2004 C220 CDI Disable fuel for compression test

[paulca]

Hi Guys, I need to do a compression test on my C220 CDI ... what's the easiest way to disable the fuel ?

 

[paulca]

Actually , I could do with some advice on diagnosing the problem. The car suddenly lost power, lots of smoke, and a horrible rattling sound from the engine. I've checked the turbo , and it's fine, then I remembered someone once told me how a drop of water could blow the tip off the injector which will rattle around the cylinder , sometimes doing lots of damage, sometimes not. The car sounds like it's only running on 3, so my plan was to test the diesel return flow to see which injector was knackered, then do a compression test before replacing the faulty injector. Just had a look , and the glow plugs look like a pain to remove, lots of bits in the way, is it possible to do the compression test in the injector hole ?

 

[umblecumbuz]

Whoah there.

It will pay you to get the car hooked up to a good scanner, or better still, Star.
Get the codes read before taking things to bits - there are several possibilities for your problem, and an exploding injector tip is way down the list.

 

[paulca]

There's no error codes on the dash , would you normally get an error code if one injector was faulty ?

 

[mersum1es]

dash shows no such errors... only EML may pop up...

like said star gives nice test procedures. Unplugging injector connectors (THAT may give engine light on dash) prevents spaying unless injector is jammed and is ****ing... well possible situation and you have now hole in piston...

 

[paulca]

Thanks guys, I'm reluctant to spend much on it incase there's a holed piston , thought compression test would be the simplest way to check if it's worth replacing the injector. Cars prob only worth £1500 so if piston of heads kaput it's off to the scrappers. heres a little video , the rattling has stopped now, and to me it looks and sounds like an injector, lots of white smoke what do you think https://photos.app.goo.gl/bUjcmlkZN6qGjl4z2

 

[Steve@Avantgarde]

Just pull a wiring plug off the injector rail...

You can also do a compression test with STAR as well as test the injectors.

 

[paulca]

OK , so I phoned around for a mobile mechanic with a star tester, and I'm looking at £70 for him to come out and have a look.
In the meantime I started it up and pulled the connector off each injector 1 by 1. 1,2 and 4 all made the engine dip, and it revved up a bit when reconnected, 3 made no change whatsoever.So, I'm fairly sure 3 is the faulty one. BUT with 3 disconnected there was still loads of white smoke ??? So is 3 just jammed on p*ss*ng out diesel ???

NOW , I can get a used injector from ebay for £50, or pay £70 for a diagnostic..... dilemma.

 

[John Laidlaw]

£70 for someone to do a mobile STAR diagnostic is a bargain

 

[paulca]

Well I had a rush of blood to the head, pulled the glow plug, only to find my compression tester was the wrong size for the hole, so I thought sod it, and took the injector out too, the injector was incredibly easy to remove, just waggled it out with my fingers. if I put 12 v across the solenoid should I hear it click ? I've ordered a cheap compression kit off ebay, starting to think the head's gonna have to come off....but I'll wait till the compression kit turns up and check it first. Does anyone know what the compression should be on a 2.2 CDi.