Hummmmmmmmmmmmm question

Re: Hummmmmmmmmmmmm question

AF- 1972-76
Christian motorcycle Association member.
Born again in 1981 and never looked back.
Praise the Lord and looking forward to His return for us. :)

"Evil Triumps when Good Men Do nothing."

In Christs love, everyone is someone.

Its not about surviving the storm. Its about learning to dance in the rain
Re: Hummmmmmmmmmmmm question

Took her for another test drive today, 75 and fairly humid. Guess we`re good to go it runs 220 down the highway at 55 and cools to 210 at 45. When it is going slow at around 30-40 or up a hill the clutch fan kicks in and holds it at about 210-220. Once in a while it will kick in at 50 and bring it down on windy roads. Got home and let it idle for ten minutes and it rose to 235 and seemed to stay there, raised the rpm up and fan kicked in and cooled it to 225 then shut it down.
Does that sound like normal and ready to go on a trip ?
Am wondering if it would be a good idea for idling to put a electric fan in front of the rad with a temp switch set for 230 in and 220 out.
What ya all think? :)


Senior Member
Re: Hummmmmmmmmmmmm question

Lenn, I tried the electric fan on my 454 when I was having heating problems. I ended up putting a new radiator in and that solved the problem. Not much difference between rodding one out and a new one. If your clutch fan is working. Don't think the electric will make a difference. JMHO If you do a search on this forum. There has been some other folks with the same problem.
Re: Hummmmmmmmmmmmm question

The problem i`m having is I don`t know what is considered overheating on this unit, Shorty says it`s right where it`s supposed to be so what is normal ?
I`ll try a search.
Re: Hummmmmmmmmmmmm question

Found this post on another board that`s interesting, according to it i`m in good shape but i`ve never climbed mountains yet.

have a 1990 motorhome w/ 454 that also overheats (red lines in hot weather). Have been running it for 9 years and hasn't burn up yet. Below are some of the things I tried and results.
Spent $1400 replacing complete cooling sysytem (radiator, oversize fan clutch, and all new hoses. Didn't solve problem.
Tried all the snake oils that are out there to reduce temp, no luck
Replaced temp gaguage with digital, no luck.
Build air dam to funnel more air to block, no luck.
Finally I pulled the two cooling fans out and cut vents in the hood, that reduced the running temp by 20 degrees.
I am now convinced the mfg blocked the air flow to the radiator by re-designing the hood and with the fans, a/c condensed and transmissin cooler of which all set in front of the radiator.
My next step will be to pull the a/c condenser and test results.
I have contacted GM concerning problem w/ 454, asking what normal operating range is? they advised 230 degrees.
A local shop states, you can run as high as 260 w/ a 50/50 mixture of antifreeze before it boils and causes engine damage. I have also heard that: by adding additional hoses in order to increase the capacity of the cooling system will help


Senior Member
Re: Hummmmmmmmmmmmm question

Mine would run in that range on cool days. But in the heat of the summer and under load it would get to around 260. I just couldn't stand it. One would tell me I was fine, another would say it was hot. Your probably fine. Do know the electric fan didn't do anything. PM Domingo, he just did some things to his.
Re: Hummmmmmmmmmmmm question

Thanks guys, looks like it`s going to be one of those things that bug ya all the time. I`ll just have to see how it goes, my wife is scared to death of heights and i`m not fond of mountain driving anymore anyway. We plan on sticking to flat ground and being it will be winter maybe things will go our way.
Re: Hummmmmmmmmmmmm question

More up-date, We closed in above the radiator and had some openings on the sides as well we closed off. Took her for a drive and it ran 195-200 down the hwy.
Big improvement so the air dam is very important to have in place.
RE: Hummmmmmmmmmmmm question

Look at my post. I had the similar problem. Recently took it to Arkansas and Mi. Temperature gage never moved. I was going on some stip mountains and hot weather.average speed of 55 and 65 for hours ata time and temp gage never moved just stayed on the normal position.There where time where i had to drop my rv into second gear to be able to climb. I tought men this climb will relly cause my rv to over heat. No problem temperature gage never moved from normal position.
Re: Hummmmmmmmmmmmm question

Found it Domingo, yepper and glad you got the problem resolved.
I`ll see how mine goes now that i fixed the air dam, sure hope that fixes it don`t want head gasket failure.
RE: Hummmmmmmmmmmmm question

I talked to a lot of RV mechanics in my area. They told me to just live with it because my type of RV would always run hot. Well I can not live with it.Have taken several trips since I fixed the problem. Temperature gage never moves from normal position.I tell you I feel better driving down the road without worries. SpeciallyTexas weather. Man it get hot.

I am now looking for a tow car. SinceI feel good pulling something. Before I fixed the problem I would not even think about pulling.

Good luck let me know how it goes for you.

C Nash

Senior Member
Re: Hummmmmmmmmmmmm question

The engines of today are designed to run much hotter than the ones of yesterday. Get as much airflow through as possible. Make sure the radiator is clean inside and out and if that fails paste something over the guage so you can't see it :eek: ;) . As long as you are not losing coolent or hear gurgling after cutting the engine you are ok. JMO Proper collent mixture is also important.
Re: Hummmmmmmmmmmmm question

I`ve been really fighting it and it`s been very discouraging, don`t know if we`ll be taking the trip or not.
Fought for three hours putting on a new waterpump by pass hose this morning.
Then i took that after market temp gauge out of the head and put thefactory sensor back in so the dash gauge works. I think they calibrated them so it would only run half no matter how hot it gets. I plumbed in the gauge with numbers on it into a heat hose using a T.
After idling for 20 minutes the temp was only up to 160, with the gauge in the head as before it would of been reading 200 by then.
I`ll have to take it for a drive after i get rested up a bit, lotta work for a gettin old old man.
Re: Hummmmmmmmmmmmm question

Well here`s the results from a nice long drive.

I new there was a issue about where they put the temp sensor , the dash gauge never got past the half way mark even at idle. With the aftermarket gauge there it would of been reading 220-230 hwy and 230-240 idle. The after market gauge mounted in the heater hose never went past 210, ran 209 most the time on the hwy and going through town dropped to 195.

Got caught idling behind a school bus three times and it never went past 210.

None of that radical fluctuating like it did when it was in the head.

The clutch fan never engaged because it never made 215-220.

Now if i was to drain out a gal of anti-freeze and add a gal of water it should do better yet.

Gents lets hope i`ve whooped this horse, i`m loosing to much sleep.

Great board and thanks for all the help.
RE: Hummmmmmmmmmmmm question

Life is good. Thanks for keeping us uptodate with what you did. I am going to look at my air flow as well. may make some improvementsas well.