Detroit won't start when cold????

They are cam and crank sensors.

I had to replace them on a 14.0L once due to a no start (with code). You're suppose to replace them together. When one goes you buy both and put them in, thats what they told me a few years ago when that happened to ours anyways.

Also when I was replacing them top one (forget which is which) came out fine, bolt new one in. Bottom one on the other hand wouldn't not come out for the life of it. Ended up having to remove the oil pan and punch the old sensor in through the block and break of little pieces at a time until we could push the whole thing through. In was a major PITA!

 

The last one I replaced on a 14 liter broke off. I didn't have room in the shop so I did it in the yard and I did not want to remove the pan out there in the dirt. I worked with it for a couple hours and got it out. I was real careful trying to take it out it was just froze up in the cover so bad.

 

There was no hope of me getting the sensor out of the block without pulling the pan. I tried everything, pry bars, picks, vice grips and couldn't get it to move out at all. First bit of movement I got on it was when I started driving it inward in the block.

 

many years ago when my truck had trouble starting when it was off for a couple day's. shop put in srs & trs sensors. it made no difference. it was the fuel back check. I usually do not support throwing parts at a problem, but since the sensors are not expensive & if they have not been replaced in a while, I would replace them just for peace of mind regardless. on my ddec3 I just gave my freightliner dealer my engine ser no & replaced them. it could be the sensors. or maybe the wires at the sensors. check for frayed or broken. good luck & let us know what you find.

 

I kept PB blasting it. Let it sit. Twist it a little with vice grips. Spray... Twist... Pray... cry... beg.... repeat..

When I was prying on that thing and I heard it crack the feeling was rather bad. I know that they can break but I always try to work them slowly out and carefully. This one was just froze up so bad. Didn't really have a choice.

 

Had a check valve issue with the same truck (14.0L) few month later. It would crank for about 30+ seconds before firing

 

There is one thing that will keep the Detroit from starting, and that's the water level sensor. Check your water level and ensure that it's full. Then disconnect the sensor and put a jumper on the plug. See if that solves it.

 

That's only if the level sensor is set to shutdown, most that I've worked on the coolant level is set for warning only. Usually the oil pressure is set to shutdown, water temp to rampdown and water level to warning only. Any of them can be changed, but I think a warning for low coolant is all that is needed.

 

Just relating my experience with my S60 no-start and what fixed it.

I'm assuming that you haven't worked on his truck, therefore you don't know whether or not it's set for shutdown.

Dismissing possibilities based on assumption without investigation is one reason why needless time and money is spent on haphazardly trying to diagnose engine problems.

Make a comprehensive list of possibilities, start with the easiest / cheapest to eliminate and move on from there.

Testing this requires a single jumper wire or paper clip, and less than 5 minutes.

 

Good point it is an easy check. But If there is no code not sure it would prevent start up. For the time it would take to jump the wire it can't hurt.