engine hunting on 3.0 ducato

[nigel67]

Hi there everyone, I have a motorhome based on a fiat 3.0 2007. When i went to go away last week, after i started it and left it on idle it started to gently rev up and down at a steady and constant pace (what i would call hunting) and seemed to have a quiet whining noise as well. It seems to disapear after about 1500revs. Any ideas would be helpful. Thanks.

 

[nigel67]

Well sorted out the problem, I had a look while at the garage for the mot and it turned out that that air pipe to the egr was split where it was pushed on. The whining/vibration was caused by the change in engine revs just enough to cause the metal sump to resonate. new piece of pipe fitted and good as new. I changed the short one as well as this one was showing signs of cracking. It looked like the pipe ends were a bit small for the fittings so were a bit stretched which i think caused their premature failure. I have fitted some gates hose now and all seems fine.