The joy of old cars

So this morning I noticed a few drops of oil under my car, which I hadn't noticed before. Not worrying about it just then, as I was needing to get to work, I hopped in the car and drove in. Stopping at the bank on my way in, I looked under the hood, and the glow plug closest to the firewall ('79 300TD, non-turbo I5) is coated in oil and there is enough oil dripping out to smoke and stink. Not wanting to deal with it in the bank parking lot, I jumped back in the car and continued to work, figuring I'd look at it more closely when I got here.

Unfortunately, I forgot and shut the motor off, so I'm not sure where the oil is coming from just now.

Is it possible that the oil is somehow coming /through/ the glowplug out of the cylinder? It really looked like that with my brief initial inspection. Typically I'd think that there's a leak in my valve cover gasket (good excuse to check the valves, at least), but it really looked like it was somehow coming through the glow plug. Any good tips for me to keep in mind when I go to look at it this weekend?

I also happened to check the transmission fluid level while in the bank parking lot, and noticed it's really low. What kind of tranny fluid do folks put into their cars? ...a fluid and filter change for the transmission is already on my list for the near-term.

thanks,

-tom!

Reply to
Tom Plunket
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Tom,

WRT Transmission. I strongly recommend you follow the procedure for checking fluid in the manual. If you have been driving ant not allowed it to "settle" it may appear low. You *do not* want to overfill, in fact over filling (in my experience) is just as bad as being underfilled, and harder to correct.

In my old diesels, I never saw oil come out of the glow plug, and for the most part oil leaks were from the valve cover gasket.

Reply to
me

There is no procedure in any of the books I have with my car, and I have been unable to locate a service manual just yet[*].

So the books I have for the car say that it takes ATF, but doesn't ATF come in a number of different grades? My '77 Olds required Dexron III, and my '98 Pontiac asked for Dexron IV; I suspect that Dexron is a specific GM formulation but again the book for this '79 TD just says "Automatic Transmission Fluid (ATF)".

Ok, just now I let it sit, idling, for about a minute and checked again; the level seems fine although the car is on an ever-so-slight nose-down incline. ...but I'm all of the sudden getting this weird clunk when switching from reverse into drive, sounds kinda like rapping the handle of a screwdriver on a tin can.

Ok- I've usually tried to err on the side of, "it doesn't quite come up to the MAX line" rather than "it goes ever so slightly over the MAX line." :)

Upon closer inspection, this looks likely. I really don't want to get into taking the valve cover off without getting a manual though; that linkage looks fairly complicated.

[*]- So I've been searching around for manuals, ideally I could find something that covers both my '79 300TD and my wife's '85 300D. The wagon is the first model year for the 123 wagon, and the '85 is the last model year, so I keep hoping...

Anyway, I found this one:

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It's $100 for manuals on CD which seems a bit steep for me, but does anyone else have any other recommendations? As much as I like paper manuals, getting a thousand PDFs is fine 'cause then I can just print out the pages that I like. Put another way, would anyone recommend against getting this set of discs, or maybe even have somewhere to get them a bit less expensive?

thx,

-tom!

Reply to
Tom Plunket

First all of mine have been the sedan diesels, never had a wagon or the smaller mercedes. I think that the fluids are pretty much the same. YMMV

The procedure should be in your owners manual.

A quick google search reveals:

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Dexron (Mercon) III and above will work fine. I do not honestly know if it is ok to mix different Dexron types. Personally I would stick with the Dexron III. Be scrupulously clean when you change the fluid and filter. Use a good quality (not Fram) transmission filter. If you are thorough, you will drain the torque converter too, but if you choose not to go that route, I would change the fluid again in 15,000 miles, just to be sure and then every 30,000 miles after that. (stick with 15,000 miles if you are using it in "severe" conditions; lots of around town driving, or abnormally hot, dusty conditions)

Sounds to me like there are a couple of things worth checking the motor mounts, and transmission mounts, and the "flex disk" which connect the drive shaft components. It could be as simple as a missing exhaust hanger.

