First time poster.
Got a 95 XLT with 3.0L from my dad. 200K miles on it. The engine overheats. I think the cooling system was neglected and caused damage before it was fixed. To date, have replaced the Radiator, Fan, Fan clutch, water pump, thermostat, timing chain, TC cover gaskets, hoses, radiator cap. The engine still overheats slowly. Fan and clutch, thermostat, water pump have been replaced twice to make sure the right parts were used and they were good to go. I do get bubbles slowly spitting into the over flow often. Not steady, but often.

The "glove" test has been performed on the cold engine many times cranking for about 10 seconds with no noticeable results. The other day I had ran the engine without the thermostat. Still gets too warm, but while it was that way, and after it cooled overnight, I tried the glove test again that morning. This time I kept cranking the engine for 45 to 60 seconds. I did not see any movement of the glove. Then when I went to "feel" the glove while on the radiator, there was a small but noticeable amount of air in it that I could form into a small ball. That air had not been in the glove when I put it onto the radiator since I made sure it was rolled flat. It was also a new one out of the box, blue nitril rubber glove. I repeated the procedure several times with the same result. Then I reconnected the spark and ran the engine for a moment to clear out any excess fuel from the combustion chamber, shut it off and performed the glove test again cranking for 60 seconds. Still was seeing air in the glove afterward. Not much, but enough to form into a ball (about half a golf ball size), and to know it had just been put there.

Does this show that there is combustion chamber air getting forced into the cooling system? Been wracking my brain trying to figure this out.

 

Welcome to the forum

Do Glove Test with engine running, cold engine of course, and at least 2" of air in rad so coolant doesn't push up into the glove

If glove starts to inflate then there is a cylinder leak

A small head gasket leak can be hard to diagnose until it gets bigger, because it can suck in coolant from cooling system and push air out so just cranking engine can give limited results, but does read like you have a leak

You can pull out spark plugs and compare tips, light brown is normal color, bright white means its getting steam cleaned by some coolant

 

Thanks. Will try with engine running as well. I did pull plugs to compare. All looked the same. They had reddish deposits pretty similar to a grey or brown deposited normal plug with ground electrode shadow and all. Two plugs, one in each bank, were a little different. One had a more solid colored reddish look to it. It was a little darker than the others and did not have a clearer area where the ground electrode caused interference. The other plug was just a tad lighter in color (but still reddish deposited) on the insulator, but deeper down into the plug, the insulator was cleaner than all the others. There was not clear indicator to me, just that those two were a little "different".

One other indicator I have noticed is it seems that there may be one cylinder that does not fire has "hard" as the others. Not a pronounced skip or miss, just a slight feel that gives it an "off" or "lope" sensation. Exhaust seems normal.

Forgot to mention I did a compression check and that did not show any abnormal signs.

 

Small leaks won't show up on compression or leak down tests, but they will still inject enough air into the cooling system to cause overheating to start because the air doesn't cool the head as well as the coolant.

Also engine compression is fairly low, 140-180psi when cranking with starter motor
When a cylinder fires its 500-1,000+ psi, so..................air gets pushed out even with smaller leak

 

well, I tried with engine running. Coolant was below the top of radiator. Still took several min of running but the glove eventually slowly started filling with air. The temp was just getting into the low normal area of the gauge so I shut it off. The radiator still puked coolant into the glove just before I could shut it off. Im not in a position to install a new/used engine right now. Was hoping some minor repairs would get it going. I may try a sealer of some sort as a band aid to stall the process for about a year just so I can get some use out of it now.

 

That doesn't read like a head gasket leak or cracked head, glove should start to inflate as soon as engine starts.
If coolant heats up glove will expand because coolant is expanding

Just for giggles..............look at the fan belt routing, make sure its turning water pump the correct direction, I guess if the fan is blowing on to the engine it is going the right way


I have used Rislone head gasket fix with good results

Lasts a few months, my neighbor got 6 months, flushed system and did it again for another 6 months until his automatic trans died, lol, but it was a chevy V6 so deserved to die

You have to leave stuff like this in the coolant because it has to constantly reseal the leak, so make sure coolant is OK before adding it
Don't use the fibre stuff in an Over Flow system, like we have, in degas system its fine but plugs up out return system

 

Have a look at this video and watch from 17:15.
I re-read your first post and I don't think the lower intake manifold was removed.
Could be part of the problem, if the system has been neglected for a long time.

 

Are you sure it's over heating, could it be a defective sending unit or gauge ?

 

Thanks for the suggestions. I will watch the video shortly. I have not touched the intake manifold. The glove test seems to act close to the same even with a cold engine just being cranked.

