Cars use various fluids to keep the engine working efficiently. The engine oil is used to lubricate engine components, coolant to keep working parts cool, and the transmission lubricates and cools the transmission system. These oils, including the transmission, are housed in specific compartments from where they function.
However, there are cases where leaks can occur in the transmission. Aside from being visible and messing up the ground, it can also result in smells in the cabin, which can be very uncomfortable. So in this article, we will be highlighting how to get rid of transmission fluid smell in your car. But first, here are detailed reasons you smell transmission fluid in your vehicle.
Why do I smell transmission fluid inside my car?
The following could account for the transmission fluid smell inside your car
1. Fluid leaks
Leaks can occur due to several reasons. The transmission pan, for example, houses the oil and could drip out transmission fluid when cracked. Even the pan itself consists of several bolts and seals that hold it underneath the car; if any of these seals are worn, transmission fluid may also seep out.
You should see puddles of red fluid on the ground to confirm this. However, there are situations where leaks may be occurring but not visible. In such cases, the fluid is likely leaking onto a hot vehicle part like the exhaust manifold and burning out immediately. If such leaks are small, they will leak out only when the engine is at work.
Here, even before the engine tries to accumulate leaks, it may blow back to the exhaust, where it burns off immediately. Here, you won’t see any fluid but will perceive a burning smell in your cabin. These leaks, whether visible or not, can make you smell transmission fluid in your car since the transmission fluid has a strong smell.
2. Overheating transmission
Another reason for transmission or gear oil smell in cars is an overheated transmission. Overheating could arise due to transmission leaks or insufficient gasoline. Using transmission fluid of lower viscosity than recommended can also cause the trans to overheat. Because such oil will not withstand the heat generated from the transmission and not be able to cool the transmission.
3. Leaky transmission oil cooler lines
Leaky oil lines inside the radiator may leak fluid into the radiator. With the coolant contaminated with tranny fluid, it will let out tranny oil smell into the cabin through the air passing the radiator core.
4. Burnt transmission fluid inside the pan
Another cause of transmission fluid smell inside a car is burnt transmission fluid inside the transmission pan. When transmission fluid is old and has lost its viscosity, it will no longer be able to withstand heat, hence will start burning.
The smell from the burning transmission fluid can seep into your cabin via the vent holes and cause your car to smell trans fluid. In this situation, you will also not see any visible leaks because the transmission oil is burning inside the pan.
How to get rid of transmission fluid smell?
To get rid of transmission smell, you only need to detect what’s causing the smell and fix it. However, be sure the smell you perceive is that of a transmission fluid because the power steering smells like a trans fluid. So you may mistake both for each other. That said, here is how to get rid of transmission fluid smell.
1. Know when it’s transmission fluid smell
While the smell may result from transmission fluid, vehicles can emit several odors. So you must first identify if what you are perceiving is the transmission fluid.
If the smell is coming from near the gear shifter or around the center of your car, chances are the transmission oil is burning, and that’s the smell you’re perceiving. In case of physical leaks, you should see a red puddle of fluid under your car when parked—that’s the transmission fluid. Another way to confirm it is transmission fluid is that transmission fluid leak smells sweet.
2. Seal leaky transmission case and change seals
If the transmission pan is cracked or its seals are worn, seal the crack with a good sealant and change the seals. Also, ensure the transmission’s case drain plug is tightened securely.
3. Seal leaky cooler lines
Check the transmission fluid cooler lines inside the radiator and seal them if leaking. If they are, change or seal them. This should prevent transmission fluid from mixing with coolant.
4. Change old fluid
If the smell stems from burnt fluid in the transmission pan, it means the fluid is too old; you need to change it. A good transmission fluid should have a sweet smell and a bright red color. It must be replaced if the transmission oil smells burnt or appears dark.
5. Wipe off any visible leak
Clean off leaks around the car. However, there are situations where the oil may leak into a place that you can’t access. In these cases, after fixing the cause of the leaks, the smell will remain if you can’t wipe them off. If you can’t replace the part the oil spilled on, you will have to live with it. Or you can keep it as a workbench.
Signs of burnt transmission fluid smell
The following are burnt transmission fluid symptoms you should look for.
1. Burning smell
When your transmission fluid is burning, you will start perceiving a burning smell from car engine or the cabin. The transmission oil may burn because the oil is too old or leaks dropping onto hot vehicle parts like the exhaust manifold. Excess friction can also cause the gears to overheat, causing a transmission burning smell.
2. Transmission leak
If the transmission fluid is not burning inside the pan, it’s likely leaking somewhere and dropping onto a hot engine part. As this happens, you will get a burning smell, indicating that the transmission fluid is burning somewhere.
3. Difficulty shifting gears
Gear shifting needs the help of the transmission fluid to do this. So if you’re experiencing issues shifting gears, chances are your transmission fluid is burning.
A transmission burning smell may indicate the fluid in the pan is old and can’t help lubricate the transmission to shift gears. If it’s leaking, the transmission will experience fluid shortage as well, not allowing proper shifting of the gear.
Are transmission fluid fumes toxic?
Transmission fluid fumes are not toxic. However, while no harm will come to you if inhaled or the fluid touching you, you should avoid such situations. When fumes enter your car, they may not harm you but make you very uncomfortable—it has a harsh smell.
However, some people are sensitive to transmission fumes as they can cause dizziness, nausea, and headache. This is evident especially when the fumes meet them in an enclosed place. The insufficient air there can make the fumes make them sick.
Learning how to get rid of transmission fluid smell not only makes your cabin comfortable but also prevents the transmission from damage. Leaks and old oil mostly cause the scent you perceive. Leaks will cause trans oil shortage, leading to inadequate lubrication and cooling of transmission parts.
Old oil, on the other hand, will lose its cooling and lubricating properties and burn, leading to a burning smell from transmission. In both cases, the fluid won’t be able to do its job, leading to transmission damage. So if your transmission fluid is smelling in your car, fix any leaks and change the old transmission oil.