Intake Manifold Temp

[rpasetto]

We took a short outing, the first after a few months.  I noticed my ISM500 Intake Manifold temperature,  rising to 140F, sometimes 150F on hills.  The reading came off my VMSpc.  Meanwhile the engine and trans temp ran the normal 180s to 190s.  When I got back I did a cleaning of the CAC, Radiator area using a Dawn solution/Simple Green mix.  Was expecting to see a lot of dirt come off but the drippings were clean.

We're still in our first year with this coach; I do not recall this happening last summer.   Nor do I recall such temps with our old  Dynasty ISL.

Recommendations will be appreciated.

 

Update:  Checked VMSpc for recent diagnostic events; none shown. 

Edited March 26, 2021 by rpasetto
updated

[jfbolkovatz]

R.  On our ISM 500 the intake manifold temp runs normally 15 - 20 degrees above the outside air temp. With increased turbo boost the temp would be higher in the hills.

JoeB 03 Exec

[planodp]

We just came back from Big Bend National Park. My ISM 500 was running in 154 degrees, as I was getting closer to Big Bend and start to claim I did notice that Engine load would be around 100% and 30+lbs boost and the Intake air temperature was at 174 degrees. Engine and Transmission was in 180-190 degrees all reading came from BlueFire. 

 

[rpasetto]

6 minutes ago, planodp said:

We just came back from Big Bend National Park. My ISM 500 was running in 154 degrees, as I was getting closer to Big Bend and start to claim I did notice that Engine load would be around 100% and 30+lbs boost and the Intake air temperature was at 174 degrees. Engine and Transmission was in 180-190 degrees all reading came from BlueFire. 

 

It looks like your experience is very similar to mine.  So the question is, are temps over 150F expected when climbing hills?  My boost yesterday was about 31psi when I saw Manifold Temp going 150F+.   Either we both have the same problem or it's not a problem at all, I'm puzzled.  

Questions to the group:

  1. What's the expected temp rise on an ISM on a hill climb with 30+psi boost? 

  2. If 150F+ is not normal could it be a bad intake manifold temp sensor?

[Pepperell]

I haven’t got a gauge for this on my 400, but it wouldn’t surprise me to be that high under those conditions.  Ambient temperature at 2 feet above the street on a hot day is likely some amount above 100.  The ambient temp in the engine bay is likely higher than that.  The cac probably doesn’t cool the hot turbo charge down to ambient.  The manifold is bolted to an engine block that’s at 185F.  I’m not surprised it is running at 150+ under those conditions.    

Edited March 27, 2021 by Pepperell
Added last three words