6 Symptoms of Burnt Transmission Fluid (Common Causes and How to Fix)

While driving, are you noticing something burning from under the hood or odd shifting behavior? Your transmission fluid might be burnt. As one of your vehicle’s most important fluids, when it burns or degrades, serious issues often follow.

Understanding the signs of burnt transmission fluid early on can help you avoid expensive repairs and having to find an alternative form of transportation for a period of time.

burnt transmission fluid symptoms

What is Transmission Fluid and Why Does it Burn?

Transmission fluid is a specialized liquid that lubricates, cools, and helps transfer power throughout your vehicle’s transmission system. It keeps all the moving parts working together without causing excessive friction or heat buildup.

Unlike engine oil, transmission fluid typically has a reddish color when new and serves multiple functions beyond basic lubrication.

Over time, transmission fluid can deteriorate due to high operating temperatures. When fluid temperatures climb above 200°F, the fluid begins to break down. Once it reaches 295°F or higher, the fluid starts to burn, losing its protective qualities and potentially damaging transmission components.

This burning process causes chemical changes in the fluid that alter its color, smell, and most importantly, its ability to do its job properly.

Symptoms of Burnt Transmission Fluid

#1 – Strange Burning Smell

burning smell while driving

A burning smell similar to burning rubber or burnt toast often accompanies burnt transmission fluid. This odor usually becomes more noticeable after your car has been running for a while, especially during hot weather or when you’ve been driving in stop-and-go traffic.

You might smell it both inside the cabin and when standing near the car after parking. Unlike the sweet smell of coolant or the gasoline-like smell of an engine issue, burnt transmission fluid has a distinctive acrid scent that, once experienced, is hard to forget or confuse with other car problems.

See Also: 9 Causes of a Burning Smell In Your Car

#2 – Transmission Slipping

One of the most common signs of burnt transmission fluid is your automatic transmission slipping between gears. Your engine might rev higher than normal before shifting or you may feel the car suddenly surge forward as it catches the correct gear.

This happens because burnt fluid loses its viscosity and ability to maintain proper hydraulic pressure needed for proper gear engagement. When the fluid can’t maintain adequate pressure, it can also cause pressure control solenoids to malfunction, sometimes triggering diagnostic trouble codes like P0776.

If driving and your RPMs jump up but your speed doesn’t increase accordingly, or if your vehicle seems to shift back and forth between gears for no reason, burnt transmission fluid could be a possibility.

Read Also: Code P0776 (Transmission Control Solenoid Issue)

#3 – Unusual Noises

engine problems

Since burnt transmission fluid loses its lubricating properties, grinding, whining, or buzzing sounds from your transmission can be the result. These noises typically become more noticeable during gear shifts or when accelerating.

The sounds occur because metal components that should be separated by a film of fluid are now making direct contact or not engaging properly. This obviously isn’t a scenario that you want. Continuing to drive with these noises can lead to internal transmission damage with metal particles contaminating what’s left of your transmission fluid.

#4 – Delayed Gear Engagement

Does it take longer than usual to shift into drive or reverse after selecting the gear? Transmission fluid could be the reason. Sometimes, you may notice a pause or hesitation of several seconds between shifting the selector and feeling the car actually engage.

The transmission relies on transmission fluid pressure to engage clutches and bands, and when the fluid is burnt, this pressure can be inconsistent. Pay special attention to how your car responds when shifting from park to drive in the morning or after the car has been sitting for several hours.

#5 – Overheating Transmission

transmission temperature warning

When your transmission fluid burns, it often creates a cycle where the transmission itself begins to overheat. You might notice your transmission temp gauge rising (if you have one) or a transmission warning light appearing on your dashboard.

Burnt fluid can’t properly cool transmission components, causing them to run hotter than designed. This excessive heat can warp metal parts and damage seals, similar to what an engine would do if it’s low on oil. If you notice that your transmission is overheating, pull over safely and allow it to cool down for a while.

#6 – Discolored Fluid

The color of your transmission fluid tells a lot. New-ish transmission fluid is typically bright red or pink and relatively transparent. When transmission fluid burns, it darkens significantly, turning brown or even black in severe cases.

The fluid also becomes thicker and may have a gritty texture due to suspended metal particles from worn transmission components.

Checking your transmission fluid with the dipstick (here’s how) provides an immediate visual indicator of fluid condition. If your fluid looks dark, smells burnt, or worst of all, has particles floating in it, you’ve got a problem.

