Diesel guy thinking about a W124 Gas - Which Engine?
 

I've been a W123 and W124 diesel guy for a while now and have really enjoyed the reliability. I keep seeing nice prices on Gasoline Powered MBs and am getting tempted to head that way. I've read a post or two by the Diesel guys that more time can be spent holding a wrench than the steering wheel if I buy the wrong one... but that can also be true of some of the diesels too (though not many). I'd assume the same is true of the gas engines.

So I will limit my scope a little:
1986-1995
I like the W124 wagons.

I suppose there are a few advantages to the later 90's W124's (better cluster, R134 AC), Here are my questions:

1. Is there more than one engine offered in those years? I think I've read it's an M103 or M104???.

2. Are there any engine issues to watch out for? I know with Diesels everyone says OM603s crack heads and the 3.5 603 bends rods. I've been driving an 87 OM603 and have loved it. But it's always made me a little nervous with the head.

3. How is the A/C in the R134 cars? I don't want to convert an R12 car to R134. I've done it on my 87 300D and it isn't as efficient as I'd like.

4. What am I getting myself into? Will I be fighting with electrical engine/sensor issues or is this a pretty mechanical engine? What's this going to cost me? How much time will I be spending working on the car? How long do the gas engines last (usually)? Seems like the Diesels are pretty regularly hitting 300k+.

Any buying tips? I'll most likely be buying a 90's W124 Wagon. I wish I could find a Diesel but they ended in 87 and there aren't many of those floating around. So time to switch to gas! I'm kindof looking forward to something new.

thanks,
Nick

93-95 E320 (300TE for 93), in my opinion, have a more powerful engine in them. Not glass smooth like the M103, but still amazing smooth. You'll have to find one that has had the head gasket replaced as the M103 and M104 engines had head gasket failures. On the 93-95 models, the wiring harness MUST be changed prior to purchase! If not, drop the car's price $1500 right there the harness alone costs around $1000 and if you don't do it yourself, right around $1500. You have/had a W124 before, so you know all about the A/C evaporator. They were all crap and would leak freon and cause you all sorts of problems. Dash has to be removed in order to change the evaporator. Very expensive job to get done elsewhere, if you do it yourself, it's not that expensive. Make sure the SLS suspension is functional. If not, it'll cause a bunch of weird suspension issues.

More will chime in.. :)

Speaking of the A/C.... It seems like there is something people complained about being too small (maybe the condenser??) Is this still the case with the later R134 models? or did they beef the A/C up to handle it?

And... After 1993 = R134? or is it later?

Yes, the 124 is a worse candidate for 12 to 134 conversion than is the 123 car due to a too small condensor. The good news is that the 124 cars were among some of the earliest to come from the factory with 134. As I recall I looked at a 91 that was factory 134, but it might have been a 92.

That said, here's my response to all these questions that you ask: None of that really matters unless you are deciding between two cars in the exact same CONDITION.

By FAR, the most important three criteria when selecting a used car are:

condition
Condition
CONDITION

With all the questions you asked, it's pretty much a wash. Just find a very nice, very well maintained example. That's more important than any of the other stuff. When you're buying a NEW car, then those are the kinds of things to consider, but not with a used car.

My $0.02,

The V8's (400E, 500E) and the diesel models came with r134a in 1992.

The 300E 2.8 and 300E (3.2) came with r134a in 1993.

I had a 1993 300E (3.2) and it had the coldest a/c of any car I've ever had.

I bought a 1995 E320 wagon 1.5 years ago and it is one of my favorite cars of all time. I paid $1500 for it knowing that the transmission needed work. I didn't discover this forum until after I bought it. It also needed the evaporator replaced and the sls spheres replaced. I just recently found out that the wiring harness has been replaced and so far no major leaks from the head. It had 168k on it when I bought it and is now at 192k. I rebuilt the transmission myself using all MB parts for about $700 (it was my first automatic rebuild). I replace the evaporator using information found here and I love the climate control.
I have done my own work on cars for the last 40 years and this has been a very enjoyable car to work on. The evaporator replacement was probably the worst in terms of time and frustration.

