'89 300E Problems - Help!
 

1.) I crawled under the car (near the driver side rear tire) and found that there is about 1/8 or less of a turn, of play in the driveshaft. No play was found when I wiggled it up, down, or side to side.

How much if any, play should the driveshaft have if the car is off and in park?



2.) The economy gauge is pegged all the way to the left while the car is in park or neutral. When in drive or reverse the economy gauge is 1/4" away from being fully pegged to the left. This is all at idle mind you.

I have also noticed while cruising the economy gauge will be pegged to the left but as soon as the car is coming to a stop say, at a red light, the gauge starts to go back to its location, 1/4 from being pegged left.




3.) Transmission shifts and even kicks down smoothly; however, when going from park/neutral to drive/reverse the engagement is rather rough. Reverse seems to be the harder of the two.




4.) Car smells rich. Engine Idle surges about +/- 50rpm from 650rpm, seems more noticeable when the car is in drive or reverse.

I just replaced the wires + spark plugs and air filter. PO had the fuel pumps and filter (rear filter) done a year ago, less then 10k miles. Also looked around to check for vacuum leaks by looking at hoses and even spraying starting fluid, nothing. One last thing was to check the EHA and O2 sensor by unplugging both, one at a time with the engine running. I noticed nothing really happened, it just kept running as if I hadn't done anything. EHA had a voltage of 9.15 DC and o2 sensor had 13.64 +/- .04 (increased with throttle). The cars check engine light did come on after unplugging the EHA.

Could this somehow be linked to problem #2 or #3? Maybe a bad cat or o2 senor?



5.) There's a loose metal sound coming from the front end suspension. I crawled under and found it to be the steering damper. The sleeve of it appears to be loose and is hitting the inner tube, very annoying (my car sounds like a metal shopping cart as it goes over bumpy roads). The alinement's is also off, leading me to believe the center link is toast too. Bushings looked ok though.

Is there anyway to check if these parts are actually still good?




I know alot of similar items have been discussed before on this forum but, after a few days of searching and alot of reading nothing has really hit the nail on the head for me. Thanks to everyone in advance and hope to get some good feedback!

#1 - don't know how much play there should be in the driveshaft, but I do know that there are wide prawls and when shifting to park from drive on a hill there is a surpirsing amount of coast before the care settles. This may be related to your driveshaft play and not an issue at all.

#2 That sounds about right for the vacuum gauge. That's how they work. Pegged left in park or neutral, slightly right in gear.

#3 That's exactly how mine has been for approx 200k, always a little louder and rougher going into gear.

#4 - Can't help, except to ask if the car runs well. These cars are known for an erratic idle once in awhile. There's a million posts and suggestions. Mine got better when I replaced the Temp sensor.

#5 Had the same annoying and scary rattle from the steering damper. A PITA to get at, so I did the seeping U gasket at the same time. Suspension components wear out. You don't say how many miles, but I'll wager it's a lot. So replace what's toast and get an alignment. You'll have a nice car that makes you smile when you get in.

89 300CE 220K

Thanks for your quick reply DWest. Here are the answers to yours...

1.) I never thought about it like that, your probably right. It seems like these car have alot of slack before they lock up. The driveshaft doesn't make any noise or anything. Plus, the rear flex disc was replaced 15k or so miles ago.

2.) That does sound normal somewhat, but even a 1/4 to right is normal? I would think 1/8 at max....

3.) I wouldn't say the car is louder going into gear but it is certainly not a smooth transition at all, its a jerky motion (think as if the car had high rpms going from park to drive).

4.) Yea, theres a billion and a half posts pertaining to rough idle issues; no one thing can fix it for every car. Where is the idle control valve and MAF sensor located on these cars? I'll try to clean them up and see if that helps.

5.) Thats what I want. The car is very clean inside and out. It drives and run very good, just the "problems" listed above. I say "problem" because I take great care of my cars and having something out of whack annoys the heck out of me. So, yep, the car has 152k now. Are there any tricks for doing the steering damper and what is the U gasket?

Anyone have any advise? I have already ordered the steering damper + idler arm bushing kit and a pair of motor mounts as the ones on the car of the originals, they seem to be getting weak.

As had been mentioned, there are like 20 different variables in the engine idle - could be any permutation of those variable (not necessarily 20, but its a lot).

In any case, some things to look at would be:

wires

cap

rotor

ignition coil (only way to test it is to replace it with a new one)

engine mixture (could be lean - also connected with carbon buildup on the valves that would lean the mixture out on you)

vacuum leaks (there are vacuum lines literally all over the car, any one of them could be the issue - not just the big ones under the hood, but also the little hard plastic lines too - your MB dealer should have the proper lines to replace them all if you want. don't forget that the door locks operate on vacuum too)

fuel accumulator

fuel delivery (filter or pumps?)

fuel distributor

injectors (these are probably bad - or at least the seals are which could cause air to sneak in the engine that way. I believe there are two seals - one inside and one outside - from what I understand you test by listening to engine idle while spraying carb cleaner on them - there are many posts on this already)

temp sensor (last sensor on the engine closest to the firewall)

crank position sensor

as for the MAF, it is locate under the air box and sits just below the fuel distributor - is the gold plate that gets pushed down.

The idle air valve is the cylinder that is located infront of the MAF (towards the radiator) and has two black hard rubber hoses going into it (the size of the hose that connects to the top of the air box).

Just for a reference, there are a lot of posts regarding the idle of the car that I originally posted (had this problem myself) - the killer part seemed to be the ignition coil. However, even that didn't fix the idle (still dips at stop in D and R). Speaking with my local mechanic, this is an issue that has plagued the cars since they were brand new (when he worked for the local MB dealer in their shop).

Good luck fixing it man.

no tricks to steering damper, eziest repair ever

one bolt (closest to drivers side) goes into a captive nut, otherwise i replaced the thru bolt/nut closest to idler arm with a new one , cant recall size.

car on ramps + penetrating fluid takes all of 20 minutes to change.

you will be amazed how little resistance the old damper has, mine literally slid up and down. good $30 repair!

PS you are measuring the O2 sensor wrong if you got 13.64, thats battery + voltage not O2 sensor output voltage, you likely measured heater wire + ...........