Overheating 2004 Limited; 4.6l V-8

[pet575]

Had some problems for the past couple of weeks with an overheat. My temp gauge was seeming to randomly shoot up toward hot but then it would cool itself back down. Checked the coolant level when cold and it was a bit low. I added a little less than a gallon of coolant and hadn't had the problem since.

Changed the thermostat last night and found this:

You can see corrosion/leakage under the thermostat housing, which explains the previous coolant loss. Trying to be proactive, I got a new thermostat and changed it last night. When I pulled off the top cap to change the thermostat I saw no evidence of leaking. It looks like it is coming from the underside of this housing, but I didn't want to tear into all of it without knowing what I was getting into.

What is the u-shaped aluminum housing that runs behind the alternator and over toward the coolant bottle? It appears that all of this is the same piece with leaking thermostat housing. Anyone had this apart before to where they can help out?

Bigger problem right now is that, since last night, I'm getting an overheat condition when driving. Test drive last night with heat on full blast went perfectly fine. Drove about 30 miles this morning with no problem. On the return trip home at about the 20 mile mark I got the temp gauge to H, warning lights, and engine went into "reduced power mode" and "service engine soon" light is on now. I pulled over to cool the engine off and then got it home.

When I parked it in the garage I was back to overheat status. Popped the hood and had a high pitched squeal and the coolant bottle was filled to the top-it was trying to boil over.

I bought a water pump but am waiting for the vehicle to cool down before I tear into it. Something tells me a new water pump isn't going to fix it but I'm changing it anyway since I'm at 200K miles on the OEM water pump. This seems more like a thermostat issue or blocked cooling system issue.

I saw NO debris in the thermostat housing last night when changing the thermostat. I'm 100% confident I properly installed the thermostat (good test drive last night and good 30 miles this morning confirms that). Anyone else agree that this seems more like a thermostat? Even though it is a new thermostat I guess it could be bad. Considering putting the old one back in and seeing if it stays cool. Guess that would answer that question.

Can't imagine this is a fan clutch. I suppose it could be a water pump if it has completely failed and is not pumping any water. No leakage at all in water pump area though.

Thoughts? Wisdom? Assistance?

Thanks!

 

[2002GreyHD150]

1. the Ushaped plastic piece is the upper Rad hose support.

2. yes T-stat can be defective new, unlikely, but has happened. I prefer Fail-safe brand t=stats that fail in the open position

3. the corrosion is not uncommon and nothing to worry about.

4. 200K, in my opinion its time for a cooling system revamp.

If it were me (which it was on the Monty about 5 months ago) I would do the following:

* new upper & lower hoses
* new fail-safe T-stat if you can find it
* new F150 Lightning high flow water pump
* Lincoln Mark VIII/T-bird electric Fan (eliminates the clutch issue)
* Flex-o-lite E-fan controller
* Redline Water Wetter or Royal Purple Ice Coolant treatment
* regular Green coolant
* inspected all heater/accessory hoses for condition they are big $$ from Ford and no one makes them.


The biggest issue is getting the air pockets out of the modern cooling systems. "burping" the system takes time and patience. Don't let everyone hood wink you on the type of coolant.

The coolant thing is just like my other pet peeve, Platinum Spark plugs. Both are tricks Ford uses to minimize your need to service at regular, aka LOGICAL, intervals. They aren't any better, safer, longer lasting. Don't be fooled. Once you have all the Ford Yellow coolant out, refill the entire system with green, call it a day. Copper spark plugs, green coolant. Going back old-school... LOL

Rob

 

[pet575]

Thanks for the response. Are telling that everything could be just fine and I've got an air pocket? I'm not familiar with how to "burp" the cooling system.

Drained and replaced all coolant last night and replaced w/ 50/50 mixed green stuff. Literally the ONLY thing I've done is replace the thermostat. I'll post some pics in a minute to verify I did everything right.

 

[pet575]

So here what the housing looks like:

Empty, I tried to clean it up the best I could but the discoloration wouldn't completely go away:

New thermostat involved:

New thermostat with rubber seal on top of it:

Here's the new thermostat and the old seal, stacked as installed:

Here's just the old seal:

It is not in brand new condition but the O'Reilly parts store near my house didn't have a listing for the rubber seal-their computer thinks it is a traditional gasket (which it is not) so I'm stuck using the old one on limited transportation.

