Help Strange Noise!

[brightbus]

ok i have a w115 76 300d with 108,000 miles. lately ive been hearing strange noises, hard to explain, like "whomp whomp whomp" kinda like the charlie brown adults talking but lower. it only seems to do it when its cold "had some 60 degree whether lately here, and after the car has warmed up i dont hear it at all- oh yeah this is only while accelerating

please help, i dont wanna drive around with a big problem and make it worse, any help please.

[brightbus]

no ideas??????

[barry123400]

I have had to resort to a friend partially hanging out windows on occasion to locate the source or at least suspect area of the noise in some cases. Make sure to use a deserted road. You might want to check to make sure the rubber mount around your centre bearing is still pretty intact as well as each rubber disk at both ends of driveshaft. The rubber disks are important to find if going bad. Could just be a tire with a problem too. But only when accelerating when cold kind of eliminates that. Another thought is a constant velocity joint on the rear axel might be on it's way out. Examine your rubber boots on the rear axel for tears or leaks.. For diagnosing that if there are no leaks perhaps get a friend with quite a bit of automotive experience to ride along. Just do a quick check to make sure all your lug bolts on the wheels are snug as well. A lot depends on the frequency of the noise and of course intensity. Noises sometimes are easily found but not always. Other than what I have mentioned nothing particular comes to mind. Wait and see what other sugggestions are posted. These things can be hard without actually hearing them. Even then sometimes they are still interesting. I suspect you will find the source of that noise by the way and let us know what it was.

[brightbus]

it definalty sounds like its coming from the front- like in the engine compartment, like i said, almost only when its cold, after it warms up, the sound dissappears ill try to check tomm, seeing as i dont have to work- and then again, maybe it just happens to be cold lately, and im just paranoid, im not really mechanically inclied, but i did check the belts when i got home today- and they seemed to be fine (all new belts put on b4 i got the car)

[Rudolphrocks]

older cold tires do that when they get a flat spot, goes away after it warms up. usually

[bill murrow]

Originally Posted by Rudolphrocks

older cold tires do that when they get a flat spot, goes away after it warms up. usually

Had me stumped until I read this post. That could be your answer.

Cheers,

Bill

[barry123400]

First of all your problem does not sound expensive. A tire doing that is common but usually will keep the noise up even when holding a fixed speed while still cold. Others experiences will vary of course. You mentioned only when accelerating so I thought it elimiated that. Since you have mentioned it seems to be in the front area it is now a good possibility. There is just not that many things up there that will do this. So move the front wheel to the rear or put the spare on one front side and see if it is gone. If not move the spare to the other side and see. If it is not one front wheel I would still check the rubber disk at the front of the driveshaft carefully for integrity as well as the centre driveshaft mount. May as well have a look at the transmission rubber mount as well to make sure it is not totally oil soaked and coming apart or just rotten rubber. This car is getting older and these parts will die from old age alone sometimes. A fairly common noise generator is if the bracket that fastens the exhaust pipe to the bellhousing area is loose it might kind of rattle more when colder and accelerating. Just check that by pulling on the pipe to make sure it is tight there.

[brightbus]

thanks, i have a busy schedule tomm, despite the fact that i dont work (school, plus finally got cheaper insurance, yay!) i was thinking it was something other than the tires (not ruling out though) as it makes the noise while accelerating, when i let off the pedal (like cruising down a hill) the noise disappears

[barry123400]

A bad tire still sounds like a good bet. Even though I have never had one quit the thumping by reducing speed to constant. Cold set was famous on older nylon cord tires at one time. But there are a lot of effects I have never or ever will experience. Sounds like your first car so try to enjoy it. It has been a long time since my first car but I think I still remember the sense of mobility and freedom it produced. Almost a high come to think of it. Certain things like gas at five gallons for a dollar and basic insurance for a hundred a year are not forgotten. Plus a carful of friends with some even in the trunk to avoid paying admission at the drive in. Wonder where all those girls landed up? if possible post the area you live in at the top. Helps to determine if you have a problem more notorious say in the rust belt or hot south sometimes. Some symptoms are climatic in origin as well. Perhaps you might make a local aquaintance with a simular car though the site. One is never too young to cultivate lifetime friends.

