Mercedes-Benz Forum banner

1 - 7 of 7 Posts

·
Registered
Joined
·
45 Posts
Discussion Starter #1
I just bought a 1990 300E which has a few problems I’ll need to fix. I do work on the cars I have owned (timing belt, water pump, headgasket, brake job, etc), but they have been mostly Honda/Acura. This is my first Mercedes and definitely won’t be my last. The problem with this car is numerous but mainly with suspension and engine startup and idle. Your response to any of these questions will be highly appreciated.

1. The car has like a body kit and appears to have been lowered by the previous owner. When I hit uneven road surfaces (bumps), the car wanders side to side and is not steady. Seems like a lot of the bushings are worn out and allowing for unsteady handling. The right tire rubs on the wheel well when I cut all the way to the left. The front brake pad needs replacing and there is a loud clicking noise that comes and goes. Loudest at low speeds. I hope it will go away when I replace the pads tomorrow. I am assuming it is the brake pad wear indicator? I like the car as low as it is, but I need to stiffen the suspension/ride. Any suggestions?

2. The car takes about 5 to 6 cranks in the morning to get it fired up. When it starts, you want to let it idle for a while before revving the engine. If you rev it right away, the car will fall on it’s face and want to cut off. I have check spark plugs and replaced one that was fouled. I hope to open the distributor tomorrow and check the condition of the rotor and cap. It idles very high (above the 10 mark, more like 12) and idles between 10 and 5 when gear is engaged. What do I need to do to correct this condition? There is a definite miss when you listen to the exhaust pipe in the rear.

3. After run and I leave the parked and idling, sometimes there is heavy white smoke coming out of the exhaust pipe. It is not coolant type smoke but does not really smell like engine oil. I did oil change when I picked the car up last weekend and added Lucas oil treatment as one quart. The car does not seem to smoke while driving. Just sometimes when stationary and idling for a while. I saw a post where someone suggested checking the modulator thing that helps with the kickdown. Something to the effect that if it is busted, tranny fluid can get sucked into the intake and result in smoke out the tail pipe. The car didn’t have much tranny fluid in it when I picked it up and there was no oil leak on the floor. It has been parked in a garage for about a year. Had to add 3 quarts of tranny fluid and it is not quite up to level. Left me wondering how it lost that much fluid and there is no drip under the car.

4. There is a lot of vibration all over the car during idle. If I engage the gear and hold the brake at a red light, the vibration is just too much. A mechanic that looked at the engine recently says that the engine mount needs replacing. He says that the engine is sitting too low (just by looking at it). Maybe that’s why the engine vibration is being transmitted all over the car?

5. Sometimes the car won’t start in Park. You’ll have to put it in Neutral to start. Sometimes the backup light does not come on either. On my Volvo 960, this has to do with the PNP switch (park neutral safety switch) but I don’t know much about Mercedes.

6. Where can I get a decent workshop manual, preferably in CD? Where is a good source for parts? Can the valve stem seals be replaced on this car without pulling the head? What other preventive maintenance can I do on this car to better the performance? Does the car have timing chain or belt? Are there any know problems with this model that I need to know about? How often on the timing chain, if so equipped? The owner mentioned that the CAT needs replacing. I also read (on an email in this forum) that the faulty modulator thing in item 3 above will result in sucked in oil ruining the CAT down the line. Also, the ABS light stays On most of the time. Maybe dirt on the sensor? Common problem with these?


Sorry about the lengthy first post to the group. The car needs a lot and I am only free on weekends to look at it.

Greg
 

·
Registered
Joined
·
45 Posts
Discussion Starter #2
I have found and fixed all the issues I asked help on a while back. I guess this is like an update type post. Let’s see... I'll take them by their number.

1. The rubbing was being caused by the wrong tire size in there. The car being lowered didn't help. I put two correct size tires in the front and no more rubbing. The clicking sound went away.

