E-350 ClassB Van-RV can barely make it up hills, get's hot

[concretebox]

So I've had my RV for two years. Only recently have I been taking her over big hills/mountains. On hills longer than a few feet I lose speed, even at full throttle. On especially long or steep hills I struggle to beat 35mph. Also, the engine temp climbs up to 245 (F). She's a little better when the gas tanks (30 gallons) are less than 1/2 full. 

I'm thinking my rig is just too heavy for an undersized engine (Ford 351) to pull it all up hill at freeway speeds.

I don't mind the speed, but the engine temp worries me. I turned on the heater (even though it was a hot day) and that cooled it down to about 230 (F). Of course outside temp and vehicle speed affect engine temperature (hotter at slower speed).  The radiator is new, 2 years old, and there is no room to add a supplemental radiator fan. And I recently had an oil change (less than 3000 miles). 

Besides taking breaks to let the engine cool, and avoiding driving during the hottest times of day...what other steps can I take to insure my engine lasts long and performs well? I blew a head gasket once and it cost me an engine (it stalled going up a hill at 30mph at a hot hot engine). There is no oil in the coolant or coolant in the oil, so I think the head gasket is good. Any oil or fuel additives I should be using?

Vehicle details: 1989 Ford E350 with replacement 351 engine (fuel injection, OBD-Mark I), hightop, extended, heavy cargo: 18 gals fresh water, 30 gals gasoline, 7 gals propane+tank, Roof AC unit, dorm fridge.

 

[highdesertranger]

well a 351 in a motor home is not going to break any land speed records. but you said you're ok with that, good. everybody drives way to fast anyways imho. so on to the overheating. did you put the largest radiator that is available in? how's your fan clutch? does it have cab AC? does the AC work? does it have an engine oil cooler? is your replacement engine over bored or factory bore? being you turned your heater on and the temp came down some leads me to believe you don't have a major problem just not enough cooling. it's right for you to be concerned about the temp. the temp will rise on grades but you really want to keep it under about 210. answer these questions and we can go from there. highdesertranger

 

[SternWake]

Does this vehicle have overdrive? Can it be turned off? My '89 Dodge will try and climb hills in overdrive if I were to let it. I don't let it, even if it has enough power to do so. I hit My OD off button and just hold 60 in third gear. Better for the engine, better for the transmission.

Overdrive is more load on the engine, and at lesser rpms the water pump is spinning slower, as well as the fan attached to the h20 pump.

Also there is a transmission cooler in the radiator. Climbing hills makes the transmission produce gobs of heat. This can reduce the efficacy of the radiator at reducing coolant temperatures.. Taking it out of overdrive reduces transmission temps, and increases the rate at which the ATF flows through the cooler.

Your catalytic converter might also be failing and restrictive.

 

[jimindenver]

I've towed in the Rockies for 30 years, going up hill slows ya down. You can cram a huge motor in to fight it, in my case a new Expedition with eco boost is very impressive. it is also a $60,000 up grade. So downshift, except what the engine will give you and enjoy the ride. You see a lot more at slower speeds.

 

[concretebox]

I'll just answer some questions real quick...Thanks for the help guys.

It doesn't have Overdrive.

Did you put the largest radiator that is available in?
I can't be sure, but it was at least as big as the original.

How's your fan clutch?
I have no idea. I'll check.

Does it have cab AC? does the AC work?
Yes it does. No, it doesn't work.

Does it have an engine oil cooler?
No.

Is your replacement engine over bored or factory bore?
I have no idea. How would I find out?

 

[highdesertranger]

ok if you never plan on fixing the ac, remove the ac condenser. if your engine was brand new it's factory bored, if it was rebuilt or refurbished or any other kinda of fancy name it is overbored. unfortunately there is no way to know without pulling a head, unless you have paper work. I don't remember off the top of my head what is a safe over bore for a 351 but if that was exceeded nothing will help.
so check the fan clutch and a cheap upgrade is a full flow thermostat. if your fan clutch is good and the full flow t-stat doesn't bring the temps down you have to start spending some real money. add an oil cooler and the biggest radiator you can fit in there. I should have asked this on my first post, are you sure your gauge is accurate? also a vacuum leak will cause elevated temps. is it idling high? also a slipping trans, elevated trans temps will also raise your temps. do you have a trans cooler? is the radiator shroud on? I wish I could look at it, diagnosing problems over the net is not easy. highdesertranger

 

[Canine]

First off, sorry you are having heating up issues. As far as power goes, unless your rig is 20 feet or shorter, a 351 is an inadequate motor. I'm not throwing rocks, I had a 23 foot 1982 GMC class c with a 350. Up grades it was lucky to keep 35. I had a 4 core ( biggest available) radiator put in it, a tranny cooler, a flex fan and a continuous t stat. Also replaced the water pump with an optional one that had more vanes inside. Mine did not overheat but I can't tell you if it was any or all of those things combined that did it. We never had air so no compressor drag. The radiator shop can tell you what size the rad is. They can also help you with the t stat and rad cap. Even a defective rad cap or t stat can be your problem.

