A cold start/running issue on a Cat. 3126E

[RCtime]

Recently I experienced a missing on the engine after a normal start and warm up. The temp. gauge read approx. 40% above the bottom mark on its way to the 1/4 mark. I had gently entered a hyw. at about 40 45 mph to finish warm up and detected the missing with a slight smoke trail.
After about a mile and a half the symptoms stopped completly as the engine warmed up.
The engine ran fine throught out the day. I pulled over and detected nothing in the water seperater, which had just been replaced 3 days prior and had traveled 280 miles the previous day to my present location.
It had run perfect throughout the previous day.
I camped put for 4 days and on start up in the afternoon at about 76 degrees, the motor didnt want to catch right off, but finally did and belched out a cloud of black smoke with a slight trail of smoke again to warm up and it again ran just perfect throught the day.
The next day start up I had elect. campsite and left the block heater on all night. Figuring it was a cold engine problem and not when it was warm.
Sure enough, the next morning it started just perfect, no smoke, no missing.
Any ideas whats going on.
Whatever failed or malfunctioned did the day of normal start and then malfuntioned as I was slowly driving it to finish warm up.

[Paul R. Haller]

Sometimes clogged injectors leak some causing symptoms you suggest or it could be a grid heater malfunction. Temperatures in the 70s however require little or no additional heat to run well after start up. Looks to me like you'll have to start looking for some clues other then missing and smoke.
-Paul R. Haller-

[MaverickBBD]

Having recently replaced two (2) injectors in a C-7, 350 I would definitely suspect an injector. Try a cleaner and if the problem persists have a cylinder cut out done to determine if any cylinder is significantly out of whack from the others. They may want to pull the fuel rail to see if there is metal flake present, indicating a bad H.U.E.I. pump but I would not suspect that from the symptoms you present.

[RCtime]

Yes, I think its an injector , bummer.
What do you think the ballpark $ damages are going to be.
Going to take it in. Got to get it to the washrack and wash a million bugs off it 1st.

[CAT Lover]

I have the same issue with my CAT. I have about 520,000 on my motor. Depending on the mileage, you could have a couple of things going on.

It could be the injectors, it could be a leaky injector cup or injector rings, Once it warms up things expand & go back into place.

one thing I have found out about CAT motors over the years is this. After owning 3 diffrent versions of the 3126 is that they don't like to sit for extended periods of time & they don't like jack rabbit starting. Once there started esspecially in cold weather they need to be fully warmed up.

[ninos]

I have a 2006 discovery with the cat c7 330HP and it does the exact same thing and I don't think that there is anything wrong with, the cat c7 needs oil pressure for the fuel system to operate and I think wile the oil is cold the high pressure causes those symptoms but there is nothing you can do that will always be there or just leave your block heater on all the time, Joe.

[CAT Lover]

When the truck was newer with a lot less miles it did not do it. The motor should run smoothly at all times. I do notice some days are worse than others. If I had a place to plug in at night I would plug it in 365 a year.

[ninos]

To all the cat owners on this forum how is your c7 when is cold ? Do you guys have the same symptoms?

[RCtime]

Just an update
this all happened a few months ago. Since then, all has been normal, but each time I turn the ignition key over and rumble out I have these willys in my stomach.
I still dont have a REAL CLUE as to what the problem was.

[CAT Lover]

Quote:

Originally Posted by RCtime Just an update this all happened a few months ago. Since then, all has been normal, but each time I turn the ignition key over and rumble out I have these willys in my stomach. I still dont have a REAL CLUE as to what the problem was.

That's pretty much how mie started, it was intermitent. How amny miles on your motor?

[RCtime]

37,000 miles, a bit over.

[CAT Lover]

Quote:

Originally Posted by RCtime 37,000 miles, a bit over.

That's crazy! That should not be happening. Mine did not develop this issue until about 450,000 miles.

I have noticed that a few posters here have less than 100,000 miles on there motors & have lot of issues that shouldn't come up until much later in life, such as the Injectprs & HEUI pumps. It's very odd.

[timdriver]

Mine did this at 28,000 miles. I had Cat do a diagnostic and run the codes and a multitude of possible codes from bad injectors to CAC was not sealed. Cat did the repair, 2 bad injectors were the problem and the only problem.All covered by Cat warranty. If I remember correctly each injector was close to $800 each, I could be wrong. Just going off of memory of the billing paperwork which I kept but is in the coach at the storage facility.

[ninos]

ok I just read the all thread again and it looks like you guys are talking about a diferent problem, what mine does is when I start it cold and I take off before is fully hot I fell a little hesitation as I just feather the gas pedal and only happens for about one split second and as I press the pedal it goes with out any more hesitation, thats why I said its normal and it had to do with oil pressure, I was wrong sorry. Joe