Weird coolant leak

[AZ59apacheguy]

Hi. So since I have bought my 2000 Expedition I have had nothing but issue after issue. Now I have a strange external coolant leak coming from between the head and block on the rear passenger side of the engine. It's really weird, I'll drive the vehicle ALL day with no leaks, park it in the afternoon and check it way later that night with NO leaks! I then come out early next morning ( 5:30 or so ) and there is a small puddle on the ground and looking up from underneath you can clearly see a small leak from between the block and head. And on top of the it only leaks for a very short time period. Engine runs great, no overheating, no white smoke coming from exhaust. It's a remanufactures engine and the people who installed said they would check it out because it is under warranty. They had it all day drove it for a while, ran two coolant pressure checks and both passed. Mechanic said both tests yielded ZERO pressure loss over an hours time. They said this test tests the entire cooling system and everything associated with it and if I had a blown head gasket, this test would show it. Does this sound right? Are they missing something? Has anyone else had this issue and what did you do to fix it. Or am I being overly **** retentive?

2000 Ford Expedition Eddie Bauer
5.4L engine 4x4

 

[american steel]

a cracked head gasket will not necessarily show up on a gasket test. the cracks or tears, can be way too small yet will let coolant leak.
on your right side of the engine you have hoses on top I know 0n 97-02 they leak and hit the back right 2 coil packs. check all of your lines and I mean check them good.
it is unlikely for a small or tiny crack gasket crack to leak in or out of the enige while in operation or even shortly after engine shut off, you have aluminum heads and an iron block metal expands when it is hot closing small cracks in a gasket.
you might not have a gasket issue theres the possibility of a bad head or deck seating going on there, the head and or cylinder deck might not be truly flat, poor machining will cause this. on the back of your head you have I think one or two galley plugs that might be something to look at.

 

[AZ59apacheguy]

you might not have a gasket issue theres the possibility of a bad head or deck seating going on there, the head and or cylinder deck might not be truly flat, poor machining will cause this. on the back of your head you have I think one or two galley plugs that might be something to look at.

Hi, thanks for response. So I can assume that you have to remove the head to check this?

 

[american steel]

Hi, thanks for response. So I can assume that you have to remove the head to check this?

more than likely. but if it still under warranty and you have checked every single hose and all of the fittings, the problem has go to be from the cylinder up! get this checked out under warranty

 

[AZ59apacheguy]

Since my leak only occurs after the engine cools down, can you run a pressure test on the coolant system when cold to see if it leaks?

 

[american steel]

dude im sorry but I don't know, I don't build engines any more I stopped a few months ago. and I never heard of this problem nor did I ever come across this.
before you do pressure tests I would check every single hose when the engine is cool with a flashlight check your cylinder deck to head area, look carefully at the mating surface see if there is greenish or any liquidy substance seeping out.

 

[Ed_Strong]

So how much Coolant have you had to add to the engine since this leak started happening?
That should give you an idea of how big or bad that leak actually is!

 

[AZ59apacheguy]

Hi. To be honest, it's not a very big leak at all, but it is a leak. A small puddle occurs the next morning after running to and from work the previous day.

 

[mr49erguy]

AZ59apacheguy - Do you have a heated PCV (valve)? I know it sounds strange, but my 1998 Expy (5.4L) has a heated PCV and there is a hose that runs heated ant-freeze to the PCV valve and I had a leak coming from this hose, where I had a similar coolant leak. It was suspicious, but as soon as I made sure the hose was on tight, my leak went away. I bumped it when I replaced my PCV and it was not on tight and that is where my leak was coming from. It initially scared the crap out of me that I had a head gasket leak.

 

[AZ59apacheguy]

AZ59apacheguy - Do you have a heated PCV (valve)? I know it sounds strange, but my 1998 Expy (5.4L) has a heated PCV and there is a hose that runs heated ant-freeze to the PCV valve and I had a leak coming from this hose, where I had a similar coolant leak. It was suspicious, but as soon as I made sure the hose was on tight, my leak went away. I bumped it when I replaced my PCV and it was not on tight and that is where my leak was coming from. It initially scared the crap out of me that I had a head gasket leak.

Hi, thanks for the reply. I'm not sure if I have that or not. My Expedition is at the shop and of course they can't find a leak. Both the shop and myself are VERY frustrated...... I'll ask them to see if I have that option or not. Thanks again

 

[AZ59apacheguy]

on your right side of the engine you have hoses on top I know 0n 97-02 they leak and hit the back right 2 coil packs. check all of your lines and I mean check them good.

Update. So I finally fixed my weird coolant leak, it DID end up being one of the heater hose connections. It's the heater hose connection that hooks up to the metal line that runs from the water pump underneath the intake manifold to the rear passenger side of the engine. It took FOREVER to find because because access to ANYTHING at the back of the engine is almost impossible and it only happened every once in a while. I went to tighten the metal adjustable hose clamp for this hose and the hose clamp disintegrated. Plus the ding dongs that installed this rebuilt engine decided it was a good idea to use a 3/4" hose and connect it to that 1/2" metal line. Removed the 3/4" hose and swapped it out with 1/2", new hose clamp installed and its dry as a bone back there. Thanks for the advice " american steel "

 

[gschwoyer]

I have the same weird coolant leak. Did you have to remove your intake to access the hoses in question? I can't find the source of the leak anywhere.

 

[onlyexilove]

I have the same weird coolant leak. Did you have to remove your intake to access the hoses in question? I can't find the source of the leak anywhere.

You do not have to remove the intake for replacing the hose. Depending on the year there are 2 hoses that travel to the side of the intake along with a hose that goes behind the motor by the firewall or the backside of the intake and then another hose that connects to the front part of the intake where the coolant line is located. The most difficult one to check is the one in the very back by the firewall. Typically you will find this setup on Expy's that were sold in the north.

 

[onlyexilove]

Here is a link to the hose assy for the PCV that I purchased for my wifes 2004. I am not sure if it will be the same setup on Gen 1 5.4's

http://www.amazon.com/Standard-Motor-Products-Z58001-Valve/dp/B009OXJQDQ/ref=au_as_r?_encoding=UTF8&Make=Ford|54&Model=Expedition|662&Year=2004|2004&ie=UTF8&n=15684181&s=automotive&vehicleId=2&vehicleType=automotive

 

[LucasLutian]

I would examine every individual hose deeply when the motor is awesome with a flash light you should probably check your cylindrical tube, look properly at the propagation surface area see if there is greenish or any liquid material leaking out.