Help-Engine and Hot Water Overheated

[D2]

We drove from the Bryce Canyon area to Ely, NV yesterday (2000 Newmar Mountain Aire Diesel towing a Tahoe) on Hwy 21 and 50.  On a couple of the climbs, the engine started overheating.  We have climbed grades before (not quite as long) and did not overheat.  It was 94 degrees outside at the time.  One variable is we were running our generator for the first time while traveling to run the air conditioner thinking this would be easier on the engine than running the dash a/c.

Last night when I began to do dishes, I realized I had not turned on the electric hot water switch.  Thinking I wouldn't have much hot water, I flipped the switch for the gas booster and it did not come on.  Upon investigation, we found we had scalding hot water!!  I figured we were about to lose our hot water heater since the scalding hot water was a symptom right before we lost a hot water heater in a previous RV.  This morning, the gas booster came on and so far it appears all is well.

Can running the generator on grades cause the engine to overheat?  Could running the generator or overheating the engine cause the overheating of the water in the hot water heater or are we about to lose our hot water heater?

Any help would be appreciated as we leave ELy Tuesday going to Carson City on Hwy. 50 and there are grades to navigate and would like to avoid the same problems, if possible.

Thanks,

D2

 

[Ned]

The generator won't cause your engine to overheat.  It actually reduces the load on the engine when you use the roof air instead of the dash air.

The hot water was probably from a heat exchanger that uses engine heat to heat the water in the hot water tank.  Since the gas burner worked normally the next day, I suspect that's the answer.  Everything seems to be working as it should be.

 

[blueblood]

My Dutch Star has the engine hot water heat and so I too have very hot water upon arrival at a CG. I don't think anything is wrong from that standpoint. There are issues with engine fans on Newmar/Spartan and kits available to retro to help overheating problem. You might check out the comments on this on the Yahoo Groups  http://groups.yahoo.com/group/newmarowners/ 

Also, one has to be sure to keep radiator and charge air coolers (if diesel) clean.

 

[D2]

Thanks, Ned.  I didn't think the generator was the culprit - but since it was a variable (never having used it while the m/h was operational) I wasn't sure.

I didn't know about the heat exchanger.  I'm glad that's what it is and we're not losing our hot water tank!!

D2

 

[D2]

Thanks, Leo for the good information and link.  Dear Husband did some research on the website and learned some operational techniques about pulling the grades which he believes will help us.  Since we have more grades to go, hopefully, we won't have the same problems.  I need to call our mechanic back home and check on the fan issue since he is familiar with our coach (it is a 2000 model and I don't know if the problem is year specific).  DH is going to check for debris around radiator, etc.

Thanks, again.

D2

 

[Jim Dick]

Hi D,

When running your generator and the A/C, turn off your dash air. That will reduce the load on the engine. If you have a recirculate position on the dash AC/heat control, turn it on. That should recirculate the air inside the coach and not bring in outside hot air. This will help keep you cooler.

 

[D2]

Thanks, Jim.  Have you by chance driven this section of highways?  I was wondering if it was "normal" to experience overheating on these particular grades to determine if we are within "norm".  The grades are 5%-8% but about 10 miles long.

Hope your summer is going well.

D2

 

[Jeff]

Thanks, Jim.  Have you by chance driven this section of highways?  I was wondering if it was "normal" to experience overheating on these particular grades to determine if we are within "norm".  The grades are 5%-8% but about 10 miles long.

Hope your summer is going well.

D2

D2:

My Cat goes up about 10 degrees on a similar grade but cools right back down when the fan comes up to full speed.

 

[Shayne]

I got gas 460 with Banks Pak  Mine goes up also and when the fans kick in the temp goes back down.  Not sure I would be as comfortable with out the Banks.  I know it wouldn't run as cool.

 

[Jim Dick]

Thanks, Jim.  Have you by chance driven this section of highways?  I was wondering if it was "normal" to experience overheating on these particular grades to determine if we are within "norm".  The grades are 5%-8% but about 10 miles long.

Hope your summer is going well.

D2

Hi D,

I have not driven that route. I would imagine a 10 mile grade of 8% could be a problem in hot weather.

 

[D2]

Thanks for the input.

Update - DH checked coolant this a.m. and it is low.  Strange as we had a mobile RV service change oil and check all fluids in April and all was o.k.  Now concerned we have a leak in coolant.  DH is going to town to get coolant and hopefully talk to tech.  We have not looked for but have not noticed fluid on the ground.

D2

 

[John From Detroit]

First,,,,, How did you decide LOW? (Depending on the age of your system it may be normal for it to be less than full)

Second, Check the radiator cap,  a bad radiator cap will cause problems

 

[D2]

O.K. - now I gotta get technical - the plastic bottle looking thing with tubes around it is supposed to have that green looking liquid in it (antifreeze).? It only had an itsy bitsy little bit.? I really should have let DH post this query but right now he is in the back trying to get that radiator cap off since, after filling the plastic bottle looking thing with the green stuff, it didn't go down as expected but filled up.

We're supposed to leave for Carson City, NV tomorrow on the "Lonliest Road in America".? This could get fun!!

Thanks,

D2

 

[D2]

Update - radiator is full.  Must not have been the problem. 

Thanks for everyone's help.

D2

 

[John From Detroit]

Ok, the plastic bottle is called the overflow bottle, it's supposed to have some coolant (The green looking liquid, a combination of anti-freeze and water) but normally only about 1/3 to 2/3 full,  When the engine overheats however it can boil off some of the "Excess" that is in the overflow bottle, and thus it will be low

Sounds like the bottle did it's job however and refilled the radiator so you are correce, it was not a low coolant issue

Now, what did cause the high temperture condition? Well, there are many things.  As I stated in the prior post a worn out radiator cap, clogged air passages (Visual inspect the radiator) Soultion , back blush with running water to wash out all the bugs etc.

Colgs inside the radiator.. I'll let others tell you there

Bad thermostat (likewise)

Other internal problems (Now we are spending serious money)

Others will tell you better than I how to check these and how to correct them (Save for the easy one)

I've had a few vehicles where I never did figure it out

 

[Marsha/CA]

D2,

I'm sure you have already left for Nevada; but just incase you can get internet on the road, here is more food for thought regarding your over-heating.

If your Diesel is a diesel pusher and it is not a side mounted radiator, but a rear mounted one, you might need to clean the radiator fins.  This is easily done with a power washer.  Open the engine compartment and spray off the engine from both the front and the back.  If you are using a power washer, becareful not to put the power washer too close as the washer can bend the fins.  Sometimes goop from the engines blows back onto the radiator.  The newer engines have a "blow-out" tube which prevents this from happening.  We have the blow out tube, but my husband still hoses off the radiator.

Enjoy that "lonely" road in Nevada.  One of my husband's favorite road is 50 (I think) It's the one where Area 54 is located.  There's a great old restaurant right near Area 54.....fun place.

Marsha~

 

[D2]

Thank you all for the great feedback.  It really helped us when on the road and in need!!!

Leo - Dear Husband went to the website you recommended and found the suggestion posted of keeping the RPM's up and it did the trick - we haven't had another problem.

We were heating up to the point the engine light would come on and the temp. topped the dial!!  Now that he has learned the RPM trick - and haven't had another overheating problem.

Thanks again for all the help!!

D2