Intro & thoughts requested .. 1994 E420

[Ian White]

Howdy there, long time lurker and w124 enthusiast. I recently sold my 95 E 300D which I had for 5 years and improved thoroughly.

I found a 94 E420 last winter for sale in Portland, Ore; I bought it, price wasn't great ($4k) given the work it needs but it gives me something to do! 195k miles, I'm the fourth owner. Black on black. Exterior is 7/10 - couple of paint issues but very straight and no corrosion. Interior 9/10 - one of the nicest interiors I've seen given the car is a "survivor" of sorts. I believe it's a non ASR model.

Issues:
Sagging headliner
Passenger rear window inop
Antenna inop
Climate control fan motor needs replaced
When cold car doesn't idle normally, it idles fast and hunts, when warm about 1/2 the time it'll idle somewhat smoothly.
Upper and lower harnesses are shot
Lifter(s) ticking - suspect oiler tubes
Passenger headlight wiper inop

Here's where I'm looking for some guidance. I'm removing the upper engine harness for R&R, removed the caps and plug wires (Beru - didn't look the greatest). Up in my car lift, it's super clean underneath. Looks to have a power steering leak but that's really it. Suspension / struts seem factory.

The intake looks to have never been removed, it's quite dirty. I want to run down all the PCV lines and vacuum lines given the poor idling. Should I pull the intake? Should I replace the timing chain and guides while I have the valve covers off? I do plan to replace the caps, rotors, plugs and wires in addition to swapping to the metal oiler tubes. Do I need to R&R the injectors? Where do I stop? Lol.

I didn't clear/check codes before tearing down (mistake), so I'll have to do that once it's back together. The car ran strong save for the idling issue. Side note, the idle smooths out when I unplugged the white vacuum line to/from the EZL.

I plan to either buy a used - updated upper harness or EBay or have Jonathon of Blue Ridge rebuild. Not sure about the lower harness yet.

Thanks for reading this far into the ramble!

Cheers from Spokane, Wash.

Ian

 

[winmutt]

Do you have a harness already? I have a good used spare, datecode is 99 IIRC. Where is the power steering leak? You'll be surprised what a tail of woe that can be, ask me how I know.

I wouldn't pull the intake unless you have a good reason to. I faced the same decision with the oiler tubes, I decided to wait on mine, they were in good condition and I had a lot of work to do on the car. Timing chain is a big job, unlikely to need it from what I understand. The guides however tend to be recommended.

My evap canister (stuck MOT valve) was one source of vac leaks, as well as the drivers side large PCV hose. I highly recommend studying the Engine Breathing diagrams in the FSM. Also start sourcing a spare LH and B modules. 92 400E will give you the 15HP WOT .

Headliner was a 2 day job for me.

 

[a777fan]

Welcome! Sounds like you’ve got a fun project on your hands. How far you go is really up to you, your overall goals for the car and how deep your pockets are. Sky is the limit really. Well.. that and the NLA situation which bugs a lot of us around here and seems to be nit picking the fun out of owning these cars on the daily.

I did a top end refresh on my e420, and our board owner/president/honch did one on his 500 and documented it here :

Thread 'RESTO PROJECT: M119 / W124 / E500 Engine Top-End Refresh'
RESTO PROJECT: M119 / W124 / E500 Engine Top-End Refresh | Member Roadtrips and Project Journals

Guarantee you most everything you’ll run across has been found and documented on this forum before so definitely use the search feature. Its your friend!

 

[Ian White]

Thanks! Very much enjoy reading through the posts here; so much collective knowledge without... the I'll say the "dbag-ery" of some forums!

My general philosophy is a balance between "if it's not broken why fix it" with preventative maintenance and "check/repair while there". So thought I'd just get others take on what's a must, what's a good idea and what would be going overboard.

@winmutt - I don't have a harness, so would be obliged to chat with you about yours. Thanks for the thoughts on the intake and timing chain. Perhaps new guides and resetting the timing while I'm there is all that's warranted.

Thanks!

 

[gsxr]

The intake looks to have never been removed, it's quite dirty. I want to run down all the PCV lines and vacuum lines given the poor idling. Should I pull the intake?

