Oily drips on inside cab floor below glove box

[seafish]

Thankfully I have Weathertech mats, but the title says it all…

These drips are happening while the truck is sitting.
I am assuming that they are refrigerant system oil leaking from a leaking AC/heat exchanger or connection.

I will pull the AC fuse to prevent the compressor from running without enough lubrication, but I have few questions—

Is there an easy way to confirm my guess?

Do AC and heat settings have separate heat exchangers?

Am I looking at a full dash removal to fix this ??

 

[Yo Hoot]

I think you need a full dash removal. Do you have an oil pressure gauge with an oil line?

 

[seafish]

Do you have an oil pressure gauge with an oil line?

Unfortunately not, though I do have a trustworthy shop that I can take it too to check it out.

 

[seafish]

anyone else with good advice??

 

[petersonj]

I am assuming that they are refrigerant system oil leaking from a leaking AC/heat exchanger or connection.

Are you certain that you are seeing an oil? Is it possible that the evaporator housing drain is partially plugged and you are getting a mixture of yucky water and whatever else that has been growing inside the housing over the years? The evaporator core is right next to the blower motor. If the evaporator core is leaking, then refrigerant oil certainly could show up on the floor. However, if the evaporator housing drain is clear, then any fluid should drain after passing through the firewall. Something is amiss here.

I have done two 2nd generation dash removals for heater core and evaporator core replacements. I think that the 3rd generation trucks are very similar. There are good "How to remove the dash" tutorials and videos regarding the project. If you decide to do the project, it will be a good time to address the blend door any mode door issues. I completely removed the dash and placed it on the bench for much better access to components. The job is very time consuming, but really not that hard.

Do AC and heat settings have separate heat exchangers?

I am not sure what this question is asking. There is a heater core and an evaporator core in separate compartments. All air passes through the blower, then leaves the blower housing to immediately pass through the evaporator core, then flows through or around a blend door that determines how much air will pass through / around the heater core, and finally to mode doors to distribute the air to the desired location.

Certain air selection modes and / or the AC button turn on the AC compressor. The "cold / hot" slide control operates the blend door to achieve the desired temperature. Since all air passes through the evaporator core first, the air will be cooled and dried. That cooled and dried air moves through or around "or is blended" via the heater core, depending on the "cold / hot" slide control position.

- John

 

[seafish]

Are you certain that you are seeing an oil?

It looks, feels and smells oily. That said, its a good idea and I'll check the evaporator drian tube as I have a long brush to do that.

Any idea where it I can access it from? Behind the passenger side wheel well or under the truck ??

There is a heater core and an evaporator core in separate compartments.

Thank you … my bad on not knowing the correct names of the parts.

 

[petersonj]

In my 2nd generation truck the drain goes straight out the firewall into the engine compartment down below the AC drier / accumulator unit. You should be able to see it with a flashlight. It is about 5/8" diameter. It may or may not have 90° elbow attached.

- John

 

[Ozymandias]

Just left of the turbo elbow?

 

[Jaysyl]

anyone else with good advice??

Heater core? Sure it’s not anti freeze.

 

[seafish]

Sure it’s not anti freeze.

My coolant system is clean and tight…this stuff is oily and smells like lube.

 

[Lordsman]

My coolant system is clean and tight…this stuff is oily and smells like lube.

 

[Lordsman]

Is your AC blowing cold through all vents where called for? Passenger side tends not to blow as cold if you've lost some refrigerant.
If not I'd stick an electronic refrigerant leak detector probe(if you can access one) in the duct as close as you can get to the evaporator coil. If it goes off it's very possible you've got a leak in there.
I believe you can pull the duct blower motor & wheel out down there on duct below glove box. If there is oil present around there try to trace it.

 

[Tuesdak]

Heater core? Sure it’s not anti freeze.

X2. The heater core is likely the source. The heater core doesn't have a drain pan.

The evaporator generates condensate, water, that goes out the evaporator drain from the drain pan under it. Any oil from an A/C evaporator leak also goes out the drain. The drain pan is big Vs. oil capacity of the A/C system... A clogged drain with a bunch of water in the pan is possible. Hopefully this is the simple to fix problem of a clogged drain. Regardless look at the evaporator drain with a UV light or bright flashlight for signs of an oily buildup. A/C oil becomes green when it leaks out in large amounts. Small leaks just attract dirt.

As you have to pull the HVAC housing to do either the heater core or evaporator: do both. The evaporator likely has a bunch of dirt reducing airflow and why risk doing the job over with a future failure of the "used" evaporator (or heater core). I do recommend MOPAR parts if still available for this as aftermarket for heater cores and evaporators is Just YUCK. Also do the HeaterTreater blend and other doors upgrade while your there.

 

[Tuesdak]

Is your AC blowing cold through all vents where called for? Passenger side tends not to blow as cold if you've lost some refrigerant.
If not I'd stick an electronic refrigerant leak detector probe(if you can access one) in the duct as close as you can get to the evaporator coil. If it goes off it's very possible you've got a leak in there.
I believe you can pull the duct blower motor & wheel out down there on duct below glove box. If there is oil present around there try to trace it.

After checking the drain isn't clogged: check the evaporator drain with a sniffer as refrigerant is heavier than air and will tend to show up there from a slow evaporator leak. Pickup doors closed, windows up in a garage to prevent wind from blowing away the leak evidence.