Hello All.

Three weeks ago I bought a 79 280CE off e-bay very inexpensively and drove it home to Minnesota from Florida. While the car ran well, since then I have been fixing a number of niggly problems, and becoming increasingly frustrated, as I'm no mechanic, don't have much $$, and am limited to crawling under the car as best I can, making do with hand tools, common sense and lots of good advice. It seems that no sooner do I take care of one problem, three more come up. I've probably spent more now than the car is worth, and yet can't in good faith sell it until the remaining issues are addressed, even if I had another car to drive daily which I don't.

Here are my current bigger issues on which I could use advice.

1. Radiator has begun to leak. I thought it was a loose fitting where the upper hose attaches and after loosening and retightening the clamp two days ago, thought the problem solved. But a few minutes ago, while waiting at the locksmith having replacement keys cut (and which the locksmith couldn't make work), I found a small green puddle under the car. It is a Behr radiator and looks to have sprung a leak near the upper hose where the top plastic part of the radiator attaches to the main portion of the radiator and stops dripping quickly as the car cools. My question is what, and how severe a risk do I run by adding some type of "stop leak"? Will I possibly plug something else up and cause problems?

2. Front suspension work is beyond me, and a week after coming home, something came loose in the front end. $600 later, with basically every suspension part from axle height down replaced, the mechanic said there was still a clunk he couldn't find. He speculated it was possibly in the newish Japanese shocks. I don't think so as the clunk is mainly present coming from the left front when I make a low speed right turn over a bump at the beginning of my driveway. Whenever I back out or come in straight, no clunk. Steering is tight otherwise. Had the car re-aligned, tires rotated and balanced, and THAT mechanic A. couldn't say where the problem is and B. While the car no longer shimmys, still pulls left, which the alignment guy said was a problem with camber or caster or something, but that only a Mercedes dealer could address. ???

3. Car does not glide down the road as a Benz should. First mechanic said forward motor mounts were ok, but I should check the rear mount. Another advises to check transmission mounts and another something he called the drive shaft mount and bushing. What am I supposed to be looking for? Are these things I can change myself? Main symptom is a brrrrr noise/vibration at certain speeds which smooths out as top highway speeds. Help?

Check to see if the radiator's top plastic nipple has cracked. If it has then .. it's time for a new radiator. If it hasn't then you need a new clamp. Just use a no-brand clamp. My 300cd's rad leaked from the same spot. Then my mechanic just gave me a new clamp and it hasn't leaked ever since.

2. check the brake calipers just in case one of them is sticking. The clunk could be the front swaybar mounts or the bushings (something like that...)

can you pinpoint where the vibrations are coming from?

__________________
2008 BMW 335i Coupe

I haven't taken the hose off yet to see if the plastic underneath is cracked, partly because I couldn't find a drain cock to lower the aintfreeze level so as not to spill antifreeze all over when I pull the hose, but after I made the post, I went out and looked again. When I first detected the problem, I could wipe my finger under the hose connection and come up wet. After re-seating the clamp and really cranking it down, no more moisture at the hose. But...there was a new and larger puddle of antifreeze and I can see wetness in the recesses where the top of the radiator is connected to the main portion. What I think happened is that sealing the hose leak pressurized the system and started the leaks elsewhere. I just drove over to the local auto parts store, and poored in a can of radiator stop leak after the manager's advice that so long as the heater isn't active, I was running no risk of plugging up the heater core (I hope). So we'll see what happens over the next few days.

Since I don't have a rack I'll have to get the wheel jacked off the ground and start jerking on stuff to find whats loose still, but with two mechanics saying they can't spot it, I doubt I'll have better luck

As to the vibration, no I can't really tell. A 280 motor isn't particularly quiet, and when that old A/C compressor kicks in it adds noise and vibration too. But with the compressor off, the vibration and subtle brrrrr... is still evident at roughly 40+ MPH

I could only think of the rear axles being a possible problem. Check the boots and see if they are torn?

I had a vibration at higher speeds (60+mph) and I had the driveshaft rebuilt and all the driveshaft mounting parts replaced (bearings, mounts, etc.)

Try jacking up the car and spinning the tires for any weird noises.

__________________
2008 BMW 335i Coupe

H.A.

