Thumps only at startup, then improves
A dull rhythmic thump starts right away, then fades as the dryer runs for several minutes.
Start here: Run the dryer empty first. That pattern strongly points to a flat-spotted dryer drum support roller.
Dryer noise troubleshooting
Dryer Thumps on Startup
Direct answer: If your dryer thumps on startup and then quiets down as it warms up, the most common cause is a drum support roller with a flat spot from sitting in one position. A worn dryer idler pulley or something caught in the drum seam can sound similar, so separate those first.
Most likely: Start by checking for shoes, metal hardware, or a loose baffle inside the drum. If the thump is still there empty, suspect the dryer drum support rollers before anything electronic.
A steady thump-thump-thump that matches drum rotation is usually a rolling part, a rubbing part, or an object hitting once per turn. Reality check: a roller with a flat spot often makes the worst noise during the first few minutes, then settles down. Common wrong move: replacing the dryer belt just because the cabinet is already open when the belt is not what makes a rhythmic thump.
Don’t start with: Do not start by ordering a motor or control board. Startup thumping is usually a mechanical support problem, not an electrical one.
Noise only with clothes in the drum?Check for heavy items, shoes, or hardware banging before opening the dryer.
Noise even when empty?Focus on drum support parts and the drum seam, not the load.
Last reviewed: 2026-04-05
What the thump sounds like
Thumps with every turn the whole cycle
The noise stays steady from start to finish and matches drum rotation.
Start here: Look for a worn roller, damaged dryer idler pulley, loose drum baffle, or something caught in the drum seam.
Only thumps with certain loads
The dryer sounds normal empty but thumps with shoes, towels, or heavy mixed loads.
Start here: Check the load before the machine. A single heavy item or metal hardware can mimic a bad roller.
Thump comes with scraping or burning smell
You hear a thump plus rubbing, scraping, hot smell, or lint smell.
Start here: Stop using the dryer and inspect further. That can mean a dragging drum, failing support part, or lint buildup causing heat and friction.
Most likely causes
1. Flat-spotted dryer drum support roller
This is the classic startup thump. The roller sits in one position between loads, develops a flat spot, and pounds until it warms and rounds out a bit.
Quick check: Run the dryer empty. If the thump is strongest cold and improves after a few minutes, this is your leading suspect.
2. Object or hardware hitting inside the drum
Shoes, snaps, zippers, bra hooks, and loose items can hit the drum or baffles once per turn and sound worse than they are.
Quick check: Spin the empty drum by hand and look for anything stuck in the drum holes, seam, or around the front lip.
3. Worn dryer idler pulley
An idler pulley usually squeals first, but when badly worn it can knock or thump as the belt tension changes at startup.
Quick check: Listen from the lower front or rear access area. If the sound is lower and rougher than a drum hit, the belt path is worth checking.
4. Loose drum baffle or damaged drum seam area
A loose baffle or warped spot inside the drum can make one solid knock each revolution, especially with clothes tumbling against it.
Quick check: Press on each drum baffle by hand and inspect the drum seam for a raised edge or snag point.
Step-by-step fix
Step 1: Run it empty and pin down the pattern
You want to separate a load noise from a machine noise before taking anything apart.
- Unplug the dryer first, then remove all clothes and check the drum for shoes, coins, screws, bra wires, or anything stuck in the holes or seam.
- Close the door, restore power, and run the dryer empty for one to two minutes.
- Listen for whether the thump starts immediately, whether it matches drum rotation, and whether it begins to soften as the drum keeps turning.
- If your dryer has an interior light, watch the drum start and stop for any wobble or hitch in the rotation.
Next move: If the thump is gone empty, the dryer itself is probably fine. Recheck how loads are being dried and avoid single heavy items tumbling alone. If the thump is still there empty, move on to the drum and support checks.
What to conclude: A noise that stays with an empty drum is almost always a mechanical dryer issue, not just laundry banging around.
Stop if:
- You smell burning lint, hot rubber, or electrical odor.
- The drum struggles to start or stops turning.
- The noise turns into grinding, scraping, or metal-on-metal rubbing.
Step 2: Check the drum interior for a once-per-turn hit
A loose internal piece can sound almost exactly like a bad roller, and this check is quick and safe.
- Unplug the dryer again.
