116.120 Issues After Prolonged Storage: - PeachParts Mercedes-Benz Forum

Doktor Bert · #1 07-20-2009, 10:19 AM

Greetings,

I just put the 116.120 back on the road this morning for the first time since my Son's April 21, 2006 collision near Kingsburg, California. As one might expect, there are a few things that are not working correctly and I wanted to get some input from some of you here in the forum that might have experienced one or more of these problems.

The temperature gauge will not go over 100°F. I tested the gauge by grounding it and the needle will immediately sweep to 250°F. Just on a fluke, I hooked the temp sender wire up to the forward most sender in the head and I got a steady 175°F reading at that location.

I remember pulling the senders during the rebuild to clean some corrosion off of them. I suppose it is possible I put them in the wrong locations????

The tachometer, which worked perfectly prior to the crash, now works and then doesn't. In each instance that it stops working, you can remove the tach adapter, plug it back in and tach operation will resume for a few miles. I cleaned the connections, but the problem persists. I am assuming this is a faulty tach adapter as all the grounds are clean.

The fuel gauge didn't work initially, but the started working on its own. However, as you drive, the needle will sometimes drop to empty and then bounce back up to full. I am assuming I need to replace the tank unit, but have never pulled one on a 116 chassis. Any tricks on replacing this from any 116 gurus???

Other than a bad door switch for the interior lights, everything else seems to be working perfectly. I don't like turning 3,000 rpm @ 67 mph, so I am still looking for a 2.47:1 or 2.88:1 axle in or around Fresno.

Thanks for your time...Robert

kerry · #2 07-20-2009, 11:46 AM

I believe one of those temperature senders controls the length of time the glow plug light stays on. I can imagine that above a certain block temperature, it has a fixed glow light period so I could see how it would not need to have a full range of indication. So it sounds like the sensors or wires might be switched.

Doktor Bert · #3 07-20-2009, 12:35 PM

Kerry,

I think I must have switched sending units, because the wires are too short in the loom to cross them up. I did take them out to clean them, as they were developing some corrosion, so it is likely that I mixed them up.

When I hooked up a jumper wire to the front-most one in the head, it gave me a steady 175°F reading. I think I will swap them back after work tonight...Robert

Doktor Bert · #4 07-21-2009, 07:52 PM

This morning, I swapped the sending units from front to back and the temperature gauge is now working correctly....Chalk another one up to operator error...Robert

Doktor Bert · #5 07-22-2009, 11:24 AM

It has been so long since I worked on a 116 that I have forgotten a lot of my tricks....

I recently swapped my sending units (I had accidentally reversed them when cleaning corossion) and now my temp gauge operates. However, in the 3 years the car has been sitting, I do not recall how long the glow plug light stays on when 'cold.'

This morning, it was about 65°F outside and I switched on the key and the glow light stayed on about 20-25 seconds, which concerned me, so I just hit the key and the engine started immediately. Yesterday, the car sat all day at work all day (it was over 100°F) and when I left for home, the glow light only came on for maybe 2-3 seconds. That seemed about right.

My tach works and then doesn't, apparently for no reason, so I swapped in a spare adapter and the problem persists. Is there a ground specifically for the cluster???

Other than that, my only other issue is intermittant 1st gear kickdown from a stop. Sometimes it works and sometimes it doesn't, even during the same stopping event, like when you stop mutiple times at a stop sign for traffic.

IIRC, there is a control unit in the car that shifts the transmission into second at stops, but I don't recall any other particulars.

Anyone have more recent experience with this system???

Thanks...Robert

Doktor Bert · #6 07-22-2009, 04:42 PM

Any grounds behind the cluster?????

kerry · #7 07-22-2009, 05:10 PM

Quote:

Originally Posted by Doktor Bert

It has been so long since I worked on a 116 that I have forgotten a lot of my tricks....

I recently swapped my sending units (I had accidentally reversed them when cleaning corossion) and now my temp gauge operates. However, in the 3 years the car has been sitting, I do not recall how long the glow plug light stays on when 'cold.'

This morning, it was about 65°F outside and I switched on the key and the glow light stayed on about 20-25 seconds, which concerned me, so I just hit the key and the engine started immediately. Yesterday, the car sat all day at work all day (it was over 100°F) and when I left for home, the glow light only came on for maybe 2-3 seconds. That seemed about right.

