I have never tested compression on one of these new fangled diesels and am at a loss how to execute the procedure.

Connecting the tester is no biggy but how do you get the car to open the intake valve and spin the engine for testing without actually starting it. I could connect a remote start easy enough but that won't open the intake. The Jaguar manual says to disable the injection system but offers no clues how this is achieved.

Is this information available in live data anywhere - I am trying to assess the engine condition ( a 3.0 V6 306DT) as it has passed 190k miles, don't want to blow money I don't need to fixing something that isn't broken givn that I have a number of things that do require attention - but once the money is spent it will take a while to accumulate funds for further big jobs so I'm trying to prioritise.

 

Hi,

Newer measured from Lion V6 (AJD-V6/TDV6/DT20) engine, what we have under hood, but since the high pressure fuel pump are mechanical and it is not advised to rotate it when dry, the only ways come in my mind are: Remove fuel pump belt (quite some work and pump have to be timed afterwards) or rotate the engine directly from starter motor solenoid. The anti-thief system build in to the high pressure pump should not enable fuel to the engine.
For unrestrict air intake, just jam the throtle valve open or remove whole throtle body. Renew the O-rings in same go and clean the body.

 

I was hoping to find a way to get the systems to do as they should but not enable the injectors, perhaps the crank sensor, the immobiliser prevents cranking I think. I could pull the fuel relay and that would prevent the low pressure pump but as you say I'd rather not put an insanely expensive high pressure pump at risk.

As you say I can turn the engine over using a remote starter, the throttle valve is actually not a throttle it's an air valve and seems to be spring loaded - would be a bad day if the item propping open the valve disappeared into the intake - just seems like a lot of messing.

The advice from Jaguar is not to operate the system with injectors disconnected (they are pretty high voltage items - 160+ volts) and ECU damage could be the result - not sure I want to experiment with that either.

I had a poke around in SDD but there is nothing obvious jumping out to 'disable injectors' - not saying their isn't one but SDD isn't the most intuitive application in terms of where things are.

 

Hi,
Correct, the intake butterfly valve are more airvalve on diesels (if any) than throttle. I quess you are going to measure the compression from glow plug holes anyway? For access to the glow plugs, you need to remove the throtle body anyway. (glowplugs sits in the valley of the V)
Agreed. The voltage on injectors are high and not recommend to operate them disconnect. Crank sensor are in difficult position behind of the engine. Propably need to remove left side turbo for an access.

 

The glow plug holes is where I planned to test yes. I also planned to do a leak down test.

The objective is to assess the engine condition overall, there is no headgasket issue. The engine has 190k miles on it so I want to know how much life is potentially left in it and where it is worst. I have already obtained 2 complete heads, 2 turbos, 6 injectors and a high pressure fuel pump for the spares box - all have a verified 27k miles on them and the condition they are in also backs that up. All I really need is to identify the condition of the bores really, I'm not going to replace the heads without good reason to do so but I may replace the injectors and the turbos though and probably throw upgraded intakes on there while I'm at it.

I wonder if removing the air valve removes some status indication that the injectors need to trigger?

Hence I want to run some tests.