8V92 running water temp

[BillhymerMD]

Just wanted further input regarding the running temp on my 8V92. Had it out this weekend for a short trip here in Florida and while driving in city traffic observed that the engine temp runs between 210 and 215 and approaches 220. A recent service has been performed at Prevost. The radiator was flushed and filled to the appropriate level. The coach is now at Coach Worx for a few updates and am going to discuss with Rick and the guys either a coring out of the radiator or whatever needs to be done. Just wanted to know if anyone has encountered their detroit diesel running at these temps and what remedied it. Thanks, Mike

[Coloradobus]

Michael, Our 1992 Silver 8V-92 hovers around 185 degrees pulling Vail Pass, a 7% grade on I-70 east bound, towing 5700 lbs of Lexus 470 with coach in 2nd gear with pyros screaming at 1000 -1050 degrees., maybe touching 1100 if I am not totally fixated on the guage, On the flat, it water temperature sits at 175, and tranny temp with Transynd sits at 180 degrees. City traffic encounters tranny temp climbs to 200.
Even pullling the "Baker Grade" east on I-15 east of Baker Ca, the raidiator temps rarely peak any higher than 185-90.
Another ex is east I-15 pulling the grade up the hill to Oak Hill/Hisperia California, pyros at 1100 tranny in 3rd gear, radiator temp 185 degrees
We have never hit the temps you are experiencing. Our coach weighs in at 41,680 pounds.

[BillhymerMD]

Is there not an engine overheat light and if so what temp does it come on to indicate that you are approaching a dangerous temp?

[Jerry Winchester]

Michael,

We saw ours run in the 210 range pulling hard with pretty high ambient temperature. The DDEC engine computer will reduce the available engine HP when the temp gets to a dangerous level. You may then see the Check Engine light come on. When we had high temp, we shut the OTR AC off and also pulled over for a few minutes at high idle. That usually cured it. I also made sure we were locked in gear when pulling a grade rather than watch the transmission swap from converter to lock-up which is a sure fire heat builder.

Short of a catastrophic failure, the DDEC computer should keep you from having a car-b-cue.

Jerry

[Charles Spera]

We usually pull a 12000# stacker and run OTR until the Divine Miss Barbie claims to be freezing. I drive race cars and the temperature and pyro gauges are a constant vigil. We run right around 185-190 (indicated) and on a rare occasion have seen what looks like 200. Just because I like to be safe, we will be pulling the radiator and sending it to the radiator shop for a check and recore if needed. New thermostats will probably be fitted as well.

[Jon Wehrenberg]

Michael,

I think the 8V92 engine for some reason requires strict adherance to the coolant maintenance schedule, and even with that it tends to plug radiator cores. That is my personal experience only.

You should run in the 180 to 190 temperature range and when pulling long steep hills the temps should stabilize at 195. You don't say if you have radiator shutters, but my comments assume if you do they are functioning as intended. If there is a question turning two valves locks them open so they are not part of the problem.

Unlikely, but just verify the fan is not slipping. The engine has two thermostats and they both have to function as intended. Ironically the gauge only registers on one side. It might be worth checking them to verify they function. If all else checks out you are looking at recoring or replacing the radiator. Don't delay this because the temps you mentioned are excessive and you are very close to having the DDEC start to shut you down. You can turn a 8V92 into an expensive paper weight very quickly with over temp conditions.

[LA-HODAG]

Michael, the early 90s Country Coaches are notorious for instrument inconsistency and I suspect yours is no different. On mine, the dash temp gauge always reads at least 10 degrees hotter than the mechanical gauge back in the engine compartment. My dash gauge shows about where yours is when pulling hills or running the desert while towing my Jeep. When I switch on my headlights or running lights, the dash temp guage jumps up even higher, by about 10%. Others on the board have similar experinces when the dash is illuminated but nobody has been able to figure out how to fix. I just take the dash gauge readings with the appropriate grain of salt. The one time I got a check engine light for high water temp I was pulling a long grade in 110 degree heat near Needles. The dash temp gauge read nearly 240. I have replaced my radiator since that time and have had no more check engine warnings. It is best to be vigilant, as you are, but as long as your cooling system is well maintained, you should be fine. Check the temp gauge in the engine compartment against the dash gauge.

[joelselman]

I agree with Jon; you are marginally too hot. I would run those temps with high ambient temps on grades with a 44000# coach and 12000# trailer. I did have the radiator replaced and coolant converted to red during my term of ownership. Someone touched on transynd; synthetic trans fluid. That change will reduce trans operating temps and, I believe, the trans oil is cooled by the radiator system; hence the benefit. I also had the series 60 radiator fan fitted (more blades) without a clutch to keep airflow up.

[Coloradobus]

JoelSelman, Your last sentense above, did you fashion a Series 60 fan blade to the 8V92? Is that correst? Cool!!!

[BillhymerMD]

Bryan...that is very interesting to hear. I have often wondered how accurate that gauge is and I should have already checked it against the mechanical gauge. Should know more soon after the Coach Worx evaluation.