2. The hard start and poor idle was due to the blown fuse on the unit behind the battery. Once the fuse was replaced, the car fires up on the first try and idle smoothly.

3. The white smoke issue has been fixed. It was like I suspected. The modulator valve had gone bad and transmission fluid was getting sucked into the intake. I replaced the modulator valve and haven’t seen the problem anymore.

4. The vibration has been fixed. I swapped out the 2 motor mounts (one on each side of the engine) and the vibration stopped.

5. I never got around to this one yet, but I bet it is

6. I sold the car and bought another 300E. The ABS light went away after a good cleaning of the sensor and surrounding around. I used aerosol spray can.

Thanks for all your help on this.

Greg
 

·
Registered
'91 300 2.5
Joined
·
234 Posts
OK...I'm new to Mercedes, but not too new to auto maintenance...but could you tell me what a modulator valve is, and what relationship there is between a transmission and an intake manifold?:eek:
 

·
Registered
1990 Mercedes Benz 300E
Joined
·
1,336 Posts
ridemore said:
I just bought a 1990 300E which has a few problems I’ll need to fix. I do work on the cars I have owned (timing belt, water pump, headgasket, brake job, etc), but they have been mostly Honda/Acura. This is my first Mercedes and definitely won’t be my last. The problem with this car is numerous but mainly with suspension and engine startup and idle. Your response to any of these questions will be highly appreciated.

1. The car has like a body kit and appears to have been lowered by the previous owner. When I hit uneven road surfaces (bumps), the car wanders side to side and is not steady. Seems like a lot of the bushings are worn out and allowing for unsteady handling. The right tire rubs on the wheel well when I cut all the way to the left. The front brake pad needs replacing and there is a loud clicking noise that comes and goes. Loudest at low speeds. I hope it will go away when I replace the pads tomorrow. I am assuming it is the brake pad wear indicator? I like the car as low as it is, but I need to stiffen the suspension/ride. Any suggestions?

2. The car takes about 5 to 6 cranks in the morning to get it fired up. When it starts, you want to let it idle for a while before revving the engine. If you rev it right away, the car will fall on it’s face and want to cut off. I have check spark plugs and replaced one that was fouled. I hope to open the distributor tomorrow and check the condition of the rotor and cap. It idles very high (above the 10 mark, more like 12) and idles between 10 and 5 when gear is engaged. What do I need to do to correct this condition? There is a definite miss when you listen to the exhaust pipe in the rear.

3. After run and I leave the parked and idling, sometimes there is heavy white smoke coming out of the exhaust pipe. It is not coolant type smoke but does not really smell like engine oil. I did oil change when I picked the car up last weekend and added Lucas oil treatment as one quart. The car does not seem to smoke while driving. Just sometimes when stationary and idling for a while. I saw a post where someone suggested checking the modulator thing that helps with the kickdown. Something to the effect that if it is busted, tranny fluid can get sucked into the intake and result in smoke out the tail pipe. The car didn’t have much tranny fluid in it when I picked it up and there was no oil leak on the floor. It has been parked in a garage for about a year. Had to add 3 quarts of tranny fluid and it is not quite up to level. Left me wondering how it lost that much fluid and there is no drip under the car.

4. There is a lot of vibration all over the car during idle. If I engage the gear and hold the brake at a red light, the vibration is just too much. A mechanic that looked at the engine recently says that the engine mount needs replacing. He says that the engine is sitting too low (just by looking at it). Maybe that’s why the engine vibration is being transmitted all over the car?

5. Sometimes the car won’t start in Park. You’ll have to put it in Neutral to start. Sometimes the backup light does not come on either. On my Volvo 960, this has to do with the PNP switch (park neutral safety switch) but I don’t know much about Mercedes.

