Bad Knock After Fuel Filter + Cetane Change - E450

[synetrics]

Ok...I'm putting the description back here because people are responding to this thread, sorry about the double post:

I just bought a box truck and it had the "water in fuel" light on. It drove fine, but had an occasional chug/lug and the "water in fuel" light would flicker. I went ahead and pulled the filter and drained the bowl. I was told to put some cetane booster in the bowl before I replaced the filter, so I did so and buttoned the whole thing up.

Well, I went to go start it and there was a really loud knock in the motor. There was also quite a bit of smoke coming out of the exhaust set-up, pre and post turbo like there was high exhaust pressure (i'm not sure if this was happening before the repair or not). I turned it over a couple more times thinking the cetane booster could be doing something funny and wanted to try and run it out, but the motor was knocking too loud and i didn't want to damage the motor. I've heard these motors can knock and ping and be just fine, but this was loud.

Questions? Would cetane booster in the bowl cause this scenario? Will it run through without causing any problems? Should I maybe open it back up and add diesel or ATF in the bowl? Is the seemingly high pressure in the exhaust (it has 188K and could probably use tightening on the clamps) a byproduct of the booster? Any advice or suggestions would be greatly appreciated.

7.3 PSD 1997 E-450 Box Truck

[snook2020]

I would try unpluging the Cps (Cam sencer)So the engine wilk not fire then turn it over for a few min to get the oct. buster out, then reconect the cam sencer then give it try. Hope that works ,

[snook2020]

I would try unpluging the CPS (cam sencer ) tune the engine over for a few mins. to get that oct. bust out . Then reconnect and ty it . Hope tha works

[dieseldan2005]

What engine? I would assume you have air in the fuel lines, but what about this cetane change? Did you add something like powerservice?

[synetrics]

I was told to put cetane booster in the bowl when i replaced the filter. So I poured some into the bowl and put the new filter in. I then buttoned everything, left the ignition in the on position for about 30 second and tried to start it. It's a 7.3 PSD. Is there a bleed off for the fuel lines? On the CPS, won't that just load up the motor and I'll still have the issue or worse when I try and start it? Thanks for the help.

[Tyler]

Originally Posted by synetrics

I was told to put cetane booster in the bowl when i replaced the filter. So I poured some into the bowl and put the new filter in. I then buttoned everything, left the ignition in the on position for about 30 second and tried to start it. It's a 7.3 PSD. Is there a bleed off for the fuel lines? On the CPS, won't that just load up the motor and I'll still have the issue or worse when I try and start it? Thanks for the help.

If there is a dead circuit from the CPS, the motor won't fuel the engine, because if it did... it would fire

[snook2020]

You can drain the fuel or oct bootser from the fuel fiter canister (water drain) You may air in the lines still let idle for a few mins. You can drain the fuel rail on the heads by lossening the bango bolts, the pasenger side it is at the back I would get from under the truck,the driver side head it is in the front you have to take loose the alt.\ power stearing braket, to get to it , the bango bolts take a 1/4 in. socket . the rest is in the injectors,the engine should work it way out quickly. When you turn the engine over with CPS disconeted . The will not start with CSP disc. because the control moduay should not let the engine build up high pressure oil for the injector to work . I hope you did not brake a piston with the oct. booster .

[snook2020]

I thank You Can get to the bango bolt on the back of the head on the driver side to drain the fuel rail , I know you can on the passenger side, there will be alot of fuel in them , you can try to get them from the top ,I have don it from under the truck on the passenger side before . Good luck

[synetrics]

Just in case this helps someone...

Cracked the fuel cap, loosened the banjo bolts...drained and reprimed...still no good. Ended up that the gasket for the aftermarket fuel filter was bad and wouldn't let it pressurize. I swapped it for the old gasket and she fired up and is purring smooth. Now it looks like I need a starter...it never ends.