W126 Benz Oil Spec and Other Questions

[Citroënbender]

I normally avoid German cars, but making an exception here. K-Jet 280SE, I think 1984. Barely used or maintained several years, rego renewal coming up early September. Starts readily and generally the functions work.

Q1: Where can I reliably find the current fluid specs? It seems implausible for one site to say 0W-40 FS and another to recommend 20W-60 Mineral. Similarly would prefer to avoid second-guessing other fluids due for renewal by age.

Q2: Nick-knacks and trim: Are dealers here surprisingly affordable, do I go Pelican, or Autohaus Az, or Eastern Europe? Front brightwork and fuel supply/periodic service parts probably the main targets.

Q3: K-Jet (shudder)… Any good online references for real world checking of components, what about injector service or specialists if it’s been tinkered with (I don’t know its status, but am aware of the hellish diagnostic loop where uneducated poking can take it)? Seems to be a couple of pots down by noise/roughness and too soft off the pedal.

[whiteSY]

Citroenbender, I have a 12 year old benz at home. Was told on all the forums . . very loudly . . not to stuff around with "affordable" oils or oil types. Those that had, paid a heavy price. If your car is still a goer, use the full synth Mobil1 oil. Its expensive ($190 for 4 L) but my car just runs and runs (C350) without hassles. You can get the OEM filters very cheaply (MANN Filters) on ebay as a set (oil, air, cabin) and they can be easily installed yourself. Physically check the oil filter type before you buy online - made that mistake once. Listed as one thing, physically another.
As for other parts, if you're looking for more complex bits or trim, try rock Auto in the states. Cheaper postage if you buy in bulk. They seem to have everything listed by car make and year, with the exception of LH to RH components on the dash.
As for the injector thing . . . not so sure. Try MB World. Its a US forum, but have a decent history trail for service hassles. May be able to point you in the right direction.
Best of luck with it all mate. They are nice cars.

[Citroënbender]

Cheers,

I was wrong about the year, it’s 1982 complianced - think also built then. Was really hoping to find out whether 229.3 or 229.5 oil spec applies.

Absent-mindedness is the only reason I’d overlooked RockAuto!

[GasoLane]

I've used Run Auto in Melb for a few years now for some suspension parts and all filters. Never a problem with them having stock (unlike Sparesbox ) and usually delivered two days after ordering.

https://runautoparts.com.au

Edit....

For Oil info give John Green a call at M.B Spares and Service in the ACT.

https://www.mbspares.com.au/Information.aspx

[sexyxe]

Originally Posted by whiteSY

Snip/ If your car is still a goer, use the full synth Mobil1 oil. Its expensive ($190 for 4 L) but my car just runs and runs (C350) without hassles.

*Chokes* You're putting $200 of oil in a C350? Wowee!

I use Liqui-Moly, Fuchs or Penrite, which ever is on sale when I change mine.

This car is 40 years old, think of oil quality 40 years ago, anything in the correct weight will be fine. Call MB service and ask them what the system says to use and find the MB spec oil.

[Citroënbender]

Good tip on the Mann oil filter - thanks. I’ll ask Run Auto as they were quite sharp on this item. I won’t likely see the car again until Sunday afternoon, that may be the first basic fluid change.

I’m reluctant to lean on Mercedes Service, on a forum I can give back with my knowledge in other fields - but MB are likely to never get a cent out of this one other than a few genuine parts. Suspect these will be quite a bit cheaper OS.

Seeing NOS W116 air filters for USD$5, but then a small fortune in postage.

[Citroënbender]

The Mann oil filter doesn’t include washers/seals. :-(

Are all K-jet fuel filters the same between W116 and W126: Two different size threaded ends, and a body OD around 74mm?

[smoo]

Originally Posted by Citroënbender

The Mann oil filter doesn’t include washers/seals. :-(

Are all K-jet fuel filters the same between W116 and W126: Two different size threaded ends, and a body OD around 74mm?

I have a spare filter in the garage and this is in the box. I’m sure the ali washer is for the sump plug.



This is the part number for 116 fuel filter that I used. Pelican doesn’t cross it over for the 126. #002-477-45-01-M14

There is also a gauze in the bottom of the tank with the supply or feed hose to the fuel pump coming off it. Might pay to change that too. Takes a large socket to get off, like a 38 or 41mm from memory.
A few parts were a hit and miss ordering off all of those yank sites. I did all the rubber fuel hoses at the tank and filter assembly and a few I ordered didn’t fit or match. Same story with the trans filter. Have had similar dramas with my E34 BMW but not too phased as they’re so cheap, I’m still better off than buying locally.

