My first extended drive - '78 300D - PeachParts Mercedes-Benz Forum

rgnprof · #1 02-12-2006, 04:08 PM

I just got this car a few weeks ago and I have posted a few questions already. Took it on a 300 mile trip this weekend and was very impressed with the way the car ran. I have made several repairs (thanks to help from this board - blower motor, replaced thermostat, changed both fuel filters, air and and oil filters).

A few observations and questions:

1) No problems with the climate control after I capped off the vacuum that goes to the door lock system - ACC worked great. I don't know if I am going to fool with the door locks or not...

2) Car never got above 80 Celsius - is this normal? Ambient temp was cold - in the 30's and with wind chill probably in the teens. Heat worked great in the car though.

3) I have to address the sunroof - the thing will not open. Motor works fine but it grinds/clicks and the roof won't budge - any ideas on how to go about troubleshooting? I obviously don't need the roof to work right now but I would like to change the seals - the most annoying part of the drive was the wind leaking through the sunroof - loud! Once I get the roof open, any trick to replacing the seals?

4) Noticed some smoke this AM when trying to start - cold this morning so it took a few times but it started - with several significant puffs of smoke? Valve stem seals?

Overall, I was real happy with the car - and considering I only paid $500, I'm real happy.

Ryan

300SDog · #2 02-12-2006, 09:45 PM

Freezing temp with chill in teens makes for difficult diagnosis. Sunroof could be frozen and start-up smoke is probly unburnt fuel.

If it was me, I'd leave it alone and wait for warmer weather when alot of this stuff - sticky door locks, sluggish elect windows, sunroof, cold start etc will miraculously fix itself.

#3 02-12-2006, 09:56 PM

Quote:

Originally Posted by rgnprof

2) Car never got above 80 Celsius - is this normal? Ambient temp was cold - in the 30's and with wind chill probably in the teens. Heat worked great in the car though.

4) Noticed some smoke this AM when trying to start - cold this morning so it took a few times but it started - with several significant puffs of smoke? Valve stem seals?

Mine run right at 80C in cold temperatures, I believe that is normal.

Don't worry about a little smoke when its cold. If it took a few tries to get started, you probably just had some extra un-burnt fuel in the cylinders. Have you checked your glow plugs? I don't think the smoke is related to the valve seals.

rgnprof · #4 02-13-2006, 11:17 AM

Thanks for the replies - about the sunroof, I know it is not related to the cold weather. It does the same thing in the 70's and when it's parked in my garage, and according to the PO it has done it since he owned the car (2 yrs).

ryan

t walgamuth · #5 02-13-2006, 12:54 PM

on checking the glow plugs. if one or more is out it will start hard, run rough for a minute or so and blow some blue smoke (unburnt fuel).

tom w

pawoSD · #6 02-13-2006, 12:59 PM

I also am curious on how to change the sunroof seals, is it fairly do-able? Or is it a pain....once its warmer I intend to do this to prevent a leak I have when it rains....

It also needs to be lubed so it can move smoother and stuff.

Biodiesel300TD · #7 02-13-2006, 01:00 PM

Quote:

Originally Posted by t walgamuth

on checking the glow plugs. if one or more is out it will start hard, run rough for a minute or so and blow some blue smoke (unburnt fuel).

tom w

I just went through this a while back. Hard starting when at or below freezing. And a puffs of bluish smoke at regular intervals along with a shake. Once the engine warmed up it all went away. Check the glow plugs. Its amazing the difference on burnt out plug can make.

rgnprof · #8 02-13-2006, 03:08 PM

If anyone has any advice on the sunroof situation...?

How do I check the glow plugs (really new to Diesels)?

Ryan

rgnprof · #9 02-13-2006, 03:59 PM

I've been reading up on GP's and I have an idea how to test them, but I'm confused as to which type I need. I have run across 2 types - pencil style and those with a loop at the end??? Which do I use - and even if my engine has one type currently installed would it be better to switch to the other type?

ryan

bgkast · #10 02-13-2006, 04:08 PM

My sunroof has the same problem. Noisy at speed and clicks allot when you try to operate it. I have taken the motor off but I can't seem to figure out how to get the gear train off of the tube that the sunroof cable runs in. The metal gears look fine on my car so I suspect the teeth on the cable are bad. I bet this is the problem on your car too. I'll keep messing around with it and post back if I make any progress. Anyone have any tips on how to get the gearbox off?

rgnprof · #11 02-13-2006, 05:59 PM

Thanks bgkast - let me know what you find out. I haven't had time to look at the sunroof yet, but I have got to get the seals replaced!