Great. Where do I look for the wiring harness woes. Wow Fred! You rebuilt your transmission. That's great! must feel good when you drive it knowing that you did it and did it right.

DIY-ing the work on these things is a great thing.

The M103 engined cars are excellent if you can find a nice one. I've had my W124 300E for almost a year now/10,000 miles and love it. Not quite as good of mileage as my 300SD....but that is probably mostly my fault. :D ;) It is a very reliable engine and does not have much in the way of sensors, just a few of them. It only posed an issue one time where the crank sensor decided to get flaky and stranded my wife on her way to work (last March)....when I showed up and tried starting it, it fired up fine....despite not having cooperated for her. I then drove it home, ordered a new crank sensor. Since that was replaced it has never had a single issue. I've even taken it on 500+ mile trips and have seen as high as 26.7 mpg going 73mph.....better than my diesel can get at that speed.

All transmissions of the era can have issues, it's a Mercedes thing.

The R-134a native system is cold, at least as cold as the R-12 systems were, I've had many 124s including new.

The M104 is as smooth as the M103, no difference there. The down-side to the M104 cars is very simple: engine wiring harness. If that is changed (date-label visible between the battery and inner-firewall, look for FD wwyy) or compensated in the price you're golden.

The advantages to the '94/'95 over the '93 are: GREAT headlamps, which in contrast to the pre-94 DISMAL US lights saves you the price of good Euros. Nice facelift front and rear, and big 4-piston brakes on the front vs the earlier 1-piston ones. Also the easier to clean 8-hole wheels.

Advantages of the '93-up is the M104 and 2.65:1 gears. This gives you better fuel mileage, an extra 35 or 40hp (from memory), and much more low-end power so you have a faster launch/more power/fast top-end/better fuel mileage, and the quiet cruise of 3,000rpm at around 73mph. On top of that you get a 1st-gear start like you're used to in your 300D/124 instead of the (IMO annoying) 2nd-gear start of the M103 cars. Also native R-134a A/C.

On the '90-up cars you get the auto-down windows, the auto close/open with the key, the body cladding, painted bumpers, improved seating, zebrano-wood dash, and leather door-panels / leather seatbacks with map pockets instead of the saggy nets.

Other minor things I'm sure also, but this is the quick version from me.

The transmission and most other things are relatively un-changed as far as electronics, the M104 engine does have more issues with a few more sensors and so-forth, but it has pretty good built-in diagnostics also (plus this forum). Watching this forum for M104 questions vs M103 questions, not a whole lot of differences, both seem to repeat the same few questions over and over. The traction-control on the M104 is nice when it works (ASR), but it seems that as they age they are another source of trouble, I think I'd avoid an ASR car if you don't live where you (or your S.O.) will really benefit.

If they don't have it in the records, you can pull back some of the insulation on the harness to see if its degraded or not. Most cars of that era have had to deal with it by now, so I doubt you'll see many original harnesses.

I love my diesels, but feel just as confident with a M103-104 going 300k plus as well. The gasser engines don't tend to be nearly as leak prone or get really dirty either. Just like with all Mercedes though, even if you buy a nice ones there's always a 1-2k of stuff that it needs.

Here's my short criteria on an average wagon you'll come across with 80- 150k in nice cosmetic shape.

The most I would pay for one is $6000, and I would deduct...

$1500 if its the original wiring harness
$1500 if its on the original head gasket
$3000 if its devoid of a good service history, fluids look old, etc.
$1000 if its the original Evaporator (even though I priced it at about half of the job would take its about a 50/50 shot you'll have to deal with it unless you keep the car for a very long time.

A PPI will also bring to light if the rear hydraulic suspension is getting weak, or the front end is starting to have issues.

If you have not seen this little gem in the sale forum, I strongly suggest you consider it. Its a very good price considering what has been done to it.

http://www.peachparts.com/shopforum/showthread.php?t=261593&highlight=e320+wagon

I bought my '95 E320 with 148k in very nice shape for $2500. It had a great service history, including a new wiring harness, but the original head gasket was leaking, and it still had the original (still good) evaporator. $2000 later I had a very nice, well sorted, turn key wagon.