6. Where can I get a decent workshop manual, preferably in CD? Where is a good source for parts? Can the valve stem seals be replaced on this car without pulling the head? What other preventive maintenance can I do on this car to better the performance? Does the car have timing chain or belt? Are there any know problems with this model that I need to know about? How often on the timing chain, if so equipped? The owner mentioned that the CAT needs replacing. I also read (on an email in this forum) that the faulty modulator thing in item 3 above will result in sucked in oil ruining the CAT down the line. Also, the ABS light stays On most of the time. Maybe dirt on the sensor? Common problem with these?

I'm a new 300E owner as well. I found the factory manual on CD at Mercedes Benz Manual - Mercedes Repair Manuals - Mercedes-Benz Service Manuels. Ordered it online the day I bought my '90 W124/m103. I think there's another book out there about the W124 series you can get at Amazon but the factory manuals are more comprehensive. I'll be doing the major tuneups and foregoing the $500 for plug, rotor & cap. Good luck!

Sorry about the lengthy first post to the group. The car needs a lot and I am only free on weekends to look at it.

Greg
Check above quoted text.
 

·
Registered
Joined
·
45 Posts
Discussion Starter #5
OK...I'm new to Mercedes, but not too new to auto maintenance...but could you tell me what a modulator valve is, and what relationship there is between a transmission and an intake manifold?:eek:
The modulator valve plugs into the side of the tranny (driver's side) and is operated by the vacuum created in the throttle's intake chamber. A vacuum tube plugs into it and comes up through the steering column area and plugs into the rear-most intake pipe closest to the bulkhead (driver's side). Vacuum builds up most when the car is standing and idling after a run (so I was told). When the seals of the modulator wear out, vacuum is able to get through and suck tranny fluid from the other side. When engine is revved up to pull away, tranny fluid starts getting in the rear cumbustion chamber and exits out the tail pipe as burnt funny smelling white smoke. Here is a thread that will clear it up more

http://www.benzworld.org/forums/w124-e-ce-d-td-class/1333098-changing-modulator-valve.html

Enjoy...
 

·
Registered
always shopping for another benz..
Joined
·
230 Posts
im glad you tackled all the items that were causing your problems, im pretty suprised nobody chimed in to offer help... cough:: you know i would have been there for you and actually suggested all of the above fixes in all, ya know cuz im god's gift to MB's, but i was like on vacation and missed your post..

seriously though, i would have thought you would have had a ton of suggestions, maybe they figured you for a "squid" given your username? hahahahahaha!! f(*&%^cking squids always given me a heart attack wizzing buy and splitting lanes a foot of my quarter panels. not sure why CA thought it was a good idea to make that legal.
 

·
Registered
Joined
·
45 Posts
Discussion Starter #7
Me too.
I thought I would have at least one reply with a suggestion of what to do. But then I figured out that most of the members of this forum are mostly the pump gas and drive type. If the car behaves funny, drop it off at the dealer, tear them off a blank check and leave a contact number for when they are done fixing the car. I am a moderator on an international Honda Legend group based in UK, even though I live in Texas. Over there, we have mostly DIY'ers that can't wait to share their knowledge. I've done numerous headgaskets, timing belts, water pumps, driveshafts and tranny swaps. But they are on Japanesse cars. This 300E is my first Benz, hence the request for guidance. Did I mention that i belong to the Volvo 960 forum also? I had a 960 for 8 months back in '06. I bought a '95 960 with a broken timing belt for $400. I jerked the cylinder head off and of the 24 valves, 12 were bent. I had Cylinderheads of Clearwater FL do the head for $600, got my parts from fcpgroton.com, put it all back together and drove the car for 8 months before selling it for $2,000. Thieves stole my Honda Accord 6 months ago. When the police for it abandoned 10 days later, everything was gone except the donut spare tire. They took my 2 toolboxes and all my tools {observe moment of silence here}. I am slowly buying new tools now. Here is a link to some documented work I've done on my cars. Click any of the 4 links on top left corner under GregE
GregE - Photobucket - Video and Image Hosting
 
1 - 7 of 7 Posts
Top