What Does Burnt Transmission Fluid LOOK Like?

transmission fluid change vs flush

As it degrades and burns, the normal bright red or pink color of transmission fluid undergoes a noticeable transformation. Burnt transmission fluid typically appears dark brown or black and loses its transparency. This color change happens because the fluid breaks down chemically when exposed to excessive heat.

Besides the color change, burnt transmission fluid often develops a thicker consistency compared to fresh fluid. Rather than flowing smoothly like thick water, it becomes more like syrup or even sludge in severe cases.

different colors of transmission fluid

You might also notice tiny metal particles suspended in the fluid, giving it a gritty texture. These particles are typically worn metal from transmission components, which indicates internal damage.

When checking your transmission fluid dipstick, smear a drop on a white paper towel to get the most accurate result. While fresh fluid spreads evenly with a clear red color, burnt fluid appears dark and may not spread as easily.

What Does Burnt Transmission Fluid SMELL Like?

Burnt transmission fluid has a distinctive odor that many mechanics describe as similar to burning rubber or electrical components, burnt toast, or scorched paper.

The smell is noticeably different from other automotive fluid smells; it’s not sweet like coolant or petroleum-based like motor oil. Instead, it has a sharp, acrid quality that can be quite unpleasant and tends to linger.

This smell often becomes stronger after driving for extended periods, particularly in hot weather or heavy traffic conditions. If you park your car after a drive and smell something burning near the transmission area (typically under the center of your vehicle), take a moment to investigate.

Causes of Burnt Transmission Fluid

#1 – Low Fluid Levels

signs of low transmission fluid

The most common cause of burnt transmission fluid is simply running with low fluid levels. When there isn’t enough fluid in the system, the remaining fluid works harder and heats up more quickly, accelerating the burning process.

How to Fix

Check your transmission fluid level using the dipstick when the engine is running and warmed up. If low, add the manufacturer-recommended type of transmission fluid until it reaches the “FULL” mark and inspect for leaks around the transmission pan gasket, seals, and cooler lines.

#2 – Overdue Fluid Change

Transmission fluid breaks down over time due to normal heat cycles and becomes less effective at lubricating and cooling. Most experts recommend changing automatic transmission fluid every 30,000 to 50,000 miles, though some manufacturers recommend longer periods.

The problem is that many drivers stretch this interval much further. They may be diligent in changing their engine oil at regular intervals, but when it comes to transmission fluid, they often follow the “set it and forget it” approach.

How to Fix

Change your transmission fluid according to your vehicle manufacturer’s recommended schedule. For vehicles with burnt fluid but no major transmission damage, a complete fluid change or flush performed by a qualified mechanic can help restore proper function.

#3 – Excessive Towing or Hauling

V8 towing capacity

Regularly towing heavy loads puts additional strain on your transmission, generating extra heat that can cause fluid to burn. This is especially true when towing up steep grades or in hot weather conditions.

How to Fix

If you frequently tow, consider installing an auxiliary transmission cooler to help dissipate heat or upgrading the cooler if one exists yet transmission temps are still tend to creep up. Also, be sure to use a high quality transmission fluid and change it a bit more frequently than the standard recommendation.

#4 – Transmission Overheating

Various mechanical issues can cause your transmission to run hotter than normal, burning the fluid even when levels are correct. Failed cooling systems, stuck torque converters, or clogged transmission cooler lines are common culprits.

How to Fix

Have a qualified mechanic check your transmission cooling system, including the transmission cooler (often located within the radiator or as a separate unit). Repair any failed components and consider flushing the transmission cooling lines to remove built-up debris. But be advised the transmission flushes are not recommended in many cases.

#5 – Internal Transmission Problems

blown transmission symptoms

Worn internal components like clutches, bands, or bearings create excess friction and heat, burning the fluid from the inside out. This often indicates your transmission is in the early stages of failure. In severe cases, the transmission oil pump may have failed.

How to Fix

This requires professional diagnosis and repair. Depending on the severity, you might need a transmission rebuild or replacement. Acting quickly at the first signs of burnt fluid can sometimes prevent complete transmission failure.

Can You Continue Driving?

Driving with burnt transmission fluid is like walking on thin ice. While you might be ok for a while, eventually, something will give. Once your transmission fluid has burned, it’s no longer providing the lubrication, cooling, and hydraulic pressure your transmission needs to function as it’s supposed to.

In the short term, you might get away with driving short distances at moderate speeds. However, each mile adds more wear to your transmission components. What might have been a simple fluid change can quickly escalate to a complete transmission rebuild or replacement… turning a $150 repair into a $3,000+ nightmare.

