Finally...Combining TWO 1985 300D's - Page 13 - PeachParts Mercedes-Benz Forum

Diseasel300 · #**181** 05-24-2018, 10:00 AM

Do you have a sloppy shifter and difficulty starting the car in "P"? If so, the bushings may be completely gone by now. Otherwise it sounds more like the parking pawl isn't engaging in the transmission.

300Drestoration · #**182** 05-24-2018, 10:03 AM

Quote:

Originally Posted by Diseasel300

Do you have a sloppy shifter and difficulty starting the car in "P"? If so, the bushings may be completely gone by now. Otherwise it sounds more like the parking pawl isn't engaging in the transmission.

Yes im sorry i forgot to mention that since id been complaining about it already here

Starting in park is hit or miss and frequently i need to put it in neutral.

Diseasel300 · #**183** 05-24-2018, 12:12 PM

Try the shifter bushings first. If you aren't able to push the linkage all the way into "P" it seems plausible that it may not engage the parking pawl. Certainly worth the $5 in parts to fix and see if it fixes the parking issue at the same time.

300Drestoration · #**184** 05-28-2018, 08:59 AM

Ok so I’m ordering the bushings. There are two different ones.
But there is also this third piece that isn’t mentioned in the peachparts how to guide for changing the bushings... https://www.pelicanparts.com/More_Info/0069970147.htm?pn=006-997-01-47-MBZ
It’s called “Transmission Seal - Gear Shift Selector”

Do I need this as well? Does this part wear out and should I replace it too? Or is it something that I should not mess with unless confirmed there’s an issue.

Diseasel300 · #**185** 05-28-2018, 09:44 PM

That seal is for the shifter shaft on the side of the transmission. You don't need to replace that.

Concern yourself with the shifter bushings under the car first. There are 2 of them on the linkage from the shifter rod to the transmission shift lever on the side of the transmission. These are the ones that tend to give you fits and WILL prevent you from starting in park. The bushings up inside the shifter affect its feel, but won't lock you out of starting.

300Drestoration · #**186** 06-19-2018, 11:18 AM

Quote:

Originally Posted by Diseasel300

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.

Well, i've been a bit held up from progress because my main tool box was stolen out of the trunk a month ago while parked in an area of town that's not so ideal. Gated lot, but creepers will creep. Lost ALL of my various types of wrenches and sockets, and specific hand tools that i had collected for this vehicle. Good chunk of change lost.

I have a question about the lumpiness...
In the next couple weeks I'm going to replace the rubber fuel line hoses and clamps, and also i'm going to drain the fuel tank and clean the fuel tank filter and replace the three rubber fuel lines under tank, but i'm still wondering about something...
Why would lumpiness suddenly dramatically increase when putting the car in park after coming to a stop? What would that indicate? I feel like that has to indicate something...?

I have twice replaced the pre filter in the past week in hopes that clearing the soot from the equation would be the answer. But it's not, the lumpiness still occurs. Will be replacing main fuel filter again too this weekend. It was last replaced in November.

Diseasel300 · #**187** 06-19-2018, 12:29 PM

Air in the fuel system can cause unbalanced injection quantities. When the engine is under load (driving the car, in gear, etc), more fuel is injected and the RPM tends to be higher, so you don't notice it as much. Idle in P or N is the smallest injection quantity that will occur on the engine, so any air will make the imbalanced more pronounced. This is assuming you have good and even compression and your valves are adjusted obviously...

Migrating back to your fuel filters.....is the prefilter collecting a bunch of black particles in it? If so, treat the fuel with BioBor because you have diesel "bug". Get that cleared up before you waste your time changing the tank strainer. Keep dosing at every fillup for the next half-dozen fillups and change the prefilter as necessary as it clogs. Changing the fuel lines is still worth your time.

vwnate1 · #**188** 06-19-2018, 12:32 PM

I hope they didn't damage the trunk lid too much when they broke in .

define 'lumpiness' ~ are you talking about lack of a smooth idle ? .

Is there any visible crud in the clear plastic fuel intake screen ? .

There are only two fuel hoses needing changing underneath the fuel tank, be ready for a Diesel bath no matter how you approach it .

300Drestoration · #**189** 06-19-2018, 02:49 PM

Crud: Yes, black specs. Lots of them.
In the fall i put a new pre filter and secondary filter in, when i did the diesel purge.
Last week i replaced it. It had a bunch of black particles.
I ran it for two days, went through a full tank for a road trip with family, then replaced the pre filter again. The 2 day old one i took out had lots of black particles again.
So i'm now on my third pre filter in just under a week. I took a look this morning and there were some black particles but not too much yet.

