Finally...Combining TWO 1985 300D's - Page 6 - PeachParts Mercedes-Benz Forum

Diseasel300 · #76 01-11-2018, 12:11 AM

Quote:

Originally Posted by vwnate1

The entire exhaust system and down pipe is behind the cross member and is not visible with the car on the ground, anyone who'd ever actually worked on one or even looked would know this .

Coming from a 126, I'm offering suggestions, I don't have a 123 and figured they'd be similar being similar vintage vehicles. You can clearly see the downpipe and exhaust pipe on the 126 by squatting down and looking up under the car, there's enough ground clearance even with tired springs and a sagging rear end to stick your face up under there and look (and I have a fat head). Since the 123 doesn't even have the noise-encapsulation panels, I figured it would be visible with nothing there to hide it.

Diseasel300 · #77 01-11-2018, 12:21 AM

Quote:

Originally Posted by 300Drestoration

My work is about a 15 minute drive, and is the most common trip i take. But i let the car warm up for around 5 minutes first usually. I have found that makes a difference in it's immediate performance. If i drive the thing straight away, it's more sluggish. Needless to say, when the car's been driven for a while it is a world of difference hitting the pedal from stop.
Hopefully this work commute trek done twice a day is not going to hurt my battery over time. I suppose i could add around 5 minutes of nonsense driving each time.

Here's another thing that i frequently do though.. go to a Home Depot / Shopping plaza about 15 minute drive away, park the car for 20 minutes, and get back in and drive back. Does the benefit of a total of 30 minutes drive lose it's luster on the battery when i break it up with 20 minutes parked in a lot?

Your driving habits aren't much different from most people's. My work is 7 minutes from my house. I'm certainly not going to drive an extra 23 minutes just to warm the car up, I'm not crazy! I do take the car to run errands and such a few times a week and occasionally take it out on the highway to keep the engine exercised. It's important to run the engine long enough to ensure that ALL of the fluids (oil included) reach operating temperature on a routine basis to drive off moisture and to allow the engine to operate at full temperature. The engine oil temperature will lag behind the coolant temperature, so don't be fooled into thinking that everything is at operating temperature just because the water jacket is. With 7-8 quarts of oil running around inside the engine, it'll take a while after the water jacket reaches temp for the oil to reach temp.

If the car is sluggish when cold, consider changing to a 5W-40 synthetic oil, it'll help in colder weather since it'll be thinner when cold and the synthetics are "slippery" in general. All IDI diesels will be a little grumpy when cold since the fuel isn't vaporizing properly in the prechambers. 5 minutes is a little long to idle in the morning, you might consider shortening it up to 2-3 minutes then just drive the car. Don't rev it hard until the temperature comes up on the gauge and you'll be fine. Look into your local ordinances regarding idling vehicles, some northern states have laws against it.

vwnate1 · #78 01-11-2018, 12:59 AM

Wow, that makes two of us here, with the fat heads......

.

The 5w - 40 fully synthetic oil is very smart, make sure it's DIESEL RATED .

You'll notice the engine cranks over faster and starts quicker with this oil .

Diseasel300 · #79 01-11-2018, 09:34 AM

Quote:

Originally Posted by vwnate1

You'll notice the engine cranks over faster and starts quicker with this oil .

I've noticed that the turbo spools a lot quicker in mine running 5w-40 synthetic too. I don't run it though because with the leaking turbo seal, it sucks it down like a sailor going through rum on shore leave!

vwnate1 · #80 01-11-2018, 09:48 AM

I bet it trails a thin blue smoke out the exhaust too......

? Guess how I know this ?

.

I overhauled the turbo my self, it's fiddly to the extreme but not terribly hard, I used a Kent Bergsma (? SP ?) kit from Mercedesssource in Wa. State, a rebuilt turbo is about $350 last time i checked .

My Son (also a Mechanic) told me they're pretty simple so I decided to ty it my ownself, getting to some of the bolts was tricky but it's all do - able in DIY .

Some fractional fasteners on the turbo proper and head scratching trying to figure out how to reach some obscure 17MM nuts .

Diseasel300 · #81 01-11-2018, 10:21 AM

At idle and low RPM's, you don't even notice the smoke, but romp on it and you notice! I used the Kent Bergsma kit on mine too, but the wear on the shaft seal lands is such that it's just a bit on the wore-out side. It dramatically reduced the leakage, but still leaks. Need to send it off for a proper rebuild, just been cheap and lazy.

300Drestoration · #82 01-11-2018, 12:07 PM

Ummmmmmm... "diesel rated" ???

I did a full change in early november and I put in "Mobile 1 10W-40 High Mileage" which seems to be a rather widely acclaimed oil for these vehicles...

vwnate1 · #83 01-11-2018, 12:10 PM

Yes, Diesel rated oils .

Most but not all are clearly marked ~ they have increased anti scuff additives and so are good for older old tech engines too .

When I bought my turbo overhaul kit I bought the new shaft & impeller too as I specifically worried about just your problem .

The pulling hooks he gives are crap and don't work .

I used a set of $12 Chinese ones I bought a while back and they worked fine .

Diseasel300 · #84 01-11-2018, 05:14 PM

Quote:

Originally Posted by 300Drestoration

Ummmmmmm... "diesel rated" ???

I did a full change in early november and I put in "Mobile 1 10W-40 High Mileage" which seems to be a rather widely acclaimed oil for these vehicles...