An inconsistency I sometimes found with parts listing mainly with rock auto. Some parts weren’t listed for a specific model, but we’re available under another model (like 450SE). Rock auto don’t list 280SE engine mounts, but they do sell that part under the W123 tab.
Found that out, out of desperation after being quoted $250+ gst per side from a local supplier. Mounts from rock auto were around $16 each. Shop locally? They can **** right off with that amount of mark up.

[smoo]

I run my M117 560SEL on Penrite HPR 30 with no dramas and before I sold my old W116 280SE with the K Jet, I rebuilt the engine and also ran it on HPR 30. A simple engine, can't see why they cannot run this oil, or need specific engine oil? A 60 year old engine at the end of the day.

K Jet don't take too kindly to vacuum leaks. If bad enough will be evident at idle or hard starting. No good off the line, check throttle linkages as the nylon type bushings wear, not allowing full throttle.
Bad spark will also play a part. Plugs, leads, cap and rotor is cheap enough out of the states. Popping off the rocker cover is easy enough to check the timing also.

K jet info check out W116.org. Although dedicated to W116 the M110 was the same between models and a heap of knowledge and archived info on there.

I was fussy and went to town on mine. Most parts bought through rock auto, pelican or FCP.
Only thing I had to buy locally was one timing chan guide which was the most expensive single part I paid for it.

I have a W116 in bits along with a complete M110 if you need anything, drop me a line.

Also check the car hasn't had the tacho swapped out at some stage for a V8 one with 6000rpm redline. M110 redlines at 6500 from memory and if not the correct tacho the readings will be out giving a false impression of performance (or lack of).

[jstanovic]

The M110 is a rock solid motor. Pretty sure it would be happy if you put used fish and chip oil in it haha! How many KM has it done? These motors seem to like 20-50 or 20-60 as they get older, Penrite HPR 30 20-60 seems to be a common oil.


Any mercedes wreckers nearby? Freight is a killer from the US.


I think injectors are still available new and are pretty affordable. K-jet is one of those systems you can't just adjust this or that and it will be good. You need to start with the basics in an orderly fashion otherwise you are chasing your tail. If it's running well, I would be hesitant to touch it unless you are prepared to start testing from scratch.


OzBenz forum is pretty good for any info.

[Citroënbender]

Mileage should be visible here:

I’m just poking at this for a third party, it will likely be flipped within the year unless they bond with it. Quite basic trim level.

HPR30 sounds like it may be the go, then. Ye olde copper plugs are good enough, or does it benefit from an up-spec?

The “soft pedal” I described was not a stumble or misfire on top of its slightly poor idling, not as bad as a cold Barra with split intake gasket, just lacking any sense of measured response to the throttle. I feinted at an intersection the first time as it would have got me too close to an approaching car - next attempt I loaded up in advance of when I’d normally start applying modest pedal.

Have lined up what should hopefully be the sole overseas order; some brightwork, ignition switch and couple of other bits, looks to be $550 Australian dollars landed. Mostly non-genuine but name brands, as the prices are often double.

The forums should be good resources, I’ll jump in as required after doing my homework.

[lamborghinifan]

https://operatingfluids.mercedes-ben.../engine-oil/en

I once dove down the rabbit hole to find diff oil or transfer case oil for my w251. I found the genuine website to sub list different brands and spec levels and found it ok. A bit cumbersome, but then comparing available oils ‘Mercedes’ spec back to the Mercedes’ spec numbers

I have found pelican parts very good to find part numbers, and ordered many odds and ends off them. A few times they sent genuine parts when I ordered second tier parts. Postage can hurt though. I have had 10 days from them, but that was probably pre COVID.
ASV can sometimes be ok, but not sure if they have older stuff.
Otherwise getting part numbers off pelican and cross shopping on eBay sometimes works.

My 2c anyway, I think Mercedes’ part numbering system is amazing. Hasn’t let me down yet.

[Swordie]

Can you call the Mercedes service department or specialist for advice on oil to use?

[eb2fairmont]

No need - the guys above have it correct on a good quality 20w-50. The extra zinc isn't a bad idea as there isn't a roller follower on the cam and rocker finger.

Pressure wise anything above the 0 is fine at idle but they have a gear oil pump which pegs the needle pretty quickly. They just need a lot of oil, the V8's can be up to 8 litres if they have the external oil cooler.

Parts see mb spares and there is Benz shed in Ballarat.

Kjet is pretty solid but vacuum leaks and hoses for vacuum perish.

Most benzes of this period have a lot of common parts so hunt around, but brightwork prices can make you cry.

