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Advocate1 · 11-06-2006, 05:45 PM

I am sre this is an oft discussed problem, 454's and cooling. Here's what's happening. during the first 30 miles everything works fine. Fan clutch kicks in at about just over normal temp (195 I think)and the temp stays at "Normal", up hills a/c on etc. After 50 miles or so the temp gauge rises almost to the red mark before the fan kicks in for a few minutes and brings the temp down to about halfway between normal and hot. Its almost like the engine is a lot hotter than the radiator, causing the fan to come on late. This is a near immaculate 1986 Coachman with only 47,000 miles and new to me. Hate to change the fan clutch if it's something else. Let me know your thoughts. Many Thanks

Advocate1 · 11-06-2006, 05:45 PM

I am sre this is an oft discussed problem, 454's and cooling. Here's what's happening. during the first 30 miles everything works fine. Fan clutch kicks in at about just over normal temp (195 I think)and the temp stays at "Normal", up hills a/c on etc. After 50 miles or so the temp gauge rises almost to the red mark before the fan kicks in for a few minutes and brings the temp down to about halfway between normal and hot. Its almost like the engine is a lot hotter than the radiator, causing the fan to come on late. This is a near immaculate 1986 Coachman with only 47,000 miles and new to me. Hate to change the fan clutch if it's something else. Let me know your thoughts. Many Thanks

Paulin · 11-06-2006, 07:40 PM

Advocate I, two thoughts:

First, fan clutches do wear and occasionnaly need to be replaced. Be careful about aftermarket fan clutches as some are not as heavy duty as OEM. At 47K miles it may well be due for replacement.

Secondly, consider adding some air dam(s)to direct air flow through your radiator and engine compartment. Air takes the path of least resistance and will therefore pass under the chassis and through wheel wells.

We did both to a 1995 Flair powered by a 454 and they helped considerably. Had the fan clutch professionally installed. Used sheet metal with bolts and nuts as a DIY project to close off most of the space below the radiator and between the rear of front bumper. Also, used sheet metal to create deflectors to force incoming air into the engine compartment.

Advocate1 · 11-07-2006, 08:53 AM

Bluewind
Thank You for the tips. I have seen several mentions about the airflow problem, but most were just complaints. I can take care of the ducting. I noticed that there are several different quality levels on the fan clutches. As hard as it is to change on my Coachman, not to mention the pain if it fails again, I will try to buy the same part that the local RV shops install. My thinking is that they install the most reliable parts as they don't want any warrantee returns where they have to eat the labor cost. Make Sense?
Thanks Again
Bob Miller, Riverside, CA

bulletLS1 · 05-30-2007, 07:12 PM

if the temp rises "unnormally" fast could be a low coolant condition, or a poorly bleeded CS, or a stuck thermostat,
If I where you I wil definetelly (in a rad shop) clean and decalcify the rad, put a new Water P, new thermostat, check for old hoses (internally broken and thus making some kinda flap) and (sorry) new cluthc... while at it, if you want some "FREE" Hp, or "free" MPG why not get rid of the engine driven fan and put a electric motor driven system from summit racing, my brothers Chev P-up 454 improved T=R=E=M=E=N=D=O=U=S=L=Y (sorry, spelling?) with the mod.
also if the engine dont use aluminium (I supose iron heads) you can get away w/ the "green" coolant.
all parts readily available @ pep boys or simmilar, OK maybe the clutch not but a Hi perf cluch will definetelly be better cheapper (least expensive) in summit than OEM!