What is wrong with my cooling system!!!

Yes I still get bubbles in the overflow reservoir, they're just not as bad, it bubbles maybe once a second till it cools down compared to a constant bubbling with the 190 thermostat, and the upper hose is quite softer when hot. I'll do the glove test tomorrow after putting the 190 thermostat in it..

I just did the pressure test on the radiator and cap, I haven't done the compression leak test with the dye, I might if I'm not happy with the glove test.

fr7 said:

Yes I still get bubbles in the overflow reservoir, they're just not as bad, it bubbles maybe once a second till it cools down compared to a constant bubbling with the 190 thermostat, and the upper hose is quite softer when hot.

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My personal experience says be prepared for head crack.

fr7 said:

I haven't done the compression leak test with the dye, I might if I'm not happy with the glove test.

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My experience with dye test is it's also inconclusive as the dye never gets really dark, just barely.

So your first start in the morning is not running rough for short time, as if one cylinder is missing?

No, no hard start, missing or rough idling, no smoke of any kind, no weird smell from the exhaust, just regular condensation if it's cold in the morning. Other than that everything is normal. If I need head gaskets or have a cracked head/block I'm ready to pull the motor out.

fr7 said:

No, no hard start, missing or rough idling, no smoke of any kind, no weird smell from the exhaust, just regular condensation if it's cold in the morning. Other than that everything is normal. If I need head gaskets or have a cracked head/block I'm ready to pull the motor out.

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Lower intake? Mine leaks oil a bit

Do the Glove test and take head or gasket issue off the table, or find out that's the problem and you don't have to waste time on non-fixes

The only oil leaks I can see are from the pan gasket and a little bit around the pcv valve. I'm picking up some latex gloves or balloons on my way home tonight.
So I unplug the coil pack, seal the glove around the radiator filler, plug the overflow tube, crank it and watch if the glove gets air in it right? Does the engine need to be completely cold?
I'll let you know how it goes, thanks again guys..

fr7 said:

The only oil leaks I can see are from the pan gasket and a little bit around the pcv valve. I'm picking up some latex gloves or balloons on my way home tonight.
So I unplug the coil pack, seal the glove around the radiator filler, plug the overflow tube, crank it and watch if the glove gets air in it right? Does the engine need to be completely cold?
I'll let you know how it goes, thanks again guys..

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We’ll be watching your thread and hoping for the best. Good luck, bud.

Well after putting the 190 thermostat back and doing the glove test yesterday and again today I cannot see any air going in the glove. I had my friend crank it for about 10 seconds at the time while I watched, we almost drained the battery and nothing happened. Did this twice, different days, I made sure everything was sealed and no pressure was escaping.
Now I'm very lost. Is there a slim chance I still have a very tiny mini little microscopic air pocket and that's what is messing with Me? I'm sorry guys for being so annoying but I just feel so dumb and frustrated right now..

fr7 said:

Well after putting the 190 thermostat back and doing the glove test yesterday and again today I cannot see any air going in the glove. I had my friend crank it for about 10 seconds at the time while I watched, we almost drained the battery and nothing happened. Did this twice, different days, I made sure everything was sealed and no pressure was escaping.
Now I'm very lost. Is there a slim chance I still have a very tiny mini little microscopic air pocket and that's what is messing with Me? I'm sorry guys for being so annoying but I just feel so dumb and frustrated right now..

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Don't get discouraged. Diagnostics can be a real pain and I know how frustrating this can be. That's what the community is here for, it's not necessarily fast but for the most part it's free and effective.

Let's break this down a bit.

The problem:
You're not experiencing overheating but you see pressure buildup in the coolant reservoir system

What you've checked:
Water Pump is new
Radiator is new
Thermostat is new
Pressure test indicated system is sealed
Glove test showed no signs of exhaust gas buildup

OK so using this I'd say there are a few things to look into still.

Temp Sender: The unit on the water pump housing that detects heat of coolant exiting engine. You say you're not experiencing overheating, how sure are you of that? Are you pulling readings from OBDII to confirm or just trusting your gauge? Simple test to check for functionality.

Temp Sensor: Sensor that sends coolant temp to the computer. If you are using OBDII to pull temps, are you sure that the sensor is working properly?

Radiator Cap: I don't think it's likely since hopefully you changed rad caps after each new radiator, but if that little jerk has failed then that would explain pretty much all of your symptoms to a T. If it doesn't hold pressure properly then it could be the source of your problem.

Leaks: You didn't mention if you have seen any leaks or puddles on the ground so I had assumed you didn't. Double check every coolant line & fitting and after running the engine take a good whiff, if there is a leak you will smell it. Also a good idea to get under the car and look up at the timing cover, sometimes there's a leak from the WP or the surrounding area that goes unnoticed as it heats up and boils off before hitting the ground.