I'll replace this seal when I can but I really don't think it is my issue.

 

[pet575]

Also, the question I was asking about was the u-shaped aluminum housing-one end is the thermostat housing and the other end is what the coolant bottle feeds in to. It is not a plastic piece: it is part of the cooling system.

 

[pet575]

Update: I googled how to burp the cooling system. Have started the process. So far, I have not had another overheat. Yet.

 

[pet575]

Well that didn't last. Overheated again, exact same deal. Was out test driving for 30 minutes-nothing. Drove city and highway speeds with no problems. Let it sit and idle for 10 minutes after and it started heating up again.

When this happens, the coolant bubbles into the bottle like it is going to boil over. It is bubbling and gurgling. After a few minutes of this, it will stop and then you can watch the fluid recede and here it emptying out of the bottle and back into the system. If you try to open the cap after the overheat it is under a ton of pressure. If you wait a few minutes, when the receding starts, you can open the cap to less pressure and then watch the coolant empty out of the bottle.

When overheated, the top hose coming from the thermostat housing and leading to the radio feels very flexible and completely empty. I'm confused now but I'm going to proceed with replacing the water pump and see what happens. Strongly considering putting the original thermostat back in as well.

 

[pet575]

So, interesting developments since my last update:

1. The u-shaped part I was referring to is actually the entire upper intake. I would have to replace it for $410 at the stealership for just the part alone. Don't even want to speculate on how long it would take.\

2. Replaced the water pump and it made no difference. Still overheated like before, but not as quickly and to just barely under the heat limit. So I guess that is an improvement. I honestly did not expect it to work but figured I've got 200K miles out of the OEM water pump and it MIGHT work for this problem. It was a $50 risk.

3. I replaced the o-ring for the thermostat housing as well and that made no difference.

So, to summarize, I installed a new water pump, thermostat, thermostat o-ring, and flushed the entire cooling system and replaced with "green stuff." After all of that, I was still overheating.

Tonight, I decided "What the hell?" and tried putting the OEM thermostat back in. When I did that, I did not get a single movement on the temp gauge despite driving at city speeds, highway speeds, and parking and idling and then doing it all over again for over an hour's worth of driving time.

So I guess I'm back at square one but with a new water pump and thermostat o-ring. I suppose it could have just been the o-ring all along. Here I thought I was being proactive and trying to fix a leak. At this point I'm considering just going with it for awhile and seeing what happens.

 

[Skynard]

At 200K miles I would check your fan clutch. With the engine at operating temp, stick a rolled-up newspaper into the fan. If the fan stops without any resistance then it is time to replace your fan clutch.

Two of my vehicles had the fan clutch go around 200K miles.

Try e-bay or a bone yard for the radiator part.

 

[05explorer1974]

If you are referring to green stuff as green coolant, it is actually suppossed to be gold coolant not green. Gold is considered long life where green is not. I would not be suprised if was the intake. They have had issue's with the plastic intakes.

 

[dwilly99]

my 02 was leaking in the same spot as yours, right under the t-stat i was slowly losing coolant. i replaced the upper intake, i think it was just over $200 you should be able to do it in a few hours

 

[xlt03]

How about the "radiator cap"? That's the cap on the overflow bottle.

 

[pet575]

Guys the overheating issue is solved. For whatever reason, the new thermostat was causing the overheat. Replacing with the OEM stopped the overheat. Took the replacement thermostat back.

dwilly99, thanks for the info.

 

[kware1]

I had the same problem with my 02. You know what they say...theyre known for that. I got mine off ebay for short money andreplaced it myself. I guess the new ones are a different design that won't leak. I was getting estimates from 750 to 1500. After the fact, a mechanic I deal with a lot said he would have.done it for 350. That would have been worth it.

 

[esclamada]

Got the same coolant leak, mine doesn't overheat but coolant drips into the bellhousing. Stop leak helped but not getting any better. I have to replace the intake manifold and coolant remains at the same level. Bought the intake from a guy in craigslist who thought it would work for his grand marquis, it won't fit so he sold it for $100.



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[pet575]

Looks like I forgot to update this thread. The thermostat swapping was NOT the ultimate solution. Replacement of the intake and thermostat was the solution. Thread is here:

http://www.explorerforum.com/forums/showthread.php?t=361187

 

[swshawaii]

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