Lumpiness: It can sometimes be VERY out of control feeling. Almost like all 5 valves are hitting at the same time. It's scary.

-When i start first in the morning, it's smooth in park.. then upon driving a couple blocks and coming to a stop sign, it is VERY lumpy.

-When the car is warmed up, and i pull into park and am about to shut down.. once i put it in park it can sometimes start gradually lumping and if i let it keep rolling for 30 seconds it may end up in full lump action.

Air:
1: If it's air in the fuel system, was it there for the last six months since the diesel purge perhaps causing it?
2: OR, is it that i have some faulty issues with fuel lines that continually leaks air in?

It turns out i have the newer primer pump design, not the old plastic top one that leaks. This one appears fine and certainly works.

Valve Adjustment: Been reluctant to have someone do it because i know i can invest in the tools and do it myself. But now that my tools are stolen i would have to get a whole bunch of tools again so i'm going to just bite the bullet and hire the guy to do the valve adjustment this week.

Fuel lines by tank: I had learned that there are two return lines and one source line, and to replace all three as well as clean out the tank filter. No?

Trunk: i left it unlocked. Doh! No damage though. They just pressed the button i guess. Jerks.

I will get some Biobor!!!!

Diseasel300 · #**190** 06-19-2018, 03:59 PM

Take care of the diesel bug before it gets completely out of control. The BioBor will go a long way to taking care of it. I got a tank infection from crap fuel earlier this year and treated with the BioBor. For the last 2 months the prefilter has been spotless, so clearly it did something! If you have any air in the system, it's from leaks. Any air you had from the diesel purge would have burped out in a few minutes of running after you did the purge treatment.

If the valves haven't been adjusted, that's a very important thing to do before throwing parts at the car. If your valve clearances are really tight (or even non-existent), they will shrink as the valves and head heat up in use. If you lose enough clearance, or work into the negative clearance region, you'll have valves start to hold open with resulting compression loss and rough running.

You should only have 2 lines under the car, a supply and a return. If the rubber lines under the car aren't all cracked up or "sweaty" with fuel, leave them be for the time being and focus on the lines under the hood and adjusting the valves.

300Drestoration · #**191** 06-19-2018, 05:05 PM

Ok, i have an appointment to get the valve adjustment monday morning.
I'll line up some biobor as well.
Here's a question about the fuel lines in engine bay...
It seems like the short line feeding the pre filter is a bit bent. Not quite kinked and definitely not pinched, but is this bend going to cause some lack of flow? This is the physics that i don't quite understand with fluid motion. Would it be unwise to lengthen the replacement segment by perhaps around an extra 4 or 5 inches so that there is some gradual bend instead of a tight bend? Or would this completely throw off the balance of fuel flow to alter the OEM short hose length feeding pre filter....

Diseasel300 · #**192** 06-19-2018, 06:13 PM

If you aren't pinched/kinked, there should be no appreciable loss of flow. Flow rate will affect high RPM/high speed operation, not low speed. The CONDITION of the hoses is important though. If they're hard, cracked, or look "wet" then they're done. When routing replacement hose make sure you route it in such a way that the hoses aren't rubbing on anything. If that means shortening or lengthening any hoses when you redo it, use your best judgement.

300Drestoration · #**193** 06-19-2018, 06:27 PM

Quote:

Originally Posted by Diseasel300

If you aren't pinched/kinked, there should be no appreciable loss of flow. Flow rate will affect high RPM/high speed operation, not low speed. The CONDITION of the hoses is important though. If they're hard, cracked, or look "wet" then they're done. When routing replacement hose make sure you route it in such a way that the hoses aren't rubbing on anything. If that means shortening or lengthening any hoses when you redo it, use your best judgement.

So it’s just called 7mm fuel hose?
And injector clamps?

Diseasel300 · #**194** 06-19-2018, 07:24 PM

The OEM size is 7mm. Several people have reported success using 5/16" fuel hose. I had air leaks, so I avoid it. Use fuel injection clamps. Google it and you'll see the difference between them and worm clamps. They do a better job of even clamping force and lead to less chance of an air leak.

300Drestoration · #**195** 06-19-2018, 10:23 PM

Quote:

Originally Posted by Diseasel300

The OEM size is 7mm. Several people have reported success using 5/16" fuel hose. I had air leaks, so I avoid it. Use fuel injection clamps. Google it and you'll see the difference between them and worm clamps. They do a better job of even clamping force and lead to less chance of an air leak.

Is there an outer diameter size of the hose that the clamps will be spec’d to match?