Really take a good look at the intake manifolds, make sure that they are sealed well. For leaks I'd recommend getting a UV dye off of Amazon and putting it in your coolant, run it for a day or two then pop the hood and go hunting for leaks using a black light and yellow tinted glasses. If there is a leak this will let you know when your engine bay lights up like a Jackson Pollock painting.

Blockage: Have you run any flushing through the system? Did you put any HG sealant in at any point? Is there a gurgling sound coming from your vents when the heat is on, particularly when you rev the engine?


There's a lot of things to still run down, and the cause of your issue could be related to any one or several of them in combination. It could still be a Head Gasket/Head issue that is very small and only presents itself when the engine is warm.

Sounds like you've got a unique beast of a problem, but don't stress yet, take your time and approach it methodically and you will figure it out.

fr7 said:

Well after putting the 190 thermostat back and doing the glove test yesterday and again today I cannot see any air going in the glove. I had my friend crank it for about 10 seconds at the time while I watched, we almost drained the battery and nothing happened. Did this twice, different days, I made sure everything was sealed and no pressure was escaping.
Now I'm very lost. Is there a slim chance I still have a very tiny mini little microscopic air pocket and that's what is messing with Me? I'm sorry guys for being so annoying but I just feel so dumb and frustrated right now..

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Good deal

Remove rad cap and top up coolant in rad
Start engine
Might get a small burp of coolant when water pump starts to spin

Let it idle for a few minutes, it should not overflow
If it starts to overflow check water pumps spin direction, it is possible to install fan belts wrong and reverse the flow so water pump pumps coolant out of lower rad hose, which would cause it to flow out of open cap

Upper rad hose should stay cold at radiator end until thermostat opens and thats when coolant at the cap opening should start to warm up
Radiator is cutoff from circulation until thermostat opens, but it is not cut off from pressure, as lower hose is open which allows pressure to be transfer to radiator, but not heat.

If you are concerned about clearing air in the system, cut one of the heater hoses at high point and insert a metal coupler with two clamps
With engine cold and idling loosen one clamp on the coupler and slide hose back a bit any air will come out while coolant is circulating thru the engine.
When just coolant is coming out all air is out, tighten it back up.

It is possible you have a blockage in one of the head's cooling passages, this would cause coolant at that place to flash to steam when it got hot enough, but that would take at least 15minutes

Hey guys, sorry I didn't post back sooner, I've been really busy at work and fixing our house.
I mentioned about the glove test being ok, well, I'm convinced now that somehow I'm getting exhaust pressure going into the cooling system.
The reason I'm saying this is the truck still doing the same thing and now I can smell strong exhaust fumes out of the overflow tank after I park it.
I'm gonna attempt to drive it one more time to our cabin which is 1 hour away and park it there, hopefully nothing blows up, and work on it a few hours on the weekends and get it fixed before winter shows up again.
I'm pulling the motor out and make it easier to fix oil leaks and everything else.
So what should I be expecting and prepare for? Best case scenario bad gasket, worst case a cracked block or head?
I really appreciate your help, it's been very helpful and I learned new things. Feel free to leave your comments, thanks everyone again.

fr7 said:

...I'm gonna attempt to drive it one more time to our cabin which is 1 hour away and park it there, hopefully nothing blows up, and work on it a few hours on the weekends and get it fixed before winter shows up again.
I'm pulling the motor out and make it easier to fix oil leaks and everything else.
So what should I be expecting and prepare for? Best case scenario bad gasket, worst case a cracked block or head?...

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Head Gasket seems to be the common answer on here for most late 90's/early 00's cooling system problems.

You've pretty much covered what to expect. Most likely it's the gasket, which is the 'best case scenario', in my experience exhaust gases in coolant point directly to the HG but there really is no telling until you get the heads pulled. Cracked heads is only a slightly worse scenario, as you can get two reman'd ones for between $300-$500 that are ready to install as soon as they arrive. Cracked block would be the 'worst case scenario' as you'd probably need a new block.

I got one more dumb question. I'm gonna try to drive the ranger to the cabin tomorrow, once I get out of the city I can take gravel roads all the the way, it just takes longer, the wife is gonna follow me just in case something goes wrong.
So, if loosen the radiator cap like halfway to the first stop, would that help relieve some pressure while I drive or will it start leaking coolant or blow the cap? It's a little over 1 hour drive on gravel roads, just trying to make sure I get there safely and with a running truck, if something happens I have a friend ready to bring a trailer but I rather not go through that. Thanks guys..

My understanding is that the first stop when loosening the radiator cap is a safety for those people that insist on opening a hot radiator, to prevent them from being scalded badly.

I'd keep it closed and take it easy.