General Discussions

TE issues (aka, the dog)

Search This Thread

WA6VQP

2/11/2019 5:30 PM

Hello all!

OK, this is totally not an M-100 question, but you folks all have way to much experience with the MB marque for me not to try...

As I may have mentioned previously, I picked up an '88 TE in pretty nice shape, body wise, with some electrical issues and lack of maintenance, for a mere $300. Right away I nicknamed it "the dog."

Anyway, I got it home, got it new tires and battery, and thought it would work well enough to drive it to where I needed to get it fixed up.

I was wrong.

So, driving it to town, it died. At first the engine ran OK, but hesitated at moderate (30-40 MPH) speeds. The it just up and died. Got it towed home, and finally got to putzing with it this past weekend. When I try starting it, it cranks, tries to fire, and sometimes seems to backfire a bit, but no joy.

I checked fuel flow to the fuel distributor. Lots of gas there, so fuel pump and filter seem OK.

A curious thing, however: After trying to start the car, the headlights and front running lights flash for about a minute, then stop. The battery is definitely OK (it's new, and I've measured the voltage, all is well). I'm thinking that somehow this might be related, though for the life of me I cannot say why.

Any ideas???

Thanks!

Jim

1979 450SEL 6.9 (Black/Safran)
1987 560SL (Red/Palomino)
and now, 1988 300TE (White/Tan)

Driven with "old man" sheepskin covers!

FEMA

2/11/2019 9:34 PM

Jim, so right now the car just starts and dies as you described? Are there any other symptoms you can think of?

Francis E. Abate

ctmaher

2/11/2019 9:55 PM

Crank sensor? That would explain the no start, but the lights issue, not so sure it's related, unless you have a power supply issue.

Chris

WA6VQP

2/12/2019 12:13 PM

Thanks for the replies...

OK, I unhooked the box that was clicking, and it says "Becker" on it. I'm guessing it might be some kind of alarm module. I'm going to check it out and see what I can find. The radio in the car is gone, so it may be that the alarm module is responding to that. Who can say? Nonetheless, I suspect this has nothing to do with the engine issues.

Chris: Thanks for the tip on the crank sensor. Anyone know how to verify whether that works correctly without simply replacing it? How hard is it to get to?

I'm going to spend some time later combing the InterWeb for schematics and service info. I'll keep everyone posted as I progress.

The dog shall live again!

Regards,
Jim

1979 450SEL 6.9 (Black/Safran)
1987 560SL (Red/Palomino)
and now, 1988 300TE (White/Tan)

Driven with "old man" sheepskin covers!

ctmaher

2/12/2019 9:40 PM

Jim, the Becker module is in fact the anti theft alarm module. That is most likely what is causing your flashing lights issue. They were prone to getting flaky and causing false activations....usually one of the door lock switches would be the culprit, but most folks simply unplugged the module.

The crank sensor should not be too hard to replace on an M103 compared to a V8, it's at the rear left of the engine where the transmission bellhousing meets the engine. Best way to test would be with a scope, as it generates an AC sine wave. You can test resistance at the connector that plugs into EZL, I believe it should be about 800 ohms. They tend to fail with heat, so on a cold engine they work, and after it warms up they fail. Very common failure item, I'd be 90% certain that is your problem. The other part that can fail and cause a stall like that is a bad fuel pump relay, but sounds like you are getting good fuel supply.

Chris

Ron B

2/13/2019 4:43 AM

Hmmm... OK, it was running ,then stopped. The alarm module is working as it should so that is not your problem. Make sure you have at least 11.9 Volts to the main connector from the battery. Check that it's clean. Is the fuel pump working? A dud relay is such a common problem that to get the car going it's a simple matter to remove the relay,connect terminal 87 to 50 with a piece of wire and you should here the pump run. If it's not running,replace it and the filter. try again
If the pumps running the car should start. ( if this car has sat around for a while,I am picking it's the old pump, dirty filter and old fuel scenario)

Check for adequate spark by pulling a lead,stick a plug into it and crank the engine over. it should click audibly as the spark jumps.
If not,remove the distributor cover and see how much oil has leaked into there .
They all leak and eventually you lose spark and the rotor arcs out and gets burnt.
That's a few things to get a M103 running .

mpmorris

2/14/2019 10:54 AM

Yes to the possible crank sensor -they are known to fail(the cable at the sensor is the common issue for open circuit- Also, you might remove the distributor cap and check the rotor mounting bracket --they are known to crack and fall off causing the car to sort of backfire and/or attempt to start as the cam will turn the rotor somewhat and have a cross fire.

