Rocket9k
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Re: FORD 460 Overheating Mystery
Glad to hear you resolved this issue! Mine was multi-faceted as well. I had a factory radiator with the lower 6 rows completely plugged with sediment, and at least 8 more partially plugged. It ran hot all the time, and extended runs out of overdrive saw near overheating temperatures. A replacement radiator saw much improvement, but still not quite right. Turns out my fan clutch was weak as well. I agree with your assessment about the radiator size. People have said it has plenty of capacity to do the job but it seems small to me, especially for a 18,000 pound rig. Subsequent years have much larger radiators as well. Your rig looks to be in beautiful shape, good luck to you!1.1KViews0likes0CommentsRe: FORD 460 Overheating Mystery
goprolocal wrote: Hi, The fan cluth was just replaced a couple weeks ago. I can hear it roaring when it kicks on and it's oriented properly (sucking air from the front of the radiator to the back). And I do see it cool things off temporarily a few degrees when I hear it come on. Over time it heats up though...despite the fan it seems. When the fan comes on, what temperature on your gauge do you see it come on? I'm assuming you have the ford NORMAL gauge and an aftermarket numerical gauge. Do you hear it kicking on and off briefly at traffic lights/stops?607Views0likes0CommentsRe: FORD 460 Overheating Mystery
goprolocal wrote: Rocket9k wrote: goprolocal wrote: All the rubber in the engine compartment is intact and directing air through the radiator directly. Here again is a list of items that have been replaced to diagnose this hot issue. SYMPTOM: Rig: 1996-1997 Fleetwood Southwind 35P Ford 460 engine I bought it from auction at 23K miles about 5 years ago. I noticed right away that it ran on the hotter side of normal when traveling down the highway at speed over time. This seems to have progressively gotten to be worse over the last 10K miles (rig now has 33K miles on it). Now, when driving down the freeway with the overdrive off to simulate towing rpm, after about 10-15 minutes at 65mph, the temperature suddenly jumps from 210 to 255 degrees....like within 15 seconds. It will then stay at 255 until we either slow down to city street speeds. If I turn the overdrive on, it will cool to 245 degrees or so. Driving around town, the rig runs at 210 no problem...even with it being 115 degrees outside here in Arizona. But get on the highway for a bit and she gets hot. The rig has never boiled completely over. It runs excellent, no transmission slipping, engine missing, hard starting, nothing...runs great! Here is what we've done and tried: Check for exhaust gases in coolant (nope, not a blown head gasket) Checked clutch fan blades to be sure they are oriented properly (sucking air from the front to back of the radiator) Flush block and radiator (some **** came out) Vacuum filled block and radiator (in case some air pocket?) Replaced clutch fan (it's oriented correctly and working..I can hear it come on) Replaced radiator (yes, it's the proper radiator) Replaced thermostat (3x) Replaced fuel filter and fuel pump (in case it was running lean) Replaced spark plugs and wires Replaced oil and tranny fluid (very small amount of metal shavings in tranny fluid) Replaced water pump Replaced radiator hoses (in case it was kinking at high rpm) It was suggested that possible hot O2 sensors may be causing the rig to run lean under load. Anyone have any insight into this possibility. It has done something like a vapor lock when it was super hot after we pulled off the highway into a gas station...the rig sputtered and died at the pump. I could hear the fuel boiling so I'm pretty sure that was why. After letting it cool for 3 hours, it ran fine again. Just in case, I also opened the fuel cap to rule out a vacuum holding fuel back. At this point, I don't even know what else to replace or try...maybe an auxiliary electric fan? The other test I think we need to try is a flow test to see that water is circulating properly. It remains a mystery! Thank you to everyone for your ideas and input. I don't want to sell this rig but it's looking like that may be the final answer...either that or drive it until it's dead. Anyone have any input on the long term damage of running it at 255 degrees for 4-6 hour legs? Goprolocal, you're in too deep to give up on it now. Sounds like a great unit otherwise. You are in Arizona correct? I have a 1997 Winnebago Adventurer 34RQ that I just went through this with. A 460 is a hot runner, but running any V8 big block at a sustained 255 degrees is never ideal and will shorten engine/trans life. I have a few questions: -What brand radiator was used? The