Like others have said, climb in D on a 3 speed or 3 on a 4 speed auto. Rear end gears are usually adequate, like 4.10. I doubt if you have anything less.

Can you reduce the weight you are dragging or hauling. Plan your water fill for closer to your destination and keep fuel down to what is needed plus a safety margin. I had double 30 gallon tanks and learned to never fill both. Same with water, didn't fill. At 8 pounds a gallon, it adds up. If you like your rig it's worth fiddling with.

 

[GotSmart]

This might be your problem, from your blog.

""[font=Verdana, Arial, sans-serif] I mean I have acquired so much stuff for daily living, that when I need to pack to RV for travel, the floor becomes so cluttered with boxes and furniture, that I can barely move around.""[/font]


From your own words, the most likely  problem.   An RV was designed as a recreation vehicle, not a permanent home.   Take inventory and list the weight.  Go to the factory specs of how much weight is recommended for load...  and also check your air intake system.  A  clogged air cleaner can make a good motor run like an old dog.  So can a plugged muffler or cat converter. 

 

[Patrick46]

Yep, weight is one big factor. All that water is ALOT of weight!!

I had an E-250 that we ran cross country for years, and it would overheat too...even when it was darn near empty (load wise)

I learned to NOT push hard going up the mountains. In fact...don't push at all!!

You'll get better gas mileage, and your engine won't work so hard going up hills (albeit slowly)...but then it won't overheat either.

Overheating your engine will slowly kill it!!!

 

[wagoneer]

call me a p@@zy but out west we got a lotta steep grades up and down. 2001 E350 heavy duty XL high top diesel towing a trailer 35 mph big grades no overdrive pull into truck lane
downshift pull in back of a big rig going about the same speed and reelax those guys pushing hard will regret it in the end.

 

[cyndi]

My Class C, E350 with a 460 hated the big hills and the mountains, too. Every once in awhile it would go up them like it was nothing. Most times, though, it chugged up a hill at 35 mph and the engine ran a little on the hot side. The dummy gage said it was just with in it's limit. As soon as we crested the summit, it was fine.

It was a little embarrassing to have the tiny 4 cylinder cars passing me. And it was hard to breathe watching the temperature go up but we made it every time. she climbed the Rockies, the Appalachians, the Catskills, the Smokies, Adirondacks and, Berkshire to name a few. She was never any worse for the wear.

 

[concretebox]

ok if you never plan on fixing the ac, remove the ac condenser. if your engine was brand new it's factory bored, if it was rebuilt or refurbished or any other kinda of fancy name it is overbored. unfortunately there is no way to know without pulling a head, unless you have paper work. I don't remember off the top of my head what is a safe over bore for a 351 but if that was exceeded nothing will help.
so check the fan clutch and a cheap upgrade is a full flow thermostat. if your fan clutch is good and the full flow t-stat doesn't bring the temps down you have to start spending some real money. add an oil cooler and the biggest radiator you can fit in there. I should have asked this on my first post, are you sure your gauge is accurate? also a vacuum leak will cause elevated temps. is it idling high? also a slipping trans, elevated trans temps will also raise your temps. do you have a trans cooler? is the radiator shroud on? I wish I could look at it, diagnosing problems over the net is not easy. highdesertranger

I'm not ready to give up on the AC system. I might repair it at some point in the future. 

I have no paperwork on this engine so...I'll proceed with other solutions.

The engine oil cooler seems like a possibility. So does a flex-a-lite fan. The oil cooler is a more expensive and more involved job. I'll try the flex-a-lite fan first. I'm also thinking about getting the rad flushed and have a shop replace the thermostat at the same time (it's not that old, but I have spent some time in dusty AZ recently; and Stant recommends replacement after overheating).

I'll also check the air filter, it's pretty new, but I haven't checked it since my desert outing. 

I've never checked the gauge for accuracy. FYI, it's an aftermarket digital one...not the useless gauge on the instrument panel (it doesn't work at all). No vacuum leaks, not idling high, trans not slipping, trans has a cooler, still the original as far as I know. The shroud is on...


Dusty98-
How was the install job on the Flex fan? 

 

[skyl4rk]

Check the timing. A late timing will make the engine run hot with low power. Also, a worn out timing chain gets loose and stretches and ignition can bounce back and forth around the ideal angle.

 

[highdesertranger]

ask the radiator guy if you have the largest radiator that is available for your vehicle. you need a high flow thermostat. I wouldn't use stant. is the tranny cooler in the radiator or external. check your gauge, it's easy. highdesertranger

 

[SternWake]

The Flex a lite fan you intend on trying, is this an additional Electric fan or a different set of fan blades to replace to put on your fan clutch?

