RIP CM2250, 2013, 800,000km 20,000 hrs

[Rawze]

(06-14-2022 )Hermjeji Wrote:  So.

Head #6, new actuator, new fuel pump actuator housing, new fuel pressure relief valve. After 12 hours of operating, started losing power again. It's failing the leakdown test now, but it can't make pressure above 20,000 psi. No visible leaking on the top of the head yet, but I assume another several hours of running and it would start.

I am getting an odd ticking sound coming from the main rail line (also when the key is turned on, it takes a while for the usual ticking noise of the pressure being built up to stop). I'm going to pull the valve cover off, and see if something else is going on (also due for an overhead). But, could anything on the top end be causing these repeated fuel pump heads to go? I don't know what to do at this point.

I would not think so, but one never knows in an odd, extreme case like that. Maybe a severely leaky injector with its internal check-valve failed, back-feeding cylinder pressures into the rail?, but that would also mean it fails a leak-down test.

It almost sounds to me like bad fuel.. or contaminants keep getting in .. perhaps something letting coolant in the fuel, air, something causing repeated pump failures.

Otherwise, fuel pumps do not just fail over and over completely on their own unless someone is using aftermarket (or the wrong ) parts in them.

Are the bottom of the fuel tanks clean and free of coolant, moisture, etc?. upon inspecting them with a bright light?

Does the commanded fuel pressure vs. the measured show a higher pressures than commanded?. and/or when test driving it at high engine loads?

Also, make sure the ecm does not have a crappy delete program in it. It could be over-working the pump .. that can happen too, but I doubt even that would cause failures so often.