83 240D Howling at startup.
 

Looked around for anything on this topic, found nothing.
When I start my 240D, it fires up, runs for second or two, then makes a "howling" type noise. Just once. Then the noise stops, doesn't happen again (until next startup) then runs normally. Just one "howl" (not sure how to describe it).
Wondered if any members experienced anything similar or might know where or what the noise is? BTW, this happens when the car isn't moving. Before it's in gear and rolling. As mentioned, one "howl" and that's it.

Could be a loose belt to the alternator. When the battery is drained to start, the alternator is under high load for a bit to recharge it. Once the alternator is up to speed and battery charges a bit, the load drops and belt stops slipping.

Check for loose starter bolts.

Thanks for the tips. Alternator belt is new and tight. Battery is fully charged. I'll check the starter motor bolts, but the "howl" seems to happen after the starter has "done it's thing" and is completely out of the picture, so to speak.
Odd noise for sure. I've never heard anything quite like this noise.
My worst fear is that it involves the vacuum pump. Although, that unit pulled a nice steady 20psi on the gauge when I checked it.

Maybe catch a video clip and upload to YouTube to show what it's doing? Are you sure it isn't the overrun clutch on the starter howling?

I've had this happen with starters that have worn bushings and / or when the " plastic washer on the commutator side that acts as a friction brake when the starter drive isn't engaged so the armature does not spin down forever " gets covered in brush dust / oil and causes a chatter. The effect is similar to a clutch / brake lining that has thick sticky dry grease on it.

Thanks for the starter info. I'll have to pull it and thoroughly check it out. Recent purchase. Cars been sitting a few years. 200K on the odometer. Not much info available from seller. Belonged to a father and the "kids" were selling it. Seems fairly well taken care of. Starts right up, no smoke cold or when driving. Not a cream puff, needs a bunch of tlc. Been lookin for something like this (older Mercedes) for a while. My 1st diesel. Paid $900. Havin a ball!!

123:

Before rushing into any parts removal, consider having another person perform the behind-the-wheel starting operations, while you listen around the engine for a few start cycles. By listening from different places, you may be able to determine the locus of the "howl". Candidates are: alternator, steering pump, water pump, starter motor, A/C compressor clutch bearing, and (if manual transmission) throwout bearing.

Whenever I get a car with miles / time I always pull the starter / alternator and take them apart for inspection / brush - bearing replacement / lube. This minimizes surprises down the road.

Given the car was sitting for a while, the starter drive / solenoid might be slow to retract causing the noise.

Once again, excellent advice from all and thanks to all for responding. Noise seems to be coming from the general vicinity of the starter. Maybe the simplest test would be to remove all 3 belts and fire it up? No "howl", gotta be a belt driven accessory.....easy enough to narrow down from there. No belts and a "howl", pull the starter.
Also neglected to mention, I've driven the car a "fair" amount since purchase. Nothing too crazy, around the neighborhood, after doing various maintenance procedures. No noises, no howls. Just the one howl on each and every startup. Burned about a quarter tank of fuel all in all.
I'm likin the "starter theory" more and more.....
Thanks again. New here and this forum is really great! You guys have been a big help. Gettin ready to adjust the valves......

Any progress on this issue?

Thanks for checking back with me. Life keeps gettin in the way of my newfound love and passion......an 83 240D lol!
Hope to "sort it out" in the next couple days. I'll definitely post my results.
This is a great community. Really. Can't tell you how much I appreciate you following up.
Also, absolutely, cannot believe how hard I've "fallen" for this car. Kinda scary..haha.
Probably a few folks on here that can relate?

Wanted to give a quick update about the "howling" (some might say it sounds more like a "quack"). Anyway, got a lot of irons in the fire with this 240D right now. A glow plug issue just reared its ugly head a couple months before the northeast winter settles in. Tires and brakes are "in the works".
The "howling" seems to have disappeared....for now. Never pulled the starter (checked bolts for torque) and tightened belts.
I did have the glow plugs out and checked them with the glow plug relay/system, 2 out of 4 inoperative (glow plug light was working, then quit suddenly). A new batch of Bosch are on the way. Doubt that could make any difference in the "noise"...but, ya never know.
Def wanna pull the starter, check the bendix, etc. clean and lube and also pull the alternator for inspection/basic maintenance. Oh yeah, and a valve adjustment, of course!
Gotta get ahead of these other basic issues before I look for the "quack". Appreciate the responses and I'll keep updating as the work progresses (if anyone gives a crap...lol) Unfortunately, gotta work for a living, too (who doesn't?...sure does cut into my Benz time)
Plan on using the car to commute to work (about a 30 mile round trip). I work a 4/10's shift, so 16 days/month. Fantasizing about using about a tank of fuel per month to my job and back. That would be super cool...heh heh.
Thanks guys (and gals?)....PC, now....thanks people! Ya'll are the BEST!!

