Hi, My 1986 300e has a strange thump thump thump sound coming from front drivers side wheel. At first I thought it was a flat because that's what it sounded like but no flat. So I got under the car and looked things over but nothing seemed broken. Any one have ideas of what it could be?

Could be a busted belt (in the tire), a "goose egg", or similar. Or, a large bolt or other foreign object stabbed into the tread.

You want to:

1) NOT drive it until you:
2) Take the wheel off and fully inspect the:
3) Tire, brake rotor, brake mechanicals, and the rest of the important stuff.

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-tp


1990 300SE "Corinne"- 145k daily driver - street modified differential - PARTING OUT OR SELLING SOON - PORTLAND OR. AREA - PM ME FOR DETAILS
1988 560SEL "Gunther"- 190K passes anything except a gas station
1997 S420 - 265k just bought it with a rebuilt trans. Lovely condition

Jack up that wheel and spin the tire by hand. Look for un-round areas in the tire as mentioned. Tires do go bad, especially low profile ones after they hit just about anything.

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1998 C230 330,000 miles (currently dead of second failed EIS, yours will fail too, turning you into the dealer's personal human cash machine)
1988 F150 144,000 miles (leaks all the colors of the rainbow)
Previous stars: 1981 Brava 210,000 miles, 1978 128 150,000 miles, 1977 B200 Van 175,000 miles, 1972 Vega (great, if rusty, car), 1972 Celica, 1986.5 Supra

I had this very same situation this weekend on the left rear of my W124. I found that a flat spot or broken belt had formed and now there is a huge cup where the steel belts are showing and the tread is separating. I ordered new tires from Tire Rack and they should be at my house tomorrow.

I first noticed the problem when I would turn right and the whole car would wobble too and fro like a fat goose.

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1993 W124 300D 2.5L Turbo, OM602.962
2000 Chevrolet Cavalier, 2.4L DOHC
2002 Ford Explorer, 4.0L SOHC
2005 Toyota Prius, 1.5L

http://www.fuelly.com/sig-us/40601.png

If it happens in curves or turning corners, suspect collapsed motor mount.

There's also the possibility the HVAC fan is hitting the box it's in.

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Kent Christensen
Albuquerque
'07 GL320CDI, '10 CL550. '01 Porsche Boxster
Two BMW motorcycles