W123 300d Lost All Oil On Road Trip - PeachParts Mercedes-Benz Forum

SonnyMorrow · #1 09-08-2018, 12:43 PM

I'm pretty bummed to be writing this, but as I was driving from Northern California to Oakland my Benz began acting strange about 60 miles into the trip. At one point the car stalled on the highway, but started right back up. I figured the primary fuel filter was clogged, no big deal I thought. I navigated to an auto part store thinking I could buy a new fuel filter and simply replace it and be on my way.

As I came off the highway I was sitting at a stoplight and I heard the turbocharger make a horrendous noise as if somebody jammed something in it. I thought maybe the air filter was completely clogged or something which would explain the stalling on the highway etc. I didn't find out what was actually happening to my car until I arrived about a block later in the parking lot of the auto part store.

Oil was absolutely everywhere when I popped the hood! At that point the engine started knocking significantly so I hit the stop lever as fast as I could, realizing the engine had little to no oil left in it. It was at that moment when I knew the engine was toast, and it was indeed not a simple fix such as replacing the fuel or air filter. I ended up renting a car in order to continue on with my plans and left the 300d in the parking lot for the next few days. Eventually I got it towed to a friends house in Sacramento where we did a quick autopsy.

Turns out the aftermarket "cold air intake" breather hose was kinked. This caused enough crank case pressure to the point where all of the engine's oil came out from the dipstick tube. Unbelievable.....

I checked the dipstick, and it had not a drop of oil on it. I then added 6 quarts of oil before starting the car up for the first time since the incident. The knocking was still present though it had quieted down now that it had oil again. I limped the car home about 60 miles north with no problems, (thankfully). The engine I'm sure is a ticking time bomb at this point, and I am not quite sure how long it has before it seizes up but here is a video of the engine I took today. It obviously doesn't run as good as it used to now that it has most likely spun a bearing. Maybe some of you with good mechanic ears can hear what I am talking about.

https://www.youtube.com/watch?v=ykUrLjkMSeY&t=2s

The compression was pretty low last time I checked (230-250 each cylinder), that being said it was sorta on its way out anyways. But still, I don't really want to deal with finding a replacement engine but that is what it is looking like I'll have to do.

Lesson learned, don't use any aftermarket junk on these properly engineered cars, you aren't going to outsmart the Germans of days past. There is absolutely no point in this sort of after market "cold air intake" system.

If anybody has a good compression Om617 sitting around in California please message me or post here.

Diseasel300 · #2 09-08-2018, 12:54 PM

Losing oil is a pretty major event on any vehicle. Was the low compression on this engine due to tight valves, or due to bottom end wear? How was the blow-by situation prior to the trip? Does your oil pressure gauge work? If so, did the oil pressure ever drop? If there was enough oil left in the engine to maintain oil pressure, you likely didn't spin any bearings. It may not come across in the video you posted, but I'm not hearing any knocking other than injector knock and an obviously shaky idle.

SonnyMorrow · #3 09-08-2018, 02:11 PM

Quote:

Originally Posted by Diseasel300

Losing oil is a pretty major event on any vehicle. Was the low compression on this engine due to tight valves, or due to bottom end wear? How was the blow-by situation prior to the trip? Does your oil pressure gauge work? If so, did the oil pressure ever drop? If there was enough oil left in the engine to maintain oil pressure, you likely didn't spin any bearings. It may not come across in the video you posted, but I'm not hearing any knocking other than injector knock and an obviously shaky idle.

The low compression on this engine is from piston ring wear. I checked the compression about 6 months ago after a valve adjustment. Each cylinder was around 230-250, I also added oil to each cylinder and rechecked. The compression went up to around 400 on each cylinder. Consequently, the blowby has been pretty heavy the past few years.

Yes the oil pressure gauge works, though I did not notice the pressure ever drop during the incident. Which makes sense as there wasn't a "hole", so to speak, in the oil system such as a ruptured oil cooler line or whatever.

What you said may be true about the bearings being okay. However the engine has a different noise than it used to. On deceleration you can hear a distinct metallic noise, which is somewhat present in the video but more audible in person. Never in my years of owning this vehicle have I heard it make that noise. Just based on the fact that the engine was knocking very significantly before I initially shut it off doesn't seem too promising.