If you absolutely must drive with burnt transmission fluid, keep trips short and avoid situations that generate extra heat. This means no towing, no aggressive driving, and minimal stop-and-go traffic if possible.

If the symptoms are really bad, have your vehicle towed to a repair shop rather than risk further damage. The cost of a tow is insignificant compared to the price of a new transmission.

Mark Stevens

34 Comments

  1. have new to me 2011 kangoo adapted automatic, has burning smell getting worse past few months, seen 4 mechanics, all say gear box as oil brown and burnt heavy contamination with metal particle[looked gittery]but specialist say over phone that its normal to be brown for these cars with some metal – just needs oil change or wouldnt work-others says needs new gear box. Works ok , some gear slippage-question is that the specialist is 60 m motorway drive away and cant do actual work for few months, so would mean driving it there initially just for diagnostics then back for actual work in few months-do you think it is safe to drive it there and back for diagnostics? He say it will be fine but he doesnt realise how bad the smell is- Ive been driving it a little just locally[uk style local..] I cant afford to not have it as rely on it as disabled and hoping to ‘stretch’ out keeping it going for the few months until he can do work..?Hope this makes sense! any advice welcome

    1. I have no idea if it’s safe; I don’t feel like I have enough information. If the burning smell is getting worse I would probably not take a long trip with it.

  2. Hi I have a 350z with an automatic transmission, I’ve noticed the gears haven’t been that quick and a very very slight burn smell when driving. this has been since a little accident I had, the coolant and other lines were cut off in the accident, should I try putting some transmission fluid and see how it goes?

  3. We have a 2005 ford e250 cargo van, ac wasn’t blowing cold so we had mechanic replace ac compressor, dryer, a line (I believe), then on way home it died twice. Took it back up there and he said fan clutch went out. Drove it home again and was fine that day. Next day van goes into limp mode. Take it to mechanic who says he can’t find anything wrong and come get it. Drives fine on way home. NEXT day again, van goes into limp mode AGAIN, tow it to mechanic shop who checks transmission fluid, says smells burnt and says transmission is shot and we need a new transmission. We had none of these issues until ac compressor was changed and i feel like its somehow connected. Any suggestions?
    P.S. taking it to a different mechanic Monday

  4. I have a Rover 45 on reg YY03 plate. My automatic gear box has suddenly started to rev up whilst driving. I toped up the transmission fluid but it is still revving up, I am not very good at the mechanical side of the car but need some advice please.
    At the moment I can not afford a garage mechanic but really need my car to get back and forth to hospital. Any help would be appreciated.
    Many thanks, Harry Gallagher

  5. i have a 2014 nissan sentra and it was having some problems shifting out. now it take off slow check engine light came on got the test done and it said transmission fluid pressure sensor/switch B circuit range/ performance. do you thing i can replace the sensor for i have to get a transmission? i heard that i need a new transmission. Any suggentings?

    1. I’m not sure. You can try replacing the sensor if it’s easy to get to. It could also be a bad ground or poor electrical connection. You’ll probably have to do some more testing to know for sure.

      1. So, first it was slight burning rubber type of smell. As it got worse, thin bits of smoke from the under side of the vehicle, gears beging to get increasingly erratic as i drive to the mechanic. Then I feel slight loss in power , so I pull over and shut car off to let it cool a bit , being that I’m now less than a mile from the shop. Then I crack it back up, shift to drive and pull into shop , where it finally loses power to the wheels. Engine runs fine, trans fluid leaked really bad from recent axel replacement. Still shifts into park, drive, reverse and neutral.

        Do u think my trans is completely ruined?? Or is a simple fix to the seal and axel plus refill of fluid gonna remedy the issue?

  6. I appreciate how the mechanic’s answers (usually Sean) matched the technical level or apparent knowledge of the person asking the question. Is.there a way to ask a follow up question to his response?

    1. I appreciate the compliment, Liane. 🙂 I am actually not a professional mechanic, just a car enthusiast who is handy with a wrench and a computer. You can ask a follow up question by clicking the “Reply” button directly under the comment you want to reply to.

  7. I had a leak in a transmission line which was replaced (also had a flush a fill). It was a mess…lots of leaking fluid. I manged to get to the dealer in the nick of time.

    Noticed a burning smell soon after and went back to the dealer to recheck. System seems fine. No new leaks.

    Residual fluid burning off? If so, how long can this last? Can an engine clean clear this up?

