Couple days ago, the engine begins to shake and the ligh on with the message down shift or stop. The cars was not able to run as normal.

A first responder mechanic said was spark plug but no, after some try outs was towed to the closer volvo dealer, they said the same. But now they said one of the cylinder is low compression then the engine needs to be replace!

We have a similar problem with a XC90 and just change ignition coils and install original spark plugs, the dealer does some reset and programming in the ECU ant all normal.

Could be the same? Because for me, it looks like the dealer wants the car due they are offering a used one by trade and loan… really?

 

If you have low compression in one cylinder - that will require major engine work. A valve job at least -

An ignition coil will not restore compression. Good valves and pistons (and a spinning crankshaft with the pistons connected) create the compression.

 

You’re right, but the engine behavior under this circumstances is different than the reason was take it at the dealer. Like I said, the engine messages a misfire sequence which is not the one related to a low compression, or it is?

 

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If you have low/no compression on a cylinder (possibly from a burnt valve) - the cylinder will not fire correctly and there will be a "miss-fire". ( fuel, spark and compression is needed for combustion)

 

Some 2016's were delivered with a faulty piston ring that, over time, could retain dirt inthe openings and starve the cylinder of engine oil. Suggest checking with your dealer to determine if your car's engine is listed by Volvo. Volvo knows which specific engines have the faulty piston ring. Even if the car is not still within the factory warranty, owner's have gotten Volvo to do the necessary repairs, although sometimes I've heard its by splitting the cost. I've also seen some talk about a class-action lawsuit against Volvo for this, but I don't think it has gone too far (I could be wrong). Of late, I've heard (don't know if it's just a rumor) that Volvo had offered, for some, to repair the engine even though it was out-of-warranty (could have been because the original owner had their car faithfully maintained by their dealership, as an example). Anyway, I'd suggest doing some research on this piston ring issue in other forums, as well, such as Swedespeed.