factory one has been discontinued for sometime, and there are more than a few incorrect radiators advertised as correct radiators. -Do you have a trans temp gauge? If so, what does it read? -What brand fan clutch was used (model number if possible?) If your engine is nearing 230F and the fan clutch is not fully engaged, it is not operating properly. The fan (once running) should be able to pull engine temp down fairly quickly (within 60 seconds). The fans on these chassis are quite aggressive, and when they are singing, capable of cooling the rig down quite well. As with radiators for this chassis, there are more wrong fan clutches than right ones. If you are not boiling over running it hard in the desert at 110+ degrees you are doing pretty good, just not quite good enough. I just called the shop that replaced the radiator a few years ago...no answer but I'm hoping they have the info. I can tell you that it was getting hot before the radiator was replaced and there was no change then after the radiator, water pump and thermostat were all replaced at the same time. The hot issue just seems to have progressively gotten worse over time. I'm going to call the shop and see what fan they put on it...they did make sure the blades were correctly oriented. I'm also going to suggest a coolant flow test of some sort. I don't have a trans temp gouge on the rig. I also plan to completely seal off the front of the rig somehow so that every molecule of air is forced to go through the radiator. We have a trip coming up in a few weeks...Gilbert, Az. to San Diego, Ca. Hopefully it will be a cooler run. :h I am suspicious of you radiator/fan clutch setup. Like it was mentioned before, Radiators for this chassis are not created equal. My money is on the fan clutch. If you are reaching 230f and the fan is not roaring, that's a problem. You can have the healthiest cooling system ever and without a properly functioning fan, it will still run hot/overheat. Fin count in the radiator can affect fan clutch operation as well as was mentioned previously.518Views0likes0CommentsRe: FORD 460 Overheating Mystery
goprolocal wrote: All the rubber in the engine compartment is intact and directing air through the radiator directly. Here again is a list of items that have been replaced to diagnose this hot issue. SYMPTOM: Rig: 1996-1997 Fleetwood Southwind 35P Ford 460 engine I bought it from auction at 23K miles about 5 years ago. I noticed right away that it ran on the hotter side of normal when traveling down the highway at speed over time. This seems to have progressively gotten to be worse over the last 10K miles (rig now has 33K miles on it). Now, when driving down the freeway with the overdrive off to simulate towing rpm, after about 10-15 minutes at 65mph, the temperature suddenly jumps from 210 to 255 degrees....like within 15 seconds. It will then stay at 255 until we either slow down to city street speeds. If I turn the overdrive on, it will cool to 245 degrees or so. Driving around town, the rig runs at 210 no problem...even with it being 115 degrees outside here in Arizona. But get on the highway for a bit and she gets hot. The rig has never boiled completely over. It runs excellent, no transmission slipping, engine missing, hard starting, nothing...runs great! Here is what we've done and tried: Check for exhaust gases in coolant (nope, not a blown head gasket) Checked clutch fan blades to be sure they are oriented properly (sucking air from the front to back of the radiator) Flush block and radiator (some **** came out) Vacuum filled block and radiator (in case some air pocket?) Replaced clutch fan (it's oriented correctly and working..I can hear it come on) Replaced radiator (yes, it's the proper radiator) Replaced thermostat (3x) Replaced fuel filter and fuel pump (in case it was running lean) Replaced spark plugs and wires Replaced oil and tranny fluid (very small amount of metal shavings in tranny fluid) Replaced water pump Replaced radiator hoses (in case it was kinking at high rpm) It was suggested that possible hot O2 sensors may be causing the rig to run lean under load. Anyone have any insight into this possibility. It has done something like a vapor lock when it was super hot after we pulled off the highway into a gas station...the rig sputtered and died at the pump. I could hear the fuel boiling so I'm pretty sure that was why. After letting it cool for 3 hours, it ran fine again. Just in case, I also opened the fuel cap to rule out a vacuum holding fuel back. At this point, I don't even know what else to replace or try...maybe an auxiliary electric fan? The other test I think we need to try is a flow test to see that water is circulating properly. It remains a mystery! Thank you