at the first turn and behaved well.
But during warming up with it’s slightly higher idle the engine wasn’t shaky before either.

When the engine reached it’s regular operating temperature (after 2 miles) idle was shaky again, however a little bit less than with the old plugs.

So – insightful – it’s difficult to tell, whether the new plugs brought an improvement to idle immediately after the first start.

Above idle the engine was and is a dream. Flawless up from the moment the wheels start to turn.

Now after 15 miles of very modest driving mostly in urban traffic with many red traffic lights, I took the plugs out again to check them and show them to you guys (pictures taken from 2 sides).

db4690 – you asked me, whether, while the engine leaks oil, it also uses oil?
And insightful also mentions oil as a possible suspect.
As you know, I can not see any blue smoke coming out of the exhaust pipe.
But maybe there is a little oil involved - more in the first cylinder, less in the others.
The plug at the end of the wood is the one from the first cylinder.

What do you guys think about the plug appearance?