Hello everyone, I Just joined, and I have a few ?'s - PeachParts Mercedes-Benz Forum

maddogg20 · #1 10-23-2006, 09:49 PM

Hello all,

IM andy. I recently got a 1983 TDT from my neighbor. Anyway, Its got a few issues that im curious about. First off I LOVE the car, it gets great miledge and I drive 70 miles round trip every day so I put the miles on it. Anyway the first thing Im curious about is.....

Sometimes, about 1/2 the time, when I shut the car off with the key it will keep running for about 30 seconds then shut off. If I lock the doors while the keys out and its still running, it will stay on for even longer. I read that there may be a vacuum leak somewhere in the system due to the fact that the cars a vacuum line night mare, but I'm just curious to see what U guys think.

Second of all, it tends to run very hot especially up long hills, I live in southern california and even though its winter here its still a bit toasty mid day. When I go up a certain hill on the way to and from work the car gets very hot, like almost to the 120 mark, and sometimes itll get there on flat surfaces. I changed the oil, filters, fuel filters and flushed and changed the coolant as some routine maintenance a few weeks ago but it didnt seem to remedy the problem, and last night I replaced the fan and fan clutch with an electric fan on a thermostat, and it helped a bit but the car still got hot as can be. Today I was told my a local mercedes shop to bridge the wires from the fan on the front of the condenser and it turned on, and the car ran alot cooler, but I'm still worried. I MAY have messed up the mixture of coolant to water, but I'm curious if that would effect it that much. Its prolly like 70% coolant to 30% water, I'm thinking thats a problem, but I still think somethign else is up.

I fixed the dash light problem by soldering the trace on the back of the dash, as I read it in the forums here.

1 last thing.... I cleaned and re-greased the sunroof tracks as well as I could, but its weird, when its hot the roof opens and closes perfectly, but when its cold it takes forever until it gets to the last 6 inches then closes fast. I think it could be the grease is thinner during the day when its hot and thicker at night, but I still think it should close at all times,

ANyway, it sounds weird, but I'm a ford diesel technician but with this car im like uhhhh, lol. I know how it worls and what not I just don't quite yet know the little things that make these cars problems unique.

THanks for reading, and If you have any info please shoot it my way.
Thank you....

Andy.

byrdandcompany · #2 10-23-2006, 10:15 PM

Save yourself a ton of time and go get a mitivac. You have to have one if you own a diesel mercedes. Use that to find your vacuum leak.

maddogg20 · #3 10-23-2006, 10:34 PM

I have a hand help vacuum pump, I just wasnt sure what lines represented what part of the car. I thought that green was the climate control system and brown was doors etc, that right?

JimmyL · #4 10-23-2006, 10:55 PM

Quote:

Originally Posted by maddogg20

I thought that green was the climate control system and brown was doors etc, that right?

Yes, and NO. Green is climate control stuff, solid yellow is door locks, yellow with gray stripe is vac reservoir for door lock stuff, black is a vent line, and brown is for the ignition/shutoff.
Your best bet is to find where lines go through firewall. Undo and plug everything but the brown, and see if car shuts off, which it should. [plug from vac side, not side going through firewall] Then plug in green and see if it makes a difference (it is very often this one. rubber bladders in vent pods). If green OK, hook up yellow, etc...... Usually a good way to do a quick check and isolate subsystem, then you can chase the actual leak from there.
On the overheat, always give the thermostat a try........
And, there really isn't a 300TDT, even though some folks call it that. That is in reference to a wagon, TD for "Touring Diesel", ie: wagon, and the second T for turbo, though by year we should already know that.

Sounds like you have an '83 300D since you have an electric sunroof. Wagons have a manual sunroof. We know your's is turbo cause it's an '83.
Welcome, and enjoy that car. Sounds like you have used the search function. Use it early, use it often...........

vstech · #5 10-24-2006, 12:18 AM

my 79 has manual, and I haven't gotten into the 80 much yet to know which it has.
I guess all TD's are not the same...
John

JimmyL · #6 10-24-2006, 12:26 AM

Quote:

Originally Posted by vstech

my 79 has manual, and I haven't gotten into the 80 much yet to know which it has.
I guess all TD's are not the same...
John

Well hmmmm. I've read that here a few times and passed it along. I wonder how rare an electric is on a wagon. I've never seen one.
At least I'm glad mine has a manual.......

kerry · #7 10-24-2006, 12:48 AM

Quote:

Originally Posted by vstech

my 79 has manual, and I haven't gotten into the 80 much yet to know which it has.
I guess all TD's are not the same...
John

What?????????? I too was under the impression all wagons have a manual sunroof. Where is the motor and how does the cable get up to the sunroof?

Shorebilly · #8 10-24-2006, 06:32 AM

G'mornin' Folks,

Welcome Andy, As a Ford Tech, you should have the necessary know how and tools to test your Thermostat, if that's working and going to full open, then perhaps your water pump is getting a tad old.....

As far as the coolant goes, I have read a lot of stuff around here and elsewhere......from what I have learned the MB Coolant is some special blend specifically designed for the alloys used in MB engines and cooling systems, and it has been stated enough that I have become a believer....and will purchase the MB product when I do a coolant change (I put it off, tested the existing coolant and found it to go below -40, will change it if I have to drain it for another problem, or in Springtime).

Something that I learned from my days as a ship's engineer.....when my company purchased several used container ships from a German company....we found that the Germans used some pretty interesting alloys in their various piping systems.....from a USA point of view......it was eventually learned the "hard way" that it was best to stick with German recommendations on Cooling Water Treatments......and to purchase welding electrodes and brazing stuff in Germany.....

SB

dannym · #9 10-24-2006, 08:13 AM

120° temperatures are not normal. Try doing a citric acid flush. Make sure you remove the block drain.

Danny

t walgamuth · #10 10-24-2006, 08:31 AM

the coolant mix most desired is 50 50. but that should not cause the temps that you are seeing.

a new tstat may help too. or if it happens to not have a stat a working stat is required to cool properly.

a flush may help. also the radiator may have the fins plugged with debris so a good washing might help there. forcing water and air back toward the front of the car is the way to go. and the condensor may need cleaning too.

and of course a loose belt would cause trouble too but you have probably already checked that.

tom, w

maddogg20 · #11 10-25-2006, 03:41 AM

Thanks for the info, I flushed the radiator, but I didnt do the acid flush, I will see bout having that done. The car has 280k on it and it was a big neglected so I wouldnt be suprised if some of the cooling system components are corroded u know.