[brightbus]

even though im not sure, sounds like it comes from front right, i have the spare tire in the trunk- ill switch them out tomm (one of the few things i know how to do )



yeah this is my first car - heres a long story of it

- paid 700 for it (701.99 to be exact) at a sealed auction at the technical school i went too. grandfather gave me flack for buying this car (whyd u get this one, not a newer one, its gonna be expensive to maintain, so on and so forth) even though he fixed my dash lights and my windshield washer issue)

anyways i was told the car has 108,000 miles (odo still working) could be more, but i belive it, interior in excellet shape and exterior too, very little rust for a 30 year old car, and before the tech school had it, the car had spent several years at fort campbell base (parking sticker for year was still on front, i think they donated it too the school) car is originally from georgia)

anyways in 4 months of owning it- only a couple of things have needed fixing (NEEDED)

after three weeks of owning it, wouldnt start one day, suspected battery as windows and windshield washers were verrrrrry slow. anyways got a jump and went to dumbass auto parts store (oreilleys and autozone - remember my knowledge about cars is next to nothing) both idiots told me that my car was only pulling 14 amps and the alternator was bad. took it too an alternator rebuild shop here in town, and they told me the idiots had no idea what they were talking about, that i just needed a new battery. well paid the 70 for a battery (maybe a duralast, not sure) and havent had a problem with that since

another problem, car started to roll in park, and would not engage in park, after reading up determined it was shifter bushings (went to my moms mechanic that runs out of his garage and confirmed this) went to mb dealer here in town that amazingly had the shifter bushings and at clips in stock) and fixed the next day, fixed that problem

oh yeah got a cd deck- i think the power line that ran to the radio was shorted out (guy at circuit city ran a new line off the batter hookup (is that bad)

oh yeah and now the noise, which is hopefully the front tire, will check tomm and report back

antenna doesnt work, maybe not hooked up,

oh yeah want to get vac lock fixed if not too expensive (front and back locks work sometimes and sometimes not- think one culprite could be front passenger door- it acts like its sucking all the vacuum hard to pull up and down

oh yeah one more think, front drivers door window gets stuck going down and up (will go down slowly but gets stuck going back up, have to pull on it) maybe bolt? there is definatly something loose in the door, can hear something clank inside when open and close door

welll a lot of rambling, but thats all the info about car to the present

[brightbus]

heres a pic of it - u can also look on the shopforum gallery here

[brightbus]

oh yeah, if this is in fact the true mileage, about how much life can i expect out of this car????? i want to make this car last as long as possible............. i did have a guy offer me 2000 for the car one day at work,,, should have taken it

any given day at work have someone come in, whos green mercedes is that in the back? mine? plan on selling it? no. repeat

and what arising problems should i watch out for? preventive maintenance to take, etc etc

though i would sell the car to someone who could make this car like mint again women at work who wants to buy it for 1000

[barry123400]

This car should slowly grow on you. You have also purchased one of the few cars out there that can teach you something. That is priceless as it will improve you self confidence and enable you to eventually do many things that otherwise you would never have been able to do. This lasts for the balance of your life by the way. Give your grandfather a couple of years and even his viewpoint might change. Great oportunity to discuss fairly long term plans for improvement and getting him involved with any planning by the way. Any involvement with him because of this car you will both remember. The winning baseline with an older car is to have it in better shape than it was in the last year. That way keeping it long term does work out pretty well. You fortunatly live in a kinder climate than mine and that helps preservation efforts as well. This car will develop more character as it gets older although some is already evident. People are trying to purchase it form you now. With a little luck you will learn the scrounging skills, cheap parts negotiation, and other source skills as well. Plus a running aquaintance with salvage yards. These skills are much harder to aquire with a newer ricebox. Do not mind your present discomfort with mechanical things as you will learn. We all started somehow about at the same level at first. The best way and time to learn about getting a lot of milage out of very little money is when you are a student anyways. Turns you into a respected astute buyer. Anyone can pay top dollar for everything in life but it is much better to know the ropes. That is a learning project in itself. Unfortunatly this is not taught in school. Anyways I would recommend a car simular to yours if I still had a child young enough to be still in school. Or a grandchild old enough to drive. In fact I have already purchased the 123 type diesel cars for that crew of grandchildren. Will keep me in contact with them plus provide an ageless interest to share with each other and myself hopefully. The granchildren seem sophisticated enough for my plan to work hopefully. Time will tell as it always dioes. One last thought. You can always sell a car like yours anytime. But you may be suprised how hard it is to replace it with a simular car. I was looking through the ebay listings of older mercedes cars probably 10 years older than yours the other day. A lot were 15,000 for close to junk cars. They never had owners that improved the general condition overall each and every year. It is more a mater of planning and disipline than money. What you are driving kept up will never depreciate. Wish I had several of my earlier cars now as my father suggested I put them in storage. We did not have enough room in the big city to do it. Too bad but such is life.

[brightbus]

well i knew the sound was coming from the front left, so like barry123400 said i changed the tire with my spare this morning. amazingly noise has disapperaed! but question is what constitutes a tire as going bad? tread looked ok...

oh yeah, my spare says its the same size as the others, but it appears slightly larger, is this a problem?