I finally got my truck running and now I have to tackle the overheating problem. On start the truck is fine until I drive about 15 miles and the temperature gauge begins to move higher and higher slowly. I can drive about 17 miles before the gauge reaches L on the normal, at which point I turn the truck off and let it cool. The oil pressure gauge reads low on startup and drops from there as the engine warms. I read that the gauges are not great so I am going to install a mechanical gauge. The water pump is new and when doing it I flushed the cooling system to clear debris and so forth. The lower intake gaskets are new, replaced a week ago. Could my oil pump be going out? I am installing the mechanical gauge today to get a correct reading. How can I know that my water pump is working correctly, is there a way to test it somehow?

 

L is not overheating. L is in normal.

A mechanical temperature gauge is dangerous because it brings some pressurized fluid into the cab. There's nothing wrong with the factory gauge - it's accurately showing the temperature. Putting in a different gauge will not change how the engine runs, unless it leaks, causing the engine to actually overheat.

The oil gauge is a fake. Any movement from it other than mid-scale or low-peg is just a simple electrical problem in the circuit (usually on the back of the cluster). It's usually free to fix. Putting in a mechanical oil gauge is even more dangerous because it brings hot, pressurized oil into the cab. If it ruptures, it can scald you, and will rapidly damage the engine. It's more-likely to damage it if it leaks slowly because you probably won't notice. Only use a mechanical oil gauge temporarily under the hood for diagnosis - not for driving.

Test the water pump by disconnecting the hose from the heater core (the one that comes from the intake manifold), aiming it into a clean bucket, and starting the engine. If it streams coolant, the pump is working. Pour the bucket back in, & top it up. But that's a test you should do just BEFORE a flush (so you don't have to catch the coolant).

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I did the water pump test as you said and water flows from the hose, so the pump is working? When it reaches L and I shut the engine off to cool, boiling water fills the reservoir and flows out. I got stuck in traffic and it over heated a little pass L and stalled out. I popped the hood and smoke was coming from the lower intake manifold. I am for sure I blew a head gasket and immediately checked the oil and tail pipe for white smoke. I replaced the lower intake gaskets and found all the below. This all started when my old water pump went out and even after the new one was installed its still doing it.
I stopped the install of the mechanical gauge when I read your reply.
This is about 10 minutes after startup at idle.

Rear driver side.


Shop vac'ed all that crap out.

Passenger side.

Driver side.

 

After driving 24 miles...

 

If I turn the heater full blast the temp tends to go down slightly as well as if I place it in park. If the oil pump is failing wouldn't it just overheat and continue even if the heater was on or I placed it in park?

 

It's NOT "overheating". It's "getting hot" - there's a BIG difference. But it shouldn't stall just from being hot.That's a couple square feet - can you narrow it down a little? Was it smoke, or steam? There's a difference.So you removed the heads & fixed that?What exactly does that mean? How exactly did it fail? What did the impeller look like?Then the WP failure was probably not the root cause. Or your repairs were incomplete.So at idle, it doesn't run hot. The problem only appears under a load.That's well beyond the L, on the verge of leaving the Normal range. But it's still not "overheating" - it's just running slightly hot.Naturally - the heater is another smaller radiator, so you're increasing the rate at which heat is removed from the cooling system.No, the oil pump doesn't have anything to do with cooling. And even as the WP begins failing, it can still work when the engine isn't heavily loaded. But didn't you put a new WP on? How exactly did you mix the coolant? What thermostat did you put in (brand, PN, & source)? Did you backflush the radiator?

It's long, but read this caption (a few times):

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Do not trust ANY of the dash gauges till you verify with a reliable test gauge. Sending units are a common problem and will give a false indication of a problem.. You need to verify temperature and oil pressure with reliable gauges. If the engine is proven to be running hot, ask yourself, when does the engine temperature rise? If it goes up idling or in stop and go driving, I look for an airflow problem. Fan clutch, missing shroud or plugged/ rotted radiator fins and possibly blocked A/C condensor fins, if equiped.. If the temp. goes up on the freeway, look for a water flow problem. Blockage of water tubes in the radiator, water pump or blockage in water jackets. Impeller issues with the water pump are rare.My suspicision would be the radiator. Now, I am assuming that the coolant level is good and the thermostat is working properly.

For your oil pressure, I would suspect a faulty gauge in the dash.The factory "sender" is just a switch which will show half way gauge deflection with 7 psi or higher.It will either work or it won't, nothing in between.Low oil pressure is usually accompanied with engine noise..I recently abandoned my stock gauge because it was reading erratically.It would indicate normal, fall low, stay there a while then go back up again. I had an electrical oil pressure gauge and sending unit sitting around from a previous departed car so I installed it and abandoned the factory dash gauge which I proved was acting erratically. The pressure on the new gauge shows 40-55 psi at 2k RPM depending on engine temperature.That indication is something I can trust and with an electrical gauge, there is no hot, pressurized oil entering the cab.

 

Sorry, I believe it was steam because it did not have that burning oil type smell, but honestly I cannot be sure. I was frantically trying to find where it was coming from and sniffing around in a panic and could see it was coming from around the lower intake manifold. It did not have a pungent burnt oil smell that made me step back though. Sorry I cannot be more precise, I was in a panic when this happened. Its not the money or time to fix it, its the fact I did that this to my truck.

Typo, "I was for sure". I have not messed with the heads.

The weep holes would consistently leak water. I would park my truck and just see the water dripping from under it and have to put more coolant in.




When it gets to the L I pull over and let the engine cool. The time it went past L the engine light came on and it stalled. I do not want that to happen again. I would love to just not drive my truck until this is fixed, but I have to get to work.

I back flushed the radiator yes, the thermostat is a Murray Ultra Thermostat, PN#MU55358, O'Reilly.

1 and 1

Currently reading your link.

 

Well, if you blew a head gasket (and I'm NOT sure you did), then that's pretty much the answer to its runaway temperature. See if any parts store near you has a loaner dissolved-gas tester. And do a compression test as this caption describes:

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So you DID put a new WP on? What brand, PN, & source? It's unlikely that a new WP is the cause of this symptom, but it DOES happen that the impeller isn't properly locked to the shaft, so it doesn't push enough coolant at high RPM.IDK why the engine stalled, but it wasn't simply because the engine was hot enough to put the gauge at the top end of its range. And doing that doesn't hurt the engine at all. Anywhere on the gauge is safe; it's the point where it pegs hot that you BEGIN doing damage.

At some point, you should test the radiator as the caption in my previous post describes.That's the wrong temperature, but it's probably not causing the current problem. Eventually, you should put the correct t'stat in: a good 195°F.

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You did install it with the spring in the engine, right?

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MasterPro Water Pump - New PN#C251670 O'Reilly

I just got back from doing that very thing. I removed the fan, clutch, shroud and waited for the tstat to open and fog did begin to show, but after about 10 mins only about 5 or 6 inches of the top were dry and the whole bottom was wet. I placed a gloved palm on it and my glove came back soaked.

At this time the thermostat opened.



I will do that today.

Indeed, I double checked the Haynes to be sure.

Now that I think about it, the fan use to sound like a plane taking off. Ever since the engine started running hot though it does not. After reading the link, if there is no coolant movement then the air does not get hot enough to activate the clutch... Is that correct?