You were right about the "nipple crack". I pulled the hose tonight. The nipple was cracked at the seam with the radiator. Because I'd moved the hose some before, it wasn't wet where it had been and that threw me off. I applied some 5 min. epoxy and held the crack closed with a C clamp. When it dried, I covered it with JB Weld liquid steel, wrapped electrical tape around it all, slipped the hose back on top of the now taped nipple and tightened it down. Going to let it cure overnight before testing it by driving to work tomorrow AM. I have my fingers crossed.

As for the rest, I paid closer attention driving home from work. You know the noise the tires make when you hit those speed bump lines on some toll roads before the booth? That Braaaaaaap sound? It is a similar noise but MUCH more subtle. You almost feel it more than hear it. It is most noticable between 45-50 and disappears above 60. Because it comes and goes from zero to 45, odds are higher that it isn't a motor mount. But with the mess of antifreeze I made on the floor, I wasn't up for crawling underneath.

As for the thunk/clunk, paying attention. it does it every time I hit a sharp bump at low speed like at the base of my driveway and the 1 1/2" lip between the driveway and the garage floor. Clearly something in the suspension. I'm determined to find it but after the radiator tonight, having to fix that the accessory key they made me today locked the trunk, but not unlock it, and sitting in the car, notice that the dash cluster seemed a might off and pushing on it had the glass fall into my hand...I'm taking a break.

hang in there These W123 coupes are beautiful cars once things are fixed up

definitely check the axles tomorrow sometime for the vibration and also the wheel bearings.

I have never had a front end clunk/thunk. I did in the back and turned out to be a stuck little screw in the lower suspension arm between the arm and the spring (It's 'thrown around' by the spring action). Took the screw out and it was gone.

on the radiator. If the fix doesn't work, try finding a thin copper tube that fits just inside the radiator nipple.

Good luck with the car!

__________________
2008 BMW 335i Coupe

FYI,

The copper tube inside the hose "nipple" was unsuccessful, and perhaps at least partly my fault. My first repair attempt failed because I used a c clamp to hold the crack shut while the epoxy dried, and later found the epoxy only had a 200 degree rating. Attempt 2 used JB weld on the crack WITHOUT the c-clamp. A small leak remained, so I tried to install an inner copper 1" coupling which IS a perfectly tight fit inside the plastic. It wouldn't enter completely, and when I tapped it with a light plastic hammer, the nipple cracked in another place. Seems that the JB weld epoxy had oozed into the first crack making the hole slightly smaller and the copper pipe was butting up against the hardened epoxy. So I slopped JB all over the nipple and into the new crack, put the copper tube in as far as it would go, and waited for it all to dry. I then reconnected the hose and fired her up. No luck. Still leaked. When I tried to tighten the hose clamp further, there was too much give and pulling it apart, the nipple had basically disintegrated.....I now have a replacement radiator for $100 from the bone yard.

In talking to my mechanic, he related that when the MB's "environmentally friendly" plastic and aluminum radiator eventually fatigues, even with the tube in place, odds would be high the plastic would crumble anyway.

If I were ever to do it again, I would take extreme care to insert the copper sleeve gently. And, I would take the extra step of wrapping a piece of epoxy soaked body repair fiberglass cloth around the plastic nipple to re-enforce the brittle plastic.

The clunk is almost certainly track rod bushings. Next time you get under the car, look at the front suspension. The track rod runs at an angle from the lower control arm to the body. If you pull the rubber cover back, you will find that the track rod is not properly centered on the bushing or other obvious signs of movment and wear. These are a bear to replace youself, but it can be done. Wait until you have a floor jack and jack stands, though... the car has to be up in the air.

The vibration can be either the bad track rod bushings allowing fore and aft movement of the front control arms, or the tranny mount and/or center bearing support on the driveshaft. The tranny mount will also cause vibration on acceleration, a distinct low frequency drumming of the floorpan.

A bad center bearing mount will also cause vibration on acceleration, but it will be centered at the rear edge of the driver's seat on the tunnel. If you put you hand on the side of the tunnel when you get vibration and the tunnel is obviously the source, you need a new bearing mount. The other check it to try to move the shaft in the mount with the bolts tight -- if you can visibly move the shaft around, the mount is shot, it should be fairly stiff.

Tires can also cause vibration, too, so take a good look at them.

Cracked plastic upper hose nipples are a common problem. Green antifreeze seems to make this worse, but the real cause is embrittlement of the plastic, and the only cure is radiator replacement. You CAN put a new tank on, but the aluminum radiator almost always refuses to seal properly (I've done this, doesn't work!). I've had two identical rads blow a hose nipple, one while I was working on it (luckily!), the other in my sister's Volvo 740 Turbo, she ended up with a new head and radiator.

