All but one at 300?....that's not bad. The one at 400 may just be carboned up.

__________________
[SIGPIC] Diesel loving autocrossing grandpa Architect. 08 Dodge 3/4 ton with Cummins & six speed; I have had about 35 benzes. I have a 39 Studebaker Coupe Express pickup in which I have had installed a 617 turbo and a five speed manual.[SIGPIC]

..I also have a 427 Cobra replica with an aluminum chassis.

so whats the consenses guys pull the head or mot? One more question does anyone know the part number for rebuild kit for injector kit for a 603 engine

For diagnosis, get some new injector heat shields, swap injector #2 with #6 and report any change.

"Permissible difference between cylinders: 3 bar 43 psi".

At 100 psi variation, five out of six are low, far past the Permissible difference between cylinders.

300 psi on a warm engine is NOT good.

IMO the cylinder head needs to come off.
* Check the head for cracks / warping.
* Replace the gasket.
* Check for bent rods.

.

__________________
ASE Master Mechanic
asemastermechanic@juno.com

Prototype R&D/testing:
Thermal & Aerodynamic System Engineering (TASE) Senior vehicle instrumentation technician.
Noise Vibration and Harshness (NVH).
Dynamometer.
Heat exchanger durability.
HV-A/C Climate Control.
Vehicle build.
Fleet Durability
Technical Quality Auditor.
Automotive Technical Writer

1985 300SD
1983 300D
1984 190D
2003 Volvo V70
2002 Honda Civic

https://www.boldegoist.com/

Couldn't it be gunked up valves not closing tight?

If this was an OM61x engine, yes.

IMO the odds are 99% against that with the OM60x engine.

.

__________________
ASE Master Mechanic
asemastermechanic@juno.com

Prototype R&D/testing:
Thermal & Aerodynamic System Engineering (TASE) Senior vehicle instrumentation technician.
Noise Vibration and Harshness (NVH).
Dynamometer.
Heat exchanger durability.
HV-A/C Climate Control.
Vehicle build.
Fleet Durability
Technical Quality Auditor.
Automotive Technical Writer

1985 300SD
1983 300D
1984 190D
2003 Volvo V70
2002 Honda Civic

https://www.boldegoist.com/

would it do any good to do a wet test and where would I find a good head at a reasonable price

Wet test is only used to confirm ring or wall is shot. It does not do any good.

I really do not think you have proved that the HG or Head is bad by giving us a bunch of compression #.

__________________
Not MBZ nor A/C trained professional but a die-hard DIY and green engineer. Use the info at your own peril. Picked up 2 Infractions because of disagreements. NOW reversed.

W124 Keyless remote, PM for details. http://www.peachparts.com/shopforum/mercedes-used-parts-sale-wanted/334620-fs-w124-chasis-keyless-remote-%2450-shipped.html

1 X 2006 CDI
1 x 87 300SDL
1 x 87 300D
1 x 87 300TDT wagon
1 x 83 300D
1 x 84 190D ( 5 sp ) - All R134 converted + keyless entry.

A wet test is to piston ring or cylinder wall damage, doubtful but remotely possible = the engine is essentially junk without $7000.00 USD repair.

On the OM60x engine with the known gasket / head issues I play the odds.
Worst case, you remove the head to find bent rods, scored cylinder liners = find a good used engine.

Best case, you find:
* Bad gasket.
* Bad valve guides.
* Bad valves.
* Bad hydraulic lifters.
* Head damage.

Mercedes Benz W126 Head 603 016 22 01 Turbodiesel Turbo Diesel OM603 300D 300SD | eBay

OM603 Head Replacements

.

__________________
ASE Master Mechanic
asemastermechanic@juno.com

Prototype R&D/testing:
Thermal & Aerodynamic System Engineering (TASE) Senior vehicle instrumentation technician.
Noise Vibration and Harshness (NVH).
Dynamometer.
Heat exchanger durability.
HV-A/C Climate Control.
Vehicle build.
Fleet Durability
Technical Quality Auditor.
Automotive Technical Writer

1985 300SD
1983 300D
1984 190D
2003 Volvo V70
2002 Honda Civic

https://www.boldegoist.com/