Is my RV running too hot?

[JimElliott]

Originally Posted by Oldvet

Back to square one, set timing at eight and test drove and it ran 220 at 55 mph and 235 at idle same as before.
Set timing back to 5-6 and same thing.
Difference is it`s 80 today and was 70 last evening.
Seems to be the nature of the beast, shut it off with dog house off and ya never hear any water boiling and it never pukes any water.
I`m done messing with it and am going to just drive it, the only thing that will cool it in hot weather is a bigger radiator. Had others tell me 220-230 is normal.
Always open for suggestions but i think that`s the way it is.

For one...The 10º increase in outside temp should NOT effect it that much, The only change was adding more A.F. which will effect it.
220 & 230 is not normal and IMHO it is looking or pointing to the radiator.
Now when I purchased my 83 and removed everything for inspection and change out it was discovered the core only had 4 rows BUT with 3/8 tubes along with the small 5 blade fan.
New core is 4 row but with 1/2 inch tubes and the fan is 18" 7 blade...
Could run 30% A.F. in the summer months and change it during the winter months if your rig is stored in the cold stuff.....

Jim

[Oldvet]

I`m not going to change anything, bet if i drive it this evening it will run at 195-200 on the hwy again.
My Dodge truck runs at 210 all the time so whats so out of line about a 454 pulling a lot of weight running 220 down the hwy.
If i was to drain all the anti-freeze out and put pure water in it right now i bet it would run the same temp.
Also the air temp coming through the rad is different now since i fixed the air dam and the clitch fan doesn`t engage going down the road as before even when the temp gage is read 220-230. So isn`t that telling me that the rad isn`t as hot as the temp gage is saying because the sensor is in the head beside the exhast passageways.
I`m betting that if i did what you did and move the sensor up on top in the intake manifold i`d get a lot cooler readings.
There is something that i can`t figure out and that sometimes just sitting there idling at 230 it will cool down to 215 and the fan never engages. How can it run cooler one time and hotter the next.

Also what would a 7 blade fan help if the fan is just coasting along as it is at a idle and going down the hwy.
The whole problem imo is it`s a poor designed radiator from the factory plus the sensor being in the gead giving a hotter reading.
Must be why the factory dash gage always reads at the half way mark, they made it that way so you could see that it was reading 230.

[JimElliott]

There is something that i can`t figure out and that sometimes just sitting there idling at 230 it will cool down to 215 and the fan never engages. How can it run cooler one time and hotter the next.

Maybe there is still pockets of air inside the engine but since the overflow bottle doesn't fill or shrink while running hot or cooling off has my head scratching....
My bottle will rise about 2 inches when the engine reaches the high temps and will refill the radiator within 3 hours...Do you think the bottle might be plugged up somehow....
You could pull off the top (radiator bottle inlet) and blow into it and see if it's clear.
Installed on mine is a clear plastic line and it always stays full of fluid.

Jim

[Oldvet]

That`s bugging me too, i did blow through it and it was clear plus i put a new hose on it.

[JimElliott]

Originally Posted by Oldvet

That`s bugging me too, i did blow through it and it was clear plus i put a new hose on it.

The thermal laws are being violated...When fluids get hot/cold they are going to expand or contract....
If your radiator is full the HOT water hasta dump into the overflow tank and when it cools it hasta pull the fluid back into the rad....
Did you operate the heater in the cab, Just turn it on and allow the water to full flow....That will burp the system.
After the rig cools please open the radiator cap when the test are complete or better yet in the early morning..

Jim

[Oldvet]

When i blew into the hose you have to blow hard to over come the rad. cap seal which i did and when i released the pressure anti-freeze shot out the hose so it isn`t plugged. I take it the water pressure has to overcome the 16 lb rating of the cap in order to let water into the overflow tank correct ?
If the water temp in the radiator didn`t get hot enough to build that pressure then no water would go into the bottle correct ?

I got in behind the rad with my air hose and blew backwards through it and am i ever getting a lot of dust and sand out of it.
As soon as its cooled off compleatly i`m going to wash it out with the pressure washer. I`ll adjust it so it isn`t shooting water to hard as not to damage anything.

[JimElliott]

Originally Posted by Oldvet

When i blew into the hose you have to blow hard to over come the rad. cap seal which i did and when i released the pressure anti-freeze shot out the hose so it isn`t plugged. I take it the water pressure has to overcome the 16 lb rating of the cap in order to let water into the overflow tank correct ?
If the water temp in the radiator didn`t get hot enough to build that pressure then no water would go into the bottle correct ?

Just the "thermal expansion" of the water would and should pass into the overflow tank....Something in that new rad cap is going on...Still believe your rad is low on water..

