[lancej62]

My 1999 IH 4900 dt466e begins to sputter, vibrate, and lose alot of power under load. The sputtering/vibrating starts anytime acceleration or load demand is put on the engine. I did replace the fuel filter primer assembly when I noticed fuel leaking from it when you pumped it, fuel coming out equels air getting in, so replaced it and got alot of missing power back, but I still get the flutter, vibration, and power loss under load. When mine starts fluttering, you can hear what sounds like an exhaust leak. I checked the exhaust, and found no large leaks, I did find a small leak around the band that clamps the exhaust pipe to the turbo, but it is very small, does anyone thing this could be causing the fluttering and power loss under load? Reduced pressure of something? Mine seems to run great cold and the fluttering response comes on as the engine reaches operating temp. When the fluttering starts you can slowly back off on the foot feet and there comes a point when the fluttering stops, engine smooths out, and you can notice a sudden increase in power, if the engine pulls down more or you give it some throttle, the sputtering starts again. It eventually will sputter up some RPM's, but very slow and labored. I repaced the cam sensor about a year ago. This is driving me crazy. Any suggestions greatly appreciated. Thanks.

 

[John_G]

Does this happen right as, or just after the engine reaches about 140*F and is accompanied by a "grey" like smoke?

What color, if any, is the smoke WHILE this is happening?

 

[lancej62]

John,

The truck starts this fluttering response at about 170 - 175 degrees and slowly gets worse as full operating temp, about 190. There is no smoke at all blowing when this happens. I put in new injectors about a year and half ago also.

 

[John_G]

That sounds like it might be related to the EOT sensor or to loss of ICP due to thinner oil at operating temp. It is perfectly possible for either to be the cause and for there to be no code/CEL indicating a problem. The ECM assumes it's getting good data (sensor values) unless the data is way off base.

 

[lancej62]

I just had an oil leak get bad enough to notice. It is on a small oil line that comes out of the block below the air compressor, then zig zags around behind the compressor and hooks into what appears to be a sensor threading back into the block kind of low behind the air compressor. I wonder if this could be causing part or all of my problem. I am going to have to do a temporary JB Weld job to plug the leak until I can get a new line. Does anybody know what that line may be called, or described as, when I go to order over the phone. I live in a very small town, and most all parts are phone ordered. Thanks.

 

[John_G]

That sounds like the compressor oil feed line.

Get yourself 2 feet of "-4" (dash 4) fabric braided hose (aeroquip), two female swivel ends and make up your own new supply hose. You will need to cut to length and to install the ends (easy) and to make SURE the fittings on the end are the right type (bring one with). About $20 in parts and 30 minutes labor and it's DONE.

 

[lancej62]

I finally got fed up and took my truck into the repair shop. They hooked up the diagnostic software and could not find anything wrong or out of the ordinary readings. They took fuel pressure readings at the filter and at the rail with both pressures being good. The session ended with the shop telling me that they don't have a clue what the problem is, but it surely has a problem. When the flutter starts, the diagnostic software immediatly would read 95-100% load on the engine, and drop right back to what would be normal for the situation when you backed off on the pedal and the flutter stops. Keep in mind that this truck runs absolutly perfect when dead cold, and starts the fluttering response at about 180 degrees. It does puff some, but not alot, of greyish black smoke while fluttering. The last thing I was told was that it may be the ECM, but he didn't think so and it would be an expensive "try and see". Finally, just for curiosity, I disconnected the EOT sensor and took it for a drive and it made absolutly no difference in the flutter whether the sensor was hooked up or not. The flutter only happens under load, if you are sitting still, you can gun the engine and it immediatly and smoothly responds throughout the RPM range. This was a very reputable local diesel shop, but not an IH dealership. I am at my wits end, and if I could just get her running decent, I would trade her off in a second and never touch an electronics controlled engine again. Any more suggestions?

 

[Jmcclures]

I finally got fed up and took my truck into the repair shop. They hooked up the diagnostic software and could not find anything wrong or out of the ordinary readings. They took fuel pressure readings at the filter and at the rail with both pressures being good. The session ended with the shop telling me that they don't have a clue what the problem is, but it surely has a problem. When the flutter starts, the diagnostic software immediatly would read 95-100% load on the engine, and drop right back to what would be normal for the situation when you backed off on the pedal and the flutter stops. Keep in mind that this truck runs absolutly perfect when dead cold, and starts the fluttering response at about 180 degrees. It does puff some, but not alot, of greyish black smoke while fluttering. The last thing I was told was that it may be the ECM, but he didn't think so and it would be an expensive "try and see". Finally, just for curiosity, I disconnected the EOT sensor and took it for a drive and it made absolutly no difference in the flutter whether the sensor was hooked up or not. The flutter only happens under load, if you are sitting still, you can gun the engine and it immediatly and smoothly responds throughout the RPM range. This was a very reputable local diesel shop, but not an IH dealership. I am at my wits end, and if I could just get her running decent, I would trade her off in a second and never touch an electronics controlled engine again. Any more suggestions?

Any update