few tips:

get a reamer and ream the carbon in the prechamber. excessive carbon can cause premature failure and seize the plug in the prechamber

check the glow plug relay that it puts out 12V on all relay pins and check the wiring from the relay to the plugs for continuity

starter bolts on diesels can be very tight.

Well, the howl (quack, squawk, honk, etc) is back. Just one "honk" on startup only. Then no more while driving or anything else with the engine running. New set of Bosch glow plugs today.
Glow system is working great! Car starting and idling great, too. Had some set backs with "normal life" last few weeks. Gonna go after the "squawk" with a vengeance, now.
If I can figure out how to do it, I'll take a video on startup, capture the sound and post it here. That's a big "if"....

Another Newbie
 

WELCOME TO THE ASYLUM ! .

It's fairly simple to take the starter apart, clean and lubricate it they rarely need more than new brushes and maybe the commutator end bushing, *do* order in the brushes and replace them whist it's all apart .

These are not speedy cars but amazingly good to drive and wonderful in Winter, you'll see see .

I love my '82 240D above my Coupe and gray market wagon .

4/10 ~ ? LEO ? .

My w210 kinda did something like this. Turned out to be the exhaust manifold bolts backing out just enough to have a gap when cold then sealed when warmed up.

Thanks, vwnate and speednjay. Appreciate the insight. Gonna go after the starter tomorrow and will check the exhaust manifold bolts, while I'm at it!
Really looking forward to seeing how this car behaves in the coming winter!

Nate, or anyone else, have the part numbers for starter brushes, commutator end bushing and any other expendables?

Enigma of the "howl, squawk, honk" has been solved
 

Great day for my 240D (small victory).....I seemed to have "solved" the problem of the strange howl on every startup. Thanks for guidance and input on this forum! Taking the advice of the members, here, I began to narrow it down, removed the drive belts one by one, starting the car each time, and the "noise" persisted. Next step was the starter.
That was fun and a great learning experience! Amazingly secure installation and a testament to how well made and over-engineered these cars really are. Incredibly solid mounting design!
Anyhow..got the starter on the bench and began to look it over. Actuated the starter with battery cables and it worked fine, NO NOISE :>( Didn't want to do a complete disassembly as the unit was starting the engine with no trouble and I've got some bigger fish to fry with this car. Pulled the bearing cap off the "brushes end" of the motor and it was dry as a bone in there. Put a little oil on the shaft/bearing area, cleaned out what was left of the old, dry grease, reconditioned the rubber seal, put some fresh grease in the cup and "closed her up". Ditto the other end, where the bendix gear is. Lots of red oxide colored dust on this end. Cleaned everything up, lubricated with oil. Removed the solenoid (2 of the 3 M5 fasteners that hold the solenoid together were missing) and found a bunch of "red" dust in there as well. Cleaned that out, polished the solenoid piston and bore (gently, no scratches). Put that back together (with new fasteners for solenoid) and polished ALL the grounding locations (engine, bracket, starter, nuts/washers, wire terminations, etc). There are quite a few if one considers them all!
Got it all back together, polished and clean, and now, the moment of truth.......NO NOISE on startup!! Have cycled the starter a bunch of times since and it's still nice and quiet. Working better than it did before, too. Now that I've been to school on 240D starter removal and installation, I'll get back in there (if and when need be) at some point and do a thorough overhaul.
Thanks again for all the input, suggestions and guidance from all the members who responded.
On to valve adjustment!!

