Finally...Combining TWO 1985 300D's - Page 11 - PeachParts Mercedes-Benz Forum

Diseasel300 · #**151** 04-21-2018, 11:24 AM

Turn signal switch not self-cancelling is likely due to a broken plastic peg internal to the switch. Buy a new one or live with it, it is NOT worth trying to take apart and fix (BTDT and I'm pretty ambitious in trying to repair things!).

Interior light not lighting with the driver's door open can be due to a bad door switch or a bad seatbelt relay. Seatbelt relay? Yep. Try the door switch first.

Is the squeak/rattle in the dash still there when the A/C is running and you just can't hear it due to the fan noise? You'd be surprised how many squeaks/rattles the blower and/or radio will cover up!

300Drestoration · #**152** 04-21-2018, 11:32 AM

I have a working signal mechanism in previous car. From reading around some threads, some people say it’s easy to replace the whole mechanism. But I find here that there are a number of wired connections going from switch into console. Hmm.
Fan rattle absolutely disappears when any HVAC is running. It is night and day.

Diseasel300 · #**153** 04-21-2018, 12:10 PM

The switch is easy to replace. All those wires go to a big plug just below the steering wheel column. Unplug it and swap the entire switch mechanism out.

The rattle in the fan could actually be the bearings in the motor being knackered. When you get in that far, grab the shaft and give it a wiggle.

300Drestoration · #**154** 04-21-2018, 12:22 PM

Quote:

Originally Posted by Diseasel300

The switch is easy to replace. All those wires go to a big plug just below the steering wheel column. Unplug it and swap the entire switch mechanism out.

The rattle in the fan could actually be the bearings in the motor being knackered. When you get in that far, grab the shaft and give it a wiggle.

It WAS easy! Already swapped signal systems and took a test drive! It’s funny how you can get by without something but then it feels like a luxury when it’s back! Not to mention it’s safer not having to remember the to turn off the signal.

Next up is the interior light trigger switch on drivers side. I’ll be looking at how easy it is to replace and pull over good one from other vehicle again.

I have to admit I’m intimidated by the dash pull now. I also will have to run a couple errands before decommissioning the vehicle until probably end of day tomorrow. I might be opening up a can of worms here with the HVAC rattle repair. I’m just hoping that I already have whatever tools I need in hand for that. Otherwise I’ll be asking for rides to the hardware store pretty quickly!

300Drestoration · #**155** 04-21-2018, 12:40 PM

Ok so I swapped the door switch but apparently it wasn’t that. Unless somehow both don’t work. My multimeter is at work so I didn’t test, but the “new” switch here worked in first car.
Where the seatbelt relay?

Diseasel300 · #**156** 04-21-2018, 01:02 PM

Not sure on the W123, but it should be up under the dash. Look for a writeup here or on benzworld to lead you to it. I think the W123 still uses the silver can style relay. On my W126 it is attached to the same bracket as the cruise control amplifier.

If it works in your parts car, you should be able to swap it over to your driver for a definitive test.

Regarding the dash, I'd personally leave that for a day when you're feeling like He-Man. Removing the dash is not an easy or quick task.

You should be able to get to the blower without removing the dash. Again not sure on the W123, but on my W126 it is accessed under the passenger side dash area. I find it easy to recline the passenger seat all the way and lay on it upside down to get to all that. Makes it easier for my fat lazy ass to get in there than trying to do it squatting down beside the car!

300Drestoration · #**157** 04-21-2018, 01:31 PM

Swapped and Solved.
3 for 3 today. Unreal.
Door light comes on, as does the belt alarm.
I think you are right about the dash. I should wait until I’ve got a true commitment in mind.
The rattle inside dash is audibly coming from a place directly behind the middle vents. It’s going to require the dash to be off, to the best of my knowledge.
I’m alressy wanting to replace the dash since this one is very cracked open up top. Looks terrible. My other dash looks rather excellent.
One other massively ambitious project is swapping the sunroofs. This one is stuck, possibly rusted shut. The motor kicks in but nothing budges. Maybe I can loosen it carefully somehow. I have the entire edge of sunroof taped with a thin strip of gorilla tape because if I don’t a TON of rain comes in from the sunroof.
But for now I think it’s time to go for a celebration ride and run some errands!

Diseasel300 · #**158** 04-21-2018, 02:34 PM

Always good when you get things accomplished easily and in rapid-fire succession! The sunroof leaking in the car is likely caused by clogged sunroof drains. Even if the seals leak, the water should collect in the channels around it and drain out the drains. Of course getting to those requires getting the sunroof open.....

300Drestoration · #**159** 04-21-2018, 04:16 PM

So I have been wondering about this..,
Let’s say I’m rolling along around 40 mph and approaching a stop light. Coming down to maybe 20mph and 15 mph, I can hear the engine start to become a little lopsided sounding, like a gallop inside of a regular roll. All the the hits become lumped together a little bit. Then as I get closer to 10mph it evens out again and at 5 mph and full stop the engine sounds perfrctly balanced.
What’s going on here? Is this the timing chain?

