Gradually rising temperature

[Seabronc]

How do I measure coolant temp after it gets hot? If I take the radiator cap off, hot coolant will burst out, and if I leave it off during warmup eventually coolant starts overflowing out of radiator...

Just as BB suggested.  Get an inexpensive laser temperature measuring gun and aim it at the radiator next to the radiator hose.  The surface of the metal will be at the temperature of the water leaving the engine.  You can get them at Home Depot or an auto parts store.

It is a great tool to have, you can measure anything that you are interested in the temperature of just by bouncing the laser beam off it.  

>-

 

[miesk5]

yo,

OK, I admit that I have C&P issues as well as some brain cell loss;

Burping, from 92 Bronco Owner's Guide:
"...1.  Fill the radiator with a 50/50 mixture of the specified engine coolant concentrate and water. Allow several minutes for trapped air to escape (bubble out) and for engine coolant to flow through the radiator.
2. Replace the radiator cap to its fully installed position, then back off to the first stop. This will prevent high pressure from building up in the cooling system during this part of the fill procedure.
3. Start and idle the engine until the thermostat opens and the radiator upper hose becomes warm.
4. Shut off the engine and allow the engine to cool. Cover the radiator cap with a thick cloth and cautiously remove it. Step back while the pressure releases.
5. Finally, check the radiator and add more engine coolant if needed, following the procedures noted above. Reinstall the radiator cap securely, when finished.
6. If more engine coolant is necessary, fill the overflow reservoir to the appropriate level marked on the bottle..."

===

One more Q;

 can you  hear some sort of fluid gurgling when you shut engine off?

 

[Rons beast]

Hey Kid ....you got tons of good info here.  A lot of us are anxious to see how this problem is resolved.  I for one believe that if you swap that 195 tstat with a 180 you will be happy... but that's just me.  Wife calls me, "delightfully odd."

I know the stock calls for a 195 like M5 said...but you're not running a stock engine.  If it were me I'd have the 180 in there, 

 

[B-Co Kid]

Miesk, I don't recall hearing gurgling sounds, but I will pay more attention to see if it does. I will also get an external temp gauge to measure coolant temp. Ron, I was going over the burping technique, and I did not have the B-Co on an incline or elevated at the front. I will also incorporate the process for burping miesk posted. I will try these suggestions first. I may try the 180 tstat afterward. They are relatively inexpensive.

 

[Bully Bob]

"I will also get an external temp gauge to measure coolant temp"

If refering to the laser.., you can point it at the block, rad, hoses, 'stat housing, etc..., any number of places.

I find it best to hold 3-4 inches from object.

These locations will be the same temp. as the liquid inside. No need to have the rad. cap off.

And of course, do this before & again when the needle is above your comfort zone.

Do it again after eng. is shut off.  Will see a rise in temp. on the laser gun.

 

[B-Co Kid]

So I did some non-financial troubleshooting yesterday, and noticed a couple of things. I parked on an incline to have the front elevated, and I burped the cooling system. I left the radiator cap off just until it got warmed and coolant started to overflow a little, and I put the cap back on. I let the engine run for 20-30 mins in park on the incline. Temp stayed between the o and r in NORMAL, (haven't gotten the laser temp sensor yet so I don't have exact numbers yet, but I wil later). I set the parking brake, put it in drive, still on the incline, and let it run for an additional 15-20 mins. Temp gauge stayed between the r and m. I pulled off the incline and drove around and stopped on a level surface, with park brake set and in gear. I stayed for about 10 mins, and the gauge gradually moved up past the L. While sitting, I noticed the engine periodically surged/stumbled and that these surges coincided with a noticeable drop in rpms and also a drop in fuel pressure. Fuel pressure regulator is set at 5.5 psi. When the surge/stumble occurs the pressure drops to 3-3.5 psi for a few secs then goes back to normal. And as I said, it happens periodically. Below is the video of it happening. After all of that, I drove around for another ten mins. The temp dropped back to normal between the r and the m. When I parked and shut the engine off, I did not hear any gurgling. I'm not sure if any of this is related, but just trying to give all noticeable info.

trim.f1P6Er.MOV

 

[nelbur]

It is my opinion that you need to hook up your thermostat bypass system.    Ford added it because there is not enough flow through the thermostat alone to cool the engine in tough conditions.   The bypass likely doubles the flow to the radiator as compaired to forcing all the cooling water to go through the thermostat.   The 90 degree bypass hose goes from the top of the water pump into the bib you have a plug on.

