Chasis A/C condenser - blocking air lfow to radiator?

Update:

I removed the fan clutch and ordered a new one. Got to looking around and decided I could probably tackle removing the radiator provided I could drop it from underneath. Turns out I was able to drop it out the bottom. With the fan out and the radiator out I had a lot of working room and decided what the heck, this ain't too hard and removed the water pump for good measure. It seems to spin ok but since they are not too expensive and have it out I might as well put a new one back in. Now I'm thinking while I'm in there I should change the alternator out but maybe I'm getting carried away. Just seem like a good time to do it now. On a side note, the water pump looked like it had a chip in the inside of the housing just behind the blades. From the looks of it, I don't think it came from the factory like that. Wonder where the chip wound up.

image by hammond_spencer, on Flickr

Bite the bullet and buy a new radiator. It is 14 years old and sat for most of its life. The thing is clogged. Just to save you from having to replace the fan clutch in the near future replace it while the radiator is out. Contrary to popular (on this forum) belief a radiator is not a part that lasts for a lifetime. If you are overheating in 85 degree weather the rad is incapable of shedding any heat. Also make sure your antifreeze solution is 50/50 to 60/40 not 100%. Prior to replacing the radiator run a descaler/cleaner in the cooling system but make sure prior to installing the new radiator that everything, including the heater core, gets flushed clean. You should also remove the block plugs to get all of the sediment out of the bottom of the block.
Randy

Thanks Scott for the information.

My RV is a 2000 Monaco LaPalma 32 foot which I bought last year. It has 25k miles on it. The over heating "issue" was on a recent trip I took where outside temps were in the mid to high 80's. I was towing and the temp gauge got up to the red on multiple small but steep climbs. On one occasion I did over heat it to the point that the engine went into "safe mode". If the outside temps are 20 degrees cooler then I don't have too much trouble. Here's a couple screen shots from my phone showing intake temps and coolant temps. I did not grab any at it's worst temps, these are mainly just cruising down the highway but the outside temp was a lot cooler.

I am almost certain the fan clutch is bad. I never hear it. I even started the engine with the motor cover off and although it turns it is not loud so I do not believe it's turning at engine RPM. It's hard to know if the lower hose collapses since I can't see it at highway speeds but I did test it in the driveway and it does not collapse. I am replacing the thermostat because I had it out anyway. I purchased a new one and boiled them both. The new one opens a little further. I think I'll replace the coolant with fresh after I get the new fan clutch and see if that fixes things.

These are just examples of my temps, neither one is necessarily alarming although I'd like to think I would be closer to 195 when outside temps are in the low 60's.

image by hammond_spencer, on Flickr
This one I am climbing a hill but it's only 57 degrees out.

image by hammond_spencer, on Flickr

flapbreaker wrote:
I had some over heating issues while towing in 85 degree weather up hills recently. I've never heard my clutch fan kick in so I am replacing that and also the thermostat (it opens but a new one opens a bit more when I compared the two). Anyway, I know it's important to keep proper airflow through the radiator. While looking around it appears that I have a large A/C condenser that sits right in front of the radiator. The condenser has very thin blades with very tiny spaces. Much smaller than the radiators spaces. Also, in front of that sit's another cooler of some sort. I feel like the A/C condenser would have to reduce airflow through the radiator. Are there different condensers that would allow better airflow or should I not worry about it?

flapbreaker,
A few things here before you zoom off to your local auto parts store and start wasting money. First, A/C condensers have been placed in front of radiators since the beginning of time and, for the most part, have never caused any heating conditions. The manufacturers have calculated all this out, including all air flow with, and without fan clutches. So, without being there and helping you with this issue, I'd say your A/C condenser is not hindering your cooling system what so ever.

Second, I had the almost exact same unit that you have now, in our last coach. It was a '99 Fleetwood Bounder, 34V with the F-53 chassis and the V-10. That unit ran flawless for the full seven years we kept it. It never moved an inch, without towing something. We ran the trip from San Diego to Moab Utah for the Easter Jeep Safari, for fourteen years straight and not one over heat condition ever popped up. We also had the earlier version, a 28' Class C with the 460 and it too, ran great without any heating issues.

