Diagnosing my wet and hot floors.

This may be a stretch but I'm struggling with my 2 local dealers, their M.O. seems to be quite uninformed & unskilled parts changers at my expense.

I called to verify how they would diagnose an issue I'm having with my 2007 Tacoma w\125k miles thats throwing no codes.

My floors are getting quite hot, over 100° when traveling. To the point it's wetting my carpets, wet as in soaked. Truck is feeling a bit sluggish and fuel economy is lacking. Moister was noticed first so I assumed water intrusion via cowl.
But while drying carpets I noticed the heat in the floor which was abnormally warm. That lead me to suspecting catalytic converters.

I checked the temp of the cats with my laser front cats are 400ish° tube between cats 260\243 2nd cats\resonators 390 Driver & 270 Pass. Exhaust pipe to tail is about 176 after a 30 min drive.

Both dealers tell me the cats would definitely throw a code so all is fine. One said the cats are good because they should get to 1700°. They were unable to tell me how long it would take for them to get to this temperature. So in my opinion that has verified nothing. However in total I made an hour-long drive at 55 mph this morning without any rain, and was able to get the floors noticeably wet and hot.

I want to know their plan of attack because I lack confidence in their ability. I'll gladly pay for their knowledge but not if they cannot find\resolve my issue. But if they plan to plug into the OBD2 port they will get no information. So I was hoping they would be able to tell me what other methods of testing they would utilize.

I'm willing to accept any advice.

Considering 02 Sensors (4), Bad cats (4) fuel injectors & coils as potential problems but first I need to know if this is actually my problem.

My heat shields are in place and in working condition. Spark plugs have only 15k miles, new intake and valve cover gaskets, -3° urd exhaust gears & .5" intake spacer in January 2024.

 

Hmm, not sure why the floors would get damp as well as hot at the same time. One thing that comes to mind is: exhaust gases contain a lot of water vapor (major byproduct of hydrocarbon combustion,) so could there be an exhaust leak somewhere that is hitting the underpan and/or penetrating somewhere that would then cool the exhaust & cause moisture in it to condense & get wicked into the floor carpeting.

Also FWIW 1700ºF sounds on the very high side for a catalytic converter's normal internal operating temp range. Google seems to suggest the range is somewhere more like 700-800ºF, maxing around 1100-1200ºF when vehicle is under heavy sustained load.

 

Cadillac converter temperature 1700°F is literally glowing hot reentry.

Those things shouldn’t get hotter than your typical pizza oven, 800°.

 

I utilize Google to come up with the same information. And now you can see why I strongly dislike my local dealerships. These are supposed to be professionals.
I'm assuming the moisture is simply condensation because it's cold in the truck and it is incredibly warm at the floorboard, it's sweating. To the best of my knowledge I cannot hear an exhaust leak nor are there odors of exhaust fumes. The only time my exhaust smokes is at initial startup, there are no other colors when revving it up or idling, there's a little bit of soot on my back quarter panel which isn't really alarming but it's just something to mention.
I'm honestly at a loss but after remodeling two rent houses I'm not in a position to just start throwing parts at the truck.
Also to note I've read that if catalytic converters go out there will be a rotten egg smell which is not existent either.

 

None of the floorboard grommets are missing or loose.
Some random pictures of the underside of the truck to show that it's in pretty good condition. Also the wetness and heat are on both sides it is not on just one side of the truck. This is just the front two seats. The rear floorboard and carpet is completely dry and cool to the touch.

 

Could the ac drain tube be clogged and condensation backing up and forced into cab?

 

The damp floors are confusing me....the moisture has to be coming from somewhere, it's not gonna magically materialize on a hot surface. Condensation requires the cooling of moist air, so if anything your hot floors would be dry and you'd see condensation everywhere else.

How's your coolant level? Could it be a leaky heater core?

Is your AC evaporator draining properly? Could the drain line be clogged causing it to overflow onto the floorboards?

If you're getting soot on your rear quarter, you're definitely running INCREDIBLY rich and that's why the cats are screaming hot

 

AC drain is clear.

I can recreate the problem with the truck idling in my carport.

 

I didn't check my coolant level. I'll do so as soon as I get back home and the truck cools off.

 

The soot.

 

I understand you're confusion, I'm living it. Lol
No condensation anywhere else but it beads on the carpet, only with the weather tech floor mats though.

 

Somehow a ton of extra/unburnt fuel and air is getting sent through the exhaust, and trying to your cat into a rocket engine. That's why it's spewing soot

That issue in conjunction with lots of moisture leads me to brainstorm maybe a leak caused some wiring or ECU to get wet and start acting crazy without throwing codes?

 

1st cat


Between cats


Secondary cat

 

Could be an electronics issue, or an injector(s) issue, or an ignition issue, or maybe you have a leaky/burnt up exhaust valve letting the fuel/air mix escape before the cylinder can burn it.

Run a compression check to rule out the latter. If you have access to a borescope, that'd be super helpful to look at the valves too.

While doing so, check the plugs. If any are caked in carbon/soot, that cylinder is getting way too much fuel and not burning it all. If any are very clean and/or soaked in fuel, that plug/coilpack isn't firing properly.

I'd check the AC drain again and run some cleaner through it anyway. and blow it out with some low-pressure air. It may visibly look clear but still be backing up.

