8V92 running water temp

[gmcbuffalo]

Would the dash guage problems be generalized to 91 Prevost not just country coaches?

[Jon Wehrenberg]

I would take what the gauge shows as the gospel and I think it is wishful thinking that the temperature problems are related to the gauge. I say that for two reasons. First, if the coach temps have been more normal and have started to creep upward it is a probability that you have been watching the gradual plugging of the radiator core.

The second reason I would rule out the gauge is because the fastest way to ruin an engine is excessive heat. I treat an over temp situation as an emergency situation that requires immediate attention because of that risk.

A well maintained 8V92 cooling system will run 30 to 40 degrees cooler than what was posted and that temperature spread has virtually eliminated the margin of safety. Those 180 to 185 degree normal temps are for the average coach pulling a toad in almost any outside temperature, with 195 being the highest seen pulling steep grades with no modifications from the original factory design.

[truk4u]

My Liberty ran 180 - 185 and I never saw anything over 195. 210 - 215 is trouble time coming. For an 8V, heat is the enemy and I would confirm the temps with a heat gun.

[Loc]

Having blown an 8V92 due to excessive heat here are my thoughts. The engine temp guage generally ranged from 175 to 190 depending on the ambient temperature and how hard I was driving. If I ever saw anything over 195 degrees I started getting nervous. When climbing grades in the summer that meant slowing down and keeping the rpms up without getting the pyros above 1,000 and shutting down the OTR air to reduce the load on the engine. Don't trust the DDEC to shut down the engine before there is a catastrophic failure. When we pulled the radiator it had significant blockage. In addition the sensor was crusted with a calcified substance and the engine failed prior to shut down or warning light actuation.

I would take the bus to a reputable shop and have them thoroughly inspect the radiator. I would seriously consider have it recored or replaced as a safety precaution. It isn't cheap to do, but it is a lot cheaper than a rebuild.

[Jon Wehrenberg]

There are three conditions which will cause DDEC to shut an engine down. Oil pressure, coolant level and coolant temp. It is not a coincidence that two of the three relate to the coolant system.

While it is theoretically possible DDEC will shut your engine down before the temps damage it, if you as a driver are relying on that happening you are likely skating on thin ice. To see those temps in Florida where the highest hill is a landfill that coach is in serious need of attention because when real hills are encountered the temps will be out of sight.

A radiator flush is unlikely to open up a radiator core that has been blocked over many miles of silicone drop out. At least you are in good hands at Coach Worx. They will make the correct diagnosis and suggest the best course of action.

[BillhymerMD]

Appreciate all the input.

[joelselman]

Coloradobus: The series 60 fan blade was installed by Prevost Mira Loma at the time they did my radiator replacement. If I'm not mistaken, there is a service modification bulletin, but it's been a long time. Everything was bolt-in though...no "fabricating".

[LA-HODAG]

I hope my experience with the dash/mechanical gauge differental is helpful. You should also check whether the dash temp gauge jumps when you switch on the headlights. You won't notice it when the engine is cold, but I see it happen when the engine is at operating temp. Prevost Mira Loma told me they have seen dash gauge grounding issues in many Country Coach conversions and at least one other Pogger with a sister bus has observed the same 10% headlight jump as I have noted. Let us know how it works out.

[rahangman]

My experience last summer (2009)- Left Home for Denver with "possible" heat problems due to seeing Drivers gauge into the 200 degree while topping a pretty substantial grade in Missouri. Monitoring, watched same happen through the Ozarks, once into Kansas stayed pretty good although a little higher than normal...Left Denver-went to Chicago then home worked around it, temps going up to about 210 or so. Got home, saw a POG note about a radiator followed up, went to get it. Found out it was wrong radiator, but had the original re cored. Wound up with all problems solved. Company doing the recorring thought it was probably the worst radiator they had seen in many a year. Visual Inspection of radiator had told me it was approaching necessary replacement, and so glad I did. Subsequent trips have proved that the radiator was my problem. We now stay right about 180-185 with small increase to 195 on long sharp grades. I had monitored temps by stopping, shut down engine run to rear of coach and saw about 5-10 deg difference on direct reading gauge in engine compartment which I figured ruled out the front gauge (also replaced temp sensor). Used my IR gun and found several different readings across the face of radiator. Hmmm not much left to do, so we did the recore. All is fine, I am happy.

[Yankee802]

My temps seem to stay pretty much at 195, needle straight up. Only a few times when going to and from POG IX did it go right of 195, I'm guessing 200, but no more. I'm doing my major replacement/overhaul this year instead of next, due to expected price increases. After reading this, I'm concerned about getting my radiator flushed/looked at by Prevost in Jacksonville, would I be better going to Coach Workx?