- Turn the drum slowly by hand and feel for one spot each revolution where it bumps, drags, or clicks.
- Press on each dryer drum baffle to see if one is loose or shifting.
- Inspect the drum seam and front drum edge for a raised lip, snag, or object caught between the drum and front support area.
- Look for fresh scuff marks inside the drum that line up with the thump.
Next move: If you find and remove a stuck object, or tighten a clearly loose baffle fastener, test the dryer again. If the drum interior looks sound and the thump remains, the support parts underneath the drum move to the top of the list.
What to conclude: A clean drum with a steady startup thump points away from laundry or drum hardware and toward the rollers or belt path.
Step 3: Check airflow and heat clues before opening the cabinet
Poor airflow does not usually cause the thump by itself, but overheating can harden support parts and make noise worse. It also changes how urgent the repair is.
- Clean the lint screen fully.
- Check the outside vent hood while the dryer runs to make sure airflow is strong and the flap opens freely.
- If airflow is weak, pause this repair path and address the vent restriction before running more test cycles.
- Note whether the cabinet gets unusually hot or the clothes take too long to dry.
Next move: If airflow was badly restricted, fixing that may reduce heat stress and keep the next repair from failing early. If airflow is normal and the thump is still there, open the dryer cabinet or access panel to inspect the drum support parts.
Step 4: Inspect the dryer drum support rollers and idler pulley
This is the most common confirmed repair path for a startup thump that stays with an empty drum.
- Unplug the dryer and open the cabinet or service access according to your machine's normal service layout.
- Release belt tension carefully and inspect the dryer drum support rollers for flat spots, wobble, cracked rubber, seized bearings, or heavy lint packed around the shafts.
- Spin each roller by hand. A good roller turns smoothly without a lumpy feel or side-to-side slop.
- Inspect the dryer idler pulley for rough rotation, wobble, or a worn groove where the belt rides.
- Check the dryer belt for fraying or glazing, but treat it as secondary unless it is clearly damaged.
Next move: If a roller feels lumpy, has a flat spot, or the idler pulley is rough and loose, replace the failed support part and reassemble. If the rollers and idler pulley both spin smoothly and look true, inspect for a bent drum, worn front support area, or motor-related knock before buying parts.
Step 5: Replace the confirmed bad support part, then test from cold
A startup thump is only fixed when the dryer starts quietly from a cold stop, not just after it has already warmed up.
- Replace the bad dryer drum support roller or the worn dryer idler pulley you confirmed during inspection.
- If one roller has a flat spot, inspect the others closely and replace the full supported set if they show similar wear.
- Vacuum out loose lint while the cabinet is open, especially around the roller area and motor base, without disturbing wiring.
- Reassemble the dryer, restore power, and let it sit off long enough to cool if you already ran it warm.
- Start the dryer empty from cold, then run a normal load to confirm the thump is gone.
A good result: If the dryer starts smoothly with no rhythmic thump, the repair is complete.
If not: If the same once-per-turn thump remains after confirmed support-part replacement, stop chasing parts and have the drum, front support area, or motor assembly checked more closely.
What to conclude: A quiet cold start confirms you fixed the real source. If the noise survives a verified roller or idler repair, the problem is no longer the common easy failure.
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FAQ
Why does my dryer only thump for the first few minutes?
That usually means a dryer drum support roller has developed a flat spot while sitting. As the roller warms up and starts moving freely, the thump often gets quieter.
Can I keep using a dryer that thumps on startup?
A light startup thump with no smell or scraping is often a worn support part, but it usually gets worse, not better. If you hear grinding, scraping, or smell something hot, stop using it until it is checked.
Is the dryer belt causing the thump?
Usually no. A dryer belt is more likely to squeal, slip, or break than make a steady once-per-turn thump. Check the rollers and idler pulley first.
Why does the dryer thump only with towels or heavy loads?
Heavy items can bunch up and hit the drum once per turn, especially if one item is much heavier than the rest. Test the dryer empty before assuming a part has failed.
What if I replaced a roller and the dryer still thumps?
Then look harder at the remaining rollers, the dryer idler pulley, a loose drum baffle, or a damaged drum support area. If the common support parts check out and the thump remains, it is time for a closer mechanical inspection instead of more guesswork.