Just back off a trip we made to kentucky. Coming down a hill we got up to 88 mph and the engine started making a load clicking noise, soon as i backed off just 1 mph it stopped. my wife suggested maybe it was the ac comp. kicking on, so i turned it off and it still did it. I have only reached this speed twice since the the truck was new and it did it both times, at first i thought it might be the speed limiter but everyone says it only does that at 95 mph. Any thoughts as to whats doing this?

Possibly you were hearing the pilot ignition.......

You probably hit the point where the pilot injections turns off. When that happens, you will hear the regular diesel clatter. You can do a search on pilot injection and see if that applies to what happened to you.

Sometimes mine does the same thing around 85 MPH. I've found that if I clean my air filter when it starts "surging" it seems to make it less noticable. It may just be my imagination but it seems to help.

my search for pilot injection turned up nothing. what is pilot injection? is my truck suppose to do this?

Click here for a search on pilot injection. It turns up 65 results.


http://dieselplace.com/forum/search.asp?KW=pilot+injection&SM=1&SI=PT&FM=0&OB=1

thanks for the education. thats what it is, pilot injection shut down. so if i powered on into it instead of backing off, my engine wont bow up or somthing will it?