Help for pistons E350 4Matic
 

I have ordered some parts from parts.com, but I have an issue to try to buy a pistons for my E350 4Matic 2.006. This mail sent from parts.com:

the parts you want to order need the engine taken apart and mesured to see what size you need, this information I can not get from the vin number. The cylinder bores need to be measured and any marking on the pistions need to be sent to me as well. Then we can get your the correct prices and parts to fix your car.

So please anyone can help to tale this orden close and fix my car.

Thanks in andvanced...

I would guess they are concerned that the engine has been repaired in the past and the bore is oversize.

I am doubting that MB engines leave the factory with other then standard spec cylinder bores. (But I am guessing on that)

Have you torn it down yet? How do you know you need a piston?

I need all pistons, because one rainy day came in water inside to engine and other parts are damaged, too. For example a rod.
Its never been repaired the pistons or engine before, I bought it with a carfax historial.

If you torn it down, measure the bores and check against spec.
Are you going to need to machine any of the bores?
If you bent a rod, also check the crank, it might be twisted.

You are right, they are many parts I had to buy.Its a list of 9 items, almost 3K $us. 😭

Given the age of the car, it might be better to drop in a used engine.


Looks like used engines are $3k to $6K (4-Matic) (less if not)
Does anyone know what is different about the 4-Matic engine?
If it is stuff like oil pan and such, you can buy a RWD engine and swap parts off your engine.

How much water did it ingest?
How is the rest of the car? There are a LOT of electrical connections in our MBs that don't like soaking in water.

A used engine price depends on the country you live. If you live where that engine and model year is popular it might be easy to buy a used engine otherwise a rebuild is necessary if water ingestion happened. But be sure to check and replace rods that are bent, checks heads for cracks.

I had not considered that saulv might not be in the US.

there are various piston sizes for proper clearance to various bore sizes. we are talking thousandths here.

without measuring, they won't sell you a piston.

Every engine I have rebuilt used either standard size, or a specific overbore (i.e. 10 thousands, 20, 30, 40), not some you have to measure it specification.


On overbore blocks the pistons were stamped with the size.

You are right N_Jay I live outside of U.S., I bought it from U.S. the car with carfax, etc. I live in Bolivia,SouthAmerica. I had already the size but in mm(milimiters) is the international messure size we use here.

I would guess the standard specification in also in MM.
Not sure what the standard overbores are for metric pistons and cylinders.


Guessing it is 0.5 MM as that was the increments in Porsche pistons back in the day.


Did you buy it with the bad engine or did it ingest the water when you were driving it?

nah, so there are typically different grades of standard sized pistons to get the piston/wall clearance to MB's spec. The difference between them is very small, but can put things at either the very small or very large end of the the tolerances whereas they would like them in the middle.

So, to help saulv out,

How are they typically marked?
What should he be looking for on the existing pistons to tell the supplier what "grade" designation he requires?

When I was driving ingest water,but in the wokrshop clean,take out water and its ran but it sounds very rare,so they took away all the engine for the pistons,rods and others parts they have to replace to be perfect.

Also, I sent messures and pics of the piston, inside it has some numbers like codes.So, hopefully with pics and messures I sent can handle and send me the exact pistons.