to everyone for your ideas and input. I don't want to sell this rig but it's looking like that may be the final answer...either that or drive it until it's dead. Anyone have any input on the long term damage of running it at 255 degrees for 4-6 hour legs? Goprolocal, you're in too deep to give up on it now. Sounds like a great unit otherwise. You are in Arizona correct? I have a 1997 Winnebago Adventurer 34RQ that I just went through this with. A 460 is a hot runner, but running any V8 big block at a sustained 255 degrees is never ideal and will shorten engine/trans life. I have a few questions: -What brand radiator was used? The factory one has been discontinued for sometime, and there are more than a few incorrect radiators advertised as correct radiators. -Do you have a trans temp gauge? If so, what does it read? -What brand fan clutch was used (model number if possible?) If your engine is nearing 230F and the fan clutch is not fully engaged, it is not operating properly. The fan (once running) should be able to pull engine temp down fairly quickly (within 60 seconds). The fans on these chassis are quite aggressive, and when they are singing, capable of cooling the rig down quite well. As with radiators for this chassis, there are more wrong fan clutches than right ones. If you are not boiling over running it hard in the desert at 110+ degrees you are doing pretty good, just not quite good enough.518Views0likes0CommentsRe: Ford F53 460 powered fan clutch options?
RLS7201 wrote: Once up to temperature my gauge never moves off the "O" unless the the engine overheats. The clutch kicks in and out and the gauge don't move. Throughout the years of being on various RV forums, I typically see 460 issues such as yours, with replacement radiators. Do what you must. Richard I have been busy the last few weeks so haven't had a chance to work on the RV until this past weekend. Richard I did read your cautions about the fin per inch count of replacement radiators. I did my due diligence researching the Superior Cooling SC-3TZ8005C that I used in my rig for this very reason. I did raise this question and was assured by them that it was more than up to the job. It does not have the fin density of the original, but the same amount of rows with wider tubes. I am no radiator expert so after scouring the forums and speaking to others here who have used it (as well as being crunched for time) I spent the money and so far it works great. I was able to locate my problem this past weekend, but just to recap: The fan clutch operation was suspect from the beginning, but seeing as I had a leaking radiator and the previous owner admitting to using stop leak to stop the tanks from leaking, I went for it first. After replacement it ran much cooler, but the fan operation was the same, It would kick on sometimes at stop lights, was slow to engage at speed (if at all) and when it did come on it was very late, outside of the NORMAL range. I then installed the Hayden 2799 which did a great job, but too great of a job. It ran quite often and the noise wasn't very pleasant, especially at highway speeds. I cleaned up the face of the original clutch, as it was lightly coated with a sticky substance and dust and grime, and reinstalled. The problem got worse, I couldn't hear it engage at all at any traffic light or city driving. I managed to locate a new old stock fan clutch, part #F2TZ-8A616-B last week on the auction site. I pulled the doghouse cover (for what seemed like the 100th time this year :S) and pulled the original clutch out. I worked it back and forth by hand and it felt normal, but as I kept working it by hand it got easier and easier until it would just free wheel in my hand, with zero resistance. I let it sit for a minute, it returned to normal and I was able to do it again. No good. I would have never caught this the first time around as it felt good initially so I didn't read any further into it. I installed the new factory clutch and took her for a hard test drive. She ran nice and cool, Never even thought about getting out of the NORMAL range on the gauge and I could hear the fan cycle on and off briefly in stop and go traffic. I'm pretty fortunate to have made it all the miles I did in the dead of summer, Through the mountains etc. with a fan that kind of worked. I believe it just weeped enough of its silicone out of the front to no longer engage properly. I hope this bit of info will help someone else out in the future. I know there's still plenty of us running these old 460 rigs, so hopefully this will save someone some hair pulling. Now maybe I can enjoy her for the rest of the year instead of wrenching! :B Thanks all!1.4KViews0likes0CommentsRe: Ford F53 460 powered fan clutch options?