Radiators available these days are mostly aluminum, and instead of having 3 or 4 rows of brass tubes with copper fins, they have one or 2 rows of wider aluminum tubes, and aluminum fins.

Lots of debate on which is better, but so much cheap aluminum junk flows out of asia these days.

The overall thickness of the radiator core is what I believe HDR is referring to, as modifying the front end to accept a physically larger width and height radiator is not likely to occur.

The Longer the AC remains inoperative, the more likely it is that much more money will be required to return it to function.

Have you checked the Level of your coolant in the overflow tank and radiator itself? Does the heater still work?

Some V8s are so well balanced it is hard to tell when one cylinder is misfiring, or not firing at all, and you effectively lose 1/8th your power.

When was the last time it had a tune up? Spark plug wires, deteriorate rapidly under the doghouse as the reflective cover limits airflow, and also concentrates heat on the plug wires. Distributor caps with aluminum contacts(vs Brass) rarely last more than 10K miles.

This lack of power and a higher temperature under higher loads could be warning signs that the engine is not running properly, not necessarily that it is being overworked or the cooling system is not working properly.

Has your fuel economy dropped recently?

 

[concretebox]

The Flex a lite fan you intend on trying, is this an additional Electric fan or a different set of  fan blades to replace to put on your fan clutch?
Yes. 


Have you checked the Level of your coolant in the overflow tank and radiator itself?  Does the heater still work?
Yes and Yes. 


When was the last time it had a tune up?
I replaced the Spark Plugs, Ignition Coil, Distributor cap and rotor myself when I bought it, so about two years. I've kept close eye on all the fluids and hoses, checking daily during extended drives and exercising her monthly during long stays.

I don't remember if the Spark plug wires were replaced during the engine swap, I'll get the doghouse off and look.

Distributor caps with aluminum contacts(vs Brass) rarely last more than 10K miles.
Humm...I might have broken 10k in the last two years, if not I'm getting close. 


Has your fuel economy dropped recently?
Yeah. I'm down about 1.5-2mpg. I assumed it was the terrain. 

 

[SternWake]

 "Are you looking into A, or B"

Answer, YES.



Ok that is definitely covered.

Often people look at their spark plug wires, and declare them fine and dandy.

SP wires can't be judged by appearance, unless they are obviously burnt and grounding out on something metal or throwing sparks while the engine is running..

If power is down, MPG down, and temperature is up, these are a prime suspect.

SP wire quality is all over the map, with bad wires straight from the box.  I'm on year 8 on a set of 35 dollar 8mm Taylors, whereas I went through 5 sets in the previous 6 years with Accel, Belden and borg warner being the brands which failed in short order.

Make sure no wires touch each other, or anything grounded, and make sure when the doghouse is returned and tightened that it does not force them into each other or something grounded.

I've stripped my older sets of wires of their exterior insulation, and doubled up on insulation where they could touch each other or chafe or rest on something grounded.

My Taylors came with 2 different coil to distributor wires.  I tried to strip off the insulation on the extra unused wire and the insulation could not be removed.

Taylor's have many different models of wires from 35$ to 130$.  No need to go nutty on this with a stock engine and coil, just make sure they are routed properly and can't touch each other or grounded objects.

At night, with doghouse removed and engine running, when SP wires are bad, one might see a light show, or if touching a wire, get a real nice 30,000 volt shock.

If the vehicle is hard to start in wet humid weather, this is also a sign the SP wires are suspect.

Hilly Terrain will certainly impact mileage, but 2 MPG less on a vehicle that only gets 14MPG is quite significant and might be more than just terrain.

 

[concretebox]

Opps, I meant to say that it's a different set of fan blades to replace to put on the fan clutch.

I did install a "Heavy Duty" ignition coil. I can't remember why now. It was an MSD I remember.

I'm shopping for Taylor Spark Plug Wires now. There are three that match my vehicle.

 

[SternWake]

I think the flex a lite replacement fan blades claim to fame is not more airflow, but that the blades at higher rpm flatten out and cause less drag on the motor.  So good for high rpm hot rods seeking to lose a tenth of a second on the drag strip, but of no use to a campervan trying to keep cooler.

I've also heard reports that they can let go at high rpms and send a blade out through the hood, and shred the radiator and shroud.

The fan is really not effective at speeds above say 35mph anyway so I doubt its lack of airflow at those speeds is a contributing factor to your engine running hot under high loads.

 

[highdesertranger]

I know I gave you recommendations to spend money, but first try to find out what's wrong. please have your gauge checked or check it yourself first. this is easy and cheap. take your radiator cap off and put a thermometer in the water and run it then compare the readings. if you have a multi-meter find a resistance chart for your sender and check. you can also get a couple resisters cheap and check the gauge itself. with the temps you were describing I am leaning towards an inaccurate gauge. highdesertranger