Yeah I got what you were saying with piston slap on start up (you’ve said it before) but it also seems that there can be lots of clatter related to faulty cams &/or followers
As far as piston slap is concerned, I wonder whether the Merc dealers warm them up prior to prospective purchasers doing their test drive like Holden seems to do
Also a little sad and odd that AMG engines produce big clouds of smoke on startup yet passed pollution laws… maybe lax test routines via regulatory capture at work
Morral of the story seems to be that poor quality NVH on startup isn’t uncommon but something possibly hidden by the sellers at purchase time via warming up the car up prior to a rest drive…
Seems misrepresentation lives everywhere and is as common as piston slap itself
At least Merc dealers have nice coffee and cakes on offer while you wait
They don't smoke as a general rule on start up, only when it self purges when the car has been started and stopped a few times in quick succession without travelling anywhere, it won't do it at all if the car has been sitting for a while.
The owner's manual explains why it does it.
If you are not someone like me who sometimes has to “
Ay Steve, can you move the Camira? I need to get the Torana out to get to the Commodore.” “Sure thing Dad, but I'll have to get the keys to the Cortina if I'm gunna move that Camira.” then you may never notice it.
My old 2010 is Euro 6 compliant, Holden could have learnt a thing or two about emissions.
AMG do videos of their engine builds and talk about tolerances and why they design them the way they do, AMG engineers will also answer owner's questions up to a point through their exclusive forum, you need to produce your VIN and details for verification through the MB database before they will let you join.
The first AMG I owned was an E63 and the vehicle I tested was sitting on the showroom floor and it took about half an hour to move other cars then they pushed it to the entrance before they started it cold, there weren't any others sitting around as it was a 7 month wait for the ordered car to arrive.
My first listen of a C63 was also of a car sitting on the showroom floor, the bonnet was open and the engine was cold, the windows in the showroom at Parramatta rattled when it started and everyone turned.
I came back for a test the next day and was not allowed to throttle hard until the car's internal warning system said the oil had heated to operating temperature, those cars back then were in hot demand and it was a 9 month wait to get one from Germany and normally a two week wait for a test drive as they were sharing the few cars they had around the Sydney dealers.
I got a next day test drive because one, I was already an AMG owner with my E63 and two, I made it plain when I finished there I was going across the street to look at the new M3.
When I test drove of the 2019 car, the car was waiting for me outside and partially warm.
All these cars made a noise on start up but MB didn't shy away from it, if you wanted one that's what you got, once they warmed up they were fine.
You don't hear much when you are driving unless you kick it in the gut and then it's the roar of the exhaust, particularly from the E63 and 2010 C63.
So if you wanted to ask a question on how does a car meet regulations then the first question you would ask is how on earth does it get under the noise laws.
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