5.0 Coolant Mystery

[mounty71]

Last week when i washed my truck i sprayed the undercarriage down for the hell of it and noticed that the water runoff was a greenish tint just like coolant. I checked fluid in the overflow and it is ok. That triggered the memory of the "sweet" smell i smelled when getting out of the car after driving it. I had never really paid much attention to it before that, although it was noticeable--i thought it was related to the exhaust manifolds which quite possibly are leaking a bit. But now that i notice it, it is a very strong smell even after just moving the car from the driveway to the street. I looked under the hood for any sign of a leak, couldn't find anything. Under the car i see it looks like there's a leak coming from the front of the bellhousing/back of oil pan, but don't know why there would be coolant on the bellhousing, so i'm presuming that's just a little ATF. I also noticed what looks to be a small leak from one bolt of the oil pan, but again i'm not sure if that's just a little oil. I was looking for a leak in a line but couldn't find any. I sprayed water all around the area and the greenish water is running off the primary cat, but i'm thinking that just might be because that is the lowest point under the car for water to run off of. I felt around and up between the oil pan and bellhousing, and what gunk i got on my fingers did not smell sweet at all.

The car's never overheated, never even gotten hotter than normal according to the gauge. And it runs as if everything's normal. Any ideas? I've tried researching on here, i've read about thermostat needing replacement, waterpump gasket, and what i dread the most-a head gasket, but i'm pretty sure it's not any of those. Please, give me some good news, i can't afford bad news.

EDIT: I've also heard about doing a pressure test, I'm not sure what's involved in that though or if anyone thinks i need to do that. My roommate suggested removing the oil pan and seeing if there's coolant in there, but i just got an oil change a couple hundred miles ago at most, and mechanics didn't say anything. Also, i'm close to hitting 100k miles, at which i was going to replace plugs and wires. I think i've heard something about checking the plugs in a situation like this??

On another note, i think my tranny is slipping/flaring/whatever from 1st-2nd/2nd-1st, could an ATF leak lead me to the cause of that problem? I haven't really looked into that yet.

 

[Cobraguy]

Your coolant leak could be from an intake gasket on one of the rear corners, one of your coolant hoses seeping back there, a head gasket seeping, etc. Your best bet in such a confined area will be to look carefully with a mechanic's mirror. A pressure check wouldn't hurt. (you use a pressure tester by Stant or similar)

 

[mounty71]

Thanks, a mirror would help since i couldn't find anything with the naked eye.

 

[nssj2]

i have the same coolant issue. check around the heater valve, and pray its not a heater core... like mine. you can't see the drips because it drips onto your cat converter and evaporates. but, i highly recommend a pressure test. very easy to do. go to a parts store that rents them, like autozone. you need the import radiator adapter. then just attach the tester to the filler neck on the radiator, and build up pressure to around 15lbs. it should hold pressure for about an hour. mine dripped from, you guessed it, right above that cat converter. i figure only loosing 1psi per hour is acceptable, being as how i don't want to pull the ENTIRE dash out.

your oil pan is there to stay, unless you want to pull your motor. the cross member prevents you from dropping it otherwise. the oil leak around the pan i've decided was designed from ford to prevent rust .

 

[mounty71]

i have the same coolant issue. check around the heater valve, and pray its not a heater core... like mine. you can't see the drips because it drips onto your cat converter and evaporates. but, i highly recommend a pressure test. very easy to do. go to a parts store that rents them, like autozone. you need the import radiator adapter. then just attach the tester to the filler neck on the radiator, and build up pressure to around 15lbs. it should hold pressure for about an hour. mine dripped from, you guessed it, right above that cat converter. i figure only loosing 1psi per hour is acceptable, being as how i don't want to pull the ENTIRE dash out.

your oil pan is there to stay, unless you want to pull your motor. the cross member prevents you from dropping it otherwise. the oil leak around the pan i've decided was designed from ford to prevent rust .

Maybe a dumb question, but does the heater core control the heat in the car? If so, it could be the heater core, for as long as i can remember the heat starts off hot and then cools down a lot. Just throwin that out there, trying to think of every possibility. I did try to look/feel for a drip on the cat but i presumed it just evaporated, causing the smell of coolant. Would doing a pressure test instigate a leak, so then i could confirm where the leak is exactly?

 

[nssj2]

Maybe a dumb question, but does the heater core control the heat in the car? If so, it could be the heater core, for as long as i can remember the heat starts off hot and then cools down a lot. Just throwin that out there, trying to think of every possibility. I did try to look/feel for a drip on the cat but i presumed it just evaporated, causing the smell of coolant. Would doing a pressure test instigate a leak, so then i could confirm where the leak is exactly?

yep, its like a little radiator in your blower box. the heater valve is on the heater lines, upper passenger side of your truck. little plastic looking thing, know for leaking sometimes. yeah, pressure testing will bring the entire cooling to the same pressure as when its driving fully warmed up. so if its gunna leak, you'll find it.

 

[mounty71]

Finally got around to doing the pressure test. I still have the pump hooked up to the radiator, it's been about 20 mins. and the pressure has dropped from 13 PSI to about 9PSI...yet i don't see any signs of a leak and once again i've never had any overheating issues. What's the deal?

 

[4x4xbrian.com]

Make sure the system is completely full, and maintain 16psi or whatever the radiator cap specs. and wait for drips.... if no drips its probably losing the pressure around the cap/tester, and the mystery will continue.
Be sure to check the heater box drain tube, if its the heater core, thats where it will leak.

 

[CDW6212R]

Turn on the blower fan, just turn on the ignition and the vent position. Smell for the antifreeze in the air blowing out at you. The leak from a heater core could go out to the firewall at the bottom of the AC housing, or into the right foot well. Check under the right side rug at the front, pull it back and check for wetness, it would run down from the AC box on the firewall.

For a tiny leak you might get away with a stop leak, the silver powder in a plastic tube is very good. Avoid using it much, it isn't completely harmless.

 

[mounty71]

I haven't tried the tester at 16 psi again, but i can't imagine it holding pressure any better than it did before. It is an autozone rental so it's possible the actual tester or adapter leaks a bit. I did notice that when i initially took off the radiator cap the coolant was right up to the top of the neck on the radiator, and upon removing the tester the coolant was down a tad below the bottom of the neck. :scratch:

Now the heater box i presume is right above the cat that was mentioned earlier...i'll try to get a clearer view of it when it's light out. Where could i locate the heater valve or heater box drain tube?

I turned on the vent with the engine off for a couple minutes and didn't smell anything out of the ordinary. I also pulled the carpet back where CDW suggested and the area was clean and dry. So the mystery continues till tomorrow.

 

[CDW6212R]

That is good, a heater core leaking is easy to identify when looking for evidence. Check the engine bay area below it also, but then you will be hunting in the tight space behind the engine.

 

[mounty71]

Maybe the pressure tester wasn't tight yesterday or something, but it's been holding pressure now for about 15 or 20 minutes.

About the heater core, i'm not exactly sure what i'm looking for. Is it the plastic box wrapped in the silver tin-foil looking stuff that's attached to the firewall? If not, then what/where is it?

 

[CDW6212R]

Yes that's it. Go to the bottom of the AC box and see if there is a hose or hole at the lowest point of it.