I don't know if you model has this arrangement but my 300SD had a weird bushing arrangement on the rear sway bar that required renewing, otherwise I would get weird clunking sounds from the back of the car when going of things like speed bumps. I would try to have someone localize the noise or see if there is any movement in the engine or the level of the rear of the car when switching from reverse into drive.

The paper manuals are probably more expensive by the time you get both the engine and chassis manuals. I think the CD covers several modes and engines and may even have information on the transmission. I would get the chassis, engine and transmission number from your car and make sure they fall into the range of the CD, rather than just relying on the model year.

There is *a lot* of information available on the internet for free.

Reply to
me

Change the valve cover gasket. Oil can't come out a glo plug hole or rather if there's a whack of oil in the prechamber where the glo pluh is you have a much bigger problem than a couple of drips on your driveway.

Reply to
Richard Sexton

It ain't. ;) It tells me vaguely what transmission fluid to use but that's it. It doesn't even tell me where the dipstick is, for transmission or engine oil.

Thanks. Gotta start depending on Google some more for this stuff... Problem is that there's so much suspect stuff out there.

k, thx.

Latest find- broken choke(?) cable. There's a knob under the adjuster for the dash lights (which also doesn't dim the dash, fun fun) which is supposed to adjust the idle speed. I discovered today that that cable is broken. Yay! heh.

-tom!

Reply to
Tom Plunket

New day, new problems.

So it seems this cracked ACC servo is leaking enough coolant, even while "off" that I really need to deal with it. I suppose the system shuts off properly in the daytime, but at night it's dropping below 65 (which is the lowest setting on the unit) and it must be opening it up. If I drive only during the day it's fine, but I get a small puddle of coolant on the ground if I drove it the night before.

So, since I don't want to throw down big money to fix this 'til "everything else" is discovered and fixed, I'm thinking about jumpering it for now. Any thoughts on that? E.g. take the servo out of the loop and go (I presume) directly from the auxillary water pump into the heater core, and then directly from the heater core into the return line? Besides the fact that this unit will now be operating without any coolant flowing through it, can anyone think of any problems I might run into? Is it "ok" to keep all of the vacuum lines hooked up as-is?

thx,

-tom!

Reply to
Tom Plunket

Tonight I did a bypass. I made the assumption, since Google yielded no information, that when the servo is open, the lines go "straight through", i.e. the left side ones connect and the right side ones connect. At least, that's how I rewired it.

I was going to remove the aux coolant pump, indeed I actually had it out, but then the hose clamp on the hose leading to the bottom of the fuel pump, but on the other end of the hose, was inaccessible without removing the alternator (!!!) due to the way it was twisted. I figure I could cut it off if I need, but then I realized I could put the water pump back in and just rotate it a bit to use it in the place where it was previously.

I still wish I had the shop manuals so I could see where those coolant lines were coming and going from.

Anyhow, this should stop the leaking in the near term. Hopefully it doesn't get too hot in the car, although I suppose if it does I get a good excuse to do the proper repair.

It's all (somewhat) photo documented and I'll put up a webpage so that others can see what I've done and read the results as they occur. I found two pictures online of a similar job on another model ('79 450SEL) but they weren't actually useful for figuring out what was going on. However, the thread on BenzWorld indicated that I should disconnect the power to the servo since it'll eventually freeze up and drain the battery, or so the story goes... I'm keeping the servo in place for now, if only because I need a place to keep the vacuum lines.

It wasn't too bad, I think I had the whole thing done in like two hours, not counting setup and put-away. Did it in my driveway, started around

10pm. Ugh.

I'll post a link to the page here when I get it together. Hoping for tomorrow night (err, I guess that's actually tonight!), but it depends what other tidbits I come across.

-tom!

Reply to
Tom Plunket

Wow, the heat cranks. Unfortunately the settings are either "max heat" or "no airflow", which I expected, but wow I didn't expect the heat to be blazing like it is. ;)

Mission successful, it seems.

-tom!

Reply to
Tom Plunket

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