Yea, for sure it is overheating. Has that hot smell to it, will feel hotter to the touch depending on if the gauge shows its hotter than normal, will have that gurgling and bubbling to it, lots of pressure in upper hose. Sometimes will pull coolant back into system from overflow, but most often will not so there is some void in radiator upon cool. All connections are tight and clean.

Fan belt looks to be correct. Use the routing sticker on the engine compartment as a guide and the fan blows air back toward engine. The fan will at times run soft and will also at times tighten up and run with a roar.

Running without thermostat, or a cut away stat causes a faster overheat. Putting a normal working stat in there allows for a slower overheat. I noticed this morning with 73 degree morning temp I came to work and it did not overheat with 60 mph interstate, however, when I got off and started a slower phase with a few stops and into a parking lot the temp started moving to center, then to just a tick above center before I got into a space and shut it off. Other times on a 95 degree day, anything over 10 min starts it moving into center and then on its way over center.

I have noticed if running the heater to try and help it keep cool, a few times during a possible over heat (gauge showing just above the center) that the heater air turned cool (outside air temp). Running the AC will make it overheat faster.

 

After looking at that video, It has me wondering if the cooling system is still clogged up. I may have said this already, the cooling system was neglected. When I first saw the truck two years ago, the coolant/water was completely red/brown. (I do see that same color on all the spark plug electrodes as a light, kind of ashy deposit. Is that normal color for the plugs or could it indicate rusty water in there?) Initially, two years ago, the vanes on the water pump had been eaten away so the water pump, fan, clutch, radiator, thermostat, cap had been replaced and fresh water/coolant put back in. Truck was driven a few times after then sat for almost of two years. Cannot remember if overheat continued. I do remember my dad saying it seemed fine afterward, but he drove it so few times after that.

Even though I recently had all the cooling apart, and then flushed everything with water pressure from the hose (block, radiator, heater core) there may still be that rusty powder clogging stuff up. I do notice that the clean green fresh coolant I had installed a few weeks back is now green and red/brown. I even noticed on several occasions that when the engine does run hotter than it should, upon cool down, I can open the radiator cap and can wipe my finger in the opening and I have a cake of that stuff on my finger. Might be worth a strong cleaning and flush before I give it up to being toast.

What is a good strong cleaner that might wipe that stuff out with a flush instead of having to tear down and pull entire manifold?

 

That right there points to cylinder leak to cooling system, cylinder injecting air into the head causes air dam to form in a heater hose blocking flow, REVing engine will often clear it

The air injection also injects pressure into cooling system, which is what Glove Test shows, cooling system is rated for 14-16psi, cylinder is minimum 150psi, but up to 1,000psi running

So higher pressure pushes coolant out of radiator and into overflow tank, and when the injected air makes it to the top of the radiator then it is pushed out to Overflow tank causing it to bubble
During cool down the higher pressure doesn't allow full coolant replacement from Overflow tank back to radiator

 

Well, back to looking for a sealer as a band aid. I don't want to repair the engine since I think with 200 to 210k miles on it, the better solution would be a replacement. I may get a wild hair and decide to tear into the heads just to see. May be a few months down the road. Have another question that may sway my decision so I will make a new thread.

 

The bottom end should be good up to, and past, 400k if oil and filter is being changed regularly, 3,000-4,000 miles


If you use a sealer(or even if you don't) then when the heads are off, if you don't replace engine, pull off water pump and use a smaller hose down coolant passages in block at the rear on each side to rinse out the block, debris collects there in lower back, also use a longer screw driver or ?? to loosen any debris, it will flush out the water pump passage on that side

 

Bringing this thread back. I never put any stop leak in. I figured it would make things worse. I did run distilled water and a strong cleaner in the system for a couple of weeks. Then flushed all areas, radiator, heater and put it back together and added antifreeze. I ran it during the winter for several weeks till battery being dead all the time, speedometer quitting and such made me mad so I parked it. During that time, I could go from one place to another but always seemed to do that thing where the guage goes up to 3/4 hot during the first 5 min of driving and then drops back to just under half and then seems ok, howevewr, I never went more than 15 min drive with it and it seemed to start inching up to 1/2 on the guage about the time I was going slow into my destination. After driving once it was cool I would often have to add water to radiator and the over flow seemed to be getting fuller. I also would see new coolant puddling on top of the PS AC bracket.

fast forward to now, I pulled the upper intake and lower intake off. looking at the lower intake and engine, I see the cooling passages but they are not clogged. Just rusty still. I did not notice any obvious to me anyway signs of coolant leakage on the PS pump AC side, but then again, I dont have a trained eye for that. I dont seem to notice any pitting of the metal like I did when I changed the front timing chain cover.