[aussiblue]

The Kent Bergsma YouTube Channel Mercedes Sources is worth subscribing to. See https://www.youtube.com/watch?v=rh0PtXwZo_Q and https://www.youtube.com/watch?v=aN_0Gqo2JaM for his views on oil. For an Oz source see https://www.liquimoly.com.au/ . And then look at his series of videos on "Fritz" his W126 280SE starting here https://www.youtube.com/watch?v=kXpckRlzE7o I am not really into Mercs but I like watching his videos anyway. Kent is an ex Papua New Guinea Bush pilot and an interesting character see https://mercedessource.com/history

[Citroënbender]

Oil sorted - HPR30 was on sale.

Hoping for some knowledge on the sump plug/seal before inviting calamity to tea. Are all the M110 sump plugs the same? Is the seal a Dowty type, a flat washer or a crush ring?

Any reason to not degrease under the car?

@Smoo: Is this the throttle bushing you meant? Pelican say it’s discontinued. https://retromotion.com/p/kienle-1163010150

[smoo]

Originally Posted by Citroënbender

Oil sorted - HPR30 was on sale.

Hoping for some knowledge on the sump plug/seal before inviting calamity to tea. Are all the M110 sump plugs the same? Is the seal a Dowty type, a flat washer or a crush ring?

Any reason to not degrease under the car?

@Smoo: Is this the throttle bushing you meant? Pelican say it’s discontinued. https://retromotion.com/p/kienle-1163010150

Yes and this plastic ball that from memory seats inside of it. Also this shackle bush goes hard and brittle over time causing it to break apart. Will give a delay in throttle response and won’t allow full throttle.
The ball is in a spring loaded contraption that goes through the firewall. Check it’s all there, if somethings fallen out or someone has lost something while playing around with it the pedal feel won’t be right.

https://www.pelicanparts.com/catalog...PCABLE_pg1.htm

Have you checked ignition timing re throttle lag?

From memory Mann filters have copper washers one for the filter housing one for the sump plug.
She’ll probably hemmorage oil out of everywhere if it’s been sitting for ten years haha.
Common for valve stem seals to leak. HPR 30 will help with that.

[eb2fairmont]

It’s all in the light switch - pull out to see if they are fog lamps.

I would have thought high beams

by the 125 I think they used more electric solenoids compared to the 116. The vacuum stuff on my 107 irritates the hell out of me

[Citroënbender]

Yes, sorted, thanks. One pull for front fogs, second pull turns on rear fog (nearside only).

Really, really, really vague steering. What’s the typical culprit? Drag link is a new-ish Taiwanese element and there’s not discernible play in the linkages between sides. The rear struts, do the damping discs fatigue? Is it slop inside the steering box? I’ve attached images of the lower ball joints and what I’d call the radius rods’ rear coupling.

All wheels seem to have play in the bearings to the point I can rock them to create a knocking sound. Do they adjust up, or are they finished?

Fuel leaks from a half-inch hose (red arrow) above the pump/filter cradle. Is it a tank vent that corrodes inside the tank, near its base?

Are the engine mounts (two pictures of one side) collapsed? Clearance looks really close at this rearward tie/brace.

[jstanovic]

I don't know much about the W126 specifically but it looks like this one hasn't had much love for a while... How much $$$ are they willing to put into it to get it on the road?

[Citroënbender]

Probably not enough. It looks, smells and drives like a dying car.

Reading across the ‘net about vague steering I’ve run over so much half baked, regurgitated dribble it’s on par with many a Beemer forum. Can’t even determine where it’s prudent to start on this problem - box preload and lash, lower balljoints, steering damper, radius rods, idler bush… There's not going to be a silver bullet but a component grouping which probably speaks to 60% of this slop and right now I have NFI which it may be.

[smoo]

You probablyneed to go over the whole suspension with a bar or put it on a shaker machine to see what is worn. I’d be guessing a lot of the joints and bushes are original at that mileage.
Buggered sway bar links will make it handle like a dog.
You can adjust the steering boxes (google).
Does it have rear SLS? Looks to be sitting low in the rear end in the above pic.

Is Grober Grosser (post 23)? I think the windows in them are hydraulic, along with the boot release.

[Citroënbender]

It does have rear hydraulic struts, the Febi spheres are dated 41st week 2007 so probably still have moderate pressure. I’d need to commission an adaptor to test them on Citroën gear.

This site has a cross-section sketch of a Citroën damper assembly, I’m sure the Sachs strut is similar in its piston head. The washers/discs can fatigue, this is where you lose damping if everything else is up to spec.

http://www.citroen-ds-id.com/index.h.../chapter4.html

Thing with the steering boxes is, they might wear in a way that adjustment doesn’t really make up for - like ovalling of a bush or taper.