"Diesel Rated" indeed. Oil formulated for gasoline engines can't keep the soot suspended in the oil. Diesel rated oils usually will say so on the jug, currently I think the specification is "CJ-4". Diesel oils have extra pressure additives and different detergent packages from gasoline oils to help suspend the soot load and deal with the increased pressures present in diesel engines.

If you didn't use a diesel-rated oil when you did your oil change, it would be a good idea to change it out sooner rather than later. It won't hurt the engine to run it, but I wouldn't wait for a 3-5000 mile oil change interval.

vwnate1 · #85 01-12-2018, 10:49 AM

IIRC, the problem there is : he's in NYC doing curbstone DIY repairs, in JANUARY so maybe let the HOT oil & filter change slide a while, non ? .

I grew up doing that, there and lemme tell ya, it ain't fun .

300Drestoration · #86 01-18-2018, 02:37 PM

I feel like i have some good news.

I've sorta tracked down the biggest offender of the exhaust smell in cabin.

If i put a large pillow down under where the passengers feet go, and make sure it's really sealing all edges around it towards the firewall, the exhaust smell is completely gone, so far. I drove for around 15 minutes and smelled nothing.

So, this makes me think that indeed the grommet(s) between firewall and cabin/dash are problematic. Or if not, then there is some sort of other leak.

I have not tested yet the result of turning on the HVAC with that pillow still in place down there. Im assuming it will bring in its own exhaust smell but not the same way that the leak in firewall brings it in.

When i test again and i do go and switch on the HVAC and i DO get some exhaust smell, I guess the confusing thing will be.. is the HVAC pulling exhaust from the firewall leak and sending it out through all the HVAC vents? Or is it simply pumping some fumes from the outside nearby engine air.

If for some reason when i switch the HVAC on and i DON'T get any exhaust smell, then my circumstance is different yet again, and i'm dealing with just a firewall/grommet issue.

So, backing up here... How elaborate is it to replace that grommet? Assuming it's not super pricey i can put in a new one. I could pull it from my parts car though. I'm keeping that sucker. I took it off insurance. To hell with the township. Its behind another car in the driveway so it'll hopefully go undetected for a few months at least.

And further.. If changing the grommet doesn't do the job, then what else might it be? I guess i just have to take it one step at a time.

One exciting thing is that today i just received an endoscope in the mail. It is a rigid cable inspection camera that allows me to put it anywhere in the engine bay that i choose and get a live HD visual with adjustable led lighting. Only 40$! So i think i'll go ahead and run the vehicle and put it down around the downpipe and rear of turbo to see what's going on and to see if there is an obvious crack or leak somewhere. I can upload the footage as well.

Diseasel300 · #87 01-18-2018, 03:52 PM

I'd be finding the source of the exhaust leak and fixing that first. The fact you can see exhaust smoke coming up the firewall says that even if you fix that grommet, you'll continue to have issues with exhaust intrusion into the cabin. You should only be getting exhaust out the end of the tailpipe....nowhere else!

300Drestoration · #88 01-18-2018, 04:18 PM

Quote:

Originally Posted by Diseasel300

I'd be finding the source of the exhaust leak and fixing that first. The fact you can see exhaust smoke coming up the firewall says that even if you fix that grommet, you'll continue to have issues with exhaust intrusion into the cabin. You should only be getting exhaust out the end of the tailpipe....nowhere else!

Correct, agreed. I am close to assuming it is the downpipe, and will be making moves soon on that when i narrow it down.
BUT, i'm still going to address the cabin leak. Why would i not? If anything, this is the perfect opportunity to properly seal off the issue because right now, and only right now, while my issue is occurring inside the engine bay, i can test it.

I am able to tell if a repair works. Where as after the source is fixed, i will not be able to test to see if the repair has worked.

I like the idea of sealing off the firewall as it was designed. Surely other issues in engine bay may/will crop up over the next few years. So why not have it not impact my health when they do.

Diseasel300 · #89 01-18-2018, 07:16 PM

There's nothing wrong with fixing what isn't right, but don't get hung up on making it airtight. There are plenty of other places for engine-bay air to come wafting into the cabin. The cabin area is not "sealed", those grommets are there primarily to protect wiring and hoses passing through the firewall. The seal they provide is secondary to their function and is a convenience. Once you get the heater running, you'll be sucking in the exhaust that's leaking up the firewall anyway!

300Drestoration · #90 01-18-2018, 07:22 PM

Quote:

Originally Posted by Diseasel300

There's nothing wrong with fixing what isn't right, but don't get hung up on making it airtight. There are plenty of other places for engine-bay air to come wafting into the cabin. The cabin area is not "sealed", those grommets are there primarily to protect wiring and hoses passing through the firewall. The seal they provide is secondary to their function and is a convenience. Once you get the heater running, you'll be sucking in the exhaust that's leaking up the firewall anyway!

I was actually going to ask that next.. how exactly does the heater source it's air and how does it heat it? Does it depend on the engine being at full operating temp before the heat can be..hot?
My heater works great when the car has been running for quite some time. But forget having hot air until at least 10 or 15 minutes of driving. I've been avoiding turning on the heat though, assuming that it was the mean way for the problematic exhaust to be pulled into the cabin. I may try running it again though, to see if it's not so bad.
I guess the reality though is that it's some of each.. the cabin leaks, and then the heat. Both pulling in the problem which is the problem to address to begin with.
But still, it helps me to mechanically understand how the heat works.