One thing I did do prior to pulliung intake is I rented a cooling system pressure tester. I connected it and pumped 15 pounds of air in and watched for leaks. I could not see anything, but it did loose about 3 pounds over 2 hours. Thjen I pumped it up to 18 pounds, then cranked the engine over. The guage never moved so I concluded there is not any cylinder pressure getting in. At this point, the intakes are off as well as valve covers. Should I work just on that to put it all back together or should I go ahead and pull the heads?

 

From description heads are OK

Pressure leak is there, because of the drop in pressure over 2 hours, shouldn't do that

I would use 20psi if you can rent the tester again after everything is back together and filled up

 

an update to this thread. I cleaned and search all over the front and side (ps ac compressor side) of the engine. I cant find anything that looks like where it is leaking. What I do know, the timing cover has been removed and cleaned and new gaskets last year when I started. The passenger side timing was pitted some and leaking. I cleaned the whole thing and added some rtv lightly as needed and sealed it back up. All that looks clean and dry. I put sealer on the bolts that went through the water jacket when I put it all together. All that was done last year. Once it was all together, I was noticing a green liquid forming up on top of the PS ac bracket beside the head. I would clean it out, but after driving and sitting, it would come back. Its seems kind of thick, oily, but seems to look and taste like an antifreeze.

Since I have the manifold off, I have cleaned and smoothed everything. I had noticed when it was all together, and I had put the pressure tester on it that it leaked a tiny amount from where a heater hose connects to the manifold and left a small puddle on top of the water pump. I never noticed any extra antifreeze seeping onto the ps ac pump bracket though like I thought I might. I should have cleaned it dry prior to the pressure test but did not. I have read about that hear hose manifold fitting having a small leak. Could a small leak like that cause some of the symptoms I am having? Is the green oily liquid on top of the ps ac pump bracket really antifreeze or could it be ac compressor oil?

 

PAG compressor oil can have a green color like coolant

A small coolant leak won't cause overheating until enough coolant has leaked out, but if there is a leak in the engine/radiator side then system may not suck back in coolant from the overflow tank when engine cools down, so each day you loose more and more coolant that is not replaced
So open rad cap every morning(stone cold engine) and check level, should be FULL to the top, no air at all
If its not FULL then coolant is not being replaced when engine cools down

 

The Pag oil could very well be what I see. It has always looked very green but I was thinking it just looked like that due to where it was sitting.

Correct on the thought about not sucking coolant back from overflow. Some mornings radiator would be full. I would drive the 14 min to work. It would do a thing where the temp gauge would rise to a little above half and the drop down quick to a bit under half during that first 5 min of driving while it warmed up. Then be ok. Sometimes I could drive further with no ill effect. Other mornings I would go out and overflow bottle would have more coolant in it and the radiator would be low so I would add a half pint. When getting ready to leave work, same thing. radiator would be low so Id have to add.

This is real frustrating but I really want to get this fixed if it is just a simple coolant leak.

 

Well the overflow system relies on the engine/rad side being air tight

As coolant heats up it expands in volume, a gallon of coolant becomes 1.1 gallons, that's where the pressure in the engine/rad side comes from, like a pressure cooker works
If the pressure gets above rad cap rating, 14psi, cap's larger valve opens and lets some coolant flow over to the overflow tank, until pressure drops under 14psi
After you shut off the engine the coolant starts to cool down and shrink back to 1 gallon
If coolant was sent over to overflow tank when driving then pressure in the engine/rad side will drop below 0psi, so -1psi, this causes the smaller valve in rad cap to be sucked open, and, if overflow hose is air tight, coolant will be sucked back in from the BOTTOM of the overflow tank, so overflow tank needs to be clean or any debris at bottom of tank would allow coolant to come IN but not flow back OUT
Pretty simple system

But if there is a coolant leak in engine/rad side then it can throw things off
Simple physics says its easier to move air than fluid
So when time comes to Suck coolant back in to engine/rad, if there is a leak in engine/rad side its way easier to suck in air thru that leak point than the heavier coolant from the overflow tank
So rad doesn't get "topped up" after engine has cooled down


The up and down of temp gauge during warm up is, of course, the thermostat, but it shouldn't be too much of a change unless you were driving up a grade or pulling a load
The wider swing of temp gauge could be the sender for that gauge, or air in the system which ends up at thermostat location, high point, which prevents wax inside thermostat from heating up steadily, so thermostat opens late and air is release to radiator, then sudden inflow of cold coolant from rad causes temp gauge drop then causes thermostat to close quickly
And then it cycles again until rad coolant and engine coolant are both warmed up
Probably nothing to be concerned with but....................may indicate an issue with air in the system after cool down