300Drestoration · #**160** 04-21-2018, 09:37 PM

Ok, now I’m concerned..
When in park, the engine slowly but surely becomes lopsided. It gets pretty jumpy and rocks the car a bit. It’s never done this ever until today.
Switch it to drive and it settles back in nice and even, even with the car still at standstill.

What did I do?
Was this caused by the some 10 or 15 times I turned off the vehicle and it sputtered down to stop before I could open hood fast enough to shut it off first? (This being due to the cracked rubber cap end on a vac line.)

Should I get a valve adjustment done right away? And have them check the timing chain for any stretching?

Diseasel300 · #**161** 04-21-2018, 11:06 PM

I doubt very seriously it's a timing chain issue. You'd have had other symptoms long before now. Usually craptastic idle is caused by air in the fuel system, mis-adjusted accelerator linkages, or on the 617's the rack damper bolt.

300Drestoration · #**162** 04-24-2018, 08:54 PM

Quote:

Originally Posted by Diseasel300

I doubt very seriously it's a timing chain issue. You'd have had other symptoms long before now. Usually craptastic idle is caused by air in the fuel system, mis-adjusted accelerator linkages, or on the 617's the rack damper bolt.

Just for my knowledge, may i ask what some other symptoms would be regarding the timing chain starting to stretch out of whack? I'd like to know, so that i can always have an ear out for it. I have heard enough about timing chain failures to at least want to know what the preliminary symptoms sound like.

I may take the car in for a valve adjustment. It needs to happen anyways, and even if it doesn't solve the occasional lumpiness it will at least be then checked off the list of vitals and also will eliminate it from the list of possible causes of the lumpiness.

Diseasel300 · #**163** 04-24-2018, 09:14 PM

Timing chain stretch causes the cam timing and injection timing to lag the crankshaft. At first it causes no real noticeable problems, but as the stretch increases, the retardation of timing begins to show up as a reduction in power, white/grey smoke especially at idle, and elevated operating temperature due to the late injection timing. If the chain is REALLY worn out, you can sometimes hear it slapping inside the timing cover. Definitely a situation you want to avoid! If allowed to go long enough and assuming the chain doesn't break first, you'll eventually have the pistons hit the valves with catastrophic results. Not to mention the chewed up sprockets in the timing pathway.

The easiest way to check chain stretch is to pop the valve cover off, line up the timing pointer on TDC, then turn the crank until the timing marks align on the camshaft and cam tower then measure your "stretch" in degrees on the crank damper. If you're >5˚, you should consider an offset key and budget for a chain replacement. If you're >7˚ or if an offset key is already installed, strongly consider a chain replacement in the very near future. If you're >10˚ stop driving the car until you get it repaired.

While you have the cover off, grab the chain on the cam sprocket and see if you can lift it off the sprocket. If you can, the tensioner isn't working properly or the chain is very seriously stretched.

For occasional lumpiness/bucking I'd be looking squarely at accelerator linkage rods being out of adjustment and the rubber fuel lines under the hood. All of them. If they're old, or if you haven't personally replaced them, use some 7mm fuel line and NEW fuel injection style clamps and replace the lot. If you have the old style "white handle" primer pump on the lift pump 86 that and get the updated one-piece replacement. Leaky hoses or leaking primer handle will let air into the fuel system and cause all sorts of unrefinement.

300Drestoration · #**164** 05-23-2018, 10:04 AM

Well the lumpiness is something i have been able to "test" many times i guess you could say...
Starting up it's fine, in park.
Once i shift into drive and pull away, all is fine until i stop at a stop sign a couple blocks away.
It starts lumping rather badly when i slow down and very much when i'm stopped for the moment. Feels like it's just about to stall. If i give it just a quick burst of throttle it smooths out.

I live in a small town and i have to go through 10 or so stops and goes before i'm on my way anywheres, and so at each slow down and stop the engine really lumps.
But once i leave town and drive somewhere 5 or 10 minutes away, and arrive at a destination and come to stop signs and traffic lights, all is well. There is no more lumping and all is normal and smooth.

I would love to be able to narrow down the list of possible causes based on this. I used to think it might be the valve adjustment needed or the timing chain being off. But that sounds wrong now.

As a total newbie, my theory is that it could be one of three things...

1. it has to do with filters causing the hangup somewhere, and once they're saturated they're ok.
2. it is the linkage needing adjustment and the stasis of the system with the throttle off is that there isn't enough fuel coming into the engine at idle, but after running the engine long enough there is enough "residual" fuel sitting in the engine for things to run smoothly.
3. it has to do with air getting into the fuel system but this gets purged by running the car long enough.

I haven't replaced the fuel tank filter yet. I did replace both the pre filter and main fuel filter in the engine bay in October.

vwnate1 · #**165** 05-23-2018, 10:27 AM

It certainly sounds like air into the fuel system to me .