W115 300D possible purchase-advice needed - PeachParts Mercedes-Benz Forum

cjlipps · #1 12-31-2009, 09:12 PM

Manufacture date 5/1976, automatic, no sunroof, around 180K miles. Owner says it needs rebuild due to hard starting and low power until warmed up. It has a little rust behind the rear wheels but a pretty good body otherwise. The interior is a little worn but mainly dirty. Headliner has come untucked around the edges in places.
When the key is turned on the glow plug light illuminates but never goes off. It started roughly and stumbled horribly for a couple of seconds before dying so I quit until I can look it over in the daylight. (Ambient temp was about 38 F.)
I know valves out of adjustment will cause hard starting and the other symptoms he described but I have a few other questions:
What is normal GP light function on this car? I have a 1983 240D and am familiar with this system but not the 115.
Owner stated that top speed was in the low 80's. Is this normal for this car? I used to have a 1978 300D and that was not the case so I'm hoping that it's just a fixable problem.
Asking price is $1000 and I'm going back this weekend to check it out again. Other than the obvious what all works and doesn't, what advice can you knowledgable folks offer?
Thanks in advance!

79Mercy · #2 12-31-2009, 09:42 PM

The glowplugs in the W115's take about 40 seconds, the light seems to stay on forever, just wait 40 sec and it will go off. Turn the idle knob up and press the acclerator just a bit when cold starting.

All diesels have less power until warmed up, so thats not a big issue.

The IP is governed to 4350RPM, so your top speed is about 84 MPH. I have tried it in my W115 300D, and 84 MPH is all it will do....

Im sure it needs a valve adjustment, it will improve the power, starting, and fuel economy.

If its pretty much rust free buy it most W115's are rusted out beyond repair, I was lucky to find one that wasn't. 1000 sounds very reasonable, thats what I paid for mine.

Did you see any smoke?

diametricalbenz · #3 12-31-2009, 10:59 PM

Rust is a sore spot on the cars flip up every mat and pull everything from the trunk to inspect the corners for rust. Look at the jack points and the frame too of course.

84mph is pretty much all mine would do even on a 6% downgrade. It sounded like a blender on frappe at that speed but it wasn't anything it couldn't handle.

cjlipps · #4 01-01-2010, 07:53 PM

It drove well, the tea kettle test was very good, the climate control system works-even the a/c and I got a great deal on the car so I bought it.
Things it needs:
The headlights don't work. Don't know if it's a switch or fuses but nothing headlight related works. Dash lights, fog lights, tail lights....nothing.
I think the brake booster is bad. The brakes are very poor and if you hold the brakes very long in gear the engine stumbles. Don't think it's a vacuum issue because the engine shuts down instantly. Also there is a whooshing sound from under the dash when the brakes are applied.
The blinkers don't work properly. They flicker but don't flash. There is a rapid flasher-type noise coming from under the dash and the indicators flicker also.
A muffler-although the teenagers like the sound.

It pulls to the right. Could be tires or alignment but overall the front end feels tight.
The fuse box is missing its lid. Any help here would be appreciated since I don't know what fuse is which.
The door locks don't work properly. No big deal for now but suspect it's one or more of the vacuum actuators.
Speedo works but not trip or odometer. Been down this road with both a 124 and a 123 so no big thing unless there's something strange about these.
Clock is inop.
No carpet in front.
It has cloth interior and no sunroof. Is this odd or possibly a Euro version?
Any and all help would be appreciated. I plan to either make this my DD and give the youngest my 240D when he turns 16 in a little over a year or vice versa. In the meantime I'll make this car right and see what transpires. All the kids like it and want to drive it so I guess there won't be a problem with it sitting.
I will also need some parts along the way so if anyone has anything for sale that I can use please chime in. I'll search the for sale section and post an items wanted thread when I have a list.
Thanks for the replies. They were helpful in my decision and I know I can count on more help from the kind folks on this forum in the future.