Yet another new old Mercedes Benz story...

Bad form here, but I forgot two things the former owner told me.

First, the EGR (air pump?) has been removed / disabled? Could this be the rough idle / start?

Second, the exhaust has been modified .... he said the 'resonators' have been bypassed?

In the W116, you could choose a two-toned horn as an option (Zweiklang Fanfare. The button would than be to change between the electric horn and the air-horn. I have no idea if this is the case in your W126, but this is something you would never find out if you didn't flick the switch while using your claxon.

This has happened with my 380 3 times over the last 18 years, and could be the result of any number of things.

Bumping or vibration?

Probably the country/city horn switch.

Sounds a bit bad for a 91...must have been parked outside all it's life.

No idea, but get that taken care of, you don't want the rust to spread.

The horn: the horn button gives a choice of 2 sounds city and country The 1991 has heated seats for front and back seats with 2 temps 2 lights is the warmest it will cut back from 2 to 1 then off automatically

Mileage is about correct Use contact cement to adhere the wood just remember with contact cement there is no adjustment so get the position right

The clunk in the back is probably a suspension component problem 3-400 Check the hydropneumatic fluid level near the front of the engine on the drivers side use the correct fluid only from MB

Real rough idle could be injectors or any number of sensors Have you checked the spark plugs and wires These are the best Mercedes try to get the best specimen/cost ratio and you will love it Paint: maybe it was resprayed with a new clear coat Al

Kev> Hello to all once again, and Happy Holidays to you all.

I played with it today. In one position, which I'll call 'on', the horn works. Not as robust as my SDL horn, but it works. In the opposite position, the horn does not work at all.

Thanks for the tip.

Thanks for the response.

So no EGR. Do these come with an air pump? That works is utilized only when the car first is started?

It bumps, under hard accelerating from a stand still. You can feel the car pitch back as it takes off and you can feel the 'bumping' behind you. Let off the gas pedal and the bump goes away. Once you're up and going, you can floor it and not get the same bump. I think it's related to the car pitching back and 'squatting' down in the rear under fast starts.

I think you're right, except on my new old car, it's actually acting as a on/off switch. One mode does not seem to work.

I believe it's bad for any Mercedes I've ever known. It is a one owner/family car, that was garage kept according to the previous owner. Who knows?

I say that because this is my 4th W126, and they all rust at the doors. Funny thing is, the only one of them I've purchases that lived it's entire life south of the Mason-Dixon line with no road salts is the car that had the worst rust on the doors.

The seats are great. It was cold here today/tonight and I quite enjoyed the heaters.

After reading the replies, I played with that horn switch. I think I may have a problem based on what I've read, because the horn works in one position and does not work at all in the other.

I've already repaired today with a good double sided adhesive.

Ok. I'm very interested in this. What is 'component prblem 3-400' mean? I'm delivering the vehicle to my mechanic later this week so I'll get him to look at all fluids...

Haven't checked anything yet. Will do though, or my mechanic will.

It seems to be an awesome vehicle.

One owner/family car that was garage kept so I was told. Original, factory paint. This defect is over the entire painted surface.

You flew from Texas to connecticut to buy a car? That seems rather insane to me.

They use road salt back east, so your new car is going to be a lot rustier then one from arizona or california.

I grew up in Buffalo NY and would NEVER buy a car from back east. I live in Seattle now, and there are a lot of cherry rust free older cars rolling around here.

Yeah, they do that. It's the pump I was talking about that pumps hot air into the engine when the engine is cold (you know the little hose going to the air filter housing, the one that has its own little square filter in the housing? That is for this pump, so follow that little hose back to the pump and if you see the belt has been taken off, that's how you know this was what he was talking about). This pump was for emissions reasons (hot engines bur cleaner than cold, so they wanted to get it hot as fast as possible), but it's pretty darn useless and not worth replacing. As far as you are concerned it changes nothing about the car other than on really cold days it will take another minute or so to warm up. Richard

It was not my intention to buy a car up north with road salts. The burgundy interior called out to me. I'm glad I got it, as the interior on this 13 year old car is flawless in my opinion. The rust bubbles is something I'll just have to get corrected. I had the car up on a lift today and I honestly don't see rust underneath in areas I've had on my other cars. The bottom of the doors inside the door jam area are in perfect shape too.

Thanks again. The seller told me that it was not really necessary to have the pump and that it was also an expensive fix.

He said something about resonators? Some type of baffles on either side of the underside of the car that the exhaust ran through to make it very quiet. I assume they were bypassed because they were bad. Are they pricey?

Not normall unless he botched it.

Yikes. The resonators are to smooth out the exhaust. The mufflers deaden the sound. It's nor surprising it seems to run rough, this could do it (but may not be the only culprit)

Yes, 126 had this option: city/country horn. Very uncommon in US spec cars.

Mine did that until I changed the diff mount. Big ole hunk of rubber. At this age most of the rubber needs replacing - I've changed most of mine out with only shock pads and thrist rods to do. It make a BIG difference, with new rubber the ride is indistinguishable from a car

That's good, I didn't mean to rain on your parade, but going from Texas to Connecticut freaked me out a bit ;~)