On another note:

Recently, we installed a Genuine fuel pump relay for the 103 engine (new fuel pumps installed) -- it failed within 3 weeks -additionally, we installed a Genuine glow plug relay in a 126 SDL --it failed withing an hour (glow plug lamp did not illuminate with key on but would stay illuminated after start up -yes -glow plugs were ohm tested as ok) --After market relays are known to fail but we are now disappointed that even the Genuine parts are now suspect. --On another note: Mono-valve heater replacements are still of good quality as Genuine ($120.00 cost) -but all after market replacement diaphragms and valves are seriously flawed --the spring lift are weak/diaphragm is stiff so the flow is restricted or will not flow at all.

tech notes
mpm

Ron B

2/14/2019 6:34 PM

Are they getting the genny parts made in Guangzhou?

Ron B

2/14/2019 6:38 PM

If it were an earlier version I would be checking the loom across the engine, the one inside the plastic boxing. That is well known as the place where the self destructing looms would fall apart,some getting so bad they burnt the car down. have a look anyway, if the insulation falls off as you rub the wires,it's time to re[pair or replace.

ctmaher

2/15/2019 11:06 AM

I would not suspect a wiring issue on a 1988 with K-jet. The decomposing wiring harness issue seems to be mainly with the cars that had the LH injection system...starting with the W140 in 1992 and ending in around 1997 when they finally changed the wiring harness materials. So that would be LH M119/M120/M104 for the most part.

Chris

cth350

2/18/2019 5:35 PM

I had some fun with my '89 TE for a while.

The flaky ground wire to the coil was the hardest thing to find.

For the rest, I let the computer tell me some hints. Like the little duty cycle check, the flashing codes, that sort of thing. There are some decision trees in the M103 engine manual to work from and several basic internet posts.

You need a digital meter that can read duty cycle, the book and time to read it and maybe a wealth of spare parts to isolate faults like bad relays a faulty altitude sensor.

-CTH

WA6VQP

2/18/2019 6:05 PM

Hello all (again),

I had a few minutes between weather fronts this past weekend to do some sleuthing on the dog (AKA the 300TE). Since I realized the "clicking" module was the alarm system, I simply left that unplugged, thinking it might be messing with the engine, since it obviously thought that someone was trying to steal the car.

At first, no change. Then, after a few attempts, the engine fired and ran at idle quite nicely. However, when I tried revving the engine, it got rough, and revving it two or three times, it died, and I was back where I started.

This leads me to believe there is something intermittent, like the previously mentioned rotor bracket, or bad coil ground wire. I will check into both items when I get the next opportunity. I started loosening the distributor, but the weather was closing in, so that will have to wait until next time. The car is parked outside, and moving into the garage is not practical without a running motor, so that is the first order of business.

I will update as things progress! If anyone has more ideas, by all means post them! Thanks to all for the suggestions so far.

Best Regards,
Jim

1979 450SEL 6.9 (Black/Safran)
1987 560SL (Red/Palomino)
and now, 1988 300TE (White/Tan)

Driven with "old man" sheepskin covers!

WA6VQP

3/13/2019 3:36 PM

New developments in the dog saga...

After reading some of the advice here on the forum, I decided to pull the distributor. The rotor looks fine, as does the cap (sort of). There is, however, a round disk behind the rotor which looks damaged, and there is dust from that part coating the cap.

The pictures show the issue.

Any thoughts? Thanks!

Jim

1979 450SEL 6.9 (Black/Safran)
1987 560SL (Red/Palomino)
and now, 1988 300TE (White/Tan)

Driven with "old man" sheepskin covers!

ctmaher

3/13/2019 11:58 PM

Umm, where is the rotor?

