dixie460

I read this entire thread and have some thoughts and advice.

Temp gauge readings... when you're real low on coolant, the gauge will fluctuate like you've seen it do because of air bubbles that form in the spaces where there should be coolant. When you see your gauge fluctuating up and down real fast, that's your sign you're dangerously low on coolant.

Losing coolant... well there's only two places coolant can go, either outside on the ground or inside the engine in places where it shouldn't be. If you don't see a leak even when watching from underneath then you're losing coolant into the crankcase or combustion chambers. First check your oil, if it looks like a milkshake then that's where your coolant is going. Stop driving the truck right away if you see this, you have a leaking engine oil cooler, blown head gasket, blown timing cover gasket, cracked timing cover, or cracked block or heads. Reason the timing components are involved are because on the Windsor motors the water pump passages go THRU the timing cover. If you don't find coolant in your oil then it's going into the combustion chambers (cylinders) and that can be verified with a compression tester or leakdown tester. If you need help using these there's several videos on YouTube showing you how. Sometimes it will be quite obvious if you're burning coolant... does your engine blow white exhaust smoke? Hard to start initially, like one or more cylinders are full of liquid? The only other place it *might* go is into an automatic transmission, because the transmission oil cooler is located in the radiator side tank (the steel lines in the last pic you posted are for transmission cooling) and if it leaks then coolant can eventually make it's way into your auto trans and then it's rebuild time. So check your trans oil too, just to be safe.

Fan... my 96 has the fan further into the shroud, there is only maybe 3/4" of blades not covered by it. I would imagine that your 89 should be the same way.

Reservoir... okay the way it's supposed to work is when the cooling system is cold the spring-loaded valve in the radiator cap (that's the thing on the bottom of it) is sealing off the overflow port that connects to the reservoir. As the coolant heats up, it expands like any liquid does when it gets hot. This expansion creates pressure in the cooling system, which is done on purpose because pressurizing a fluid will raise it's boiling point (the temperature at which it boils). When the pressure in the cooling system reaches a preset pressure (13 lbs as stamped on your radiator cap) then the cap opens up the overflow port and coolant flows into the overflow tank until pressure drops enough to close the cap again. When you shut the engine off, the coolant starts cooling down and this creates a vacuum in the system, which pulls right thru the radiator cap and sucks the overflowed coolant back into the radiator. Now, if you overheat the engine then the coolant gets hot, pops the overflow valve on the cap open, and it goes into the overflow tank. This tank can only hold so much, and with the engine constantly overheating the tank is constantly filling until it eventually runs over. Coolant has to escape somewhere so it just leaks out the (non sealed) reservoir cap. The reservoir does not actually do any drawing of coolant as you say.

Randomly down on power... no idea. Fix the temperature issue first, then worry bout getting her running right. Did you check for fault codes in the computer? That might give you a clue as to where that problem is.

So... I would start with checking the oil in the engine and trans, then do a compression test on all eight cylinders. You don't want a variation of more than 10% between highest and lowest readings, but what you're really looking for is one that has real low compression, OR two next to each other with low compression. That would be a POSSIBLE blown head gasket or cracked head/block. To double check you can do a leakdown test, this just blows air into the cylinder and you can listen at the intake, exhaust, crankcase, and radiator to find out where the air is leaking out.

WolfgangFox

Alright lots of pics:

Temp Level at maximum:



Pressure Test at Start:



Pressure Test after 2 minutes:



Pressure Test after 5 minutes:



Pressure Test after 30 minutes:



Oil Color (does not look milky)


Tranny Fluid (does look watery to me, what do you guys think?)


Now a couple of things I just thought about. I have pretty much 90% water in the system right now because it's been overflowing so much. Could this be an issue?

When the temperature gets up that high, it never goes beyond it, and after driving, it cools down to between the O-R range. After sitting at idle for a minute or so, it gets hot again.

After letting the engine completely cool, the water still does not go back into the radiator. It just stays in the tank, unless its already overflowed.

I did replace the coolant reservoir hose, and replaced the clamp on the radiator itself.