    1. It could be residual fluid burning off, especially if it leaked onto any hot components like the exhaust. I’m not sure how long it will last, but it could be months. An engine clean should help. Try to clean the hard to reach places, especially anywhere that looks like it was recently wet from oil.

      If the burning smell persists after the cleaning, it wouldn’t hurt to bring it back to the mechanic to get it checked out.

  8. Hi I’ve just had my automatic transmission box changed for a second hand one that had done 68000 miles when the transmision specialist received the box he noticed that the old fluid was very dark in colour not pinkish they exchanged the fluid and told me to do about 1000 miles and bring it back and they would change it again they thought that the gearbox had done a lot more miles than ide been told.Any way the gearbox I’ve purchased is just the same as the one I’ve taken out sets off great in 1st and 2nd and sum times 3rd if I get into 4th and I want to pass something It want Change dawn.ime a bit lost with it at the moment.Have you got any suggestions for me I’ve got warranty with the gearbox but I don’t want to send it back as faulty if it’s something els.Hope you can help a bit.
    Cheers Gordon Watson

    1. Lots of 4 speed automatic transmissions have an overdrive gear for their top gear. If you’re in 4th and you step on the gas to pass someone, you’ll usually downshift. That part seems normal. If it feels wrong or like the transmission is slipping, I would take it back and use the warranty.

  9. 2007 mazda Cx7. When shifting into 2nd gear the vehicle shifts hard, but only that gear. The “AT” light comes on the dash for the automatic transaxle. Pulled my scanner in and the code PO976 appears for Shift Solenoid B control circuit low. Any suggestions on how to fix this?

    1. You may have to replace the shift solenoid. Before you do, check the condition of the transmission fluid. Does it look good, or is it dark and burnt smelling?

      If the fluid checks out, the factory service manual should have a procedure for testing the shift solenoid circuit. If the solenoid fails the test, replace the solenoid. The manual will also have the location of the solenoid and the disassembly/reassembly procedure.

  10. 2009 subaru forester thinking of buying , everything seems very good , but transmission fluid is brownish and has a slight burnt smell , anyway to know if tranny going bad or just need a flush

  11. 4l60e transmission will go into reverse and 1st but has a delay on the other gears. Sometimes it wont even shift but sometimes it will. Tranny fluid is brown also. Truck milage 230k.

    1. Bad transmission fluid can definitely cause problems like this. But it could also be others things such as the valve body.

    1. Check your transmission fluid level. If that’s fine, it may just be some fluid that got somewhere on the case or other part and is simply burning off. It should go away on its own. But I’d mention it to whoever did the swap just to document it in case the smell doesn’t go away.

  12. Is it true overaccelerating can cause automatic gearbox to burn? Not comment but question.

    1. Not sure what you mean by overaccelerating. Do you mean too much power is given to the wheels which causes them to lose traction and spin?
      If so, it’s possible but not likely. You’re causing additional stress to the torque converter which can cause failure over time though.
      If it’s wheel hop (tires lose and gain traction in rapid succession), then yes, it can cause a transmission failure from the repeated stress.

  13. My ford f150 stx 4×4 tranny jus wouldn move i change the fluid drove it but still didn have the power so i put 3 more quarts of tranny fluid in an it moved so now it just stopped i took the tranny out does anyone have any options that could help me?

  14. i bought a 1995 dodge grand caravan and have a transmission issue the guy said it is a seal thats out and im gonna guess he used the same seal it had and didn’t change the seal when he changed the sealinoid B. But that’s it. it runs and drives just fine but don’t know if it’s safe to drive without changing the seal please help me thanks.

    1. could be many things , such as low transmission fluid, undone shifter cable, or some more unusual things , like the torque converter ,or even worst of all the transmission is ” slipping” badly , and needs repairs .

    2. 99 Toyota Camry le automatic 6 cyl

      Check engine light one and scanned with code reader and got code P0500 vehicle speed sensor A

      Changed the speed sensor.

      Started car back up, drove a couple hundred feet, check engine light came back on and the scanner read the same code.

      Only difference now is that the odometer isn’t reading. That’s the only thing on the dash not reading.

      1. You may have a wiring issue that is shorting the speed sensor, or a bad ground that is preventing the speed sensor from reading properly.

    3. What ended up being the issue same happened to my 08 Honda accord EX-L V6 sedan because coolant line to transmission broke ran dry while driving now does that revs but won’t engage into gear.

      Drove 30 mins bone dry but I think my transmission should be okay honestly.

      That is the question

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