No compression in piston 3

Hello my 2006 4 cylinder lost power on the freeway and wouldn’t go over 20mph, towed it to the shop and he said it’s got no compression in cylinder 3 and is saying it may need a new engine. I’m wondering if anyone has had this happen to them and did you really need a new engine? Can’t he just replace that one piston ?
It also runs hot an burns oil and makes a preignition pinging noise
Any info is much appreciated I’m super worried I’m gonna have no car , the mechanic is going to take it apart and find it out this week hopefully

 

I'd say shes done.

Reman or junkyard pull engine

 

Could just be a blown head gasket

 

I wouldnt think a head gasket could allow 100% compression loss

At least I've never seen it

 

Might’ve cooked a hole in the piston if it’s been detonating for a long time

 

Your best and cheapest option is to swap a junkyard motor in

 

Replacing just one piston is an utter waste of time unfortunately

 

Could be a stuck valve. If the valve stays open you won't build compression.

 

Did your mech put a camera down into it?

 

Especially if it goes through the piston.

 

Take what apart?

 

This.

Or your crank is done, which would lead to loss of compression which would lead to total loss.

No compression is different from a seized piston. Which may be from a head gasket. Done.

Or it could be a million other things and be fine.

 

If the valve is stuck open, the piston will destroy it. I guess it could be stuck open a thousand or two and it might not. But...

 

No compression can mean a lot of things. I had a Volvo that lost compression in one of the cylinders. Was caused by the end of the spark plug breaking off somehow and destroying 2 valves. No damage to cylinder wall or piston. Did require a new head though as the valve seats were toast.

Pull the head and see what you've got.

 

A lot of times it will blow between two cylinders and you lose compression on those two cylinders, however I have seen the gasket material act like a valve and open one way and close back to seal the other cylinder. A borescope would be handy about now.

 

https://youtu.be/xm3UUVIPdMk

Edit:

No, this one:

https://youtu.be/hpcudSBLaqc

 

Are these zero clearance engines?

 

Causes of lost compression ....

Blown head gasket

Burnt valve

Stuck valve ( from piston to valve contact or worn / damaged valve guide)

Hole in piston from contact with valve or burnt piston

 

If a compression test is the only test the mechanic performed before stating that you need a new engine, you need a new mechanic.

 

Exactly