Common issues with the 400E?
 

Hi all,

My brother is looking at buying a 1992 400E with about 80,000 miles on it that's for sale locally. We went and looked at it the other day, it looks like it's in OK shape but there were a few issues I couldn't track down the source of in a parking lot (oil leaks, mainly-or possible oil leaks, at least), so he's having a pre-purchase inspection done on it.

The only major issues that I recall these cars having were that the A/C evaporators had a higher-than-normal tendency for developing leaks, the camshaft oiler tubes get plugged and brittle, the engine wiring harnesses go bad, and the potentiometers on the throttle position sensors wear out. Am I missing anything?

This particular car has a few minor (or at least I think they're minor-if I'm overlooking something that could be a major issue, by all means let me know) issues:

• It doesn't seem to reach operating temperature; even after a run up the freeway including several WOT runs from 55-80ish the gauge never moved beyond about 70*C; the owner has records for a thermostat replacement a few years (and about 6,000 miles) ago, I'm thinking the thermostat may just have been weak. The fan clutch isn't locked up or anything, and unless it's a sender issue or a cluster issue I can't figure out what else it could be.
• The transmission shifts a lot harder @ part throttle than my 300D or my 560SEL, and it shifts harder than I remember it shifting in any other 4G-Tronic equipped car that I've driven; basically it has the same firmness that a normal WOT upshift would all the time. The fluid is clean and was replaced recently, according to the owner.
• Has some seepage from the left and right axle seals. I'm thinking that just cleaning the breather tube on the diff might be enough to let this go for a year or two; it's not that bad.
• Cam adjuster magnets are leaking (normal)
• Engine mounts are collapsed (normal)
• Engine takes a bit longer to start than I'd like-maybe 7 seconds or so (+/-2) of cranking; it idles fine, it runs smoothly otherwise, power is what I'd expect out of the 4.2 (though this is the first 4.2L M119 car I've driven), it revs willingly and doesn't exhibit any abnormal characteristics otherwise. I'm thinking it may just be worn distributor caps & rotors and worn plugs/wires.
• Throttle pedal is stiffer than it should be; linkage probably just needs lubrication.
• Steering is looser than it should be; I'm figuring it needs a steering damper like almost every Mercedes of this age I've dealt with does, might need tie rods, a center link and idler arm bushings.
• Inside of gravel shield is wet with oil; can't see where it's coming from without pulling it. Could be due to PS leak that the owner has records of being fixed, that never got cleaned up properly. Driver's side valve cover is seeping. The 119 didn't have head gasket issues to any significant extent as I recall... is my memory correct on that?

I don't see anything on that list other than the transmission that strikes me as unusual for a 400E in average condition (mechanically, at least) at this mileage. And the interior is excellent; it's a two-owner car and it's been garaged at least since 1995, possibly since new, so the interior is basically flawless. Gauge needles are still orange and everything.

The paint has a LOT of swirl marks, but it's black, and given the car's age and the way most people wash their cars (badly), that's not unexpected. Just needs to be buffed out.

But yeah, thoughts and opinions would be appreciated. Thanks.

Kevin,

• Low operating temp: It's either a bad t-stat, or bad temp sender on the front of the intake manifold.
• Tranny shifts should not be that harsh. Could be a broken or disconnected vacuum line, or bad modulator. It should be smooth shifting at part throttle, and not very firm at WOT (they're programmed differently than the older diesel trannies).
• Engine mounts are expensive for the V8, and a RPITA to replace.
• 7 seconds is far too long to crank. Check caps & rotors, if you're lucky they can be cleaned (scrape the green crud off the brass contacts). Otherwise, they are $$$. Wires rarely need replacement, so if there's no "light show" in the dark, leave them alone (also $$$).
• The 119 doesn't have a history of head gasket leaks like the 104, but they can still leak - it's just not common.
• The oil leak is quite likely the power steering pump and/or hoses. Could also be the cam solenoids. Tranny cooler hoses are another common fluid leak. Valve cover gaskets are spendy ($30 ea?) and awful to replace since it's a RPITA to R&R the valve covers.
• If the engine harness has not been replaced, plan on shelling out for that. Pretty likely the ETA will follow, although if the car hasn't been in a high-heat environment, you could be lucky. Both of mine had a new harness and rebuilt ETA installed by PO's.
• The 1992 model has weak front brakes... 1993-up received thicker brake rotors. Just an FYI.

What color black (040 or 199), and what color interior? What options? Available options were heated seats, ASR, rear roller blind, rear reading lamps, cell phone, and orthopedic seats.