Peter

Peter

__________________
1972 220D ?? miles
1988 300E 200,012
1987 300D Turbo killed 9/25/07, 275,000 miles
1985 Volvo 740 GLE Turobodiesel 218,000
1972 280 SE 4.5 165, 000 - It runs!

Peter,

You have been a great help with my multiple problems on this 280CE, which I'm now not-so-affectionately calling "Money Pit".

Right now I'm focused on the tranny problem (another post). The car is up on ramps waiting to cool a bit so that I can pull the vacuum modulator cap apart, and hope I DO get dripping ATF as my local shop lent me a new modulator if replacement is needed, otherwise its new tranny time. (I have no vacuum tester, but the hose seems intact all the way back to the manifold. Is the fact that the vacuum locks don't work either indicative of anything?)

While under there tonight, I'll do the driveshaft wiggle, and I've seen that mount and bushing assembly for sale on e-bay for $25. Looking at the rear tranny mount last night, how do I tell if it is bad? It looked like a fairly easy disassembly, and there was some sort of adjusting bolt in the center. What do I need to know about replacement adjustment of this one, and on the center shaft mount, whats the procedure for replacing the bearing?

Yes, lack of door locks indicates a vac problem (or just busted door lock diaphrams).

You really need to spring the $35 or so and get a MitiVac at the first opportunity, makes life very much easier (so you can find out what's wrong with the tranny, for instance, rather than replacing blind!).

You must pull the driveshaft to replace the center bearing and support, and pull it apart. MAKE SURE YOU MARK THE FRONT AND REAR HALVES!!!! if you get it even one spline of, it may shake like crazy. Use a paint pen and PLEASE make sure the marks don't wipe off (this is the result of driving my 220D with an unbalanced shaft from screwing this up, sorry about the caps!).

To remove, mark the flex disk and driveshaft tripod, the remove the three bolts front and rear. Leave the flex disk in place. Loosen the slide clamp with a very large pair of channel-locks or a pair of pipe wrenches and then remove the bolts or nuts that hold the center bearing carrier in. You may also have to drop the exhaust and unhook the parking brake cables. Compress the front half of the driveshaft toward the center bearing until it comes off the pilot on the tranny flange, lower the front, and them pull off the rear pilot.

To replace the bearing and carrier, you must pull the shaft apart, the remove the snap ring retainer and press the bearing and carrier off the back part. Press new one one, install carrier, replace snap rings and boot, then re-install the front half. Splines mush go in original locatoin, and unlike Volvo, MB doesn't key the shaft!

Installation is the revers of above, with the exception that yyou must roll the car back and forth on it's wheels before tightening the clamp nut -- if the shaft isn't preloaded correctly, it can shake.

Old benzes aren't really bargains once you start getting them back to factory condition.....

Peter

__________________
1972 220D ?? miles
1988 300E 200,012
1987 300D Turbo killed 9/25/07, 275,000 miles
1985 Volvo 740 GLE Turobodiesel 218,000
1972 280 SE 4.5 165, 000 - It runs!

Well Peter,

I am thoroughly bummed out. Under the car tonight I couldn't detect wobble in the shaft. I could rotate it a bit, but not move it otherwise. I was under there recall to check the vac modulator and replace if necessary. I pulled the cap off the old one and there was ATF present making me hopeful this was my problem. To get a wrench on the old one I had to remove some sort of bracket that was bolted right behind the tranny pan. A piece of flat iron about 8-9" long with three holes in it that appears to do nothing as the holes looked like something used to fit there but not now. And I had to drop the tranny mount bracket to get access too. Rear mount looks ok as far as I can tell and I sure had to do some heavy pushing to compress it enough to get the bracket back in place when done. I pulled the old modulator and let the fluid drain. I was advised to watch for the pin inside and was told it would be loose since the new modulator came without the pin. Not so. It was stuck tight into the old modulator and I had to pull it with vise grips. Mounted the new unit reusing the pin. Under the assumption that the modulater was set to factory spec. and no idea how to adjust it otherwise, I refilled the tranny and went for a test drive.