LOL. So if the car has had none of that done, then: 6000 - 1500 - 1500 - 3000 - 1000 = -1000 So the owner would have to pay you $1000 to take the car? :D ;)

True that the wagons are harder to find, and do get a little higher price, but they're also harder to sell.

Sedans in good condition are worth around $3500, a wagon might be worth $4500, it'd have to be exceptional IMO to be worth more (and Archie's might be). I think it would have to be no more than 80,000miles, heated leather and good colors, 3rd-seat and pet-net, documented, not rust-belt, wiring-harness (es) / evap replaced and a clean bill of health to be worth over $5k. The used-car market just isn't that strong.

Pretty much. I've walked away from plenty of cars because it would cost more to fix then they're worth. Its not even worth making an offer, especially since most have really ambitious asking prices. Of course, I buy some cars to flip, so I ignore some things knowing that I won't have to deal with them in the 6 months or less I own them. If I were shopping for a long term vehicle, and the majority of that list was not addressed, I would simply lowball and move on.

Both the M103 and the 104 are pretty mechanically bulletproof as long as they are maintained properly. The 104 is an interference engine (don't know about the 103). Any car you consider at this age/miles will need repairs sooner or later. The head will need to be gone through (at least for valve stem seals and guides) because the seals are shot by now. Budget $1200 for a head rebuild if you R&R the head yourself. If the car is using oil/marginally passes smog due to HC, you know the seals are gone and possibly the guides. Experienced guys will tell you the 104 head doesn't use up guides as often as the 103 but if you have the head off you might as well do the guides. The 104 is a DOHC 24-valve motor with variable valve timing that makes quite a bit more mustard than the 103. When it hits about 4000 rpm it really wakes up, sticks you back in the seat and makes this terrific sound as it revs.

The later 124s came equipped with 134 as the others have said here. Mine ('93) blows ice cold.

There are a few sensors but they are pretty reliable. You don't read about too many sensor problems. I don't think any of them are outrageously expensive. A car of this age might need new cooling system sensors. The bottom ends on these motors are way stout and they will run over 500,000 if they have been maintained. The heads will have to be rebuilt every 150k or so. I had my 104 head off this summer for a rebuild and with 145k on mine, there was zero ridge at the top of the cylinders and the cross-hatching in the bores is still plainly visible.

The biggies on these cars are the wiring harness, the evaporator, and the head gasket. Some cars need the harness and some don't. Mine doesn't - I got lucky and believe me I have checked. Same with the evaporator: some need it, some don't. I read someplace that we 6-cylinder 124 owners should just plan on a head gasket replacement and timing cover reseal being on a 5-year PM cycle because they ALWAYS leak eventually due to the design. You should plan on replacing all the components of the cooling system (radiator, pump, all hoses, fan clutch, t-stat). Budget $650 or so for that if you do all the labor (some of the hoses are $25 - $30 each). If you get an ASR car or a 4Matic car, you better have a big checkbook. There is a reason why 4Matic is referred to as $Matic. Another thing. A car of this age will need a suspension rebuild because the rubber bushings are getting hard by now. So you should plan on that. But that is true with any old MB. The transmissions are spotty on service life. Mine has 142k and is starting to do the dreaded reverse-delay which means it's on its last legs. Some guys have gotten over 200k out of these trannies. I think the PO of my car did not R&R the trans fluid and filter like he should have and I am paying the price.

Take any propose car to a MB indy wrench and get a pre-purchase inspection. This is imperative. Remember the old adage: There Is No Such Thing As A Cheap Mercedes. I learned this the hard way. And recite the MB Mantra: fluids and filters, fluids and filters, fluids and filters. :-)

Hope this helps! Pete

I think condition and servicing history are the most important factors when looking at an older car. I would forgo a newer W124 over one that was a couple years older if the older one was in better condition and better maintained. I would drive both M103 and M104 cars and see which one you like more. I could see the more powerful M104 being better suited to the larger and heaving wagon than the M103. Check the car over carefully and make sure to get it inspected before purchasing. There are a lot of electrics to check over, so make sure that all those switches and accessories are working as they should. On the wagons the rear tailgate self closes itself in so you do not need to slam it shut, so make sure it is working.