6CTA-M3, 8.3L, Diamond – injector pressure

[Paul Hampton]

Hi Guys
I recently became the proud owner of a cracked exhaust manifold, got me stumped how it is cracked! This put coolant
Into no 6 cylinder.

Now that I have the injectors out, should I get them tested?
Also while they are out, I read on other forums about increasing the pressure, but I am not sure if this only applies to the 5
Hole injectors. Mine are 4 hole I believe, s/n 46029990, cpl 2172. They are stamped 260bar
If it is advisable to increase the pressure, for cleaner running and less sheen, what does it need to be ?

Thanks and regards
Paul

Topic

[Paul Hampton]

History

A little history
I got the boat in 2009 with 50 hours, launched in November.
in early 2010 I was out and the coolant pipe blew out of the back of the block.
I saw steam, stopped and shut down, it got the turbo hot enough to take the paint off. ( you won’t recall it ) both you and Paul Foulston kindly took time to advise me on what to do and check on another forum (BD)

I had no symptoms of cracked manifold or head, no bubbles in header, fitted alarms and fitted a new clamping plate that retained that coolant pipe to the block (it was never fitted at the factory) that pipe is a push fit with a oring seal.

The guys I bought the boat off hadn’t put the boat or engine in the water, so the initial 50 hours I have no idea of, but that engine was pristine.

The boat has never missed a beat until 2000+ hours later.
The engine did not smoke but had slight sheen out of exhaust.

Last summer when I was out I pulled up as I normally do and after a minute the exhaust started bellowing whitish smoke for about a minute, then cleaned up on idle, this happened a few times with slight coolant loss in header tank.

Because of working overseas I went away and when I came home, I tried to start the engine, normally it is instant even after standing 6 weeks or so, this time it stuttered to turn over, I stopped the start up. I never got it fired but it turned maybe 1 or twice.
I checked coolant in header and it was empty, over time it had drained through the manifold. I thought it may be the gasket on the top of the manifold or turbo, when I opened it up, I could see the coolant.

I changed both gaskets and refilled with tap water, this drained fairly quickly
Injectors out and 5&6 had coolant inside.

Dropped the oil, drained all coolant remaining, vacuumed each cylinder through the injector bore, turned the engine to fire excess water out, new engine oil & diesel 50/50 mix in each cylinder, turned / barred the engine, then I had to go away overseas again.

Came home 12 weeks later, poured new oil into tappets , barred the engine sprayed wd40 in each cylinder, manifold off.

This is where I am.

On the injectors, all I did was remove them, I haven’t had them checked, maybe I should ? But while they are out do I check/ set to the 260bar or increase the pressure as I mentioned in my op.

Thanks again for your time

Paul

[Paul Hampton]

Crack 3

Last shot

[Paul Hampton]

Internal crack

Sorry I’m on this crap iPhone bear with me

[Paul Hampton]

Hi Tony
It’s cracked between 5&6 internally. I blanked the turbo off and filled the coolant side with no pressure, prior to an air test. The water was weeping out. See photo.

What I can’t understand is how it has happened, I am propped to 2700 loaded with 9 people and full fuel. However I would max out with 6 people, never go above 2000 and cruise At 1900 which is sweet spot. Water Temp never rise above 85ish, egt runs 875, boost around 10-12. The only time it went above 2000 was to go to WOT for a minute or 2 when I was alone coming back in one day.
High idle 3020
The rpms are photo tacked against the vdo tach.
I have tested the hx while it off and no leakage
I have done my Aftercoolers as per your way 5 times in 9 years and 2000 hrs.
I have checked valve lash 4 times over that period.
I have a 10” dry swan kneck exhaust (maximum) with exhaust water exit down hill. Turbo outlet was in good condition, with no signs of water intrusion

The engine seemed to empty the expansion bottle over 6 or 7 years but the header stayed full until last year.

I seem to get good flow through exhaust at idle but I intend to change the impeller while I am down, it has been in 7 years (your pump was fitted in 2010)

Paul

[Tony Athens]

You are sure the manifold in cracked? Usually from a overheat..

Injectors————have the set to the high end of the spec for your CPL..

Tony

[Author]

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