 

[Bully Bob]

I like nelbrs point.  Thought that was already corrected.

W/O re-reading 4 pages :-B ..,  how old is this 351 block..?  Re-built..?

That flowing out the rad. cap hole is suspicious..., in that there may be a restriction in the block, or elsewhere.

(if that hasn't already been mentioned)

 

[B-Co Kid]

So how exactly do I reconnect the bypass system? The top hose on the water pump, now, goes to the tstat housing. The bottom port on the water pump, for the heater, is plugged. Sorry if i sound elementary, but my engine bay caught on fire many years back, and all of the original setups were destroyed or deleted. So I don't recall how the thermostat bypass was setup. Bully, the block is the original block. It was

Rebuilt about 4 yrs ago. I've put about 1-2k miles on the engine since its been rebuilt. As far as the flowing out of the radiator cap, isn't that normal..if I leave the cap off and the engine warms to normal operating temp, shouldn't the coolant start to come out?

 

[Seabronc]

So how exactly do I reconnect the bypass system? The top hose on the water pump, now, goes to the tstat housing. The bottom port on the water pump, for the heater, is plugged. Sorry if i sound elementary, but my engine bay caught on fire many years back, and all of the original setups were destroyed or deleted. So I don't recall how the thermostat bypass was setup. Bully, the block is the original block. It was

Rebuilt about 4 yrs ago. I've put about 1-2k miles on the engine since its been rebuilt. As far as the flowing out of the radiator cap, isn't that normal..if I leave the cap off and the engine warms to normal operating temp, shouldn't the coolant start to come out?

I thought we already went over that.  If you have the bypass hose on the way I told you before, the only thing you can add is the heater hoses.  By the way, the purpose of the bypass hose is to allow for minor circulation of coolant in the engine and to allow your heater to put out heat before the thermostat opens. 

Yes, you will have some overflow due to the expansion of the fluid as it heats up, if the cap is off.  If it is on tight, generally there should be no overflow to the expansion tank unless the coolant exceeds the cap designed overflow temperature.

I need to ask a question, perhaps you have already  answered it someplace.  Where do you live?  And what was the outside air temperature when you ran your non-financial test?  OK, that's two questions.

Keep one thing in mind.  The water system, as designed, is most inefficient when the engine is running at idle and in drive. The reason is that your water pump is running at it's slowest, (moving the least amount of water), the least amount of air is flowing across the radiator fins, (which means poorest dissipation of heat).  Combining those two conditions will generally cause the engine temperature to slowly creep up. I would expect to get the exact results you got.  Since you already said you have an external tranny cooler ahead of the radiator, the only thing I would recommend is a larger radiator, (in your case the radiator that is used on Broncos with A/C), and an electric fan like one on the 4.6L Ford engine.  I had similar problems in the Summer until I made those modifications.  After that my engine never got much more than 2 degrees above the fan temperature setting.  That included driving on roads with surface temperatures exceeding 130 degrees or parked at stop lights or just crawling along at just above idle speed. The great thing about an electric fan is that it is running full speed no matter when it comes on unlike your mechanical fan.  

Oh yah, by the way, that fan draws 4200 CFM.  That"s a lot of air!

And one other thought on your radiator cap, are you sure it is functioning properly? Is it a new one?

Also, is your transmission oil being circulated through both the transmission cooler, that is mounted ahead of the radiator, and the cooler that is built into the radiator core?