Diseasel300 · #4 09-08-2018, 02:22 PM

If the low compression is from piston ring wear, it's not really worth fixing up unless it has some significant value to you for some reason. If you're the curious type, it may be something worth tearing down and doing a post-mortem when you find a replacement. That's what I'd do, though I'd probably then try to resurrect it because I'm a glutton for punishment.

jake12tech · #5 09-08-2018, 05:59 PM

Save yourself the work and get a new motor and keep a few old parts off the old engine and scrap it. Too expensive and time consuming to fix these engines and take them apart.

SirNik84 · #6 09-09-2018, 01:25 AM

I sympathize with you. I had something similar happen years ago, only it was my oil feed line that cracked and let all my oil out on my way home from LA. I made it to Stockton. My engine was also low on compression so when it let out its oil I figured it was just asking for a new engine. I got an engine from a wrecker in Berkeley. I still have that engine today.

I used car-part.com to find the engine.

gottarollwithit · #7 09-09-2018, 01:49 AM

Just run it the way it is. Might not be nearly as bad as you think. These motors are the epitome of tough and it might surprise you by running a good bit longer.

Just because oil isn't on the dipstick does not mean that oil inside is nonexistant.

Have you changed your oil/filter yet?? Is there a bunch of metal in your oil?? In the mean time, while it is still working, figure out where to get a motor if you end up needing it. Garrett up in Sac is pretty resourceful...

mabbonizio · #8 09-09-2018, 10:00 AM

Quote:

Originally Posted by gottarollwithit

Just run it the way it is. Might not be nearly as bad as you think. These motors are the epitome of tough and it might surprise you by running a good bit longer.

Just because oil isn't on the dipstick does not mean that oil inside is nonexistant.

Have you changed your oil/filter yet?? Is there a bunch of metal in your oil?? In the mean time, while it is still working, figure out where to get a motor if you end up needing it. Garrett up in Sac is pretty resourceful...

this, I would run it while sourcing a new motor. It may surprise you and run for a good long time..

Diesel911 · #9 09-09-2018, 10:51 AM

Remove the little Oil pan and look inside and see if here is metal fragments that would indicated a bad bearing.

97 SL320 · #10 09-09-2018, 11:16 AM

Quote:

Originally Posted by SonnyMorrow

The low compression on this engine is from piston ring wear. I checked the compression about 6 months ago after a valve adjustment. Each cylinder was around 230-250, I also added oil to each cylinder and rechecked. The compression went up to around 400 on each cylinder. Consequently, the blowby has been pretty heavy the past few years.

Was this car primarily 'round town transport and this long trip something recent?

What were the speeds and loads on this trip? ( Constant higher speed highway driving or just a longer round town trip? )

Have a look at bottom of this post for an article in an automotive trade magazine about a Toyota that lost oil on a trip. While not a 100% direct comparison to a worn out low compression engine, the 33,000 mile Toyota was in seemingly good condition and consumed all of it's oil in 2,000 miles.

Quote:

Originally Posted by SonnyMorrow

Yes the oil pressure gauge works, though I did not notice the pressure ever drop during the incident. Which makes sense as there wasn't a "hole", so to speak, in the oil system such as a ruptured oil cooler line or whatever.

A sudden loss of oil pressure is actually preferable in terms of making a repair over a slow loss of oil. Sudden loss of oil pressure first affects rod bearings causing the engine to quickly seize / knock where a slow loss causes all parts to suffer reduced lubrication over a longer period of time.

I've repaired engines that had a sudden loss of oil with a crankshaft polish and bearing replacement. Engines that were chronically run low on oil suffer cylinder wall and upper valve train damage making the engine not worth repairing.

Quote:

Originally Posted by SonnyMorrow

What you said may be true about the bearings being okay. However the engine has a different noise than it used to. On deceleration you can hear a distinct metallic noise, which is somewhat present in the video but more audible in person.

The only real way to know is to pull the oil pan and inspect bearings, all else is a guess given loss of oil. Running it longer ( with oil replaced ) diminishes chances of repairing this engine.

Quote:

Originally Posted by SonnyMorrow

Never in my years of owning this vehicle have I heard it make that noise. Just based on the fact that the engine was knocking very significantly before I initially shut it off doesn't seem too promising.

When ever engine friction exceeds the power it can make, the engine is severely damaged.

This engine was in extremely poor shape prior to the trip so your losses are minimal at this point.

