Are the W210 diesels user friendly? - PeachParts Mercedes-Benz Forum

Matt300ZXT · #1 02-09-2019, 09:17 PM

I'm considering purchasing a 99 E300TD. I've never owned a diesel before but I usually do a lot of my own wrench turning. My truck, girlfriend's truck, my 300ZX, Audi S4, SC300/400s I used to own, etc. I'm not a trained mechanic or anything but I can generally follow Youtube videos or online guides pretty well. Over the past few days I've been looking into some common issues with these cars but having trouble finding many guides/videos on repairs. Once I saw that people build these engines up quite extensively and started looking at OM606 this and OM606 that, I've found some more information. All I've really seen so far is changing the glow plugs and where the plastic fuel lines are that are apparently infamous and from what I've seen they don't look too hard to do.

I do have a garage that does a lot of work for me if it's something I don't have time for and they're familiar with working on at least domestic diesels, but I'd like to do as much myself as I can, because being a Benz, I'll probably need to be getting my hands dirty lol

tjts1 · #2 02-09-2019, 09:38 PM

Pretty much everyone on this forum DIYs so you're in good company. W210/OM606 is a mix old school mechanical fuel injection and electronic 722.6 transmission and body electronics. So if you can turn a wrench and handle a scan tool you'll be fine. Welcome to the forum.

pimpernell · #3 02-10-2019, 08:35 AM

Great car overall, with two issues that need to be addressed. Number one is the glow plug issue. That can start out as an hour job, and about $75 in parts and can turn into a first class horror show, when one breaks off leaving part of the plug stuck in the head. When purchasing a car, make sure you inspect the engine to insure that all the plugs are intact. Some sellers, after a plug breaks off in the head have tack welded a good plug to the side of the engine and attached the glow plug wire to that plug so that a code would not show up on the dash. Second issue are the SPRING PERCHES up front. Have the car inspected prior to purchasing it to insure that there is no corrosion taking place under the factory applied coating. My 96 E300d was up on a lift to have the tires rotated, and while up there I inspected the spring perches. The factory coating looked perfect along with the surrounding area. One week later, the passenger side spring perch let go while the car was parked for the evening. The spring was broken in half, and the passenger side of the engine compartment was extensively damaged and corroded from the inside out. Said corrosion was not visible to the naked eye and took place under the factory coating. Other than that, the car was outstanding to drive and fairly easy to maintain. Good luck!!!

Father Of Giants · #4 02-10-2019, 12:36 PM

IMO, no the OM606 is not that DIY friendly, If you got fuel leaks, intake manifold has to come off which is annoying.

The M112 is just as reliable if not MORE because of the lack of fuel leaks and glow plugs to go bad and cause a living hell.

The OM606 drive belt tensioning system needs a simple special tool in order to hold the belts still so you can service it, plus everything is jammed up front.

The M112 requires no special tools, and is far easier to service front end components .

Try making someone new to basic maintenance do the above on an OM606 and they'll be in for a world of hurt. (that was me a few years ago on an OM603)

In the end is it worth DIYing a W210 Diesel, because their power band is so much more linear than an N/A gasser. So driving is very smooth, also the big MPG increase, and last but not least the diesel sound.

Also about glow plugs and checking if they're good, just have the owner start the car, it shouldn't chug or smoke AT ALL, NOT ONE BIT.

The car I got sat for over 4 years and when it started it STONE COLD, it made no smoke what so ever, and idled smooth as glass.

If the car smokes, chugs, and makes loud diesel rattling, the glow plug or plugs are bad.
If the smoke and crappy idle DOESN'T go away, AVOID that car and run away.
The OM606 changes the feeling of this car by a lot, all of sudden the W210 feels industrial yet refined coming from the M112.

Shrimpblue · #5 02-10-2019, 12:52 PM

Matt300ZXT,
I have owned my first ever Mercedes and it being a 1998 e300 turbo diesel for around 3 months now. I don’t mechanic for a living but have always tried to do my own repairs and preventative maintenance on my vehicles. With that being said, I have replaced/repaired and performed several PM items on my car. Also, parts have been relatively cheap (nice surprise). I have found that this car was meant to be worked on. So far, everything I have done was no more a challenge than working on any other vehicle with the exception of a couple special inexpensive tools. Search for Shrimpblue in the forums for the details.

Prior to me purchasing mine, I didn’t have the knowledge to inspect any of the common issues and fortunately didn’t have the Spring purch issues. Mine is a southern vehicle with zero rust anywhere.

The most valuable resource is from the fine folks here on the forum. They have guided me throughout my process with shared experience and knowledge that one can only obtain with years of working on these vehicles. Thanks again folks.

Don’t hesitate to contact me if I can be of any help.

Shrimpblue · #6 02-10-2019, 01:56 PM

I forgot to mention that this is one nice driving,riding and running car. And, I really really like it.

83w126 · #7 02-10-2019, 03:29 PM

They are mostly not bad, but as mentioned the glow plugs are a problem, constant fuel leaks and rust. Also the EGR tube snapped on mine and that was the last straw that ended up in me selling it because its about a $500 part and takes major work to replace.

Matt300ZXT · #8 02-10-2019, 04:27 PM

Meh, I may have to pass. I came across the car on Facebook Marketplace with many less miles than the Craigslist ad stated, so I thought it may be an old post from a previous owner. It's the same guy, must have just typo'ed the mileage on the FB ad. Anyways, in the FB ad he mentions it has an SES light on for something about a passenger seat weight pad? Also that is has a slight oil pan leak. In just a quick search on Google, it appears it's a very very involved job to replace the gasket

ESchwab · #9 02-10-2019, 05:11 PM

I have a '98 e300, which I bought 12 years ago. It has served me very well.