Back to the glow plugs - on the online parts places I find 2 GP's listed for my application (1978 300D, nonoturbo) - those for chassis end numbers up to 085945 and those for chassis numbers that go from 085946. My car is in the second group but I clearly have the GP's (looped end) listed for the first group (up to 085945).

I'm confused as to which I should use? I read DieselGiant's article on upgrading - should I just do that?

ryan

300SDog · #12 02-13-2006, 07:40 PM

Quote:

Originally Posted by rgnprof

I've been reading up on GP's and I have an idea how to test them, but I'm confused as to which type I need. I have run across 2 types - pencil style and those with a loop at the end??? Which do I use - and even if my engine has one type currently installed would it be better to switch to the other type?

ryan

Your '78 300D uses the older loop style plugs. When loops burn out, the loop is broken same as a lightbulb filament, its really obvious. I've got a couple of extra loop plugs you can have for postage if you need em.

Meanwhile the newer style pencil plug "upgrade" saves you 45 seconds at warming em up - at the expense of being difficult to diagnose without special tools.

Try www.**************.com for the sunroof kit, they've got an excellent cable cleaning system that can get you started.

83-240D · #13 02-13-2006, 07:54 PM

for the rubber seal on the outside of the roof. i just did brownie last year and discovered the leak was the drains, but i digress. pull the old one out and find a blunt pointed object(don'tcha just love the irony?) to push the fastening lip into the tracks.

for the cable and gear tube www.**************.com has a kit to work on the sunroof and a great how to booklet on taking the thing apart. i recommend it.

#14 02-14-2006, 10:29 AM

I don't know if there was a car ever built that was more reliable for long distance driving than a four cylinder, manual transmission 123.

I drove my second 240D to the 450,000 mile mark before giving it to my sixteen year old son. At the time I was traveling all over Texas and surrounding states. That 240D had a homing instinct. The VERY FEW times that it ever gave me trouble to the point that I was stuck beside the road with no way to repair it, was within about 15 miles of home.

All the way up to the point that it 450K, I would jump in that car in the morning for anywhere from a 200 to a 500 mile one way trip and always had as much confidence as anyone could have that I would be at my meeting on time.

I was driving about 60,000 miles a year and that thing just kept going. The ONLY time that I was late to a meeting due to problems with the car, I lost the water pump/alternator belt while about 5 miles from Hope, Arkansas on the Interstate. I drove on into hope with the fanblade windmilling the water pump.

I pulled into an auto parts parking lot, bought a belt and asked them if they would mind if I changed it in the parking lot. They were very nice and accommodating about it and even gave me facilities to wash up when I was done. The worst part was the fear of spending that much time in Bill Clintons home town.

The weather was nice so I rolled down the windows so I could hear my car phone, called the folks to tell them that I would be late, stripped to my shirt and rolled up my sleeves. I was wearing an expensive suit.

The phone rang once in the middle of the job, and I made the call as short as possible and got back to work. It didn't take too long and I washed up and got on the road. I was almost on time for my meeting.

Also, I figured up one time what it took to drive that car including fuel, repairs, tires, cost of car, insurance, license, everything. And I then added up what I drew in mileage for the business miles I drove it. I was $16,000 to the good. How many cars are reliable enough and economical enough and long lasting enough to make money just from charging mileage on an expense report.

That old 240D sets out by my barn today in need of restoration. I work at home these days and have PLENTY of vehicles around here to drive. I can, in no way, come up with any practical reason to restore that car, but it may end up happening. How do you have such a love affair with a car? I guess it's because the car earned my respect.

Have a great day,

rgnprof · #15 02-14-2006, 02:57 PM

OK, I've been researching this GP issue and I figured out my earlier confusion about chassis numbers - the GP's listed online are using the engine numbers and my 617.xx number clearly indicates the loop type GP.

I am trying to troubleshoot and I've read most of the posts and online manuals but I have a couple of questions:

How long should my preglow light stay on? Mine only stays on for a few seconds - 5 maybe, regardless of ambient temp? Does this short time indicate a particular problem (online manual says something about preglow system preglowing too slowly and too fast???)

Second, should I upgrade to the pencil style - it sounds a lot easier to just stick with the loop style and it doesn't get THAT cold here in Oklahoma?

Thanks, ryan