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Cooling System Overhaul - Stumped and Frustrated

dhcomp said:
Thats good info right there, thanks. I need to figure out WTF motor i've got.
Don't anyone search the forums for how many times i've said that... :haha:
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Does the motor run right? When I was a kid we had an old ford van, that after a new motor was put in, wouldnt pull like it should, and would always get hot regardless of anything we did. (big radiator, big fixed fan) Several years later, we figured out that the cam was retarded a tooth or two (cant remember for sure). After that was fixed it was a whole new truck. NO more overheating and pulled like it should.
 
black dawg said:
MY post kinda made it sound like I could accel to those (with the tbi 350) rpms. Basically it will hold its own down to 3500, but any slower and I would have to slow down and down shift to first.

Even with the 454, I am considering lower gears. Probably 4.56. gotta get an overdrive figured out first though. With a 4l80 I would go 4.56 in a heartbeat.
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383/4l80e/4.56/35s and 70 mph is 2300 all day long.
 
I find it interesting that you guys are running WOT while pulling hills... I have NEVER held my throttle to the floor while pulling anything. Always no more than about 80% and I LET the truck slow down but usually holds no less than 35mph if I'm real heavy, but 45mph is a typical pulling speed, which is usually fine to keep rolling with the big rigs doing the same thing.
 
4xcrazy said:
I find it interesting that you guys are running WOT while pulling hills... I have NEVER held my throttle to the floor while pulling anything. Always no more than about 80% and I LET the truck slow down but usually holds no less than 35mph if I'm real heavy, but 45mph is a typical pulling speed, which is usually fine to keep rolling with the big rigs doing the same thing.
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4600 lb boat and going 65 to 75 mph at WOT. Sure I could let off and slow down to 55 or 60 but why? :whistle:
 
4xcrazy said:
I find it interesting that you guys are running WOT while pulling hills... I have NEVER held my throttle to the floor while pulling anything. Always no more than about 80% and I LET the truck slow down but usually holds no less than 35mph if I'm real heavy, but 45mph is a typical pulling speed, which is usually fine to keep rolling with the big rigs doing the same thing.
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Its what happens when your family outgrows the old ford crewcab diesel, and you get to do your towing with a 350 powered suburban. Gas motors feel broken to me while towing, after using the diesel for 10 years.

with the 454, I rarely use more than 3/4 throttle, I cant afford to use more.
 
4xcrazy said:
I find it interesting that you guys are running WOT while pulling hills... I have NEVER held my throttle to the floor while pulling anything. Always no more than about 80% and I LET the truck slow down but usually holds no less than 35mph if I'm real heavy, but 45mph is a typical pulling speed, which is usually fine to keep rolling with the big rigs doing the same thing.
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I have no choice. I can back off a bit, and do sometimes, but for the most part, it needs almost WOT to keep going 25mph +.

Remember though, i am talking about long grades. Not on flat lands. On flat land, i get up to 60-70, and let it settle into od. Then just keep the torque converter locked and cruise.
 
I understand, I am also referring uphill grades, we have decent 6% uphill grades here Arizona as well, and while pulling a heavy trailer up these hills out of the Phoenix area, I personally have never held my throttle at WOT climbing them with A decently heavy trailer behind the truck. It just wasnt my thing to FORCE it to go any faster than it could.

I feel something is not set up right with your rig for pulling that kind of weight, be it the motor not running right, fuel pressure not right, something in the motor just doesn't seem right. I'm running a TBI 350/700r4/241 with A 14 bolt/ 4.10 gears with 35" tires and it pulls decently uphills without ANY overheating or bogging of the engine during normal downshifting.

Everyone wants to maintain 55-65 mph while towing heavy loads, I used to drive trucks OTR, It's not going to happen. You just need to maintain an acceptable speed at which your engine, transmission gearing, and rear differential gearing are going to be happy with that stays within the max torque range of the engine..
I've had a few to drink tonight while typing this on my phone, but I still believe It's something with the settings of, or mechanical workings of the engine causing your problems.
 