Generally don't need to remove the intake manifold, but if you have the time... all the rubber stuff likely is in need of replacement. It isn't likely to fix your idle issue, but you could do a smoke test to verify there's no major intake leak. All the PCV hoses may be fossilized, if so, replace with new OE/dealer only (not aftermarket).

Should I replace the timing chain and guides while I have the valve covers off?

Inspect the chain rails and measure chain stretch. The chain almost never needs replacement. If any rails are broken... yeah... replace all of them (except the 2 lower ones that rarely wear/fail and are inaccessible with timing cover installed).

I do plan to replace the caps, rotors, plugs and wires in addition to swapping to the metal oiler tubes. Do I need to R&R the injectors? Where do I stop? Lol.

No need to pull injectors unless perhaps you decide to pull the intake manifold.

I didn't clear/check codes before tearing down (mistake), so I'll have to do that once it's back together. The car ran strong save for the idling issue. Side note, the idle smooths out when I unplugged the white vacuum line to/from the EZL.

Hmmm. Verify all the vacuum lines / tubes are going to the correct location.

I plan to either buy a used - updated upper harness or EBay or have Jonathon of Blue Ridge rebuild. Not sure about the lower harness yet.

Upper harness - buy new, or good used, don't rebuild.
Lower harness - only option is to rebuild.


Is your car ASR or non-ASR? Have you verified the modules/EZL are all the correct part numbers?

 

[Ian White]

Generally don't need to remove the intake manifold, but if you have the time... all the rubber stuff likely is in need of replacement. It isn't likely to fix your idle issue, but you could do a smoke test to verify there's no major intake leak. All the PCV hoses may be fossilized, if so, replace with new OE/dealer only (not aftermarket).

I think that is a good idea. With how nasty it looks in there and how the rubber components have become brittle plastic; I think I may go for it. Cheers to Gerry for his COVID writeup of the top end R&R.

Inspect the chain rails and measure chain stretch. The chain almost never needs replacement. If any rails are broken... yeah... replace all of them (except the 2 lower ones that rarely wear/fail and are inaccessible with timing cover installed).

Agreed, that is the plan thus far.

No need to pull injectors unless perhaps you decide to pull the intake manifold.

The O-rings were slightly cracked, but not too brittle.

Hmmm. Verify all the vacuum lines / tubes are going to the correct location.

Thanks - I may have my throttle actuator ETA checked out.

Upper harness - buy new, or good used, don't rebuild.
Lower harness - only option is to rebuild.

Thanks @winmutt for the offer of his good used upper harness. Mine has a late 1992 build date and it is SHOT. The lower harness, I haven't completely inspected it yet. The wires near going to alternator do not appear to be as crispy when I slightly bend the wiring. More investigation to do.

Is your car ASR or non-ASR? Have you verified the modules/EZL are all the correct part numbers?

I am 90% sure non-ASR -- VIN is WDBEA34E1RC060017

 

[winmutt]

WDBEA34E1RC060017

lastvin.com is a decent site

 

[gsxr]

I am 90% sure non-ASR -- VIN is WDBEA34E1RC060017

Yup, non-ASR, no option code 471 - click here for the datacard.

BTW, if you replace the ignition stuff... probably want Bosch caps, OE/Genuine rotors ($$$), and don't forget to consider new Bosch insulators while you're in there. Replacing the cam seals would be a good idea as well, and definitely add the vent slots to the new caps (details here). You can measure the resistance of the wires/boots, should be around 2000 ohms, ±20%. Wires/boots can last a very long time and generally don't need periodic replacement.

 

[grmichaelj]

Do you have a harness already? I have a good used spare, datecode is 99 IIRC. Where is the power steering leak? You'll be surprised what a tail of woe that can be, ask me how I know.

I wouldn't pull the intake unless you have a good reason to. I faced the same decision with the oiler tubes, I decided to wait on mine, they were in good condition and I had a lot of work to do on the car. Timing chain is a big job, unlikely to need it from what I understand. The guides however tend to be recommended.

My evap canister (stuck MOT valve) was one source of vac leaks, as well as the drivers side large PCV hose. I highly recommend studying the Engine Breathing diagrams in the FSM. Also start sourcing a spare LH and B modules. 92 400E will give you the 15HP WOT .

