2020 Tundra Smell?

What's up truck lovers?

I have a 2020 Tundra with about 50k miles on it. Within the last few thousand miles, I've noticed a "propane-y" smell while stopped at lights and after I park. Not full blown propane with the rotten egg smell, but close. Maybe if propane and gas had a baby.

I've read a few things suggesting a gas leak, bad cat, oil leak, coolant, bad fuel pump.

I've worked on older cars quite a bit, so I know my way around. I can confirm there are no leaks of any fluids. I'm all too familiar with what an oil leak smells like, gas burning up on the block, coolant burning up on the block or the headers. Also other smells like brakes and clutch—which this is definitely not.

My guess is a bad cat? But when I park and go searching for the smell, I'm not getting a strong whiff of the smell near the cat.

The smell is very strong in the cab, and strong on the driver side under the hood.

Also worth mentioning there is no smoke coming off this truck. White or black. I'm at a loss...

Anyone have any ideas?

 

20 Pro owner here.....no smell.

 

Check the cabin air filter? Also sometimes rodents etc make nests in the cabin air intake which is near the windshield/under the hood. Doesn’t match the smell but who knows. You likely already looked but check if anything is spilled in the interior of the vehicle, there are some funny “just rolled in” situations where the customer had coolant bottle or gas can in the trunk haha.

 

I checked the cabin filter after this all started happening. It was pretty clean. I also just did an interior detail complete with shampooing the seats. No weird spills on the interior of the vehicle. Good tips, but I think I have that covered.

 

Could be a small leak in the exhaust somewhere. When you’re not moving it wafts up into the cab, but when you’re moving it obviously blows away.

 

I'm guessing I need to go searching along the exhaust pipe for some leaks? I've had to do this with an old truck in the past ('73 GMC). Little soapy water while the engine is running and a whole lot of patience. With an old truck, I can see where a worn out pipe would be rusted through... But man, this truck is pretty new still. Suppose it's possible I ran over something and cracked the pipe somewhere?

I'll give this a go and check back. Great suggestion. Thanks!

 

Yeah I would think it’s a bit unusual as well given the age of the truck, but y’never know. May be one of the flanges

 

There could be a dead rodent in multiple locations, maybe on top of the tranny. Just a possibility.

 

My first guess would be the cats. Only other thing I can think of to look at (outside what you've already checked/eliminated) would be electrical - is a wire getting hot somewhere? Perhaps a rodent got in and chewed a wire?

 

I'm familiar with dead rodent smell. But not cooking dead rodent... I'll give the under carriage a peek. Thanks!

 

It's definitely not an electrical smell. Unfortunately, I'm familiar with that smell too!

The more and more I read my responses, the more I realize what a crappy mechanic I must be!

 

Haha hard to tell on new vehicles! Toyota have been known to have smelly cats...er...higher precious metals in their cats and apparently that smells...4runners tend to modify their exhaust from straight out back to the side as when the rear window is down, they often get the eggy cat smells...I k ow I did on mine and it tremendously helped...just brain storming...

 

Propane is odorless...

Mercaptan is an additive to propane to give it the smell. It is also used in pesticides and some plastics. Have you had anything chemical-wise spill in the cab? Or exposed the interior plastics to any abnormal extreme heat?

 

Nothing spilled... I have used APC to clean the plastics and all weather mats. Plus some 303 for the trim. Nothing that would warrant the smell. Plus, the smell only occurs after driving for a while. It's definitely related to the vehicle running in some capacity.

Abnormal / extreme heat? I live in TX. So... But seriously, I don't think it's due to heating the plastics. When the truck is just sitting—like first thing in the morning—there is no smell.

 

Out of curiosity, what octane fuel are you running? Had similar complaints years ago with customers running premium fuel in vehicles with engines that didn't require it (read as "lower compression" ratios). If you ran premium to "drive your engine clean" in your average commuter vehicle, you're going to be causing yourself issues that you wouldn't have if you used the fuel that the people who designed your engine intended. If it says "regular 87" use regular 87. Wow, flashback to some really weird conversations trying to convince people to follow quality advice.

ETA: completely aside, remembering a "discussion" with a customer who was upset because the temperature gauge was always between the "r" and the "m" in the word "normal"

 

When you get the answer, please post it up! Might be helpful to the next member.

 

Fuel cap says 87 and that's what I run. No need to do anything more! Got two other vehicles that require premium. It's nice to put the cheap stuff in! I say "cheap," but filling up a 38 gallon beast ain't cheap!

 

Absolutely will post the results. Hope to have a chance to chase down this gremlin later today.

 

I only have one cat... The exhaust pipes funnel down to one big ol' cat and out to a single pipe. Maybe the shielding around the cat makes it look like there's only one and there's really two cats wrapped in shielding? Not sure yet. Haven't had a chance to crawl under yet.

 

You've actually got four cats, two on each bank of pipes from the manifolds. One on each side is right up next to the engine itself, just off the manifolds, and then a second one on each side just a little downstream of that, if your exhaust is still stock, that is.

 

You might have five cats, number five being wrapped up in the fan and drive belt. They like to climb up into warm engine bays at times. Sometimes they have a bad day.

 

Dear God. Why?

Thanks for the tips.

 

If you only had one, it wouldn't cost nearly $8K to replace them. What fun would that be?

 

Replace?!? I'm gonna figure out a way to run this thing without all that junk!

 

And now the OP knows why the Tundra is target #1 for cat thieves!

 

Does it smell like a gear oil?

 

Hmm... It smells more like gear oil than gas. There doesn't appear to be any leaks under the diffs though...