Driving in extreme heat & engine light

The friendliest place on the web for anyone with an RV or an interest in RVing!
If you have answers, please help by responding to the unanswered posts.

garyb1st

Well-known member
Joined
Dec 31, 2010
Posts
3,921
Location
Southern California
Oil was changed in January. Have probably driven 3,500 - 4,000 miles since. Looking at the dip stick, I wasn't sure if it was actually a quart low. It appeared to be above the add line. So low but likely less than a full quart. Didn't know that high temps exacerbate oil pressure. Thanks for the heads up.
 

garyb1st

Well-known member
Joined
Dec 31, 2010
Posts
3,921
Location
Southern California
I just looked and did not see oil pressure on my phone with Torque Lite, but it is there on my paid version on the tablet I use with the RV. Making a trip today so I'll try logging it and see what the pressures are like over the course of my run.

In my experience with hot/thin oil I've seen some oil pressure lights flicker only at idle, under way pressures were always normal. Have never seen the oil light come on with my 8.1 Vortec at any time. It will be interesting to see the data log after the trip today.

Mark B.
Albuquerque, NM
I'm not familiar with the data log. Are you referring to logged info available on the paid Torque app?
 

Ray-IN

Well-known member
Joined
Mar 16, 2014
Posts
302
Location
North America-somewhere
This all sounds like a storm of low oil level, excessive speed up a long grade-which overworks a gas engine - and creates more heat than the cooling system can dissipate efficiently.
I suspect it would have been prudent to lower speed to 60 MPH and manually downshift to keep RPM's high, this would cause the water pump to spin faster and move more coolant through the now-less stressed engine then through the radiator.

With the engine off squeeze the bottom radiator hose, if you can sqeeze it flat with your hand it should be replaced. That is the suction side of the water pump, a weak hose can be pulled partially closed, restricting hot coolant flow from engine to radiator. Most of these hoses have a metal spring inside to prevent this from happening.
 

Heli_av8tor

Well-known member
Joined
Mar 3, 2017
Posts
908
Location
NW Illinois
Hey Gary, You should be able to monitor display the oil pressure on the dash LCD readout. (At least I can on my coach). It's one of the options using the "MODE" button.
 

garyb1st

Well-known member
Joined
Dec 31, 2010
Posts
3,921
Location
Southern California
Tom, now that I think about it, I believe we have the same oil pressure readout. I'll have to take another look next time we're on the road.

The OBD adapter is a simple plug in OBD 2 scanner and maria connects via bluetooth with her Android phone. I think we got it on Amazon for about $20.00.
 

garyb1st

Well-known member
Joined
Dec 31, 2010
Posts
3,921
Location
Southern California
Ray, I rely on the Allison to do the shifting. Unfortunately from time to time it will not downshift soon enough on a grade and the RPMs drop off to a point where it's almost impossible to pick up speed. Not sure if it's an issue with my Allison or just typical behavior. It doesn't always happen but some times the RPM's will drop to below 2,000 before it downshifts. When it does, it drops to 2nd gear and the RPM's are over 4,000. Don't like running that high but if I don't keep the pedal to the metal, it hunts between 2nd and 3rd.
 

Utclmjmpr

Well-known member
Joined
Sep 14, 2009
Posts
5,153
Location
Cedar City, UT
Low oil also causes the oil to circulate more often and it lays in the pan for a shorter time,, thus increasing the cooling problem..>>>Dan
 

Ex-Calif

Well-known member
Joined
May 15, 2020
Posts
1,547
I would say your indications were perfectly normal for the conditions you describe.

I would also say that if you were a quart low on oil you definitely should have topped it up. Oil also carries a great deal of heat. If you plan to drive in those conditions you might consider adding an oil cooler.

That grade is a killer. I just did it in like 105* conditions. I reduced speed to like 55 in my old slow 454 powered machine and everything stayed in the green.

Did you notice if the engine had downshifted to a lower gear? What speed were you carrying? I am overly conservative probably but I slow the coach down until it runs in top gear.

I have a 4 speed box. I will slow until 50 and then switch to 3rd. I have not hit a grade yet that I could not pull at less than 40 in 3rd gear. Again that's all based on the weight of my rig and the theoretical 230hp available...
 

Utclmjmpr

Well-known member
Joined
Sep 14, 2009
Posts
5,153
Location
Cedar City, UT
On a similar matter,, climbing out of the Salt Lake City valley on I80 in 100 degree heat My cummins and trans gauges were climbing rapidly into the red zone and bells were ringing.. I pulled over to allow it to cool and when opening the rear "tailgate", was nearly blown over with exiting heat..
I left the tailgate open ( gas struts ) and it looked like a whale tail Porsche,, but it worked great at allowing trapped heat to escape and more air to enter the radiator and better fan efficiency..
The rest of the trip was a breeze.. Now in the UP of Michigan and cool wet weather..>>>Dan
 
Top Bottom