Compression Gauge and fitting

[ANDYD]

Hi,
Does anyone out there happen to have a Compression Gauge and the fitting to screw into the glow plug hole on a 300TDi Diesel that I could borrow. Need to confirm the compression on each cylinder,
What is a typical compression range I should be seeing on each cylinder?
Cheers,
Andy

[swamijake]

I've got a diesel compression gauge with a kit of adapters. It is buried at my parents place. I'll dig it out this weekend.

I seem to recall that pressure should be 450 to 500 psi. Also, pressure variation between cylinders is important as it will affect the timing of injection.

[ishapiro]

I am not sure if these are the correct figures for 300tdi.

See this:
http://forum.difflock.com/viewtopic.php ... 342ca298ba

[red90]

From the genuine workshop manual.

1. Start and run engine to normal operating
temperature.
2. Switch off engine.
3. Disconnect spill return hose and fuel pipe from
No.1 injector.
4. Remove retaining nut, release clamp and
withdraw injector from cylinder head. See FUEL
SYSTEM, Repair, injectors
5. Disconnect electrical lead from fuel cut-off
solenoid at injection pump to prevent delivery of
fuel to injectors. On vehicles fitted with a digital
diesel shut-off valve (DDS) immobilisation
system, disconnect DDS multi-plug.
6. Ensure injector port is clean, If necessary, crank
the engine a few revolutions to remove any
loose carbon.
7. Fit dummy injector, from diesel compression
tester kit LRT-19-007, into the cylinder head and
clamp securely in position.
8. Connect flexible hose and gauge to dummy
injector as shown above.
9. Crank engine for 10-20 seconds and note
reading on gauge. The gauge will indicate the
compression of the cylinder and maintain the
reading until the pressure release valve on the
gauge is depressed.
Expected readings of a crank test, with vehicle
battery fully charged, compression ratio 19.5:1
should be 24 bar (348 lbf/in2).
10. Repeat test procedure for remaining clinders in
turn.
NOTE: A variation in compression
readings between cylinders is often a
better indication of an engine problem
than the absolute values of compression.
11. If compression is appreciably less than correct
reading, or varies by more than 10%, piston
rings or valves may be worn or damaged.
Low pressures in adjoining cylinders may
indicate a faulty cylinder head gasket.

[red90]

You can download the manual here: http://www.landroverweb.com/landrover/p ... r-manuals/

[ANDYD]

Thanks, if you can dig that gauge out it would be appreciated. I have a petrol engine gauge that goes to 300 psi but doesn't have any small adapters that would fit into a glow plug thread.

John, thanks for the info, there are more steps than I expected.

Cheers,
Andy

[swamijake]

I wouldn't bother with pulling the injector as long as this kit has something that fits the glowplug. Then you have to go to all the trouble of bleeding the fuel system.

I'll let you know when I find it.

[red90]

Then you have to go to all the trouble of bleeding the fuel system.

The TDIs self bleed.

As noted in the other thread, if you use the glow plug, the readings will be different than the injector method. You are more concerned that all readings are within 10% of each other.

Be careful removing the glow plugs. They have been known to break their tips off, leaving it in the head.

[swamijake]

I broke a few glow plugs in an old volvo marine diesel I was working on. My solution was to turn the engine over to pop the tips out. I was lucky that they came out instead of dropping in.

[swamijake]

Hey Andy,

I found the compression gauge if you need to borrow it. Shoot me a PM and I'll send you my phone number.