Chris

WA6VQP

3/14/2019 1:44 PM

Chris,

I took the rotor off to check it. It was originally installed correctly, but I'm waiting to put it back on until I understand the wear I'm seeing a bit better.

Thanks,
Jim

1979 450SEL 6.9 (Black/Safran)
1987 560SL (Red/Palomino)
and now, 1988 300TE (White/Tan)

Driven with "old man" sheepskin covers!

StianL

3/27/2019 2:20 PM

Have you checked the OVP? This seems to be failing regularly on 80-90s cars, and producing mysterious faults.

WA6VQP

4/8/2019 10:43 AM

Hello all,

Spent an hour or so over the weekend futzing with the dog. Put the little rubber ring in the distributor assembly, hooked up the battery, and turned they key, expecting little, if any, improvement.

Gratifyingly, the dog started right up; incredible!

Also, I've had some water intrusion into the front of the cab, and I found some plugged drains. Cleared those, and the problem seems to have been fixed (it's been raining heavily here ever since).

Progress on two fronts...

Next, some brake issues. The water intrusion has made some stuff freeze up a bit, so I've got some WD-40 soaking into some key areas, and we'll see how that works. At least I can drive it, more or less, so I can get it into the garage to work on it more, even when raining. Yay!

Regards,
Jim

1979 450SEL 6.9 (Black/Safran)
1987 560SL (Red/Palomino)

Driven with "old man" sheepskin covers!

WA6VQP

4/16/2019 10:24 AM

Greetings!

Well, some progress, some congress...

Got the parking brake pedal assembly freed up. Penetrating oil, a torch and some freeze spray. Cleaned it up, and now everything moves freely.

I wish I could say the same for the main brakes. Here are the symptoms:

1) The ABS indicator is on all the time.
2) If I stop hard, the ABS does, indeed, work (brakes pulse).
3) When I step on the brake, the brakes work, and work well (as would be indicated by #2).
4) The vacuum servo seems fine. Undue pressure is not needed to stop.
5) The problem: Once I step on the brake pedal, it stays down, not hard, but hard enough that I have to pull it up with my foot to make the car go.
6) It's hard enough that if I have the car in gear, it won't move at idle.
7) The pedal return spring seems OK.
8) I've tried lubricating all of the interior pedal bearings and sleeves, no change.
9) I've checked all the wheels, and when the brake pedal is pulled up, all spin freely, so no stuck calipers.

Anybody have any ideas? Thanks!

Regards,
Jim

1979 450SEL 6.9 (Black/Safran)
1987 560SL (Red/Palomino)

Driven with "old man" sheepskin covers!

WA6VQP

4/17/2019 11:04 AM

Hello all, here's an update!

It's not fixed, but I found it...

The water leak I've since fixed got into the main sleeve bearing of the brake pedal and has gunked it up, making the pedal action stiff. The spring simply doesn't have enough strength to make the pedal return all the way. I unhooked the braked servo from the pedal, and all of that became immediately apparent.

Now I have the wonderful task of getting all that stuff out, cleaning it up and re-lubing the assembly. What fun! Not...

Regards,
Jim

1979 450SEL 6.9 (Black/Safran)
1987 560SL (Red/Palomino)

Driven with "old man" sheepskin covers!

WA6VQP

4/18/2019 1:41 PM

Well I'm stoked...

I was able to get the entire brake pedal assembly out with one bolt and four nuts. Way easier than I expected. I got the pedal off the assembly, and was able to get everything cleaned up nicely, and now it's smooth as silk.

However, before I put it back, and also the parking brake pedal assembly, I have an important question: As I mentioned in a previous posting, these pedals have a sleeve of some kind as part of the "bearing" that lets them turn freely. I'm not sure if this is soft metal, or some kind of plastic. The question is, what kind of lubricant, if any, should I put on these sleeves?

I don't want to put something on there that ultimately ruins the operation of the assembly, but I do want to put something on there if it's supposed to be there, to reduce wear and make the operation smoother. I have many, many options available to me, from light silicone, to heavy silicone, to lubriplate, to "liquid bearings" to who knows what...