There are a lot of helpful papers listed on this page. PeachPartsWiki: Do It Yourself Articles - Mercedes Vehicles

My big problem was the air conditioner evaporator, which had to be changed. I've had few other problems. I changed to glow plugs twice myself. The changes were not difficult; they just took quite a bit of time.

Bigdaddybenz · #10 02-10-2019, 05:36 PM

My wife drives a E300 turbo diesel and quite honestly she beats the crap out of that car. I’ve seen that car do things and maneuver in ways that I thought not possible. I’ve seen her backup inclines at 30 degrees angle like my driveway which is 200 plus feet long, so fast that it looks like the rear end is coming off the ground. It corners incredibly (trust me I know this because as a passenger I find myself reaching for the grab handle above the window) .... We’ve had many Mercedes diesels, 240Ds, 300Ds. SDs, SDLs and she beat them hard and they could take it, they were tanks..... So with the additional speed that the E300TD offers she goes all out.... If you didn’t see the words turbo diesel on the trunk lid you would swear it was a hopped up gasoline engine.... Abd despite the brutal daily beating this car takes it stands up like a trooper.... I highly recommend this vehicle..... My E320 CDI is faster and a lot more silkier but it could never withstand that kind of punishment.

jay_bob · #11 02-10-2019, 06:44 PM

I’ve had one since March 2013 and now my son daily drives it at Clemson University.

I have done quite a bit of work on it:
Replaced front wheel bearings
Rebuilt the A/C including disassembling the dash to the naked firewall
Replaced front control arms and sway bar links
New alternator and crank position sensor
Replaced glow plugs, to include drilling one out that seized in the head with special tooling from Germany.
New engine mounts.
General maintenance - brakes, oil changes, fuel filter and air filter changes

Here are a bunch of links of my experiences from the forum
http://www.peachparts.com/shopforum/diesel-discussion/382492-couple-useful-links-w210-owners.html

http://www.peachparts.com/shopforum/diesel-discussion/377507-w210-compressor-seized.html

http://www.peachparts.com/shopforum/diesel-discussion/363054-check-those-front-wheel-bearings.html

http://www.peachparts.com/shopforum/diesel-discussion/341600-attn-om606-inspect-under-engine-cover.html

http://www.peachparts.com/shopforum/diesel-discussion/397076-om606-glow-plug-change-one-broke-off.html

http://www.peachparts.com/shopforum/diesel-discussion/393787-w210-can-bus-issues.html

If you end up getting it here is a list of items that I would consider to be proactive maintenance and should be done/checked immediately when you get the car.

- Front wheel bearings - stupid easy to change if they aren’t seized. Painful if they are, you will need a new spindle $$$ and a spring compressor to change.

- Crank position sensor - car will die if this fails. Get only the genuine MB sensor from the dealer, for some reason the aftermarket suppliers are selling a Bosch “equivalent” that is not compatible with the computer for some reason. Went through hell this past summer with this.

- Plan on doing a glow plug replacement. Yes it is scary but wow does the car run so much better with good glow plugs.

- Pull your injectors, renew the seals on the valve cover and injector well shields, send your injectors to member Greazzer to be rebuilt and recalibrated, replace the fuel hoses, return hoses, and all 7 injector line clips and pads.

- Change the transmission fluid, these were marketed as “lifetime fill” not so much. You want to also replace the “pilot bushing” electrical connector on the right front corner of the transmission. These can leak and the fluid gets sucked up into the transmission controller in the engine bay by capillary action. The fluid has graphite particles suspended in it from the normal wear of the friction disks, this shorts out the transmission computer. I would also recommend doing the “conductor plate” while you’re in there.

You will need some special tools to work on this car.
Good E-torx and standard Torx sockets (not Harbor Freight or any other Chinese product) you want Snap-on or Lisle
Special socket for removing the fuel injectors
Pulley holder and the stubby 8 mm hex key for removing the fan.

I highly recommend purchasing a cloned diagnostic computer (search “Xentry” on eBay). This car has an OBDII port but it is very limited what it can do. Most aftermarket diagnostic hand helds cannot do anything with most of the systems on this car. The diagnosis has to be carried out through the 38 pin connector under the hood.

I’m usually on the forum frequently so if you have more questions/concerns please let us know.

alsevi · #12 02-10-2019, 07:09 PM

Fantastic car. As stated, determine the condition of the glow plugs: stuck-there is much wisdom on this forum. broken-major scope change. Probable head removal for repair. Although there are some W210 specific tasks, the rest is typical well designed, high quality Benz work. This turbo diesel was a game changer.

jay_bob · #13 02-10-2019, 07:52 PM

Broken glow plugs can be dealt with successfully without removing the head.

See my thread above on broken glow plug removal.

It takes about $700 in tooling to do this, but much cheaper than R&Ring a head and machine shop charges.

OM617YOTA · #14 02-10-2019, 10:13 PM

If you're used to wrenching on an Audi, an MBZ will be no big deal.

If you're used to Japanese vehicles(as I mostly am), these things are both a huge PITA and maintenance pigs.

jake12tech · #15 02-11-2019, 12:41 AM

Best car I’ve ever owned low maintenance reliability, easy to work on. Fix the fuel lines and it’s good to go. Glow plugs are no problem. Hot engine and an impact gun make them cake.

I always brag, my om606 w210 has 560k miles on it and is in need of a head refresh but starts up regardless in 5 degrees the first glow cycle. I posted a video about a week ago on the forums. Tough car, even tougher engine. I have the highest mileage 606 on this forum all original if I’m not mistaking.