>-  

 

[miesk5]

yo,

  Here is what I have from past long-gone bulleting boards & mail lists;

WP can stay in-place; drain some coolant; figure on what is needed to be drained. I am ****, I strain coolant, gasoline thru coffee filters before pouring it back in.

This hose part # may be made for both the 5.0 & 5.8 so it , so if it's too long & Kinks @ bend cut enuf off to fit

http://www.supermotors.org/getfile/135781/fullsize/coolanttemp.jpg

pic by Jermil

By-Pass Hose Installation Info & pics in an 87
Source: by 87BroncoEB (87EBBronco, Mike) at http://www.supermotors.net/clubs/superford/registry/9228/32330
 



Heater hose routings in 87 351W Bronco by Chilton

 

[B-Co Kid]

Seabronc, I thought he was referring to some other type of coolant bypass that I may have been unaware of.  I live in Houston, TX..so its been pretty hot and humid here.  the B-Co does the same when its super hot outside (100+degrees), on hot days (90-95), and in the evening when its even cooler (80).  The outside temp was about 90-95 degrees when I did the testing earlier this week.  The radiator cap is not new, but it is still providing a pretty good seal when in place.  what is the procedure for checking proper transmission fluid flow through the cooler??

I did some searching online and I came up with the photos below.  Since my heater is not connected, can i route the bottom port of the water pump to the top of the manifold as seen in the photo? Will this help with cooling??  This port on my edlebrock perform intake is plugged as of now.

 

[Seabronc]

 

Seabronc, I thought he was referring to some other type of coolant bypass that I may have been unaware of.  I live in Houston, TX..so its been pretty hot and humid here.  the B-Co does the same when its super hot outside (100+degrees), on hot days (90-95), and in the evening when its even cooler (80).  The outside temp was about 90-95 degrees when I did the testing earlier this week.  The radiator cap is not new, but it is still providing a pretty good seal when in place.  what is the procedure for checking proper transmission fluid flow through the cooler??

I did some searching online and I came up with the photos below.  Since my heater is not connected, can i route the bottom port of the water pump to the top of the manifold as seen in the photo? Will this help with cooling??  This port on my edlebrock perform intake is plugged as of now.

I have to apologize for my reverse labeling of the heater hoses.  As far as that hookup is concerned, I would not loop the heater hose ports if the heater is cut out of the system.  The reason being is that hookup will pull a lot of hot water out of the engine and just pump it, un-cooled back into the engine.  It bypasses the radiator.  the way you already have it is best.  

OK on where you are located, on a 90 - 95 degree day, you would be amazed at the temperature of the road surface.  

There is no need the measure the flow of the transmission fluid.  I only wanted to make sure that the hookup allows the fluid to flow through both coolers.

Radiator caps are a pressure release device, it needs to not allow overflow into the reservoir unless the coolant system pressure exceeds the cap design.  The system needs to have pressure for normal running to in order to prevent the bubbles developing in the system which would reduce the efficiency of the system, (watch a pan of water as it heats up and starts releasing oxygen as it gets up close to 200 degrees).  Keeping the pressure high in the system prevents the release of oxygen bubbles. Developing bubbles in the system reduces the heat transfer. Only liquid contact to the metal will help cool the engine.

Just to be on the safe side, you can have your system pressure tested or just buy a new cap.  

Also, since you live in a normally hot area of the US, I would not use a 50/50 mix, adjust up in the Winter if necessary.  The 50/50 mix is for areas that normally regularly get down to the 0 degree area. Without looking, I believe 50/50 is good for about -20 degrees. Real frigid areas would need a higher ratio of antifreeze in the Winter.

So, my suggestions are:

1. New cap

2. Adjust ratio of antifreeze to water so that it still has protection for your area based on the chart on the antifreeze bottle.  The more water the better the efficiency of the liquid to cool.

3. If necessary, I already told you what I did as far as the radiator and fan are concerned. That, along with adding an external tranny cooler to my system made my system bullet proof for the "Dog Days" of Summer.  

