old 300

Hey guys and gals, I have a few questions about our 2002 4300 International DT 466-230hp and 620 ft/lbs torque.
The problem is since the engine has been rebuilt in chassis it just doesn't have the power it use to. They replaced sleeves, pistons, etc, etc. The problem for the rebuild was a sleeve seal failed and the coolant was going into the oil.
The engine runs fine, smooth, quiet, doesn't use any oil. They also replaced the turbo at the same time as it was very rusty and looked as it could fail. They also sent the head out to be redone as well.
The truck now drives unloaded the same as it did when we had 7 or 8 ton in the box. The truck has a 6 speed and what you could do on a hill in 6th now requires 4th. I asked the dealer and he said to run it through to its first service ( 12000 miles ) and see if it loosens up, it didn't change one bit.
What could have happened to this little engine that could, it would pull, you could feel it pull, now it just seems to fall off as you come into a hill. Could it be turbo trouble or fuel restriction or what? I am making an appointment tomorrow for a bunch of other work and would like to find the lost power..
Thanks in advance.

kingofdodge7131

They should be able to get it going for ya. As long as they didnt screw with any updates should be as easy as a boost leak or something simple like that. Could be exhaust leak pre turbo, Could be fuel system not obtaining total pressure like it should. either way they should be able to find it very easy.

Hvytrkmech

Liner o-ring failure is usually caused by an over fueling injector. Did they replace any injectors? I would do as previously stated. Check all the boost boots, I would also pay very close attention to the CAC. Look for rot or damaged core veins, especially along the bottom of the CAC. They love to fail at the bottom from built up road grime rotting them out. Do you hear a nailing sound when flooring the accelerator from a dead stop?

Keep us posted on what you find.

old 300

Hvytrkmech not to sound too stupid as I only shift gears but what is the CAC you speak of ? Is it the charge air cooler ( air to air ) ? As for injectors they didn't replace those but did say that sometimes they don't get back in the same cylinder. I'm not sure what that would have to do with the power issue. I will look at the air cooler and I haven't noticed any strange sounds but I will say the engine is alot quieter since rebuild. Thanks to both of you guys for the replies. I hope to get it in on Wednesday and I will keep info posted as this could help someone else another time.

Nick02Ram

How's your oil pressure?

old 300

According to the guage it shows just above 50 psi at any speed off idle. This is where both trucks have always been.

kingofdodge7131

The cylinder issue with the injectors is the computer learns the injector in the whole. I believe over time that year of truck will relearn the injectors

old 300

Just another thought. The injectors in that motor are HEUI or something. They are actuated or driven by engine oil pressure. If coolant was in the oil and the oil controlling the injectors, could the coolant have damaged the injectors in any way? The engine just doesn't seem to dig in or pull when the call for power is given. Almost like you were driving on the flat and come into a hill and not move the fuel peddle any, the truck just falls off.

Hvytrkmech

Check the fuel pressure. The shrader valve is on the fuel filter hosing. The fp should be 60psi, +- 5psi. Also change out the fuel filter, when you have the fuel filter off look just to the rear of where the filter was, you will notice a small plastic housing on the fuel line. Remove this housing, it is the prefilter water separator that contains a fine screen to capture particles and water. It is the single most overlooked piece of maintenance on these engines. Clean it with brake clean then gently blow it out with air, refill it and the fuel filter and reinstall. I would like to think that the tech at International did this when he did the overhaul.

When you take it back to International ask them to dead head the hpop (high pressure oil pump) on the laptop. The hpop takes engine oil and uses it as hydraulic fluid. The hpop pressurizes the oil to 900psi for engine start (min spec) up to 3000psi at wot. If the hpop is weak it will cause lack of power. You could also have a bad map sensor, it is responsible for controlling boost pressure. The injectors HEUI (hydraulic electric unit injector) does not have a specific memory for which cylinder it was in. It does not matter what so ever which hole they went back into on an International. The Cat engines are the ones that are sequenced numerically and have to be programmed into the ecm individually. I am surprised that you had a liner o-ring failure without an over fueling injector. It can happen without an over fueling injector but it is rare. The second largest cause is improper ph level in the coolant causing the actual liner to pit out and leach coolant into the oil.

Any coolant that may have been in the oil and ran through the heui system is negligible and not a concern. I would not have gone 12k on the oil change though. International say 7,500 service interval on that year dt466. Any time I inchassis a 466 it goes about 3k then gets an oil change.

Keep us up to speed.

BBWD

"They also replaced the turbo at the same time as it was very rusty and looked as it could fail."

Did they replace it with the same part number or a different turbo? This could account for your lack of power. Just something to check.

John (DH)

old 300

As for the turbo I'm not sure what they put in it, all I know is it was new. About the oil change I asked about when to bring it back and he told me to run it 12000 which is what they recommend. He also said to drive it like we stole it. We didn't do that, took it a little easier than that. Have app. for monday.

old 300

Well the turbo boost is at 20psi they say 22psi is spec. The fuel pressure is at spec. The injectors are all good. They can't find anything to suggest a problem. He did say that sometimes after a rebuild that when everything is back to new, the injectors should be replaced. He also said that at $3000 plus plus its a shot in the dark. I guess we will punish her with less power, could always find a 5.9 and bring her to life.