( Link to full article )

https://www.motor.com/magazine-summary/dealing-with-oil-consumption-issues-march-2014/

Quote:

2 Engine Oil Gone M.I.A.

This case involved a 2002 Corolla with the familiar 1ZZ-FE engine. The car was owned since new by an older gentleman who drove it only to and from his teaching job at a local university. His wife did all the shopping in her own car, which they also used for all their social engagements and family trips. Reaching retirement age, he decided to relocate across the country to the West Coast and sent his wife ahead.

He brought his car to a local shop for an oil change and a trip-check. The odometer at the time showed about 32,400 miles. Everything seemed to be shipshape. About a week later, he set off in his Corolla, fully loaded with stuff not previously moved. The first two and a half days of his trip passed uneventfully.

Then, somewhere in the Badlands of South Dakota, the oil warning light came on, and the engine made a noise “like a threshing machine.” Undeterred, the man pushed on until the engine seized a mile or two later. He was towed to the nearest Toyota dealership. When the drain plug was removed, no appreciable oil came out, although the oil filter was still full. Examination of the tailpipe showed some oily black sootlike deposits.

I was hired as an expert witness after the man filed suit claiming that the local technician had drained the oil but failed to replenish it. The claim was obviously false, since he had by then driven over 1900 miles before the failure, and since the filter was full of clean-looking oil. But the questions remained: What happened to that oil? Why would a car that had never used oil in the past suddenly consume nearly four quarts in less than 2000 miles?

The answer lay in the sudden change of driv*ing style. Here’s what I believe happened:

( My note: basically, the piston rings got stuck in piston grooves causing them to be smaller and have reduced tension, this lowers compression )

During the man’s previous local driving, the upper reaches of the cylinder walls had accumulated a thin coating of varnish consisting of deposits of unburned gasoline, condensed PCV gases and other contaminants. These deposits were situated just above the upper piston ring, in the area “shadowed” by the top of the piston. On his trip, the first time in tens of thousands of miles that his engine had been thoroughly warmed up, the upper piston ring began to come into contact with some of these deposits. (Remember that metal expands with heat, allowing the relatively thin connecting rod to “stretch” just slightly relative to the height of the cylinder wall.) As the ring entered the previously untraveled portion of the top of the cylinder wall, it began to scrape off the varnishlike deposits. Some of these gooey accumulations landed on the top side of the upper ring. Compounding the problem, the ring was forced further than usual into its groove by the reduced effective diameter of the upper cylinder wall.

To achieve better fuel economy, Toyota, like virtually all modern carmakers, uses low-tension rings to reduce internal friction and wear. The upper ring now began to stick in its groove, glued in place by the scraped varnish. The engine still ran reasonably well at this point, but it was likely beginning to burn some oil. The rate of consumption was still fairly low, so there was no large smoke cloud visible to the driver.

Additional varnish deposits then began to accumulate as the top ring’s scraping action became increasingly ineffective. A small amount of varnish was then deposited on the upper surface of the second ring, leading to ever-increasing oil consumption. (Toyota, to its credit, apparently anticipated such a situation. In its Owner’s Manuals, it admonishes drivers to check the oil level at each refueling stop.)

This case, like most, never went to trial, and was settled by the local shop’s insurance company whose analysis was that a jury would likely ignore the facts and concentrate on compensating the “innocent” driver. Nevertheless, it raises a very real question: If (and it’s a big if) the driver had checked the oil, topped it up and brought it to you for diagnosis and repair after the oil had run low, how would you have proceeded?

Experience suggests that dramatic increases in oil consumption are moderately widespread. In most cases, vacuum waveform and compression readings are essentially uniform across all cylinders, and cylinder leakdown is not remarkable. In advanced cases, there may be some discoloration of the spark plug ceramic tips, but in most cases it, too, is minimal.

I find deposits on the oxygen sensors and in the tailpipe to be the most reliable marker. An upper-engine decarbonization treatment often helps, though it’s by no means a sure-fire cure. Still, it’s a valid first and maybe even second attempt, especially at a fraction of the price of a ring job (see “Upper Engine Decarbonization” on page 28).

This is one reason the 1950s fixation on low-mileage used cars is no longer appropriate. Give me a high-mileage used car every time; it at least knows how to go!

97 SL320 · #11 09-09-2018, 11:27 AM

Quote:

Originally Posted by SonnyMorrow

Turns out the aftermarket "cold air intake" breather hose was kinked. This caused enough crank case pressure to the point where all of the engine's oil came out from the dipstick tube. Unbelievable.....