1982 240D Starter Parts
 

O.K. ~ I'm far from my ECHLIN (good stuff, often EOM) catalogs and I don't have any BOSCH parts catalogs but here goes :

Starter brushes : STANDARD MOTOR PRODUCTS GB2008 {#0001515914, 1515914} Intermotor; Direct OE Replacement; Package Quantity: 4 Brushes Info
(Only 3 Remaining)

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Part image
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$22.89
Add to Cart
WVE/AIRTEX/WELLS 5A1167 {#0001515914, 01001515914, FAX129} Info
(Only 2 Remaining)

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Part image
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$26.79
Add to Cart
ACDELCO E733A {#89057174} Professional Info

Commutator end bushing : STANDARD MOTOR PRODUCTS X5413 {Click Info Button for Alternate/OEM Part Numbers} Intermotor; DE Starter Bushing;Outer Diameter (O.D.) - Inches: .634";Material: Brass; Length - Inches: .627"; Inner Diameter (I.D.) - Inches: .474" Info
OE No. 0031510701; Drive End (Only 4 Remaining)

Part image
$1.98
Add to Cart
STANDARD MOTOR PRODUCTS X5436 {#0001513550, 1513550} Intermotor; Direct OE Replacement; Material: Copper Info
OE No. 0031510701; Commutator End

Part image
$2.75
Add to Cart
WVE/AIRTEX/WELLS 7D1136 {#5434B} Info
Commutator End

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Part image
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$6.63
Add to Cart
ACDELCO E1627 {#19113677} Professional Info
OE No. 0031510701; Commutator End

Solenoid : BOSCH 31035 SOLENOID Info
OEM NO=0 331 402 001

$46.79
Add to Cart
WVE/AIRTEX/WELLS 1M1181 {#0001523010, 88923057, SS851} Info
(Only 2 Remaining)

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Part image
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$68.99
Add to Cart
STANDARD MOTOR PRODUCTS SS277 {Click Info Button for Alternate/OEM Part Numbers} Intermotor Info

Drive / Bendix : STANDARD MOTOR PRODUCTS SDN305 {#0001519613, 1519613} Intermotor; Number of Gear Teeth: 9 Info

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Part image
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$50.89
Add to Cart
ACDELCO E2063 {#19113446} Professional Info

I hope this is helpful .

90 + % of the time all you needs do is take it apart clean and grease (not oil) well, replace the brushes and solenoid every time even if you think they're O.K. .

Another poster stated Bosch DOES NOT recommend grease, but oil. Was why I just used a little oil, quite sparingly. I'd like to get that info "sorted out", too.

Found the post from the member that stated "Bosch recommends oil, not grease". If you've seen other posts from this member, it's pretty obvious he "knows his stuff". It's about the 5th post in, where he's putting the armature back in.....I believe.
http://www.peachparts.com/shopforum/diesel-discussion/293895-om617-starter-motor-life-not-just-christmas.html

A bronze bushing or bearing should NEVER EVER see grease. You'll ruin it in very short order. Oil only, and non-detergent oil at that. The bearing is porous and "sweats" the oil onto the bearing surfaces. Grease will very quickly form a varnish which clogs the pores and ruins the bearing, quickly leading to squealing and seizure. Grease is for ball/roller bearings. Oil is for sintered bushings and sleeve bearings. This is universal, not specific to Bosch or starter motors by the way.

20? Not sure science is ready for more than atmospheric yet ...

Thanks diseasel, appreciate that. Are you also saying there should be NO grease in cup at the back of the starter, either? There was remnants of old grease in there when I opened it up.....

What looked like grease was more or less brush dust and some oil that had leached out of the bushing.

^^^This.^^^

Even the oil will turn to sludge with age, usually by that time, the rest of the motor is pretty tired. Electric motors used to come with oil cups that you added several drops of oil to every year. Kept lubricated, they'd last for decades running 24/7/365. Modern motors are cheap and deleted the cups with "oiled for life" bearings that usually have little more than a vapor deposit of oil in them from the factory.

Correction
 

Thanl you for the detailed link .

I didn't realize they are oil lite bushings .

They're supposed to be soaked in oil .

? What oil to use ? . maybe "Zoom Spout" ? .

Some of my old Mercedes starters might even be the originals. Even if not they have been in the cars a long time. The porous bearings seem to hold enough lubricant for decades. Or if it has been dissipated the bushing material itself might stand up for quite some time unlubricated. The length of a starter cycle is not long enough to build much friction heat.


I do not suspect other than a good petroleum based medium weight viscosity oil would make much difference. I did wonder if soaking them in oil might be a good ideal before installing them though. As well. They may come partially pre soaked as well.

Starter Life
 

And therein lies the rub :

Many (? most ?) don't take the time and effort to maintain their vehicles so the starter only runs a second or two, tjis of course means it gets hot and so wears faster....

I see then grinding away and wonder why ? .