Third, fan clutches are great inventions. When working as designed, they give additional power to the engine, when not needed and, under certain working conditions. About 99.9% of the time, on a cold start, the fan clutch will go to almost full lockup, due to its programming. But, if you were to drive off, when the engine is still dead cold, you'd really hear the thing for the first few hundred feet. Then, miraculously, it goes instantly silent. When operating our Bounder and driving away from our home, it could plan the exact spot in the next block, when the clutch would go silent.

So, one point here is, before you go buy either the factory fan clutch, which, are you sitting down, is right at $140.00 or, an "el cheapo" at your local Auto Zone, which is around $49.00 and, you really get what you pay for here, make sure your fan clutch is in fact, DEAD! Many fan clutches, when dying, will "Lock up" to a full 100% and stay that way. Not all, but many. I'm not saying your fan clutch isn't bad, it very well may be. I'm just suggesting you do some tests before tossing an expensive part.

Fourth, you don't say what exact coach you have, the mileage, how long you've owned it and, what, if any, maintenance has been done on the cooling system. The lower radiator hose can cause the same heating issues you spoke of because the spring, inside it, has either disappeared, rusted, collapsed, or ? You've dug into the thermostat and tested it and found it works but, you're thinking of replacing it with another one and, that's fine, it's not much of an expenditure.

You say you had a "heating issue". May I ask, what exactly do you mean? Did it boil out? Or, did the needle on the gage just climb up into an area that it normally doesn't go to? Another thing. If you have one of those infra-red heat temp guns, (you can get them in many places), you can start your engine up, and keep shooting that gun at the thermostat housing, top and bottom, to see at what temp, the thermostat opens, when operating the engine during warm up.

And finally, you can do a flow test. Leave the cap off the radiator and start the beast up. The coolant will just sit there while in the warm up stage. But, when the thermostat opens, you'll see an instant flow if, the water pump is functioning appropriately. Then, it will come to an abrupt stop because the thermostat closed again. If all that is well, then you should have a clear set of tubes in the radiator. You can also see, during hard revving, the collapse of that lower hose, if the spring is missing. That would cut off the coolant supply during hard acceleration or, hill/grade climbing. Not good.

Anyway, hope you get this situation remedied without ruining your A/C system. Good luck.
Scott

My fan wouldn't turn on because a wire got bent by the fan clutch. Mine was a cheap fix, I just bent wire back and it made good connection.

Maybe you'll get lucky.

Bert,

Thanks for the tips. I did shift down and any increase in RPM's only added to the problem.

A couple of possibilities you might try. You might check on the addition of an electric 12V fan, push or pull, in front of or behind the radiator and thermostatically controlled. They have been used on some motorhomes and cars and trucks also. Another thought might be to try shifting down one gear and let the engine rev a little higher up the hills to work a little easier. Hope this may help, Happy trails, Bert

Since I've never heard the clutch fan I am replacing it. Not sure if this is a valid test but when I removed the clutch fan I applied some heat to the thermal coil. It did move but I could still turn the fan by hand. Not sure if more than the coil needs get hot before the clutch would kick in. Either way, everything I have read say's that the sound is unmistakable and I just don't hear anything different hot or cold.

To awnser your question, Reddot corp. makes a roof mont condensor that works well.
Looks good ,just like you're roof AC unit with plastic cover.Down side is you have 2 hoses & wires to run up to the unit,
One thing you might check is fan stat.When thermostats opens usually around 180 will let water circulate it will cool some,As heat rises to around 200 fan stat will tell fan to kick in.your AC will make your fan run also to cool condensor if needed so you have a lot of variables. I would check coollant flow ( radiator as mentioned earlier) a swell as fan stat before I jumped to mounting a roof top.

It's a 2000 F53 v10 with 25k miles on it. I bought it last year when it had 23k miles so I don't know it's history as far as the radiator is concerned. Everything looks to be of the same age so I don't think there were any aftermarket additions. It did come with a couple partial bottles of anti freeze. Not sure why as it does not leak any. I'll flush the radiator. Was considering just replacing it while I have the clutch fan out but really not sure if it's necessary.