Don't be so quick to blame the breather hose ( or the air intake ) . With your compression numbers being so low, loss of would have likely happened even if the hose was full flow.

Was the hose fully kinked to the point of zero flow or slightly restricted? In any event, if the oil didn't push out of the dipstick, it would have come out of the breather hose.

Quote:

Originally Posted by SonnyMorrow

https://www.youtube.com/watch?v=ykUrLjkMSeY&t=2s

Was the engine fully warmed up in this vid or just a cold start?

I've had majorly damaged engines be pretty quiet until the oil thinned out a bit.

The key is listen for a sharp noise when you first snap the throttle open then hold engine at 2,000 RPM and listen for a random rattle. High RPM is not needed or desired.

97 SL320 · #12 09-09-2018, 11:31 AM

Quote:

Originally Posted by SonnyMorrow

The low compression on this engine is from piston ring wear. I checked the compression about 6 months ago after a valve adjustment. Each cylinder was around 230-250, I also added oil to each cylinder and rechecked. The compression went up to around 400 on each cylinder. Consequently, the blowby has been pretty heavy the past few years.

Adding oil when testing compression isn't a valid test. The presence of oil in a high compression engine reduces cylinder volume / raises calculated compression ratio and will show an increase in measured compression.

And besides, with worn rings the cylinder walls are going to be heavily coated in oil already.

SonnyMorrow · #13 09-09-2018, 01:24 PM

Quote:

Originally Posted by gottarollwithit

Just run it the way it is. Might not be nearly as bad as you think. These motors are the epitome of tough and it might surprise you by running a good bit longer.

Just because oil isn't on the dipstick does not mean that oil inside is nonexistant.

Have you changed your oil/filter yet?? Is there a bunch of metal in your oil?? In the mean time, while it is still working, figure out where to get a motor if you end up needing it. Garrett up in Sac is pretty resourceful...

I mentioned I towed the car to a friend's house in my first post. Funny you mention Garrett, as it was his work-yard I towed it to. And he unfortunately doesn't have any engines at the moment but we are looking.

Quote:

Originally Posted by 97 SL320

Was this car primarily 'round town transport and this long trip something recent?

What were the speeds and loads on this trip? ( Constant higher speed highway driving or just a longer round town trip? )

Have a look at bottom of this post for an article in an automotive trade magazine about a Toyota that lost oil on a trip. While not a 100% direct comparison to a worn out low compression engine, the 33,000 mile Toyota was in seemingly good condition and consumed all of it's oil in 2,000 miles.

A sudden loss of oil pressure is actually preferable in terms of making a repair over a slow loss of oil. Sudden loss of oil pressure first affects rod bearings causing the engine to quickly seize / knock where a slow loss causes all parts to suffer reduced lubrication over a longer period of time.

I've repaired engines that had a sudden loss of oil with a crankshaft polish and bearing replacement. Engines that were chronically run low on oil suffer cylinder wall and upper valve train damage making the engine not worth repairng.

The only real way to know is to pull the oil pan and inspect bearings, all else is a guess given loss of oil. Running it longer ( with oil replaced ) diminishes chances of repairing this engine.

The thing is, I have taken this car many times on the same trip from Grass Valley to Oakland. And this being all via highway (75 mph) never did I have a problem. Garrett and I concluded that the breather hose was the main culprit. It was completely kinked when we inspected it (it is aftermarket and rubber so it was able to fully kink.)

I ended up not doing an oil change, but I added about 6 quarts of fresh oil. I'm not going to bother rebuilding or repairing this engine, so I will be running it the way it is now until it seizes up. And in the meantime I will be sourcing an engine from somewhere in California.

In the video I posted, the car was cold. With that being said, the noise does get a fair bit louder when warmed up. I'll post a video of the engine warmed up later today for the hell of it. But when driving the car, you can hear a metallic knock at high rpms on the highway and it doesn't sound good at all.

97 SL320 · #14 09-09-2018, 01:39 PM

Quote:

Originally Posted by SonnyMorrow

The thing is, I have taken this car many times on the same trip from Grass Valley to Oakland. And this being all via highway (75 mph) never did I have a problem. Garrett and I concluded that the breather hose was the main culprit. It was completely kinked when we inspected it (it is aftermarket and rubber so it was able to fully kink.)

OK, given the hose was completely kinked, that would throw oil out of the dipstick ( and any other weak point ) .

renaissanceman · #15 09-10-2018, 12:16 AM

What's the over-under for number of miles until seizing?