A leaky heater core would present a sweeter smelling odor from the coolant which you may or may not notice

Hoping the moisture and richness are a weird coincidence and not the result of fried electronics. But I worry because running that poorly should definitely throw some codes.

 

Now admittedly I'm more familiar with the behavior of older engines (1970's.) Running rich or lean,the odor\fumes from the exhaust would burn your eyes and your nostrils. I'm not experiencing that in this case.
I don't see a physical leak at my radiator or any of the hoses. The engines too hot to open up the cap but I'm pretty diligent with fluid levels and vehicle maintenance.

 

I blew out the AC line and the cowl drain areas Monday.
Initially the moisture made me think it was the cowl that was leaking so I pulled that thing apart and couldn't find a problem. That was my Monday. Tuesday when the floor was dry and it wasn't raining I put the floor mats back in and took a drive and that's when I realized that under the floor mats were wet but not the floor itself below the carpet. So the moisture somehow starts between the floor mat and the carpet and then gets wet enough on my long drive from Texas to home (6hrs) that it seeps into the insulation and then onto the floor. And that's kind of when the brainstorming and Google searching began.

I don't have a borescope, One of the technicians that overheard me speaking to their service manager got my phone number and gave me a call. He requested that I go in Monday morning and let him take a look at the truck. He at least shows concern and some knowledge so hopefully they can help me resolve this because I can't figure this out heads or tails. I honestly feel like I may be making it more confusing for myself.

I have an entire parts list that I almost pulled the trigger on earlier. Fuel injectors, spark plugs, coils, 02 sensors and set of cats.

I did just get the truck tuned by YotaWerx last month. So that's an added caveat that is relatively new to myself and the truck. But I probably have1300 miles on the tune.
With that being said up until the heavy rains I hadn't really noticed the wet carpet, that doesn't mean it was caused by the rain I just did not notice it until that day. There was no identifying factor, I simply picked up my floor mat to clean it and the floor was wet, I then made the assumption that it was the heavy rains. This issue could have been longer because they were no identifying factors above floor level.

 

If you're into growing your collection of tools, very good quality flex-neck cameras (useful for lots more than a straight-rod borescope) are very cheap these days. $75 or so.

DEPSTECH Endoscope Camera with Light, 5" IPS Screen, Dual Lens Borescope 7.9mm, 1080P Plumbing Snake Inspection Camera with Split Screen, 32GB TF Card, Hardshell Case, Gadgets for Men, Mechanic-16.5FT

https://www.amazon.com/DEPSTECH-Endoscope-Borescope-Inspection-Mechanic-16-5FT/dp/B0CB1FPQKG/

Here's some footage I took of my own 4.0L V6 1GR-FE internals. Note that the unit actually has two separate cameras, an end-on camera, and a 90º side-pointed camera.

https://www.youtube.com/watch?v=8jalnAEdXOo

 

In my experience (along with what I've read across many forum posts) the taco cats are very robust, far more efficient and effective than decades past. It takes a lot to run dirty enough to notice to spit soot out the tailpipe. like it should be throwing 10 different codes.

Looking at your temp gun readings though...they don't seem crazy to me? I could be wrong on that.

Do you have any way of checking transmission temps? I have a 6speed so that's outta my wheelhouse. Maybe the trans is heating up and we're overthinking the exhaust thing?

 

I really like this, I'll be adding it to my utility belt.

I'm actually starting to think that I'm too close to the problem. My scan gauge does not have a transmission temperature reading so other than a physical laser I don't have a way to read it. I agree with you though those temperature numbers don't look crazy high to me. But I'm also not very familiar with this. Even the soot at the back of the truck doesn't really concern me that much because my truck does stay parked for about 2 weeks while I'm at work, that little bit that is shown in the picture it's probably months worth of build up. I'm just not sold on any of my speculation.
I also just checked and my radiator is full.

The truck doesn't feel like it runs horrible I just don't understand what else could be generating that kind of heat through my floor. Literally if I put any drinks in the cup holders they will become like hot chocolate. The cup holders are 106° as are the floors.



This was taken after the truck was idling maybe 15 minutes in my carport.
Now how hot is your floor normally I really don't know but I can tell you my back floor is only 92°. But I expect that to be cooler because they're less things acting upon it. I think I'm just driving myself crazy.

 

Well if it's just idling there, theres no airflow running over the underside taking that heat away. And even in motion there really isn't much for thermal insulation, so seeing a 100+ degree sheet metal floor pan that's inches away from giant heat producers isn't really that bonkers.

Not to mention, these trucks have no valve on the heater core, so it's always got full-temp coolant running through it radiating more heat especially between the center console and trans tunnel. I've actually thought about insulating/designing a peltier cooler for the cupholders lol

Starting to think you may just have a leakage issue somewhere and got pulled down a rabbit hole with the warm floors lol.

seeing your temp readings and lack of emissions codes, I'd assume they're unrelated and chase down the source of the moisture first and go from there. Cause like I said, the water is coming from somewhere, since warm floors would only deter condensation/wet carpets. Give it a sniff test, does it smell like coolant?

If the windscreen has ever been replaced, that's a likely culprit too. Huge possibility of a bad seal.

As far as reduced fuel mileage and whatnot you mentioned, that's worth checking into as well. I'd throw some new spark plugs and maybe O2 sensors at it(if plugs don't help), and go from there.

EDIT TO ADD:
Change spark plugs, clean the MAF and throttle body, check/change air filter, yada yada before moving to more parts like O2 sensors.