So to give this topic some closure: I took the motorhome for a drive yesterday and ran it hard to see how hot I could get it before the fan kicked on. It never happened, not even sitting at light, which it would always do for a few seconds after sitting still. I took it off last week to clean the spring and make sure the bearings were still tight, as well as test it with a heat gun. I must have let the rest of the smoke out, who knows. I am going to search for the original Ford part# F2TZ 8A616-B (which is discontinued) or tweak my Hayden so that it does not run continuously. I will post here again when it's all resolved so hopefully nobody else with one of these old rigs will have to chase their tail like I did!1.4KViews0likes0CommentsRe: Ford F53 460 powered fan clutch options?
Richard, it looks like you were moving the spring around considerably on that thing. Is that a Hayden 2799? From what I understand, 1/8" gives you approximately 10 degrees difference in engagement temperature. Did you find you had it move it more to get a change? It's going to be 84 degrees here tomorrow, so I may go wring its neck a bit and see how it does. To answer your radiator question, I have an all aluminum replacement from superior cooling, as well as a complete banks system. It seems to do the job very well. The temp gauge stays between the O and M on the ford NORMAL gauge (190-210 according to my IR gun) which is well within acceptable temperature range for the trusty 460. If I am out of overdrive in 3rd gear going down the highway at 65-70 the temp will goto A, WITH the dash A/C on. I am sure if i'm climbing with a load on it will go beyond that, which is why I want to be sure my fan is working properly. Where exactly did/does your factory fan clutch kick on if I may ask, on your \__NORMAL___/ gauge? I may have no problem whatsoever, but I would like to be 100% confident that I do not before I venture out on long runs.1.4KViews0likes0CommentsRe: Ford F53 460 powered fan clutch options?
Thanks everyone for all the info. I still need to check and probably change the transmission fluid. Last I checked it will still clear and smelled correct but i'm sure it's due for a change. RLS7201, your name has come up a bunch of times in the forum posts i've skimmed on this topic. I came across a post you did about making your fan clutch adjustable, but it's older and the pictures are gone. I'd like to see that if you still have the pictures? I'm thinking I can tweak mine to get it where I want it.1.4KViews0likes0CommentsRe: Ford F53 460 powered fan clutch options?
Now that I have replaced the plugged radiator it will run pretty cool between 190-210. The only time I can get it higher than that is if I'm in 3rd gear climbing an incline or out of overdrive going down the highway at 65-70. I have an electric fan mounted on the front of my condenser which helps slightly. It pretty much just keeps A/C temps down. Richard, thanks for the info. The Murray 2799 is a reboxed Hayden 2799, which I have already tried. It ran nearly constantly and the thermostat was in a tug of war with it trying to keep the engine temp up. I'm assuming yours does not operate this way? Also, before your OEM one failed, when did it kick on and off, at what temp scale, and how did it behave when it did fail?1.4KViews0likes0CommentsRe: Ford F53 460 powered fan clutch options?
Gijac, I did notice a coating of sticky goo on the spring and a little on the face of the aluminum casing. I cleaned it thoroughly when i had it apart and tested it with a torch. It seemed to work. From what I read, the clutches used on the F53 from 92-97 engage at around 200 degrees air temp. The Hayden severe duty that I tried engages at around 170 degrees air temp. It ran almost constantly. The factory clutch may be fine, but I would think it should come on long before it's getting that hot.252Views0likes0Comments
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