1985 300TD SERIOUS front oil leak and smoking underneath air filter housing - Page 2 - PeachParts Mercedes-Benz Forum

Zacharias · #16 12-23-2011, 11:23 AM

Quote:

Originally Posted by tomas_maly

Zacharias,

Well, my 300SD seems to be in quite good condition in the sense that it was taken care of well.... Nobody in their right mind would take that good care of a car unless they spent $40k on it, or whatever it cost originally..

My experience has been that the quality of care is steady from the original owner to the second owner (actually sometimes better with the second, as we 'enthusiasts' often cannot afford these cars new).

From then on, it's open season. By the time a car makes it to its fourth set of hands, unless it's moving between people in a group such as this, all bets are off.

Quote:

Originally Posted by tomas_maly

Going over any bump, I hear a grinding metal noise (it has a 'push/pull' sound to it, ie two equal sounds with a slight pause in between, not just a thud, so I am guessing shocks)

Sure it isn't just the stabilizer bar links? Could also be the trailing arm bushings. My 300d creaks like that in the rear, on cold days, but the shocks are fine.

If your shocks are gone you will be having a very bouncy ride, but the ones on my old SD didn't make any noise even when they were shot.

Quote:

Originally Posted by tomas_maly

There is rust on the driver's trailing arm, which actually prevents the shock from being bolted on with two bolts. Which may be why they never changed the shocks. Probably said the trailing arm would be $2000 parts and labor, etc and better to get rid of the car.

Not a reason to get rid of the car. It's a big job but many people have done it on this board. Be careful, rot in the arm is a safety issue. If it's that rusty it ought to be changed.

FYI the arms on w123 and w126 SDs are interchangeable.

Quote:

Originally Posted by tomas_maly

My 300TD however must've sat around for YEARS. So many things neglected. I think it's one of those perpetual project cars. I'll probably never really have it in 'excellent' shape, not unless I throw another $3000 in parts at it.

I feel your pain. My 300td was the same way. And I ended up throwing a couple of grand of parts at it... and then the transmission calved. SIGH. But I look forward to having it on the road again.

Quote:

Originally Posted by tomas_maly

Either way, I only can manage because I have two of them (the POS wagon was $500 and the sedan was $1000).

The price was right! Especially for the SD as you seem to be happy with it overall. Keep up the good fight. You will get to the light at the end of the tunnel.

Quote:

Originally Posted by tomas_maly

I do quite like the 81-85 W123/W126's, though. After that, it just starts getting complicated with all the modern 'features'.

I agree but I foresee a w124 or later w126 (SDL) in my future. Those cars are still well within the DIYer orbit and the additional complications aren't onerous.

Unfortunately, once you get past that generation, the chassis electronics start to get a bit daunting for the backyard mechanic.

whunter · #17 12-23-2011, 01:16 PM

Quote:

Originally Posted by tomas_maly

This may be totally different, but after repairing my steering box on the wagon, the steering is nice and tight/stable, but depending on my speed or whether I just start the car, or are moving from a stopsign, etc it seems the tension radically changes, almost like the power steering gives out (about 75% off, still moves ok, but feels much tighter).

I'm wondering if since the steering pump uses a belt attached to the crankshaft pulley, if this is being all affected (ie loosening tension randomly) because the crankshaft seal is giving out?

When I replaced the steering box, I just left the steering pump as is. I pre-filled the box with fluid, bolted it on, and then ran the steering wheel back and forth probably 50 times. I'm fairly sure I purged all air, but wasn't sure if I needed to turn the steering wheel with either of the pump tubes off the box or the pump (ie return line loose sticking into the pump top so air gets out better).

But I drove it for maybe a week, and was fine, didn't notice a thing wrong with the tension, until just now as I'm noticing this major oil leak from the crankshaft seal.

I changed my alternator maybe 6 months ago and tightened it back up (never having the steering lock/tighten up until just now), new fluid (no leaking), etc. Will check tension on belt, but seems a bit odd since it comes and goes, like either the belt is at the end of it's life or something else is moving around.

What you are describing could be:

* Sheared harmonic balancer dowel pins.
* Damaged harmonic balancer.
* Harmonic balancer PULLEY cap screws stretching/shearing.

