Ran my 671 at 215 degrees for 4 hours. Water pump drive hub was slipping on water pump. Should I be concerned. Never lost any coolant during that time. Thanks in advance
Hi;
As I understand it, you can do engine damage at 212 deg. I am sure someone else
will input some more info. What kind of bus?
Good luck, Merle.
Some buses seem to handle hot stints just fine. Others melt down if you just say the word "overheat" at this point I say drive it and check your oil for coolant and watch for smoke.
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Its in a 4104. Changed water pump and drove it out to the lake 1 hour away with no issues. Just not sure if I should trust it on a long trip
I wouldn't worry about it the old 6L-71 can withstand more heat than any V models Detroit made,if you are not blowing white smoke drive it
Sometimes damage from overheat doesn't show till a couple thousand miles later. Hopefully your temp gage reads a little on the high side.
I notice the temp gauge on our 4104 being electric is sensitive to whatever the voltage reading is. Higher the voltage, higher the temp. If you didn't loose any coolant you should be OK. Even though 215 is hot, sounds like you didn't make any steam. Assuming your coolant system is up to snuff (pressurized with antifreeze) your coolant was doing what it was suppose to - not boiling, no steam. Being optimistic, I'd say you dodged the bullet.
A dry-liner engine does have its advantages.
Just drive it and monitor.
How do you know what the temp really was? Dash gauge are useless in this regard.
No smoke?
No steam?
No hot engine warning?
How did you ultimately decide you had a problem? It ran fine for 4 hours at whatever "temperature" it was at, so just how bad was it?
Does it start up cold and hot like it always did?
Find something else to really worry about?
You won't believe the things that Big Transit and their paid employees routinely did to these natural '71 engines and they just kept going. It is somewhat amusing the lengths that we busnuts go trying to protect the old whore's virginity... The problems we encounter, and blame on some immediate apparent issue, is that we inherit engines that are ready to fail, that's a major reason why the coach was for sale in the first place.
For instance, run-in to garage with burst hoses, coolant all pumped overboard miles ago, engine seizes coming in the shop door, push it into a bay with a tractor, the smarter foremen with the best recovery records would leave it cool for the next shift, the gamblers would just fill it up with water and see what happened... replace hose, fill with coolant, back in service next day.
Leaking injectors pouring fuel into the sump, diluted engine oil level is so high, driver reports "low power" ( crank is splashing through the oil/fuel) the mechanics drain off to the dipstick level, lift valve covers, identify which injectors are the culprits, swap for new ones, fill with good oil, good for service on the next shift. No angst over cranks journals and bearings, stop the fuel leak, and carry on.
In summary, if there's nothing unusual being emitted, starts and runs as it did and fluids are not co-mingling, celebrate another bullet dodged, and congratulate yourself on the preventive maintenance that has been done?
happy coaching!
buswarrior
What buswarrior said and if you dodged the bullet, next time, stop and don't drive 4 hours at 215 degrees. ;D
And if you don't already have one, get yourself a good coolant temperature gauge of known provenance, test it after it's connected so you know exactly how close it is to accurate, then trust it implicitly when you are driving! After I got my new Speedhut gauge connected to the bus's existing underfloor wiring loom I put the sender into boiling water - the gauge read just over 212, so I know now that it's trustworthy. For something as critical as engine temperature you want a gauge that doesn't lie!
John
John, at what altitude did you test that sending unit?
Lol
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Quote from: Scott & Heather on June 13, 2017, 03:25:09 PM
John, at what altitude did you test that sending unit?
Lol
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According to Google Earth my bus is at 81 feet above MSL, plus about 3 feet from the ground to the gauge's sender, so let's say 84 feet above MSL. OK, I know water boils at slightly less than 212 degrees at that vertiginous altitude. Mind you, atmospheric pressure on that day would have been a factor too, and I didn't check whether the water's impurities also affected its boiling point. Sorry . . .
(Does "anal retentive" have a hyphen in it?)
John
Thanks to all who replied. To answer some questions,the hot light was on ,checked block with a heat gun,same as dash guage. No smoke or steam,oil good. Why did I drive it? Tow bill from USA to Canada would have been lots. Mistake on my part,probably,i took a chance. The old girl got me home
lol John. Gave me a good chuckle
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If you still have worries you could always do an oil analysis and see if you got metals in your oil. I would think a '71 series could handle a moderate overheat condition much better than a '92 series.
Before you do that, verify the accuracy of your temp gage. If the gage was reading 10 to 15 degrees too hot, then there isn't a problem, except for the gage.
Compare your dash gage with the one in your engine compartment.The one in back tends to be more accurate!!
I think every bus-nut should have a laser temp gun in their bus ($25 at Harbor Freight). And I also think anyone that has a Detroit 2-stoke (etc.) should get get that laser temp gun and compare the temp at your engine sending unit to the dash temp gauge. And I also think that when your engine reaches 200F you should pull over and analyze the situation. I can also add that every bus that tends to overheat should have a radiator water SPRAYING system (not misters). Follow the above and save your engine!
--Geoff
(gently getting off his stool)