Jim

[Oldvet]

I ran the heater as you suggested and after a bit the overflow bottle went down about a quarter inch. Hope that takes care of that and it`s not burning anti-freeze or something.
I`d think it would boil over if a head gasket was that bad and smoke.
I`m thinking that radiator is pretty full of crud so we`ll get that washed out tonight.

[Oldvet]

Well i`m at a loss, washed rad out and took it for a drive, 220-230 hwy, 235-240 idle and now the fan doesn`t kick in until 230.
Can`t take off on a trip like this.

[JimElliott]

Originally Posted by Oldvet

Well i`m at a loss, washed rad out and took it for a drive, 220-230 hwy, 235-240 idle and now the fan doesn`t kick in until 230.
Can`t take off on a trip like this.

Dang...You are going into reverse cuz it was better last night...
Lettuce review what has been done....
Added some A.F. today to bring it up from +5º to -20º...
Tweaked the timing back and forth....No change.
Flushed out the junk from the radiator...How much dirt fell out?
Burped the heater core and the overflow bottle responded by dropping.

When you timed the engine what plug number did you hook the light to?
Did you use the lower engine tab? (4:30) position as your timing point?

Jim

[Oldvet]

Not a lot of dirt, far from plugged up.
Timed it off number one plug and used the timing plate on top off the damper.
Tried the lower one before and the mark ain`t even close.
When i first got the rig it wouldn`t idle very good, float was sunk so was loading up. Took a float out of another carb (same float) and it was idling great till today now its loading up again. Those good ole black junk floats, so i`ll have to order a new brass one for it.
I`m taking that aftermarket temp gage senser out of the head tomorrow and put it on top somewhere even if i have to drill and tap a hole in the thermostat housing. I`ll put the factory sensor back in the head and see what the readings are.
I find it hard to believe that the temp can get up to 240 at idle and not boil or puke .
It gets pretty discouraging, things are rough so ya want to get away but can`t even do that.
Shouldn`t of sold the horses so quick.

[JimElliott]

Originally Posted by Oldvet

Not a lot of dirt, far from plugged up.
Timed it off number one plug and used the timing plate on top off the damper.
Tried the lower one before and the mark ain`t even close.

I`m taking that aftermarket temp gage senser out of the head tomorrow and put it on top somewhere even if i have to drill and tap a hole in the thermostat housing. I`ll put the factory sensor back in the head and see what the readings are.
I find it hard to believe that the temp can get up to 240 at idle and not boil or puke .

Doubt if it will puke with a 16 # cap on it....
Didn't know about the after market sensor, Might want to purchase one from your "Chebby" stealor for the perfect match.
Timing off the lower tab requires hooking up to the #5 plug, How can you see the tab on the top side? Isn't the fan shroud blocking the view?

Jim

[Oldvet]

It`s hard to see but there`s a small area ya can just see it.
I`m not sure about the float, usually it will be dribbling out the secondaries if the floats sunk but it ain`t doing that.
It was idling perfect yesterday now today it starts idling rough, checked all the vacuum lines and everything looks good.
I think the aftermarket gage is accurate it`s where they put the sensor is what i don`t like.
When the factory sensor was in the head it ran just past straight up on the dash gauge, never went in the hot zone.
I put the aftermarket gauge on so i could read what the actual numbers were.
I`m still wondering if the water is actually as hot in the radiator as the gauge says when the sensor is in the head.
How about all this polution garbage can it be causing a problem, air pump, vac hoses running every where, EGR valve?

[JimElliott]

Originally Posted by Oldvet

It`s hard to see but there`s a small area ya can just see it.
I`m not sure about the float, usually it will be dribbling out the secondaries if the floats sunk but it ain`t doing that.
I think the aftermarket gage is accurate it`s where they put the sensor is what i don`t like.
When the factory sensor was in the head it ran just past straight up on the dash gauge, never went in the hot zone.
I put the aftermarket gauge on so i could read what the actual numbers were.
I`m still wondering if the water is actually as hot in the radiator as the gauge says when the sensor is in the head.
How about all this polution garbage can it be causing a problem, air pump, vac hoses running every where, EGR valve?

Ain't all of those hoses fantastic OK, Back to business, With the stock gauge running straight up I've measured it to be 210º with TWO laser heat detectors (about the same temp) so once you place it back to the stock just see what it indicates.
My fan kicks in just slightly to the right of the center hash mark which is about 213º and that big 7 blade pulls the temp down real quick...
Home Depot has a decent laser temp unit for $29.95 so I have another one for my collection and it is helpfull for anything below 600º.
When we get this water/heat problem solved I'll give some insight on the "EGR" but only through the PM...

Jim