Be prepared to replace the harmonic balancer with a good used one.

I suggest you buy six dowel pins to give you four spares.

000007008244 Dowel for harmonic balancer, Large Engine Application List
000007008244 Dowel for harmonic balancer, Large Engine Application List

Main seal front/rear and harmonic balancer + Pulley

I generally use the "FEBI"
Spacer Ring, for Front Crankshaft Seal
MB# 615 031 00 51

I like the Victor "Reinz" Front Crankshaft Seal, but use the "Elring" almost as often.
MB# 011 997 22 47

I always insist upon using six NEW cap screws for the pulley.
MB# 000912008203

andrewjtx · #18 12-23-2011, 01:27 PM

You really need to power wash the motor and determine where your leak is. With the air cleaner and turbo drains on the passenger side of the engine, those are well known leak areas. I think if it was your front seal, you'd see oil being blown down both side of the engine.

BTW - you'll hardly see ANYTHING from the top of the passenger side unless you take the air cleaner off.

tomas_maly · #19 12-24-2011, 08:49 AM

andrewtjx, with the car running, a puddle of oil is dripping immediately in front of the oil pan gasket in the front of the engine. There's grease on the passenger side of the engine over the years, but I'm seeing when the car parked that a 4 inch puddle instantly forms in 1 minute. Oil pan gasket was changed, it's definitely on tight enough. My observation is that it's coming from above the front of the oil pan. Won't know 100% if it's the crankshaft seal until I have it taken apart and see the oil around it, but I'm 95% sure right now.

tomas_maly · #20 12-24-2011, 09:13 AM

Quote:

Originally Posted by andrewjtx

You really need to power wash the motor and determine where your leak is. With the air cleaner and turbo drains on the passenger side of the engine, those are well known leak areas. I think if it was your front seal, you'd see oil being blown down both side of the engine.

BTW - you'll hardly see ANYTHING from the top of the passenger side unless you take the air cleaner off.

I figured that if it's leaking at the bottom end of the crankshaft seal, the combination of the fan rotating clockwise (lower end toward the passenger side) and the air blowing from driving would potentially cause the leaky oil to end up mostly on the passenger side of the engine. The passenger wheel rim had thick grease all on the inside, too.

After the crankshaft seal is done, I will see if there are any more oil leaks (running or off) and will then consider washing things to further diagnose if that's the case.

jkubica · #21 12-24-2011, 11:56 AM

Quote:

Originally Posted by tomas_maly

Just noticed a major oil leak at the front of my engine, directly above my oil pan. I thought it was the oil pan gasket, but I changed that.

While running, it drips a 4 inch puddle of oil in a matter of 30 seconds. And noticed the oil was real low the other day (after changing it maybe 6 months ago). I also notice that the oil pressure is really low at idle, maybe 1.25 .

Is it fairly safe to say that it's probably the front crank seal leaking? I'm wondering if that's a do-able job, and how long that typically takes. This is a W123, so it's a bit less room than the W126, so maybe there are some tips to make it easier to get to, even if I have to take more stuff apart.

I also notice that there's an incredible amount of grease all over the passenger underside of the engine, but NOT the drivers side - so I'm wondering maybe as it's leaking, the fan (since it rotates clockwise, toward the passenger side) may be blowing the oil toward that side.

Possibly a separate note, that I'm noticing all of the sudden some smoke coming from underneath the air filter housing. I sprayed the throttle linkage with some heat-resistant WD40 (and may have leaked some fluid over the passenger edge of the engine block), but I doubt it's that. The smoke seems to get worse as I drive more, ie perhaps as more oil gets on the side of the engine. It's not any thicker/darker smoke than would come out of the valve cover into the air filter housing, anyway.

Perhaps I'll put the car on ramps and take a peak from underneath to see exactly where the smoke is coming from.

I went through same with my 85tdt.

I suggest that first thing - you get some Purple Power (cheaper than Simple Green) and using parts brushes and water hose - completely clean the engine from the valve cover down. Its a lot of work - but you will appreciate have everything clean.

The oil from leaks has a way of showing up some distance from the source - and a clean engine makes them much easier to pinpoint the actual leak.

In my case, most of the oil came from the oil separator drain tube setup.

Joseph