For any teenager's first car, I normally wouldn't recommend something with this much power... I would strongly recommend finding a 400E with ASR if possible. At least the 2.24 gears keep it slightly more sedate leaving a stop, but when running properly, the car will pull above 100mph faster than you'd think possible. You can slow it down slightly by installing a 94-95 LH module, which also drops the top speed governor from 155 down to 130. Any 6-cyl 124 would be a better choice, IMO. Find an M103, or an M104 that already had the head gasket fixed.

:euro:

Thanks Dave,

It's the non-metallic black, so 040 I believe. I didn't check too closely for options; there's a spot for the ASR light in the speedometer but I didn't see a button to switch it off, so I'm not sure if it has it and it's just not defeatable on these cars or if it doesn't have it and Mercedes used the same speedometer for cars with and without it. I didn't really look that closely though; if my memory is correct and it does have it, the ASR light will illuminate with the key in position 2 and the engine off, along with all the other lights, right?

Don't think it has heated seats or the roller blind; doesn't have a phone or orthopedic seats, either (I'm half-convinced that nobody ever ordered that option. Ever. I haven't seen a car with it yet.). I'll have to check on the reading lights.

Out of curiosity, do the 93+ rotors and calipers bolt in or do you have to replace suspension components as well? (in which case it might make more sense to just throw SL brakes at it, eh?)

Also, he was looking @ wheels on tirerack, and I noticed while looking with him that there are quite a few more options for my 300D according to their site than there are for the 400E. This wouldn't be the first time they've been wrong... As far as I know, any wheel that will fit on the 300D will also fit the 400E, as long as it clears the bigger brakes. Right?

And yeah, the 6 is probably a better choice, from a performance standpoint. That'll come down to how much my parents trust him. He's not as irresponsible as most 16 year old boys are (not that I'll admit that anywhere that he can hear it, of course). But then, neither was I. And I still had my 560 more-or-less flat out a couple of times. :rolleyes:

If there is a yellow triangle light in the top/center of the speedo, yep, the car has ASR. There is no defeat switch from the factory - you can add one if you like, but the only purpose would be for hooligan antics, or doing a burnout to warm the tires at the dragstrip (as seen here).



Most of those items are pretty rare. My E420 has all options (including the dealer-installed CD changer), except for the phone, which is fine with me... I like having the center visor above the rearview mirror. I had never seen a car in person with the orthopedic seats, until I bought my E420. I kinda like the ortho seats, particularly the adjustable side bolsters! But, ASR is the most important option, so if you have that - you're set. The bun warmers are #2 on the desireable option list. Roller blind & reading lamps are just bling you'll never use.



You can bolt up any brakes you want, no suspension changes needed. To install he 93-up 400E brakes, you just need the later calipers & rotors. You can also install larger brakes from the 500E or SL600, but those would require 16" wheels.



Basically - yes. I would highly recommend getting used OE wheels. They are cheap, look great, and are often available with decent tires. Donors are most anything except an S- or SL-class... 170, 202, 203, 208, 210 are the primary ones. 16 or 17" diameter, with 7.0 or 7.5 width, is ideal - assuming the offset is correct. If you go with 7.5's you'll likely need to roll the fender lips and maybe add the fender spacers up front. Also make sure the tire size is correct, I drives me nuts when I see people put narrow tires on wide wheels to help with 'clearance' when they should have just used a narrower wheel in the first place. :rolleyes:



Yep - that's what I'd be concerned about, lol! Maybe sneak in a 1994-95 LH module when he isn't looking. :D


:batman:

Almost forgot... if you don't yet have an LED blink code reader that works for the 38-pin diagnostic connector, you'll want to get one. And for serious diagnostic work, you'll need a digital scanner to access the live data available from the engine management system. But, you can worry about that if he ends up buying the car!

:1eye:

FWIW: My 93 400E took rotors and pads for a 92. I think it was made in late 92 and MB must have been using up the old parts. I didn't realize this until the pads I purchased for a 93 wouldn't fit in the caliper with the pistons fully pushed in.

The 93-95 has 25mm thick rotors, so the thinner (22mm) 1992 rotors will bolt up to a later car, but at the end of the pad life the pistons could be dangerously close to coming out of their bores. The break was by model year, not production date... all 1992's should have the 22mm rotors, all 1993-up should have the 25mm rotors. It's also possible that someone installed used calipers at some point from the "wrong" car.

:nuke:

Or someone at a shop decided they wanted 93 brakes for an earlier model.

They didn't do the 25mm upgrade until production date mid 11/92 (also same 25mm rotors are in 94-95 E320/E420)
You can run minimum thickness 22.4mm rotors but the center vents must be at least 10.5mm wide (not 8mm like predecessor 400E, they will rub inside the caliper because of a small lip protruding down), and you must run the thicker pads.

