Different compression in the piston

No compression and no start with a cam sensor code makes me think that you have a broken timing belt. If true, there has been some engine damage. The pistons will hit the valves and cause bent valves/ holes in pistons.

-Low compression is always lost power.
there are few things cause this.
-Worn out piston ring.
-Worn out valves (Not seat properly tight)

Good luck

Mai

The compression ratio does not depend on the piston, it depends on the application.
Different engines/motors have different compression ratios.
This piston will fit more than one model year and application, so you will want to look it up by "what motor you are fitting it into".
However, this being said, TRW may very well have limits of compression their piston of that number will take.
All pistons are designed to meet certain criteria.
TRW alone might know their limits.
God bless your efforts.

There are 4 main possibilities:
- Bad Valve seats
- Bad compression rings
- Bad head gasket
- Bad piston.
If there is no compression as in ZERO on a compression test, I'd look for a stuck open valve or a hole in the piston.
A blown head gasket will give different symptoms depending on where it's gone. Look for water in the oil, low coolant level, pull the oil filler cap and look for water vapour.

When an engine gets hot, you must shut it off before it gets so hot that it begins to lose power. Sometimes this simply can't be done safely. Once the engine gets so hot that it shuts down, permanent damage may have be done. Bearing can gall, piston rings can break, piston crowns melt, but usually the oil breaks down and the main damage is to bearings and perhaps the crankshaft. Diagnostics would include changing the oil, attaching a good mechanical oil pressure gauge then spin the engine with the spark plugs removed to see how bad the damage is. If oil pressure is adequate, run a compression test. This should give you enough information to decide if the engine can be saved without a major overhaul. Low compression can mean blown head gaskets, warpped heads, broken piston rings, warpped valves, etc.

Truck is only twelve years old. How many miles? I would shop around for a replacement motor, changing the entire motor may be cheaper than rebuilding the old one. Get quotes.

what probably happened is that when your timing belt broke the #3 piston most likely hit the valves hence the lost of compression. you will need to take the cylinder head off and have it rebuilt.

Bent valves would be number one cause. Check the timing. If you lost time, your valves are tapping the pistons causing the knock. When the valves tap the pistons they bend and don't close all the way, so the cylinders cant make compression.

Hello, You can still have Ring issues with good compression. The pistons have different types of rings on them to do different jobs. The top rings are your power rings, the bottom rings are your oil rings.

The oil rings prevent the block pressure and oil slop from being drawn up into the cylinder. The piston creates a siphon action and the oil rings prevent the oil from climbing the cylinder walls. All it takes is for the rings to rotate around the piston and have the ring ends line up.

That is why you offset the rings on installation from 90 to 120 degrees. It staggers the gaps of the rings for a better seal. Now you can get oil vapor if the compression rings line up to allow compression into the crankcase through the gaps on the piston rings.

Sometimes the valve stem seals can leak and allow exhaust into the upper block if you have valves that are not seating correctly.

probly lost compression in some of the pistons, do a compression test on all cylinders