The point I was trying to get at is EGT's are one way of measuring heat, so is coolant temperatures, which usually sit around 200 degrees at the thermostat. Engine oil makes direct contact with moving components and comes closer to heat sources than coolant. Add to the fact that you don't have an oil cooler, and it's pretty much impossible to register cold oil to activate the EBPV, as you suggested could possibly happen while the engine is cruising down the highway.

Think of this. In sub freezing temps, how long does a truck have to sit (with an engine that was run to normal operating temps) with the engine off before the oil is cold enough to activate the cold air feature? I'll give you a hint, it's several hours.

The only way the EBPV would activate while driving would be either a serious malfunction (which is NOT normal), or immediately after a cold start and driving (which would indicate a pluged back pressure line or faulty back pressure sensor, again NOT normal).

I'm not trying to give you a hard time here, I'm just trying to point out the fact that the idea of engine oil cooling off that much while driving is impossible, and that a closing EBPV while driving down the highway is not a normal function. To give someone else advice and tell them it is normal is setting up for problems later that should be diagnosed and repaired now.

 

well, just changed the oil and drained the fuel filter housing unit and its still doing it, but like I said it doesnt do it all the time. What gets me is that it doesnt do it only when its cold or only when its hot it is intermittent which makes me lean more towards a tps or maybe a faulty injector. ????????? I think Ill drive it a couple days and see what it does. Thanks for all the advice, Im slowly learning about these diesels. I will try to get back to this ASAP. thanks again

 

You could check for codes stored. If it's a TPS, injector problem, harness, or anything else, there's a possibility that a trouble code may be stored and could tell you what's going on.

The TPS will normally only flash the check engine light once, and it's for a split second, so you have to be looking at the dash to catch it.

At least finding a code is better than part swapping.

 

alright guys, no more problems (I HOPE). I just drove 210 miles and it didnt do it once! I think changing the oil did it plus I got 2 more mpgs !!! I never would have thought that the oil made that much of a difference. It starts easier, runs smoother, and doesnt chug between 40 and 50 mph as bad as before. THANKS TO YOU GUYS THAT HELPED ME ON THIS ONE

THANK YOU THANK YOU THANK YOU

 

You're welcome! Stick around and learn more about your truck! Always a lot to learn and share, here.

 

Chage your fuel filter now too. The oil is what makes you injector work and and fuel is what makes your truck diesel so change the filter and not the color of the filter as well as any seditment.