Detroit series 60 15:1 issues

I have a 97 ddec 3, that smokes like a freight train on cold start up and it doesn't have to be that cold.
the thing will start and run perfect for a couple of seconds then start missing and smoking, untilo it warms up.
It didn't do this when new, but started after somewhere around 300,000 miles, overhauled at 1 million with no change. It is bone stock and the only time I can remember the ecm being messed with was when it was overhauled, they did the software (low nox) package.

Recently I have read that a restriction in the return line off the back of the head can possibly cause this? the reason I ask, is somewhere around the time it started this, I had to replace that line. I had to get a line built and it was a little smaller diameter in the fittings, or looked like it.

 

I don’t know, but there’s a restriction fitting on the return, set at 80 mm , I believed that controls fuel pressure in the head. I can’t imagine the fuel return line being narrower than that.

 

You are probably right.
I knew there was a check valve, did not notice about a restriction valve.

Mine sounds and acts like the timing changes a few seconds after startup, it will do this anytime it is much under 30 degrees. I have tried to get detroit mechanics to find the problem, they always tell me to make sure exactly what it does and when, then come back. I always tell them I just told you exactly what and when it happens. lol

 

Mine, ( and my last Truck) , both had a lo nox OH. I never noticed a difference. But they were reflashed, I’m sure. Both Trucks start up, and about 20-30 seconds later, you hear it increase idle, and start making a God awful fuel detonation sound. Till warm. The white smoke, is usually there, but minimal, I always figured it was Due to the fuel itself being cold,Until the return line gets the fuel in the tanks warmed. A Detroit, once it’s started, usually won’t gel up. Always a rough start when real cold. I’ve noticed my neighbors Trucks, same engines, but 97 models smoke and choke, like my old Cat, Mines getting an OH now, w/ original style forged 16.5:1 pistons. Maybe it’s just a 15:1 problem? I’d like to know. I think you need to change the rods to use 16.5-1 pistons, along with the snap ring wrist pins. I just read what year, the blocks are drilled for squirters, and capped on non premium engines. (PK and BK). But I think it was on later, 97 or 98 blocks. Having 16.5-1 pistons without squirters might be a problem, as they need to be cooled. 15:1 cast piston tops, not so much. Let us know.

 

They all do that, it’s normal, but why? What the h### is it? Lol

 

Mine did not act like this when new, this started somewhere around 300,000 miles or a little more, and smokes plenty enough to be embarrassing.
It would miss and beat and bang, to where you thought it was going to disentergrate, when new, but it had to be below 0 for it to do it then.

 

I found a reference, claims that as of May ‘ 98 they started drilling blocks for cooling nozzles, and are capped on non premium engines

 

This is what mine does, except the white smoke in cool weather is terrible, at least to my way of thinking.

I do not know about the fuel warming up thing, but a few years ago we got in some 72 below temps at Tok, and the detroits started knocking even though they were warm. A quart of tranny fluid in each tank quietened them right up, and you would have thought a rod was coming out the side before we added the fluid.

 

I’m planning on being very diligent on 15 k oil changes, and fuel conditioner, after the OH. Not sure what to use. Trans fluid, ( not red type Lol) . Or 2 stroke oil, maybe. Not interested in expensive snake oil. Maybe Power Service, by the case. I want to keep injectors and rings clean, and sealed up. Need to get my home made APU put together.A pint of trans fluid, in each tank. Old Timers used to swear by it.

 

trans fluid is garbage in the newer motors be better off peeing in the tank