[Archived]

I monitor ours constantly and it has always stayed between 197 and 205 degrees. Trans temperature, however, usually stays between 200 and 215 degrees, depending on use of the retarder. Steep down grades will push the trans temps even warmer.

That’s been my experience, anyway….

[Archived]

Sounds about the same as mine Bonz.

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Yup, the numbers sound right.

I’m not suggesting you ignore high oil temps, but once they start approaching 240 then you should be concerned. I don’t know if we have a stated limit for our coaches.

[Archived]

Well, that gives me a lot of leeway!

The transmission temps were around 203, and coolant temps via the analog guage seemed stable. I did have to add 1 1/2 gallons at the third stop though.

[Georges]

1.5 gallons of coolant!!!??? If you check regularly, this is an unusually large amount of coolant to use in a short time unless you just flushed or something which may have introduced some air in the system. Hope you don’t have coolant in your engine internals.

[Bob]

It has been my experience that transmission temps track very close to the high end of coolant temp swings when operating below 65mph unless you are in the hills. If I turn my dash air on I can what my coolant temps swing from about 175 to 197, pretty much in line with the thermostats.

A gallon and a half of coolant is way too much, unless already stated you just performed a flush or otherwise had the coolant system open.

[Archived]

Karl just had a complete coolant change and was checking frequently to make sure it had burped the trapped air out. It was not because he was inattentive.

He had a 100% full surge tank so 1 1/2 gallons did not get down to the low coolant sensor.

Once he is confident it is fully burped he can feel comfortable allowing it to drop to about half its level for expansion.

We did not run the bus long enough or the Webasto long enough up to a full operating temperature to minimize the amount of trapped air due to time constraints.

[Archived]

Jon’s right, again. After adding what I did it seemed stable. I wish we had thought to clean the sediment out of the sight glass when the levels were low though.

It was also about 100 miles of driving before it was visible that it needed more.

[Archived]

And, did you guys clean the stainless strainer in the port bay where the evaporator fans lives, a must clean due to junk in the coolant that cycles with the OTR for heat and temperature blend?

I got ya on this one, didn’t I?

[Archived]

You did. I completely forgot that. All is not lost. That is something that should get done at normal service intervals and at JAX they can show Karl how to do it.

I can say my 8V92 created a lot of black slime in there, but the Series 60 not so much.

[AL]

I hope I don’t have to remember that in two years when it’s due again. Hopefully they just do it, maybe with a flush and fill?

[Archived]

My oil temp runs between 195-200

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Just to be sure everyone is talking the same thing there are two oil temps. Usually one is the transmission oil temp and the other engine oil temp.

The transmission oil temp displayed on some coaches is taken at the point at which the transmission fluid leaves the transmission, and if the transmission is equipped with a retarder that temp can be seen to vary widely, from the normal which tracks the engine temperatures to one which spikes as the retarder is employed. Later model coaches apparently measure the transmission temp at another point because use of the retarder does not display the spikes as the retarder engages.

Engine oil temp generally tracks the engine (coolant) temp fairly close and is not prone to wide swings unless something unusual is happening.

[Archived]

Actually, many of the earlier buses had diff oil temp gauges; I know my 1989 Marathon did and I’ve added one to my current coach. As I recall, the 1989 had no trans temp gauge, but I could very well be wrong on this point.

[Thomas]

My Prevost computer measures engine oil temp.