Zoom Spout oil is an excellent oil for bearings/bushings. It's light enough to impregnate the pores in the bearing and saturate the wicking (if it has any) but heavy enough and with enough paraffin content to maintain a lubricating layer on the surface of the bearing.

Hmmm, solenoid too?

My starter does a chirp (and doesn't turn over) roughly every 20 times I crank.
But it used to be every 50 times, then 40, etc.

I'm not sure what causes that sound... would love not to throw parts at it, but something is definitely up down there. Brushes and a cleaning were as far as I had gotten.

What are the symptoms of a failing solenoid? Or even brushes for that matter?

Sometimes a worn starter ring gear or starter pinion gear will cause this. Engines tend to stop on a compression stroke and as a result tend to chew ring gears in specific locations. A 4 cyl will have 2, a 6 will have 3 and 8 will have 4. Rotate the engine and inspect the ring gear.

All cars and especially older neglected cars maintenance wise really benefit from a serious maintenance run. For example I wish I had a dollar for every year all the door hinges on all of the old 123s have never seen a shot of grease. It speaks volumes for the design of those door hinges that we are not dealing with serious wear issues with them now.

Neglect in oiling the hood hinges is another favorite. It can become a repair job I was not thrilled with when one side broke out at the very back point.

Dry window regulator systems probably cost motors. Periodic lubrication of the window channels as well should not be neglected. The list goes on and on.

The throttle linkages are actually designed for periodic attention but get little in the majority of cases. This is easy stuff to do and you build up a variety of lubricants over time. Neglecting to lubricate the sunroof is not a good ideal either. You do the cable as well.

It may or may not be in the mind. Knowing that you have attended to all the 30 to 40year old places and got them lubricated again. It makes the car feel better to you usually.

Perhaps it is a form of bonding as well. In the process you probably also learn more about lubricants and their specific applications. I know I have a shelf full of all types of specific lubricants and do not have them all. Even door and ignition locks get ignored all too often.

I just got through explaining to the wife that the keys hanging off the end of her ignition key case. Are hard on the the ignition key tumbler because of the leverage. On her new used car. Did it work? No.

I was then on the verge of explaining this had also killed a lot of people with GM cars. When the first discussion did not work. Then decided it was too early this morning to be reminded the car was not their product.

Is this a gear that's part of the starter? Or the gear that's part of the engine?
Having a little difficultly with terminology...

The ring gear is usually heat shrunk to the flywheel or a part of the flexplate. They have historically been changeable on flywheels.

Zoom Spout Oiler
 

Thanx ~ I've been using it when I service HVAC blowers already .

No problem, sometimes there are many terms for a particular part.

The large diameter gear that tends to wear in a couple of specific spots is the ring gear / flywheel gear ( on a manual trans car ) / Flex plate ( many auto trans cars ) / starter ring gear ( not part of the actual starter motor )

This ring gear is generally replacable on a manual trans car. Race cars tend to have the teeth cut directly into the flywheel. The ring gear on an auto trans flex plate is welded to the flex plate and generally replaced as an assembly

The small gear that meshes with the above gear is a starter motor pinion gear / starter drive / " Bendix " ( an old brand name applied like Kleenex / Band Aid / Xerox )

Fortunately ring gear wear failure on this vintage of diesel Mercedes is very uncommon. Even though by now many have exceeded their design requirements and expectations. I never remember a case posted. Flexplate failures do fail on them sometimes though.

Seems then I have a flywheel gear (i.e. manual trans).

This is beginning to sound like a large service item...

In order of operations, I take it removing the starter for a
1.) cleaning/re-oiling
2.) replacement of brushes
3.) possibly the commutator end bushing
4.) solenoid
5.) check flywheel gear and or starter bendix for missing teeth.

Your issue sounds more like the yoke binding or the pinion gear/bendix seizing on the shaft instead of sliding freely.

A failing solenoid typically makes the "clunk" but nothing else happens. No starter motor operation at all.

Worn/failing brushes typically does nothing at all unless you whack the motor with a hammer. The solenoid grounds through the brushes, so if they don't make contact with the commutator then the solenoid has no ground path and won't pull in.

The old Presolite starter on our test generator at work does what yours is doing from time to time. It was the pinion/bendix assembly sticking on the shaft and failing to engage the ring gear. We tore it down and repaired it several times, but once they gall the metal you're kinda screwed. Finally opted for a rebuilt and never had a problem since.

Thanks for that - found a solenoid for $10, brushes for about the same.
Worth a shot before anything more drastic.