My tach works and then doesn't, apparently for no reason, so I swapped in a spare adapter and the problem persists. Is there a ground specifically for the cluster???

Other than that, my only other issue is intermittant 1st gear kickdown from a stop. Sometimes it works and sometimes it doesn't, even during the same stopping event, like when you stop mutiple times at a stop sign for traffic.

IIRC, there is a control unit in the car that shifts the transmission into second at stops, but I don't recall any other particulars.

Anyone have more recent experience with this system???

Thanks...Robert

In my experience the 116 glow light duration is considerably longer, even with pencil plugs, than the 123. It almost seems as though they continued to use the glow light controller from the old loop style plugs.
The 116 has a separate switch for downshifting to first. It requires a full and complete stop to make the downshift. I envision a swinging pendulum which moves forward upon braking and causes the downshift once it swings backwards and makes a contact. Don't know where this switch is, but I do know that 'California' stops will not cause it to engage.

Doktor Bert · #8 07-22-2009, 05:21 PM

Hmmmmm....

I am making complete stops...many times, awaiting cross traffic. Anyone care to expound on this??? I believe this feature will be critical to my 2.47:1 installation....Thanks!!!!!!

Doktor Bert · #9 07-22-2009, 05:24 PM

Quote:

Originally Posted by kerry

In my experience the 116 glow light duration is considerably longer, even with pencil plugs, than the 123...."

I didn't time it this morning when I started it, but it seemed like a LONG time. I finally just hit the key out of concern for the plugs...

kerry · #10 07-22-2009, 05:26 PM

Quote:

Originally Posted by Doktor Bert

Hmmmmm....

I am making complete stops...many times, awaiting cross traffic. Anyone care to expound on this??? I believe this feature will be critical to my 2.47:1 installation....Thanks!!!!!!

Try a 'harsh' stop to see if it engages the switch. I have a vague idea that the switch is by the left foot panel of the driver's footwell but that could be based on my imagination and not forgotten knowledge.

kerry · #11 07-22-2009, 05:29 PM

Quote:

Originally Posted by Doktor Bert

I didn't time it this morning when I started it, but it seemed like a LONG time. I finally just hit the key out of concern for the plugs...

It's waaaaay long. I just start it before the light goes out quite often. I think I once timed the length of the actual glow, comparing my 85 123 and 79 116. The 116 actually glows longer also.

Doktor Bert · #12 07-23-2009, 10:02 AM

This morning,m it was about 72°F outside when I left for work at 3:30am and the light glowed for almost 30 seconds, so I just started the engine without waiting any longer. When the car was in Dad's shop and the core support was out of it, we had the glow plug controller off the car to straighten the inner fender. The car will start immediately without glow plugs above 75° to 80°F. On really cold mornings, that's around +40°F here, it will start after about 3 to 5 seconds of glow.

I am starting to realize that I have never waited for the light to go out on a cold engine!!!

The owner's manual states the glow process can last up to 1.5 minutes and to press the throttle 3 times when starting below -4°F ambient temperatures....????

piccolovic · #13 07-23-2009, 11:10 AM

when I bought my '84 300D, the transmission timing on the rebuild would not stay in adjustment. Peter Hedary played with for a while, and took out his vacuum diagrams and tester. Turned out the four vacuum hoses were switched around, and after he put them back where they belonged . . . voila!!! Shifts great now . . . . solid.

I would also check for good ground.

Torie

Doktor Bert · #14 07-23-2009, 07:07 PM

I am in search of these elusive 'grounds' of which you speak...

Anyone familar with their location???

barry123400 · #15 07-24-2009, 08:47 PM

Those sensors will die sitting around for no apparent reason in my experience occasionally. Is it possible the two sensors have the same part number?

If that were the case you did not really swap them as such but instead installed the bad temperature sensor in the glowplug relay circuit. Then the long cycle is more understandable to me. Mercedes would not be the first to try to use same the same sensors for more than one function.

I would try your wire with a couple of aligator clips to put the glow relay on the other sensor to see if the time shortens up. By now you may have already figured this out and are way ahead of me. Sometimes it is the simple stuff we miss.

Let us know what you find in the long run. As mentioned already.It is too bad you do not get enough time to post more often. As your posts are very imformative in my opinion.