4xcrazy said:
I understand, I am also referring uphill grades, we have decent 6% uphill grades here Arizona as well, and while pulling a heavy trailer up these hills out of the Phoenix area, I personally have never held my throttle at WOT climbing them with A decently heavy trailer behind the truck. It just wasnt my thing to FORCE it to go any faster than it could.

I feel something is not set up right with your rig for pulling that kind of weight, be it the motor not running right, fuel pressure not right, something in the motor just doesn't seem right. I'm running a TBI 350/700r4/241 with A 14 bolt/ 4.10 gears with 35" tires and it pulls decently uphills without ANY overheating or bogging of the engine during normal downshifting.

Everyone wants to maintain 55-65 mph while towing heavy loads, I used to drive trucks OTR, It's not going to happen. You just need to maintain an acceptable speed at which your engine, transmission gearing, and rear differential gearing are going to be happy with that stays within the max torque range of the engine..
I've had a few to drink tonight while typing this on my phone, but I still believe It's something with the settings of, or mechanical workings of the engine causing your problems.
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If only i had something to compare it to.

I've got good fuel pressure, good spark, upgraded TBI stuff (CFM tech upgrades), built trans.

Not sure what is up with it.

But, that being said, WOT is all i've got. Not necessarily my style either, but sometimes you have to.

And at elevation, there are a few slow corner/grades where i've hit 7mph. At WOT. Quick hairpin at 10mph, then no power to accelerate from there.

Nothing like wondering if you'll have to stop and put in in 4 lo....
 
Ok, WTF.

My wheel bearings are going out on my BMW, and waiting for parts/tools to replace them. Of course, i've just started commuting again, so i get to start driving the burb. Go to drive it last friday, get about a mile from my house, and realize the temp gauge is almost pegged. WTF. It had run with the remote start for a bit, but not long.

Pull over, go to check coolant, and it looks like it spewed coolant out the radiator cap.

Open the cap, and the radiator is mostly dry.

Figure the tstat didnt' open. Cant say if the coolant leaked out and failed to get the Tstat warm, or if the Tstat failed and made it spit everywhere.

So, fill it with water, fire it up again, no issues.

Drive it for a few days, watching closely, no issues.

Decide its a good time to replace tstat and rad cap (although, delco stat and staun lever vent cap were replaced 6 months ago).

Flush coolant with tap water, then with distilled. Replace tstat/cap, refill with coolant mix.

Seems to not want to open before 3/4 temp gauge (210 is middle). Stock 195˚ tstat, not opening til 230+. Then, once its open the gauge fluctuates between just below and just above 210. Load, no load, doesn't matter.

Temp sensor was replaced recently. Whats a good way to verify my gauge isn't freaking out?

Getting sick of these stupid cooling issues.
 
IR temp gun, or my preferred method would be to hook up a scantool/ALDL cable and see what the ECM is reporting as engine temp.

Not to start a flame war, but there is nothing wrong with the factory gauges. They have proven to be incredibly durable and reliable in my experience. When I see something like you are I would verify that it's reporting correctly, but I'd expect it is, especially since you know it WILL read what t-stat rated temp is.

Only time I've seen temps "flutter" is when I was low on coolant. Did you double check after having driven, to make sure the radiator is still full? Stupid question I know, but if you are losing coolant, or just refilled, it may have gone low again.

You aren't the only one with cooling issues, I'm still losing coolant over long periods that isn't showing up anywhere, even after pressure testing the coolant system. :(
 
Yep, checked the coolant multiple times.

Wonder if i'm losing pressure somewhere? Leaking cap seal or something?

Wierd it would boil over out the top of the cap, vs going into the overflow tank.
 
On the towing on grade issue here comparing to the guys in AZ etc. Keep in mind that he is towing up to lake Tahoe at 6,224 feet above sea level - and I think the pass is a good thousand feet over that. The motor is just not making as much power at that altitude.

