440-3 running hot but not overheating

[MSN Member]

From: 67imp  
Sent: 8/26/2008 

Took the coach out for the first real stretch of it legs since I bought it.
I ran into two problems and will address them separately.
While on this trip the engine ran hot, never overheated and stayed in the upper regions of the normal zone the whole way on the highway.
One the return trip the same thing happened and when we stopped for fuel coolant ran out of the front . I assume it was the overfill . probably only about a quart or so. I hopped back on the road without a problem and it just ran hot.
The previous owner put a rather large trans cooler in the front of the radiator and it covers probably 1/2 of the radiator . transmission stays very cool but this might be causing my problem.
Also in the glove box I noticed a new thermostat and it was not the shielded type so possibly there is the wrong stat in it.
Is there a better place for the trans cooler than directly in front?
If the thermostat is not the correct one which one should I go with 160 deg. or 185 deg.?

[75Travco]

Sent: 8/26/2008

The 440 should have a skirted style thermostat, non-skirted units can cause overheating as the coolant will recirculate (bypass th radiator).  The 185 degree thermostat should work OK.  These engines are well known for boiling out a little coolant after a hot shut down; the recovery tank should catch the expelled liquid so it can be drawn back in when things cool down.

Can't help you on the external transmission fluid cooler, I'm still using the internal cooler in the radiator.  Does sound large - more like the size of an air conditioning condensor.

[Oz]

Sent: 8/26/2008

The aftermarket tranny cooler should be able to be relocated, or you can get a smaller one.  If it's blocking half the radiator, that isn't good.  You need as much cooling surface as possible so you really don't want to block it at all.  A small tranny oil cooler mounted below the bumper line is a good set-up and they aren't expensive.

Everything you want to know about the 440 thermostat can be found using the Message Search.

[MSN Member]

From: Moesyn
Sent: 9/3/2008M

Anyone experiencing the exact problem described above who is sure they have covered ALL the bases (as we experienced in Carson City on the drive home to Socal from Burning Man )  is encouraged to check the condition of their Mr. Gasket skirted thermostat ASAP!! After ruling out everything else (Pandora's engine and cooling system, including thermostat, are virtually brand new) I decided to pull the thermostat and replace it with the spare I carry. The second I took off the cover was revalatory. The %#$@^ thing had sectioned in TWO separate pieces... the top breaking clear off of the mounting point where it is press-sealed on. I put in the new thermostat, and didn't hit more than 200 deg. the entire drive home through 95 deg weather, hills, etc. I realize this problem was progressive, as my report on the supplemental Derale electric fan I installed about a month ago was informed by the higher temps I was experiencing (hence, the fan, switching to super unleaded, water wetter, new rad caps, refitting rad skirting etc etc... it just kept running hotter).

Long story short, I now keep two spare skirted thermostats in the rig, and will probably be switching them out before major trips just to be safe. Not exactly a quality part when it breaks in two pieces @ ~ 4K miles (?!) or am I expecting too much.

Either way, Pandora is a trooper... poor Mr. Gasket done lost his mojo!

Dave/Moesyn

[West coast redneck]

Sent: 10/19/2008 

These engines run hot.I put duel 3 inch exhaust.Increased power & reduced operating temps.Sounds great to.

[nikoj]

I had cooling problems with my 440-1, (ugh) decided to have the radiator checked out but considering  the cost made me think taking a poke at it myself was a reasonable risk, as it turned out it was a good risk indeed.  Pulled the radiator and removed the top with an air/acetylene torch - mapp gas would work fine, mapp is a mixture that burns hotter than propane, it comes in yellow cylinders. I use it plumbing work. A standard homeowner propane torch may work ok.  I don't remember the exact number of tubes, seems like about 110 - 120 of which 27 were completely restricted. I used a piece of brazing rod to clean the tubes, slightly melted the leading end so there were no sharp edges and gently punched them out, flushing with lots of water. Ended up ruining only one tube. I used a high lead content solder purchased from a welding shop to put it back together - definitely would not use any other type of solder. I think it was 50/50, perhaps someone on this site knows the correct type for certain. Use a good commercial flux, with patience and plenty of time  and you can save a lot of money.  Cleanliness and good fluxing  are really important. Solder is easy to work with, you can work your way around the top during reassembly, the whole thing does not have to be heated at once. For disassembly the whole top does have to be heated, I didn't find  doing it difficult - why is taking something apart always easier than putting it back together? A couple of important points:1 !Do Not Make This Repair In The Chassis!  Burning a Winnebago is not permitted!   When I was talking to radiator shops about having this done (4 years back) they had to pull the rad - I think its law in CA.   2  Pressure check the radiator  before reinstalling it,  having to pull it twice isn't fun.  The soldering skills required are like plumbing skills, if you are good at plumbing, as most who are reading this probably are, you should be able to handle the job.  The big risk is not being able to complete the job - for whatever reason, in that case the radiator will be out and ready to go to the shop.

[Cooneytoones]

50/50 is the best to use for the job... anything with a higher brass content could easily cause you to melt the tubes. and then you'd be.........Well... Up the creek without a paddle.....the higher lead content the easier it is to solder with ...or, should I say, the lower the temp needed to melt the solder. the higher content of lead is harder and harder to find in some places, even 50/50 is hard to find sometimes, ever since the National Plumbing Code will not allow it's use on water piping.

Sounds like you did a great job of it and saved mucho denero.

[DaveVA78Chieftain]

50/50 solid core solder is normally avaialable through stained glass supply shops.  Used for soldering lead came together on stained glass.

Dave