 

Ron D
you quoted me and then mentioned in a previous post :
"Quote:
I have noticed if running the heater to try and help it keep cool, a few times during a possible over heat (gauge showing just above the center) that the heater air turned cool (outside air temp). Running the AC will make it overheat faster.
That right there points to cylinder leak to cooling system, cylinder injecting air into the head causes air dam to form in a heater hose blocking flow, REVing engine will often clear it

The air injection also injects pressure into cooling system, which is what Glove Test shows, cooling system is rated for 14-16psi, cylinder is minimum 150psi, but up to 1,000psi running

So higher pressure pushes coolant out of radiator and into overflow tank, and when the injected air makes it to the top of the radiator then it is pushed out to Overflow tank causing it to bubble
During cool down the higher pressure doesn't allow full coolant replacement from Overflow tank back to radiator

Do you think at this point there may very well be cylinder leak to cooling system? Perhaps a small one, or do you think the issue is just a tiny leak in the radiator/engine area of the cooling system? At this point, I guess in order to tell for sure, the heads have to come off. You think I should bite the bullet and go ahead and pull the heads? I just hated to go that far if I did not need to, but everything is currently moved out of the way. There is that connection for the heater hose onto a screwed in nipple into the intake manifold right there at the thermostat housing. I did find evidence of a tiny leak right there during the pressure test. Do you think that tiny leak is causing the problems, or do you think that there is a cylinder leak that is causing issues as well? As a reminder, while I had the pressure tester connected and pumped to 18 pounds, I actually turned the engine over and it started and ran sputtering for a couple of seconds. The needle on the pressure tester gauge never moved though. I know, the only way to know for sure is to pull heads but I sure did not want to. Thoughts?

 

Well I can't give a definitive answer either

You can check spark plugs tips, coolant leak into that cylinder will cause Steam Cleaned look to the tip, while the others will be a brownish shade

 

Well, thanks for the advice. I had checked them before and they pretty much looked ok. I could however pull them again now since it has ran some during the previous year. Maybe it has ran enough that some tell tale sign will show on a plug and give me an indication. I guess if I wanted to be thorough with this, since it is this far down, I would pull the heads.

Here is a question, If I pull the heads, and the gaskets are not blown nor the heads cracked, would they warp because I pulled them? If they check out ok, then I could get the new gaskets and bolts off of rock auto, make sure to fix any coolant leaks at the intake manifold/heater hose connection, put it all together and if I do it correctly, it should be good to go.

Any good pointers for self checking the heads? since the rockers and push rods are out, could the engine be spun to check compression or is that a no no? I may actually go forth into this.

 

Hard to see a blown head gasket, especially if its a small leak, so that won't be definitive

A machine shop can pressure test the heads and surface them, no way to do that DIY unless you build a plate for the head to seal it

You could do a type of Leak Down test if you have an air compressor and gauge
You pump air into a cylinder via spark plug hole while its at TDC, both valves closed
Most engines even NEW will leak about 10% pressure, via valves and rings
So if your compressor pressure is set at 100psi the gauge at the spark plug should show 90psi, 10% leakage out of that cylinder

BUT............the thing to watch for is a change in coolant level in radiator, there should be no connection between a cylinder's pressure and cooling system

 

Well, got the bad news. I did find one plug that looked whiter than the others. After much back and forth I decided to pull that head. To my surprise, the cylinder next to the one with the spark plug that was a lighter color was scored. I'm not certain but I think another cylinder was scored as well, but not as bad. The gasket on that bank also looked like it could have had some issues at some water passages. My untrained eye is not totally sure, but I do know a trashed cylinder and that is what I have. Its not a straight up and down scoring. but more like a patch of pitting. . Its like the The truck is not worth much . Interior needs some care, power windows don't power up without binding and grinding, speedo and odo no longer work, fuel fill is cracked, has a drain on the battery and will kill one in 2 days. I just dont want to deal with it any more.

It does however have a new timing chain, cover gasket and front main seal, new fuel filter and new tires. The transmission I am told was a replacement with less than 30k miles on it. So what would a 95 ranger xlt in this condition be worth?

 

Manual or automatic?

Running small pickup usually stays at $1,200-$1,500 depending on area, even at 25 years old
Not running.............................???

Whats a head gasket and 6 head bolts go for?
You could reuse intake and exhaust gaskets
Use a little RTV, very little, on the intake gasket

Once its running sell it

If you are going to keep it have that head tested