Have observed the odometer and trip meter do not turn, speedo works though. Mileage could be measurably higher than indicated.

It’s also definitely leaning out, hot idle with AC on is over 1200RPM and the economy gauge is pegged to the right side (red). That’s a vacuum leak for sure.

[GasoLane]

Originally Posted by Citroënbender

It’s also definitely leaning out, hot idle with AC on is over 1200RPM and the economy gauge is pegged to the right side (red). That’s a vacuum leak for sure.

Does that model have an idle control valve?

[Citroënbender]

I believe it’s got an auxiliary air valve, if that’s what you’re referring to.

[GasoLane]

Originally Posted by Citroënbender

I believe it’s got an auxiliary air valve, if that’s what you’re referring to.

Yeah same thing I think. One of the lads in the OzBenz group was having trouble with his W116 4.5L v8 idling fast, tested the valve in a saucepan of hot water and it was seized.

[smoo]

I think MB system is a more simplified version of Citroens?
The only way I’ve found after research on diagnosing spheres or accumulators on MB SLS is measure how far the diaphragm is from the thread with a vernier or something that fits in there for reference, like a screw driver. Greater distance means they’ve lost pressure (apparently). I think I have a couple of good spheres somewhere I can check.
Bad spheres will have a bouncy ride, or if no pressure in them at all the ride will be rock hard.
Struts can also go bad an leak internally which can make them sit low in the rear end when parked.

Front bearings are tapered with adjustable pre load. Rear bearings not too sure.
Those engine mounts look buggered, looks like there is a visible split in one?

Failed odometer is common with age. Check out this site. I did my W140 odo gears and cost about $120 inc postage.

https://www.odometergears.com/produc...peedometer/117

Cluster removal tool #140589023300 or use a couple of 90 degree picks but make sure you pull from the correct spot otherwise the pick can grab the cluster screen and crack it.

[eb2fairmont]

The tanks on k-jet cars are total seal - no breather. Replace the hose they generally don’t corrode internally as long as the cap is on.

If it’s been sitting check bushes and ball joints they will most likely need replacement. The main thing for good steering is steering box adjustment, and a good steering damper. This is like a mini shock absorber mounted to the main arm and body and filters out most vibration.

Benz recirculating ball isn’t the last thing in road feel either.

[Citroënbender]

Starting to wind down a little, thanks for all the experience shared. Phoned a friend to wiggle the steering wheel while I observed the Pitman arm. Mega slop in the steering box. Compared the rear bounce to an hydraulic Citroën. It rebounded about triple the number of times. This would absolutely be contributing to the vague sense of steering.

The “testing spheres via plunge measurement” is sadly a furphy. Benz only have 23 Bar in theirs, along way down from some Citroën spheres. Pumping hydraulic pressure against their gas reserve while watching a test gauge is the only reliable metric; when the gauge plateaus, it’s service pressure of the remaining nitrogen.

Put a fuse into the central locking circuit after discovering this was blown (no hazards was my clue). Locks cycled endlessly, took it out again! At least I now know the doors lock in this way - saves taking them apart to test each component.

Can’t establish what is missing from the grommet here. I stuffed a bolt in to seal it.

There’s what looks like an old AIR type system on the exhaust manifodl. I’m surmising the missing linkage was a WOT buffering system to avoid over-rich fuel post-combusting. Does this sound about right?

Ye olde splitte hose, as found on many cars. I haven’t yet followed the other end through. A good discovery was the air filter element being near new. I’m assuming these cars came with rubber bungs in the spring turret top holes.



The mighty K-Jet (my phone auto-corrected this to K-Нет!) in all its glorious simplicity.



And my “soft pedal”. This plastic coupling is 2/3 broken away, causing the bulk of throttle freeplay.

And finally, credit to RockAuto. Ordered 10:30PM Thursday, delivered 10AM today. That’s with FedEx “economy” freight, too. Glad I was reminded about them!

[smoo]

That grommet in the air filter housing is where you can adjust the fuel mixture.
You can see it in your second to last pic in front of the fuel distributor.
If you push down on the AFM with the key on you’ll hear the fuel pump run and the injectors working.
The adjustment is suppose to be half a turn out from when it starts to inject, from memory.

MB spheres - I probably read the back yard ‘diagnosis’. Theory is, if there’s no gas left in the sphere, the hydro pressure from the pump or the weight of the car will bottom the diaphragm out in the housing. Makes sense I suppose.

That split hose may off the top of my head run to the idle air control valve which sits behind the dizy, p/s reservoir and under the intake manifold, a real bitch to get at with multiple hoses connecting to it.

What Citroen are you comparing to, out of interest?