It does look like I have a small leak. I can't "hear" anything, nor see anything leaking (I'm just looking at the ground and glancing around the hoses etc). Is this still a sign of a bad head gasket?

Toplait

Have you pulled the Thermostat yet?

fltdriver

I had issues a while back with "disappearing" coolant and couldn't figure out where it was going. I had replaced the water pump last year as it sprung a leak, turns out I didn't quite get it sealed correctly and there was a VERY small leak on the bottom side of the gasket. Not big enough to make a puddle on the ground as what was leaking out was evaporating off, but big enough to have to refill the reservoir tank a couple times a week.

May not be you problem but just throwing that out there.

WolfgangFox

I haven't pulled the thermostat yet. I'll take a look around those inlets again. I have before, and nothing is wet or stained.

What do you guys think of those readings?

I did see one of my buddies yesterday while I was at lunch, and we took the truck to his shop. He did the pressure test as well. I didn't see the actual readings of it, but he said it was ok.
He did mention that the fan clutch is not operating properly. When the engine gets hot, the fan is supposed to speed up and "roar". It never does this. I'm wondering if this is the explanation of why when it idles, it gets hot, but never overheats or goes over a certain temperature, and when I start getting up to speed, it cools back down. I'm also wondering if this is the reason for the loss of power, when it tries to turn the fan up higher, the clutch just isn't working right causing a lot of unnecessary resistance.

I'll grab the block tester today when I take back the compression test kit.

-----

I just wanted to say thanks to everyone for helping. I wanted to give a little backstory about this truck. I bought it from a retired Army mechanic. When I bought the truck, he stated he had done all the major tests on it to make sure the engine is not worn out. He specifically commented on the compression test, block test, and pressure test and that the engine is just fine with no major issues with it. I live in a small town, and people just don't lie to each other about the status of a used vehicle. You hear a lot more about how people need help with cars, or the vehicles are just sitting around because they don't want to sell a bad vehicle to someone who isn't prepared for it. I've never heard of a story from someone in which they bought a bad used car in which a big problem was hidden from the buyer, where I am now in East TN. I guess I could be the first though.
Everytime I talk to someone about this problem, most people scream "HEAD GASKET". I guess he could be mistaken with his tests, but I was looking at some other repairs he did, and they do look professionally done. I get very frustrated to think I bought a truck in which someone stated it was fine, but had a bad head gasket. This is why I want to make sure it is not a bad head gasket or cracked block, but, if I can, try to fix an easier repair in the meantime.

WolfgangFox

Got the block tester. I took 2 pictures and placed them side by side with different backgrounds. hard to see the color otherwise, but it looks blue to me.



It would be a more greenish / yellowish color wouldnt it? I did the test with the engine warm, and sat there for about 3 minutes continually squeezing the bulb.

So, with the pressure test results, and the block test results, does this mean I do not have a cracked block / bad head gasket officially?

-Pat

WolfgangFox

I did remove the thermostat, but I'm embarrassed to say I put the housing on incorrectly and have a big leak there now (forgot to clean off the engine gasket material portion). I tested the thermostat also, and it works perfectly fine. I was going to leave it thermostatless, but now I'm just going to put it back in, and possibly upgrade to a triple bridge in the future.

More to come tomorrow when the big leak is fixed.

-Pat

WolfgangFox

I fixed the leak I had caused at the thermostat housing. The radiator hose going to the thermostat housing was leaking. The hose clamp wasn't tight enough.

What do you guys think about the readings I've done, in regards to the cracked block / bad head gasket? I'm going to drive the truck a bit over the next couple of days to see if it still runs hot. I don't see why it wouldn't, I didn't really do anything, unless I just tightened the hose clamps tighter.

-Pat

Toplait

When the water stats boiling out and your engine running hot did you check for a Collapsing radiator hose?

fltdriver

First off, the fan can't "SPEED UP" it's belt driven and can only possibly turn as fast as the drive belt is spinning it's pulley.

Second, when the clutch fails it allows the fan to sort of free spin, or not turn as fast as the belt is spinning the pulley, causing overheating issues at lower speeds.