Headliner was a 2 day job for me.

Did you sell the harness yet?

 

[grmichaelj]

Re roof

Howdy there, long time lurker and w124 enthusiast. I recently sold my 95 E 300D which I had for 5 years and improved thoroughly.

I found a 94 E420 last winter for sale in Portland, Ore; I bought it, price wasn't great ($4k) given the work it needs but it gives me something to do! 195k miles, I'm the fourth owner. Black on black. Exterior is 7/10 - couple of paint issues but very straight and no corrosion. Interior 9/10 - one of the nicest interiors I've seen given the car is a "survivor" of sorts. I believe it's a non ASR model.

Issues:
Sagging headliner
Passenger rear window inop
Antenna inop
Climate control fan motor needs replaced
When cold car doesn't idle normally, it idles fast and hunts, when warm about 1/2 the time it'll idle somewhat smoothly.
Upper and lower harnesses are shot
Lifter(s) ticking - suspect oiler tubes
Passenger headlight wiper inop

Here's where I'm looking for some guidance. I'm removing the upper engine harness for R&R, removed the caps and plug wires (Beru - didn't look the greatest). Up in my car lift, it's super clean underneath. Looks to have a power steering leak but that's really it. Suspension / struts seem factory.

The intake looks to have never been removed, it's quite dirty. I want to run down all the PCV lines and vacuum lines given the poor idling. Should I pull the intake? Should I replace the timing chain and guides while I have the valve covers off? I do plan to replace the caps, rotors, plugs and wires in addition to swapping to the metal oiler tubes. Do I need to R&R the injectors? Where do I stop? Lol.

I didn't clear/check codes before tearing down (mistake), so I'll have to do that once it's back together. The car ran strong save for the idling issue. Side note, the idle smooths out when I unplugged the white vacuum line to/from the EZL.

I plan to either buy a used - updated upper harness or EBay or have Jonathon of Blue Ridge rebuild. Not sure about the lower harness yet.

Thanks for reading this far into the ramble!

Cheers from Spokane, Wash.

Ian

did you fix headliner? I replaced mine with soft fabric… looks nicer and absorbs noise! I was very pleased and since the fabric was not special, wallet was happy too.

 

[Ian White]

Did you sell the harness yet?

I bought it from him. I'm still looking for a lower wiring harness.

 

[Ian White]

Re roof

did you fix headliner? I replaced mine with soft fabric… looks nicer and absorbs noise! I was very pleased and since the fabric was not special, wallet was happy too.

I am going to replace the headliner with black fabric as well. I don't like the look of the roof headliner and grab handles being grey adjacent to all black interior trim pieces, it looks too stark a contrast in my opinion. Although I am partially colorblind so perhaps its "all in my head".

My E300D I replaced the headliner with OE material ($$) and I wouldn't do it again given what the material cost, it had a grey interior though so looked better.

I ordered $600 worth of odds and ends from MB Laredo so I'll get the intake put back on it and go from there. I was surprised at the amount of crud in the intake with 195k miles. I have the valve covers off and it is clean as a whistle inside. Going to replace the upper chain guides and do lifter tube oilers while I am there. Also a new thermostat (debating water pump) and resealing the power steering reservoir and replacing the little 2" hose which was gushing fluid. Beyond that, I need to replace the headliner, letherique the seats, replace the LR window regulator, replace the blower fan and I'm off to the races.

The car has nasty flakey chrome wheels for a non w124 - l bought Evo II wheels and imported them from Hungary, if I sell this car I'll keep these wheels. I paid about $450 USD each shipped.

My spouse says I have an illness.

 

[northNH]

The regular strict admonition to only use MB OEM parts to replace original MB parts that one could make a good case have failed prematurely seems ironic to me…
To me virtually the whole lot of rubber part (suspension, hoses, seals, gaskets, etc.) deterioration rates over time is disappointing for cars of this overall quality.
There are cars for which “fossilized parts” never applies.

 

[Ian White]

Probably like talking politics or religion - no perspective is the right one. Nuances abound.

Put four fellow enthusiasts together and you'll have 5 opinions on parts, supplier etc.