Cat 3126 starter

[Willis Bushogin]

My friend has a GMC dump truck, with a 3126 engine. I dont have all the info, but here goes the question.
About 3 weeks ago, the truck wouldnt crank over, so he checked and found the starter bolts (2) missing, it still had one left, but it was loose. He installed new bolts, this lasted about 2 days and same thing. He had ordered Cat bolts, for the starter and he installed them (2) he found the top/BADDDDD bolt broke.
He installed the 2 new bolts with lock washers, he made it back to the shop and he started it a couple times and found the bolts loose again.
I have been messing with engines a long time and I dont think, I have run across this one.
Looks like now he has to pull the bell housing, to get the broke bolt out (this is not good)
I told him he needed to have the starter checked out, to see if it had a bent armature shaft
What do you think guys??

 

[willie59]

Did your bud make sure the nose of the starter is a proper fit in the hole in the bell housing? If it doesn't have a snug fit going in, all the pressure will be on the bolts.

 

[Willis Bushogin]

Thanks, Ill pass it on

 

[Willis Bushogin]

3126 starting problem

A friend of mine, has a 1999 (?) Sterling/Ford with a Cat 3126 engine. The truck has about 650,000 miles and last week it began having starting issues. When cold, it wont start without ether/starting fluid. I have read somewhere, about this problem, but cant remember the suggestions. He had the Cat mechanic hook the computer to it today and he couldnt find the problem. Both sensors were changed, before the Cat mech checked it, but the problem still is there.
Someone told him, the engine needed rebuilding, it might but why did the issue start all at once.
Any suggestions??

 

[John C.]

I don't have any experience working on these motors but we are changing seasons. 650,000 is a lot of miles for this little mill and a compression issue might not be seen in the summer but shows up when the outside temps starts dropping below 40 degrees F. in the fall.

Does this engine have electronic controlled injectors? How about a PCV valve? How much load does it usually carry? Does it work in city transfer work, agriculture or open highway? How much crankcase pressure is generated when under load. Are there multiple leaks all around the engine. What other work has been done to the engine over the years?

It is my experience that cold start problems are not caused by a sudden problem. They usually show up suddenly when the climate changes.

 

[willie59]

Also, does it have an intake heater that has suddenly stopped working?

 

[Komatsu 150]

Our 2000 Sterling with same engine has intake heater but a problem there should show up in the scan. I had understood that using ether on an intake heated engine was a BIG not to do.

 

[willie59]

I had understood that using ether on an intake heated engine was a BIG not to do.

That's my understanding as well, which is what provoked me to think it ain't working because willisbushog said his bud was using ether. Just a thought.

 

[superwrench0166]

injectors in the 3126 have a habit of going bad. they will not take water at all. The needle and seat inside will start leaking. cause low fuel pressure. will not start without help. low power. remember its a heui fuel system it requires oil pressure to fire the injectors. the high pressure pump develops upwards if 3000 psi. there is a electronic selonoid valve on the pump that controls pressure. icp valve injector control pressure. Have seen the final output of the injector driver in the computer goes bad will not show on testing.

 

[Red Bank]

The only advice I can offer is to go back to the basics and check the fuel lines, etc and see if they are leaking. It could be loosing prime when cold, but cranks and starts fine after it is warmed up.

 

[carogator]

also look at the timing retarding sensor.(TRS)

 

[cndiesel]

I don't have any experience working on these motors but we are changing seasons. 650,000 is a lot of miles for this little mill and a compression issue might not be seen in the summer but shows up when the outside temps starts dropping below 40 degrees F. in the fall.

Does this engine have electronic controlled injectors? How about a PCV valve? How much load does it usually carry? Does it work in city transfer work, agriculture or open highway? How much crankcase pressure is generated when under load. Are there multiple leaks all around the engine. What other work has been done to the engine over the years?

It is my experience that cold start problems are not caused by a sudden problem. They usually show up suddenly when the climate changes.

Too much questiones.:usa