Is there an official lubricant for these things? If someone has knowledge, please share. Thanks!

Best Regards,
Jim

1979 450SEL 6.9 (Black/Safran)
1987 560SL (Red/Palomino)

Driven with "old man" sheepskin covers!

cth350

4/18/2019 10:13 PM

silicone isn't much of a lubricant, especially for steel parts.

White grease should work, as would classic "brake paste" (which is a kind of white grease these days). After a couple of decades, it will loose most of its good properties. But until then, you should be fine.

-CTH

WA6VQP

4/23/2019 1:58 PM

On to the next hurdle!

The instrument cluster is pretty trashed with water damage, schmutz and other issues. I've seen at least one for sale on the Internet that looks right, but the tach number is different, even though it says it's for an '88 TE. So:

1) Anyone know how important that is?
2) Anybody got a cluster you want to sell?

Your thoughts, please...

Regards,
Jim

1979 450SEL 6.9 (Black/Safran)
1987 560SL (Red/Palomino)

Driven with "old man" sheepskin covers!

cth350

4/25/2019 7:09 PM

hmm, I'd send you a private message on that, but I don't see that option here. Is that a forum choice or yours?

Basically I was going to ask which numbers you were expecting? I am sure I have a cluster here in the parts pile, no clue if it came from a 300TE, 300SE or 300E, as they've all passed through my fingers over the years.

-CTH

WA6VQP

4/26/2019 10:28 AM

Not sure why you cannot e-mail me, but my address is jim at radio design dot com (of course without the spaces).

Send me pictures, front and back, and I'll be able to tell right away. Thanks!

Regards,
Jim

1979 450SEL 6.9 (Black/Safran)
1987 560SL (Red/Palomino)

Driven with "old man" sheepskin covers!

WA6VQP

4/30/2019 10:45 AM

Hello folks!

Well, while still looking for an instrument cluster, I decided to take matters into my own hands, so to speak. I washed all the pieces in an ultrasonic cleaner, which made a real improvement in appearance, but I still have repairs to do.

That leads me to my big question: Both the speedo and the tach have a dial indicator that is attached to a very tiny shaft. I've tried pulling on them, thinking they might simply be a press fit, but there is a limit to how much pulling I'm willing to do while being ignorant of how things are supposed to happen.

Does anybody know how you get those little pointers off the shaft they are attached to? If so, please share your wisdom. Thanks!

Best Regards,
Jim

1979 450SEL 6.9 (Black/Safran)
1987 560SL (Red/Palomino)

Driven with "old man" sheepskin covers!

FEMA

5/6/2019 8:40 PM

Why don't you try testing them before taking them apart? The speedo should work on the principal of magnetic induction, and maybe the tach is the same way.

Francis E. Abate

mpmorris

5/14/2019 8:59 PM

Hello Jim --thought you would see the humor here --a '92 300TE fell into my lap-- like you, wasn't looking for one but the price was right with 190k miles and well maintained --have put a thousand miles on it thus far-- A sewing machine.

mpmorris

WA6VQP

5/16/2019 11:46 AM

Mike,

Yeah, but I'll bet you paid more than $300 for it!

Project cars are such fun!

:-)

Regards,
Jim

1979 450SEL 6.9 (Black/Safran)
1987 560SL (Red/Palomino)

Driven with "old man" sheepskin covers!

mpmorris

5/17/2019 3:11 PM

Not much more -it was too cheap to pass up --which is always the hook --I have a yard and basement full of cars that were 'too cheap to pass up'.

mpm

WA6VQP

5/17/2019 6:05 PM

Mike,

Now you're making me feel bad!

:-)

By the way, you wouldn't happen to have a spare instrument cluster, would you?

Regards,
Jim

1979 450SEL 6.9 (Black/Safran)
1987 560SL (Red/Palomino)

Driven with "old man" sheepskin covers!

mpmorris

5/20/2019 1:32 PM

Not for a 124 -sorry

Return to Forum