Didn't work. Absolutely no change from before. Help? Ok, your advice on the vacuum gauge is noted although if I find a problem I don't know what to do about it. And I read the post you referred me to as well. Here are all the added clues I can think of to mention: Door vacuum works nowhere including gas cap and trunk. As I seem to recall there are two lines connected to a coupling at the manifold. Is it possible a leak on the door side is affecting the tranny side? If I accelerate slowly, the 2-3 shift is very smooth, and the 3-4 shift happens at around 30mph. Both these shifts are so smooth you have to be paying close attention to notice them. If after the 3-4 shift feels like it has locked and I try to accelerate normally, it will start to slip again badly until 40+ and then the car accelerates normally. I can't tell if the slipping is because 4th hasn't locked fully until 40 is reached or because it is trying unsuccessfully to drop back into third. ATF is right at the full mark after test drive.

This car is my only transportation, and I can't afford a tranny rebuild, let alone having no other way to work, so any hints and advice is much appreciated.

Your tranny problem is the stuck pin -- if it won't move, it cannot transmit pressure to the control valve the modulator operates. Clean it off, clean the bore (no abrasives, please) and see it you can get it to slide freely. If not, get a new one. Also make sure it isn't in backwards -- I've not seen one, so I don't know if you can install incorrectly or not.

Does the tranny shift more firmly at wide throttle? If so, the modulator is working.

Another thought is to replace the filter in the tranny, but a filter and fluid change on an old transmission can be worse than leaving it alone.....

That braket is a possible source of the vibration, by the way -- it is supposed to have a clamp on it that holds the exhaust up at the rear of the tranny. No bracket, and it will vibrate badly at resonance speed, and cause the exhaust to drum on the floor pads. Also check the rubber rings that hold the exhaust up at the rear, if they are stretched or broken, the rear muffler will pound on the body pad there making a horrible thunder.

The rear tranny mount gets soft when it goes bad, so the tranny can move up and down. This causes a drumming on acceleration, otherwise it's usually quiet.

Peter

__________________
1972 220D ?? miles
1988 300E 200,012
1987 300D Turbo killed 9/25/07, 275,000 miles
1985 Volvo 740 GLE Turobodiesel 218,000
1972 280 SE 4.5 165, 000 - It runs!

I agree with Peter on the suspension noise and would really look closely at the trans mount from your description of the noise at speed.

Most driveshft vibrations are worse at low speeds and high loads.

I am giving that advise because I am trying to be civil fisrt before I go ballistic:

"which I'm now not-so-affectionately calling "Money Pit"."

This has to be the most amazing tale I have ever read. A non technical, out of funds person, buys a 25 year old car 1500 miles away on ebay as a daily driver.

Am I supposed to feel sympathetic since you are now not affectionate to this characature called a "money pit"

Just how can anyone with any intelligence buy an antique automobile at distance and expect to have no costs and use it as daily transportation.

Don't blame the GD CAR! And don't blame ebay!

__________________
Steve Brotherton
Continental Imports
Gainesville FL
Bosch Master, ASE Master, L1
33 years MB technician

Steve:

When I bought the 220D (and paid way too much for it -- wish I'd had this forum then!), the dealer asked me if I wanted to trade my POS Buick in on it.

I laughed -- I figured that a difficult to start rough idleing diesel wasn't the best car to use as my only transportation.

That said, I understand the attraction of an MB even with limited resources -- they CAN be very reliable and relatively repair free when in good condition.

I also got my 300D for a good price since the PO bought it on eBay and got screwed -- car was NOT as represented and he couldn't get out of it once he paid the deposit in Florida.

I suppose one could call my 280 SE a "money pit" also -- nothing truely insurmountable, but there is an endless list of things that need to be done eventually.

A friend of mine got rid of his when he spent $5000 on it in less than a year -- subframe mounts, injectors, brakes, water pump (for some reason he was always replacing water pumps on MBs), rebuilt transmission, etc.

Go gently, we all make decisions we regret....

Peter

__________________
1972 220D ?? miles
1988 300E 200,012
1987 300D Turbo killed 9/25/07, 275,000 miles
1985 Volvo 740 GLE Turobodiesel 218,000
1972 280 SE 4.5 165, 000 - It runs!

Geez Steve,

For response shortness, I didn't feel the need to explain that A. I had a financial reversal after buying the car and B. Even though I knew the seller and trusted his opinions and the car's history I had the car checked over before committing by an MB tech you probably know, and C. Not only did I look the car over hard myself, but I pounded it home to Minnesota and it performed perfectly, and D. I had a backup vehicle just in case. At first the car ran so well and I had such confidence, that when the money problem arose and I got an offer for the back up car, I took it....big mistake. But ok, dumbness point taken and 20-20 hindsight doesn't solve the present problem. Back to it, in response to Peter's latest post.