I did not see this in this thread:
Do you have the full fan shroud installed?
You mentioned that the lower radiator hose was kinked a bit, did you fix that?
With your engine at full operating temp, rev it up to 2,500rpm or so and make sure that your hoses are not colapsing.
When your motor heats up, do you hear the fan clutch kicking on? It should be very noticable, and sound almost like your motor down-shifts.
If you don't mind draining your motor again: Drain all the coolant, fill motor with a bottle of CLR then top off with water and let it sit overnight. Drain the CLR and flush with water. The CLR does a great job of disolving calcium and rust deposits.
What is going on in/with your overflow tank when the motor overheats? Do you see fluid getting pushed back into the overflow tank?
Could the wrong intake gasket cause this if water passages are blocked?
 
Keitha said:
I did not see this in this thread:
Do you have the full fan shroud installed?
You mentioned that the lower radiator hose was kinked a bit, did you fix that?
With your engine at full operating temp, rev it up to 2,500rpm or so and make sure that your hoses are not colapsing.
When your motor heats up, do you hear the fan clutch kicking on? It should be very noticable, and sound almost like your motor down-shifts.
If you don't mind draining your motor again: Drain all the coolant, fill motor with a bottle of CLR then top off with water and let it sit overnight. Drain the CLR and flush with water. The CLR does a great job of disolving calcium and rust deposits.
What is going on in/with your overflow tank when the motor overheats? Do you see fluid getting pushed back into the overflow tank?
Could the wrong intake gasket cause this if water passages are blocked?
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Hm, lots of good points.

Stock shroud is there, in good shape. Rad hose isn't kinked.

Need to see if they are collapsing. What would cause this? I'm guessing the upper would collapse? The hoses are only 6 months old.

The last time it started to overheat, there wasn't anything really in the overflow. Weird. Just seemed to have sprayed out around the cap area. Hard to tell though.

Will double check that the overflow hose isn't plugged.
 
Hose collapsing on the suction side if you have a restriction somewhere or have the wrong hose - like sucking on a straw and plugging the end with your finger.
 
Keitha said:
On the towing on grade issue here comparing to the guys in AZ etc. Keep in mind that he is towing up to lake Tahoe at 6,224 feet above sea level - and I think the pass is a good thousand feet over that. The motor is just not making as much power at that altitude.

I did not see this in this thread:
Do you have the full fan shroud installed?
You mentioned that the lower radiator hose was kinked a bit, did you fix that?
With your engine at full operating temp, rev it up to 2,500rpm or so and make sure that your hoses are not colapsing.
When your motor heats up, do you hear the fan clutch kicking on? It should be very noticable, and sound almost like your motor down-shifts.
If you don't mind draining your motor again: Drain all the coolant, fill motor with a bottle of CLR then top off with water and let it sit overnight. Drain the CLR and flush with water. The CLR does a great job of disolving calcium and rust deposits.
What is going on in/with your overflow tank when the motor overheats? Do you see fluid getting pushed back into the overflow tank?
Could the wrong intake gasket cause this if water passages are blocked?
Click to expand...

I never thought of that stuff, but it does do a good job outside of a motor. I wonder how much it could clean out a block and heads. :dunno:
 
With the weather in your area, you could just run the tranny on a separate cooler. All the built in coolers in radiators really do is WARM the tranny up to operating temps, then obviously hold it there. I never run mine through the radiator, if it leaks, antifreeze will wipe a tranny out in a heartbeat. Now if you lived in Alaska or something, thats different. In the winter here, I let mine warm up quite a bit before I flog on it so the tranny is warm.

Anywhere above 210 on a tranny is way to hot, the seals harden at 220 or so. 180 is best for them. I still have no idea why they have gauges that read up to 300 or so on trannys, by then they are done smoked and the clutches are being burnt into submission.

Sounds like your cap is bad, or your overflow bottle hose is plugged, it shouldnt boil out of the cap at all.
 
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