Just purchased a Damon Challenger 2006 with Vortec 8.1 and Allison trans. While driving, a noise would seem to come from the engine/trans that would be intermittent. When it occurred, it didn't seem to affect the RPM's. It is difficult to describe but it seemed to happen at different speeds and on both level and various inclines. This my first travel with this vehicle and I went a distance of approximately 300 miles. I purchased vehicle from a dealership and mileage was reported as being very low (less than 10K), suggesting that the vehicle hadn't been driven very much. We are selling a 2005 Hurricane/ Workhorse and this kind of "driving noise" doesn't seem to be present.Is this Vortec 8.1L gas engine with Allison trans. a normal driving condition?

Is this a roar that is caused by the fan clutch engaging when the coolant temperature increases? This usually happens when the coolant temp reaches about 207-210 degrees and will roar until things have cooled down. It can happen on level roads or during a climb since it happens because of coolant temp increase, not road conditions. It could also be an indication of the fan clutch starting to fail.

I think you may have figured out my problem. I wonder if the water temp should also rise above normal, on the dash gauge, in combination with engine over-heating? If it is the fan-clutch potential problem, with these events occurring, is this in anyway detrimental to the engine and/or trans? And, is this a major repair and/or cost?Thanks for your quick response.

Actually, if that is the noise, it is not a "problem"-- it how the system was designed to work.The fan clutch engages as coolant temperature rises above thermostatically controlled temperature. It disengages when coolant temperature returns to normal.

One final question. The fact that the engine temp is running "hot" causing this fan to engage "frequently", are there any concerns with excessive-heat from the engine? And, if so, what would be the cause and remedy? Is it possible that coolant levels are too low? Thanks again!

It might be a good idea to have your cooling system checked to see if the coolant is sufficient and that the radiator is functioning properly. Most rigs with the 8.1L engine ALSO have electrically operated fans in front of the radiator that provide cooling when temps get too hot. All of the fans must operate properly to keep things under control, especially in hot weather. The mechanical fan clutch, which causes the roar, does occasionally go bad and needs to be replaced. If the temps are continuously running too hot, for no obvious reason, it is time to get things checked.

intermittent noise coming from engine and/or trans.

ArchHoagland
Explorer
Jul 06, 2014
UltraGauge

I use one of these and keep an eye on engine temperature.

Last week the engine temp went up to 219 degrees and the gauge on the dash didn't move a bit. My normal range is 199 to 204 degrees.

If your gauge on the dash is moving up to the hot marker you have some serious cooling problems and need to have it looked at soon.
bsinmich
Explorer
Jul 06, 2014
I haven't gone through all the settings on the Actia display on the Workhorse chassis lately but if I recall there is one position that gives coolant temp in F or C
degrees.
Clay_L
Explorer
Jul 05, 2014
John Wayne wrote:
If your really worried about the Temp. buy a ScanGauge II it will give you the real water and cylinder head temps. Along with Trans temp. and a whole lot more. Will read and reset codes.

X2
LizzieB
Explorer
Jul 05, 2014
thanks everyone
John_Wayne
Explorer II
Jul 04, 2014
If your really worried about the Temp. buy a ScanGauge II it will give you the real water and cylinder head temps. Along with Trans temp. and a whole lot more. Will read and reset codes.
sch911
Explorer
Jul 04, 2014
I don't think you any problem at all. To me it sounds like the MH is performing normally. The fan is supposed to go on and off. Normal period.
Clay_L
Explorer
Jul 04, 2014
LizzieB wrote:
I think you may have figured out my problem. I wonder if the water temp should also rise above normal, on the dash gauge, in combination with engine over-heating? If it is the fan-clutch potential problem, with these events occurring, is this in anyway detrimental to the engine and/or trans? And, is this a major repair and/or cost?

Thanks for your quick response.

The temp gauge is a glorified idiot light. It won't move until the coolant is really hot.

There was a post quite some time back describing the temps that cause the gauge to move.
rgatijnet1
Explorer III
Jul 04, 2014
If you do need a new fan clutch, they are a little difficult to find. The part number that I have is GM#28210308 and it is made by Hayden. This is the replacement for Workhorse part #0000193.
LizzieB
Explorer
Jul 04, 2014
Great forum! Thank you very much for the technical advise. I feel better going into a repair-shop with some idea as to what the cause of this "roar" is.
rgatijnet1
Explorer III
Jul 04, 2014
It might be a good idea to have your cooling system checked to see if the coolant is sufficient and that the radiator is functioning properly. Most rigs with the 8.1L engine ALSO have electrically operated fans in front of the radiator that provide cooling when temps get too hot. All of the fans must operate properly to keep things under control, especially in hot weather. The mechanical fan clutch, which causes the roar, does occasionally go bad and needs to be replaced. If the temps are continuously running too hot, for no obvious reason, it is time to get things checked.