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Tachometer - What is going on in this video?

2K views 14 replies 7 participants last post by  anthony9004 
#1 · (Edited by Moderator)
My W210 is having this problem although worse and lasts longer ** tach bounce / shake at 2-3k rpm**. Issue in the video starts at 1:05. The car shifts into gear *722.3* typically from 2-3, 3-4 after bouncing the tach a bit.. I'm unclear if this is the transmission or throttle / gas issue.

 
#2 ·
NICE WATCH MAN
This is W210 section, where we drive with different transmissions, but watching the video, the first question is what is G-force sensor telling when the bounce happens?
I do have pretty good G-sensor in my back, but it doesn't work over the internet.
 
#3 ·
I'm afraid I do not have one of those devices. My guess is less than half a g? It's like 10 percent brake and release. The car does shake a bit.. almost like a clutch slipping. Vroom vroom vroom from 2-3k and then shift from 2-3.. this is during steady throttle.. repeat on the 3-4 shift. I can describe this as a ghost blip.. Once the car is warmed up the issue is not as severe but definitely still there. If I kick down it will shift better.. I can control it a little bit with the throttle. It's more of being gentle and releasing a small bit.. also keeping a smooth velocity helps with the shifting. The transmission fluid looks good although still pending the gasket / filter replacement. My suspicion is the throttle position sensor or something along those lines. It's hard for me to believe the transmission would start acting up out of the blue.. it feels electrical. I could be wrong being used to manual transmissions, clock is 147k. I would like to narrow it down before parts start flying. I had some codes previously.. replaced 02 sensors, battery in the last 2 months.. plugs / wires were about 15 months ago. The car sits most of the time.. fuel pump was also replaced over a year ago. I read somewhere the fuel filter may cause this as well. Currently I'm not getting any codes.. just trying to pass smog. Taking some time.. I don't drive it enough to keep the monitors going.. a work in progress.
 
#4 ·
The problem is, 1996 W210 is a orphan year when it comes to mechanical/electrical issues. Nothing makes sense in that car.

For one, it (as you know) uses 4 speed transmission from older gen, but most of the electrical protocols don't match up. Hell, the guy at my work using the $9000 snap-on scanner couldn't even connect to it, let alone diagnose it. I had to bust out my SDS to read it. That snap on works perfectly on my (now sold :() 1997 E320...so that means different ECU management, and different transmission management unit.

I don't know anything about that year...all I know is that it doesn't make sense, lol.

Try to unplug the mass air flow sensor and see if it still bounces about?
 
#6 ·
I haven't tried the MAF disconnect yet although it is a cheap replacement. That may be an issue. Also.. my neutral safety switch started having issues a few years ago.. this is probably unrelated but since it is part of the transmission may not be far off. I can start in park once in a while and always start in neutral all depending how the car feels that day.
So I'm now at the point of vacuum pressure in transmission / transmission issue / fuel pressure / MAF / or some electrical gremlin unresolved. This morning before taking the videos.. I tried the throttle body reset procedure.. did not seem to help much. There was slow engagement shifting into drive.. also slow take off from drive. Off course this is after sitting for 2 weeks. Could there be an issue with the control module? Does SDS show those issues or would that be far fetched?
 
#9 ·
I would suggest manual shifting the transmission to see if the same problem occurs. If it does then you know, it's most likely the transmission. The transmission is known to have problems on the older w210's anyway, so what the shop said could be a problem but it's still hard to know without actually driving the car myself. Just start driving in the lowest gear and upshift one gear at a time, and downshift one gear at a time. Keep doing this the throughout the day as you drive the car. If the problem does not show itself, then most likely it's something else. At least it may help you narrow down the problem and possibly avoid a trans rebuild.
 
#10 ·
Dont pull anything just yet .Check put the CPS sensor first .Remove it and give it a good clean. This sends a message to the ecu for it to fire in the right place . Next one is a little harder .The throttle body might need rebuild .As the throttle is electronic .You can see this rebuild step by step on youtube. See picture. Plus you can do this last check at a stand still .Note the revs when it starts and do on the road .Then do the same at stand still in park, or nutral . Keep foot on the brake in doing so .
 

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#11 ·
To me, it looks more like a vacuum leak / actuator problem. The leak in transmission needs to be addressed and the proper ATF fluid level need to be restored. This seems to be a separate issue. Make sure your coolant sensor display is within operating limits (it did not show in the last set of videos).
 
#14 ·
My W210 is having this problem although worse and lasts longer ** tach bounce / shake at 2-3k rpm**. Issue in the video starts at 1:05. The car shifts into gear *722.3* typically from 2-3, 3-4 after bouncing the tach a bit.. I'm unclear if this is the transmission or throttle / gas issue.
After watching both the speedo and tach, I vote for trans issue - those look like flares when he tries to accelerate.

The trans should be easy enough to test during driving. If it feels like you punch the gas and speed doesn't increase but revs do, it's commonly a trans issue.
 
#15 ·
To me, it looks more like a vacuum leak / actuator problem. The leak in transmission needs to be addressed and the proper ATF fluid level need to be restored. This seems to be a separate issue. Make sure your coolant sensor display is within operating limits (it did not show in the last set of videos).
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Mrboca.. you have addressed one of my concerns. For the other replies.. I suspected the throttle body although have not removed that. I'm trying to be as least intrusive as possible, I also have other cars to drive. I figured it couldn't be the throttle body or the fuel system since the car drives fine at highway speeds without any kind of hesitation. My tach bounces during street driving or when taking off from a slower speed. My concern about the temperature is it seems to rise quite a bit when the A/C is on..goes up to about 101 in traffic.. dual fans test ok. I am suspecting either there is something off with the cooling system or what my a/c guy told me "you should probably replace the fan clutch." I didn't think much of it until my temperature started rising over a year ago. This may be playing a factor in the whole transmission slipping problem. I also considered my leaky head gasket could be dropping excessive oil around causing the transmission to run hotter than normal. I replaced the thermostat, nothing changed. I'm looking at transmissions, I hope to solve this issue. I'm considering reaching out to mava on this.. can anyone reach out to him for me? Does anyone know about the 722.3? There may have been more than one transmission used in 96.. I know there was the 722.369, was there a 722.329?
 
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