Your tranny problem is the stuck pin -- if it won't move, it cannot transmit pressure to the control valve the modulator operates. Clean it off, clean the bore (no abrasives, please) and see it you can get it to slide freely. If not, get a new one. Also make sure it isn't in backwards -- I've not seen one, so I don't know if you can install incorrectly or not.

This hardened steel pin was stuck into its recess inside the old modulator, but the diaphragm inside seemed to be working as the pin would rock from side to side. When I got it out with vise grips, it looked liked caked ATF had caused it to be stuck. The steel is so hard, the vise grips made no mark and it fit loosly into the new modulator, which I presume is normal. I can't get up between the frame and the modulator hole to peer inside, but I imagine there is something the pin's end fits into inside the tranny.

Does the tranny shift more firmly at wide throttle? If so, the modulator is working.

NO. I have to start from a stop very slowly and then both the 2-3 shift and the 3-4 shift are VERY smooth. The 3-4 shift happens at 30mph, and slips until about 45 when it seems to finally lock in and I can then accelerate normally. If I try to accelerate before then, it slips.

Another thought is to replace the filter in the tranny, but a filter and fluid change on an old transmission can be worse than leaving it alone.....

There was a filter change 8K ago (part of my checking before purchase though all the receipt said was "transmission service- 162K) and with the radiator change and still another change of fluid when replacing the modulator, the fluid is certainly fresh.

That braket is a possible source of the vibration, by the way -- it is supposed to have a clamp on it that holds the exhaust up at the rear of the tranny. No bracket, and it will vibrate badly at resonance speed, and cause the exhaust to drum on the floor pads. Also check the rubber rings that hold the exhaust up at the rear, if they are stretched or broken, the rear muffler will pound on the body pad there making a horrible thunder.

Yup, it does do that. Exhaust is all new. (something else I checked) Doughnuts are all in place, but somewhere near the muffler there is a loud heat shield type rattle when sitting at idle and the compressor running. I haven't tried to hard yet to find it, partly because I have these more pressing problems, partly because the florida plate on the rear was vibrating and loose too, and hoping this was the problem, I waited till the Minnesota plates arrived (2 days ago) before epoxying the loose female license plate bushings tight. And finally, when I get out of the car and my 240 pounds aren't lowering the car, the rattle/vibration disappears, so I need a fat friend to sit in the car while I search.

The rear tranny mount gets soft when it goes bad, so the tranny can move up and down. This causes a drumming on acceleration, otherwise it's usually quiet.

Then the tranny mount rubber is probably bad and so the source of my vibration at speed problem. When I removed it to get wrench access to the modulator, I first took out the two bolts in the center of the mount's support bracket, and then the 4 bolts holding the support bracket. With the bracket off, there is this odd metal part around the rubber that has an allen head bolt which passes thru the rubber and holds the bracket itself in place loosely and the bottom of this odd part is where the bolt holes are that connect the mount to the support bracket. I had to push hard to get the bracket close enough to the frame to get the bolts back in, but lying under the car which was up on ramps, I doubt that I was exerting more than 40-50 pounds of push...far less than I'd guess it would take to adequately support the tranny.

I read Steve's article on modulator adjustment, and while I've been calling friends to see if I can borrow a vac gauge, I haven't had luck yet, so here's what I have tried. I put in a new modulator last night leaving it set just as it came out of the box. Refilled the tranny and went for a drive. No change. Talking to the same tech who blessed the car, he said to turn the key in about 4 turns and try again. No change.

Thinking it possible a leak on the door vacuum was denying vacuum to the modulator, I went to the manifold connection, unscrewed everything, cleaned the residue of ATF off and stuck my head down into the compartment and blew into the hose with the door side blocked, figuring if I could force air through there would be a hose leak. That didn't reveal anything. So before I put the door side hose back on the manifold fitting, I put elec. tape over the nipple and then pushed the hose on on the guess that this would redirect vacuum to the modulator line. Then I went to the store and bought 8 feet of vacuum line. No change on this drive. If anything it might have slipped a bit more. I'm typing this, waiting for the car to cool down enough that I can pull the hose at the modulator, start the car and see if I can feel vacuum with my finger over the hose end. If I do, then I'm guessing that while the old modulator was bad (ATF leak), the real problem is inside the tranny. If I don't feel vacuum, I'll bypass the entire old line with new hose.

Is my plan logical?

Peter