Seems my 2002 F150 5.4L has developed a small coolant leak. Its passenger-side front, you can see the green coolant on the frame pooling. After looking around to see where it's coming from I found that the part circled in red in the image below has a bit of fresh coolant on the bottom where its then dripping down, its right above the drip too. Can somebody tell me what that part is? Would it make sense that it could be the source of the leak? The metal fittings and tubing leading to it do not seem to be leaking. I think its part of the AC system, not the "engine cooling" system though, maybe I'm wrong. Should there even be engine coolant inside that part?

The other thoughts is this part is held in-place by a metal fitting attached to the motor. You can see the black metal "holder" going around the part, which then attaches to a bracket on the side of the motor. Taking a guess, but could it be the coolant is leaking from the intake manifold? Was reading that other people have had that issue. Could be leaking there and running down the bracket onto the other part in the picture.

Excuse my ignorance, not much of a mechanic, but don't mind trying to figure things out to save some $$. This truck only has 106K miles and was great until the last few 2K miles or so when things are starting to fail (fuel pump, exhaust manifold leak, etc).

Thanks!

 

Now, actually wondering whether this is coolant or not. Reading its possible the AC system is leaking oil (saw posts of PAG oil and maybe dye) which causes the leaked fluid to be green? So, here is another clue. This leak was occurring already, but had a friend help me with some work on the truck changing the brakes and adding some AC refrigerant to the system using one of the kits from Autozone. The pressure seemed pretty good and it was "somewhat" full, but took a bit of coolant. We did not overfill it. Now, it could be the leak that was there is now worse. But its still from that one spot described above.

Ideas?

 

See if the valley between the heads under the intake is full of coolant

 

No, there doesn't seem to be coolant there, at least not that I can see. I did wipe everything down earlier so that maybe I can see a bit better where it's coming from in the morning hopefully. Read somewhere that if it's lubricant/refrigerant mix it would show up under a blacklight, but coolant will not. Does that make sense?

Interestingly, neither the refrigerant or the coolant levels are going down, at least not noticeably at this point. That's good, but ironically it seems to make it a bit harder to tell whats happening.

Thanks

 

I never mess with AC systems. They are too temperamental. Those cans at the auto parts stores are crap.

 

I hear you, but like I said, the leak was there before we tried adding refrigerant. We were looking at potentially multiple issues with my truck and assumed the leak was engine coolant since it was green fluid. The AC hadn't been running great so adding that to help that problem and if there was a leak there, the can we used included some sort of leak repair additive. The AC is running ok, maybe better but tough to tell as it isn't as hot now. The leak seems to be getting slowly worse.

 

If your ac is out of refrigerant, you have a mechanical failure that needs to be addressed. Not a can of junk from vatozone.

The ships that can fix it, and won't rip you off, can probably get you squared away pretty cheap.

While not the greatest test, taste it. Co9lant has a distinctive taste. It does not taste like kool-aid. Hasn't for some years. They put stuff in it to be nasty and deter drinking it....

 

i cannot get oriented to where this pic is coming from...

 

Standing in front of the truck, looking down on the left side (passenger-side). I think that is the evaporator? So, it looks like this is definitely a a/c issue, not engine coolant. Using a blacklight you can see the leak below from the dye the repair shop put into the system. Can't tell for sure yet, but it looks to be coming from that round canister in the picture. Going to a shop tomorrow because if it is an AC leak I do not have the skills to work on that. Hoping its not a huge bill. The leak is very minor so far, in fact its barely registering on the gauge that anything has been lost when connected to the low-side ac.

 

Actually I think that part is a component on the AC hose assembly, not the evaporator.

 

Yeah, the evaporator is in the dash. The condenser is in front of the radiator.
I just went out and looked at my truck. That small canister is part of the high pressure hose that connects the compressor to the condenser.

 

Ah, thanks.