All of my modifications came from suggestions in, "Ford Muscle Magazine", and they worked far beyond what I expected.

Those are all the recommendations I can give you based on my experience.  I actually had a proposed  change to the pump, but never went that far as it was not necessary.

That's all folks!

>-

PS.  From a picture you posted, if you want a heater, it appears that yo have a bit more work to do than just re-plumbing the coil.

 

[B-Co Kid]

Seabronc, I will try suggestion 1 and 2 today and hopefully post results.  If all else fails, I guess I'll be looking to do and electric fan upgade.  I sure appreciate everyones help on this!! 

 

[Seabronc]

Seabronc, I will try suggestion 1 and 2 today and hopefully post results.  If all else fails, I guess I'll be looking to do and electric fan upgade.  I sure appreciate everyones help on this!! 

If you do the fan, i'd do the radiator upgrade also.

>-

 

[Bully Bob]

Those two pics above are very clear.

I speak from past experience but none with a 351.

--- what Seabronc said but including the original by-pass hose ---

The way I see it, there's now TWO by-pass hoses.  Both take hot water from the intake manifold

& send it back into pump & back into the engine. (no passage thru the radiator)

That's what by-pass means.., water that by-passes the radiator...?

One looped hose being the cabin heater elimination.

I would think both heater ******* plugged is the better way.

Water will flood out the rad. cap hole when the 'stat opens. When warmed up & settled down.., no more water should flow from the cap hole at normal idle. The level can rise & fall as the T-stat adjusts normally.., maybe some dribble-over then.

 

[Bully Bob]

Here again, some of the issues on this board are tough to diagnose without "boots on the ground"..!

This appears to be one..,  & it's possible the answer is something simple.

We sometimes ask the same questions over on a long thread like this, so bear with us.

As to the re-build & 1-2 thousand miles on this eng.  Has this climbing heat always been there since the re-build.?

Do you know how much over they bored the cylinders.?

Sometimes the wrong head gaskets or intake gaskets are used.

 

[B-Co Kid]

Bully, its hard to say if the climbing temp has been there since the rebuild.  I only drive it occasionally on the weekends, now.  After the engine/transmission/rear end/suspension got finished I started on the interior (all over the course of 4 yrs).  So its been a restoration project, that is now nearly finished.  and as i am starting to put miles on the engine now, im having problems that I didnt notice before because i wasnt driving it alot, because I was focused on other areas of the restoration.  the engine was overbored .060.  The engine runs strong, no fluid leaks, no symptoms of leaking head gasket, and i did the vaccum leak test using carb cleaner around the intake. all seems ok in those areas.

the plan is to do the following until the problem is resolved:

1. replacing radiator cap

2. replacing the newly installed 195 degree thermostat with a new 180 degree thermostat

3. wrapping the headers

4. upgrading radiator and electric fan swap

5. lastly, I dont know.

 

[B-Co Kid]

Im want to say im convinced my problem is the heat generated from the engine.  I replaced the radiator cap, let it run in park for about 20 mins.  Put it gear with the park brake engaged, temp stayed between the r and the m in NORMAL (But the hood was up).  Closed the hood, put it in gear, with park brake on, and the temp rose to the a in NORMAL after about 5 mins.  should i try header wrap, or go directly to electric fan/radiator upgrade?

 

[Bully Bob]

It's good you have a sense of humor...... ^_^ /emoticons/[email protected] 2x" width="20" height="20" />

The # of a T-stat only means that's the temp. it fully opens.

Changing to a 180 with an overheating issue won't do a thing in that a 180 will open fully at 180deg. then just sit there wide open no matter what the temp rises to.  Meaning it won't make the eng. run any cooler.

Pretty sure that year rig is designed to run at +- 195 for best performance.

The heavy duty rad. as Seabronc suggested is a good start if it isn't HD already.

The elect. fan is a great helper.., but shouldn't be a solution to some failure in the cooling system.

Wrapping can't hurt a thing....

This may be a record thread length... /