Hey so I am completely lost on this problem first time owning a duramax. I have a diesel leak that’s puddling in my engines valley and I believe it runs down and leaks off the bell housing, it only starts to leak when the engine is up to operating temp and it leaks quite a bit I took off the alternator and stuff to look down in the valley more and I replaced the fuel pressure sensor and when I was doing it it looked the cp3 was wet and there was a short hard line that was wet and then obviously the valley was all wet. Can anyone tell me what they think this might be?
Diesel leak
- Thread starter Brennan123$
- Start date
Going to be hard for anyone here to see the leak and pinpoint it for you. You can try cleaning everything up and seeing where it starts getting wet first.
My guess would be a leaking rubber line. But that would probably only happen if you have a lift pump. If not then start looking around the metal lines and fittings. Another posablely is the gear pump on the back of the CP3. It is sealed to the CP3 with some O rings. But this is something you're going to need to do the work on.
Photos might help if you can clean out most of the diesel and dry it. Then watch where it comes from. We can help diagnose it for you
Also moved your thread to the fuel section
My guess would be a leaking rubber line. But that would probably only happen if you have a lift pump. If not then start looking around the metal lines and fittings. Another posablely is the gear pump on the back of the CP3. It is sealed to the CP3 with some O rings. But this is something you're going to need to do the work on.
Photos might help if you can clean out most of the diesel and dry it. Then watch where it comes from. We can help diagnose it for you
Also moved your thread to the fuel section
You didnt include what model Duramax you own, but doesnt matter: Its one of the rubber lines. Time to replace them all. Rubber does deteriorate.
I don’t have a lift pump everything about this truck is stock i believe
Will I even be able to see any lines that could be leaking around the cp3 if I have it running because then i think I’ll have to have it running to see the leak because it only does it when it’s warmed up
You can run the engine with a handful of items removed. Like the intake, coolant crossover tube, etc. but keep the fuel and electrical connections and only run it for a short time as needed to see the leak. I think you might be able to put the crossover tune and coolant lines back on and still see the CP3. But it's been a long time since I've done it on an LB7