My car was lucky to be included in the upgrade (since it was made in 11/92) it has ASR (with snow chain switch that allows additional (upto 25mph) wheel spin, heated seats, phone cabling (phone & mount were gone when I bought it), Mercedes labeled 6 CD changer. About every option except the rear window shade (windows are tinted 18% anyways)
I dislike having the cap & rotors since my previous 96 C280 had the coil packs, though I don't mind having the upgraded 275 hp vs the 92's 268 hp

Slow starting is a fuel pressure regulator. My 400e was exactly the same. 7 or 8 seconds of cranking to start. I swapped out the fuel pressure regulator (its on the top of the engine on the drivers side near the firewall) and it starts right up in about 2 seconds.

The upgrade to 25mm rotors varied by chassis. The EPC indicates that the 400E (124.034) received the 25mm rotors as of model year 1993, regardless of production date. The 6-cyl cars received the larger rotors based on a VIN break (which seems to begin as of 11/92 production). See the attached screen shots of the EPC. Also, click here to see the specs in the factory service manual, page 3, footnotes #4 and #11. If you disagree with this, talk to MBNA, but don't shoot the messenger.



Yeah, it's a shame the 124 never got the .98x engine with ME injection (which used the coil packs). I also hate distributors.

On a side note, if you swap in a 1992 LH module (which has WOT enrichment) into your 1993-95 engine, it will boost power to approx 290hp. I've got the dyno sheets to prove it (back to back dyno runs) and also dragstrip data. The 93-up engines have 11:1 compression ratio, 1992 had 10:1 ratio. I personally think the 1992 engine was mis-rated at 268hp, but that's a whole separate argument. ;) Note that the identical 119.975 engine in the 1992 S-class was rated at 282hp. And, some of the factory service docs (click here) also indicate that the 119.975 was rated at 282hp, not 262, in both 124 and 140 chassis. 93-up are all rated 275hp regardless of chassis. I think MB was playing a numbers game. The only place that 262hp number appears is in the USA sales literature.


:blink:

Wow GSXR!! I'm not in the market at this time for a gasser flavor of Mercedes, but when I am I'll be confident that I can get the pertinent info from you. (or diesel for that matter)
Your information above is amazingly thorough and logically laid out. Nice of you to do for the original poster.
Very nice job Mister!! :thumbsup2:

Any chance you know where I can get a 92 400E LH module? Or what model or s/n would I be looking for on the (Bosch?) ECU? thanks

Email sent.

:cool:

Hey guys,

I've been really busy over the past 9 months and I totally forgot about this thread (and the internet in general, for the most part) until recently. Thought I'd give y'all an update.

My brother ended up buying the car. We got all of the paint oxidation (it was bad, the car had always been garaged but it seemed like it had never been waxed. The gauge needles were still orange but the paint on the hood was milky dark gray instead of black) buffed out with Klasse. The car ended up needing about what I figured it would in the way of catch-up maintenance, he's put about $7k into it (could've been substantially less, but he had a shop do the work). Engine wiring harness, distributor rotors and caps, engine mounts, a bunch of other stuff that I don't remember. Nothing atypical for a 400e. It hasn't left him stuck though.

The car doesn't have ASR; I found this out when we picked it up from the previous owner to take to our mechanic for a pre-purchase inspection (since my brother didn't have his license at the time). I found myself first in line in the wrong lane at a red light. My 560 never had a problem with wheelspin, but my 560 never had those piece of **** Michelin MX4 Energy tires on it, either, and it had a LSD. I didn't think about that at the time. Light turned green, I stood on it. Didn't expect the 400 to have enough power to light up the tires most of the way across the intersection. Apparently that expectation was incorrect. No harm done, except that my brother was in the passenger seat at the time. Excellent example. :angel:

Ehem. Anyhow. The car's been fine; he did have one accident, but it wasn't his fault (some ass cut him off and slammed on his brakes while he and my dad were on the way to the mall). Didn't do much damage, just needed a grille, headlights, a bumper and (I think) a hood. He ended up replacing the headlights with Depo euros and doing the wiper delete, replaced the taillights with smoked MHWs, had the windows tinted and threw some OZ rims with Bridgestone RE-960s (not what I would've chosen, but they're decent tires) at it. He's happy with it.

Oh, and my girlfriend needs a car when she starts driving later this year, too (19, never had a driver's license >_<)... I've been teaching her on the 300D, and I insist on baptizing her in the Church of Mercedes before letting her contaminate her mind with a BMW or some Japanese or American car or something. ;):D:P I'd love to pick up another 400E/E420 for her (just so I can drive it :D) but I think we're going to go the 210 E430 route for that.