Newbie from Portland, OR saying hello!

[WrightSounds]

Just thought I'd finally say Hi and introduce myself considering I've been plowing through the forum, reading posts, for weeks now! My dad drove an '85 300TD when I was a kid. I got to drive it occasionally while I was in high school. I loved it. I wasn't a car guy then and I'm not one now (I build and repair guitars and fuzz pedals) but I love these automobiles!

I recently purchased a 1980 300SD with 216k miles. Thistle Green with beige interior. It was a single-family car. Well taken care of and very clean. The car was maintained exactly according to the Service guide that comes along with the owners manual for at least the first 100,000 miles. It's been serviced at the same reputable Mercedes-Benz repair shop here in Portland for many years. The car drives super smooth and is a pure joy to drive. Embarrassing as it is to admit, I've never owned a car that I actually WANT to drive. Like right now... I could easily go drive around on the highway going nowhere.

Repair records from June of 2010, or 16,000 miles ago, show the former owner had the following done:

NEW
-oil pan and gasket
-brake rotors and pads
-rear brake hoses
-fan clutch
-water pump
-alternator and p/s belts
-motor mounts
-fuel injection return hoses
-inline fuel filter and hoses
-vacuum pump
-a slew of axle work including two new front axles
-transmission fluid change
-new tires

It's got some water leaking into the trunk in the right wheel well. I took it into a glass shop and they assured me the glass is NOT leaking and that it's coming from the rear taillight assembly. It definitely is after a couple of days of detective work. Haven't decided if I'm going to try and seal the leak myself or turn it over to the pros.

The a/c doesn't work (of course) but seeing Portland, OR had 6 days above 90˚F over the last TWO years, a/c isn't a top priority.

There seems to be a leak in the vacuum line because the door locks aren't working. The car is shutting off fine and the vacuum pump is a year old so I'm hoping it's just the tubing somewhere.

The back left window doesn't work.

Other than those issues the only other thing I want to replace right away is the thermostat. The car is definitely taking too long to warm up, the heat isn't that warm and gas mileage isn't what it should be.

Anyway, Hi and thanks to everybody that takes the time to share their knowledge, experiences, or even just opinions 

[Tony66_au]

G'day and welcome WrightSounds!

Nice old girl you have there, thanks for sharing!

Tony

[oversize]

Oh yes she's very nice!!!  What a great find!  I'd hang onto that one; she's a keeper....   

[ZCarFan]

Yes, that is a very clean car.  Amazing how long they stay nice if you take care of them, isn't it?  I see the sunroof, are the hood and trunk lid steel or aluminum?

What are you seeing for fuel economy?

[WrightSounds]

Yeah, it's in such nice shape. I feel very lucky.

ZCarFan: the hood and trunk lid are aluminum. Regarding the fuel economy; the family and I just took a short road trip (170 miles round-trip) for Thanksgiving and I figured we got about 26.3 mpg. Should be closer to 30-32, no?

I'm taking the car into the shop in a few days to have the thermostat replaced along with some other things looked at. I'm guessing the mpg will improve once the thermostat is working correctly.

Thanks for the greetings everyone!

[JasonP]

It is a very nice car!

The injectors affect mileage as well. Over time, they get clogged and lose efficiency. Looks like your filters and hoses are new. There was a discussion earlier around her about the fuel filter inside the gas fuel tank, and how to replace it.

[oversize]

It's a real shame we never got the diesels here, because they're obviously very popular.  And I'd love some aluminum panels!!!  BTW a badly clogged air filter will affect economy and the list didn't say if it'd been changed

[WrightSounds]

Thanks for the tips guys! I'll check the air filter. I'm guessing it's crystal clear considering the attention the previous owner put into this car. I'll also update after the thermostat gets replaced.

[Tony66_au]

Slowly and bit by bit she will come together as a perfect car, sometimes even the Pro's take a while to find solutions but if you stick with the car through the nitty gritty stuff it will be well worth the wait.

[Tony66_au]

About your central locking!

As well as doing all 4 doors it also locks your Trunk and fuel flap and the system uses a few miles of Vac tube and a hand full of diaphrams.

Often the fix is simple enough once you find it and a cheap enough diag tool is a hand vacuum pump and gauge set and other than that a basic understanding and a bit of time and you can usually find the issue.

The last 2 times I have had W116 Vac issues both times its been the Trunk/Boot Vac system which when isolated restored function to the door central locks.

Cheers,
Tony

[JasonP]

Can you recommend any vacuum tester tools/pumps/guages?

[Tony66_au]

Sure but they are an unusual item with a hand pump.


radum.com.au is where I got mine (Which I lent out and never got back)  type Vacuum into the search box and it will get you to the item currently showing $56.00 AU so marginally higher in USD and freight shouldnt be more than $35 ish to the US Via USPS.
Their part number is [RDM-BM94-4039]   http://radum.com.au/catalog/product_info.php?products_id=9400


Summit racing used to have similar items as well but I cant seem to find em anymore...


http://www.summitracing.com/search/part-type/vacuum-and-pressure-test-kits


And they are a great source of Vacuum parts, diaphrams and pumps.


Hope that helps!

[ZCarFan]

I only saw 29-30 tops with the two I had.  Mostly in the 25-26 range in mixed driving.  The gearing on these is too low (high numerically) in my opinion.  A 307 Olds gas motor will pull a 2.14 ratio with the same tire size and vehicle weight and deliver mid 20's (sometimes better) economy, so 3.08s and no overdive on a diesel is sub-optimal.

Probably the best thing to do for fuel economy would be the 2.65 gears from a 6.9 and modifying the transmission to start in first all the time.  As clean as that car is, it will last nearly forever, so maybe a good long-term approach.

For now, I'd recommend keeping the alignment right ( toe can really kill fuel economy along with tires) , the tires filled and not worry about a few bucks in fuel.  Do change the thermostat, but I wouldn't get too worried if the mileage does not pick up much.

I did not see any mention of a valve adjustment, so put that on the list.  Make sure that the guy doing can do it right.  Seems to be a lost art lately.

[JasonP]

Thanks, Tony. I forgot you were in Australia, but now that we're a global economy and all ...

[WrightSounds]

I'm loving the input guys!

Tony66: I'm very intrigued by the vacuum system and all the tubing. I think it's pretty genius. I've watched the Mercedes Source YouTube videos showing how to use the hand vacuum pump to diagnose the problem. I'm a bit leery but I might give it a go!

ZCarFan: Thanks for the valve adjustment heads-up and the mpg info. You lost me with the beginning of your post though  (remember, I'm a guitar guy... still learning about engines) I think I get your point just a little lost with the numbers 

The guy who sold me the car included a Haynes Repair Manual book but for W123s, not W116. There isn't a W116 Haynes book is there?

thanks again... let me know if you ever have any guitar questions!