BenzVince

Hey guys, I needed to find out what does your RPM read at when you're cruising at 70mph. I have a 96 E320 and it's a four speed auto. I was driving and i noticed that when I'm at 70mph and it's reading at 3k RPM. I thought there's something wrong with my tranny. Since I have a 2001 Maxima and it's a four speed if I was going that fast, my RPM reads at 2500. I wonder if that's normal for a Mercedes at 3000 RPM going at 70mph.

BenzVince

Since I got no replies, I have been wondering what your RPM should be reading coasting at 70mph for those who have a E320 with a four speed tranny.

zam2000

It could be that your instrument cluster display it incorrectly. Use the AC Panel to read your rpm (do a search on the forum, you'll see instruction).
My 98 (5 speed) RPM reads 3000 at 85 mph.

my E430 rocket

what would u search for. seems kinda broad

MBWorld1

I have a 96 E320 and I am close to 3000 RPM at 70 but not 100% sure about that. Will check on Monday and let you know.

gmacosta

On my 96 E320, on the accelerator maintaining 70 my rpm was at 2900, right about were you were. When coasting from 70 rpm was dropped aroud 2300 I think.

Greg

Inline6

In my 96, I am crusing about 75 at around 3000 RPMs. You can expect that the 4 speed would have higher RPMs than the 5 speed going at the same speed. Other factors could be the ratio of the rear end and your tire / wheel size.

E-Klasse

I just noticed mine this morning. At 3100 RPM, I am doing 80 MPH and 3500 RPM at 90 MPH. The final drive ratio with the 4 speed transmission is 2.73 where the E-Class with the 5 speed has a 3.07 rear end ratio.

In the 4 speed, 3rd gear is 1:1 with the 4th gear being the overdrive or 0.8:1. With the 5 speed, 4th gear is 1:1 and 5th is 0.8:1.

So the big difference is the ratio of the rear differential because at those speeds, both transmissions would be at 1:1 or in overdrive at 0.8:1.

The 96 has the 4 speed transmission but 97 and on has the 5 speed.

MBWorld1

I just checked on my 96 with 4 speed trans.

at 70 MPH - 2850-2900 RPM
at 75 MPH - 3000 RPM

Hope it helps

akbro93704

Ive searched and searched for the AC panel RPM readout instructions,cant find anything about it...can you give instructions on here?thanks!

DslBnz

The 210 has the same 4 speed transmission used in the 124 models from '93 - '95 with accordance to the second gen. M104 engine. The differentials would either be 2.65:1 or 2.87:1 with a 1:1 4th gear transmission.

They did not go to overdrive transmissions until the 726.x series which are the driver-adaptive-electronic-solenoid 5-speeds we all know and love.

DslBnz

I just checked.....The 210 E320 with the 4 speed transmission has a 2.87 differential. Confirmed by Bergwerks.

So.... I have a 300SDL with a 2.88, and I'm humming along the highway at about 3000 at 70 mph.

I have a very high stalling torque convertor. I'd imagine the '96 E320 has a looseness in it's torque convertor as well. Do you?

Everything seems normally proportioned to me for you folks.

E-Klasse

Hold the "REST" button in for more than 5 seconds. This will put you in daignostic mode. You can scroll through the 20 or more values to get to RPMs on #21. Go through the readings by pressing the AUTO button.

01 = In-car temp sensor
02 = outside temp sensor
03 = left heat exchanger (heater core) temp sensor
04 = right heat exchanger sensor
05 = evaporator sensor
06 = coolant temp
07 = refrig. pressure in bar
08 = refrig temp sensor (23*9 = 23.9deg C)
09 = nothing
10 = Blower control voltage (great for evaluating blower controller problems)
11 = emissions sensor (B31) e.g. 3.1 = 31.v
12 = sun sensor 4.2 = 4.2v
20 = aux fan control 6.1 = 6.1ma (max 10ma)
21 = engine speed
22 = vehicle speed
23 = Circuit 58d e.g. 99 = 99% of battery voltage
24 = BATTERY VOLTAGE e.g. 12.5 = 12.5v
30 = left rear air conditioning heat exchanger temp sensor (not all vehicles; obviously)
31 = right side
32 = rear evap temp sensor
33 = blower control voltage rear 0.8(MIN) - 6.0(MAX)
34 = left rear temp selector
35 = right side
38 = software status e.g. 37 rear air conditioning
38 = hardware status e.g. 37 , rear air conditioning
40 = control module version software status (?)
41 = control module version menu hardware status
42 = control module variant code 1st number
43 = variant code second number.

akbro93704

thanks! how do you set it back to the air conditioning readout?

E-Klasse

push the "REST" button again to return to normal display.

Green E-300 DT

Since your '96 has the four speed tranny, and fourth gear is direct drive ( 1 to 1 ) and your rear-end ratio is 3.07 according to the official MBZ website, your multiply that 3.07 figure times the number of revs that the stock size Michelin tire turns which is 814, and that is the correct rpm at 60 mph, or 2499 rpm.

Divide that figure by 60, you'll get 41.6496 for each mph, and multiple by 70, equals 2915 rpm.

Now there is slippage contrary to what many will, and have argued
of the T/C not locking up, it will be difficult to see that exact figure.
In other words, you'll not see a steady tach reading with your car.
Even with the C/R set, in my car I see 200 + or - of its figure of 2428 rpms depending on terrain, wind, etc.

By the way, the new W-211 CDIs have gone to a rather "tall" ratio of 2.65, and I noticed the difference right away as soon as we went for a test drive from my '99 E-300 which has 3.08s with the overdrive equipped five speed.
It seems the factory types final got that figured out correctly.

The new W-211 E-320 CDI has ratios of 2.65 X 0.83 (overdrive fifth gear) X 810 (225/55-16s) for only 1782 rpm at 60 mph, or 2079 at 70 mph, and it definitely does lock up the T/C in that vehicle. It's about time! My '99 E-300 turns 2428 at 70, so you can see the diifference. Also, mine does not lock up!

Even though the difference is only 350 rpm, that difference should make for a much more relaxed high-speed cruise!

HTHs

akbro93704

thanks! On number 21, at idle, the number on the right side of the display reads 42, and at about 3000 RPM it's around 85. The numbers do get higher the more the engine is revving, but the numbers dont relate to the RPM's...is that how yours is too?thanks

E-Klasse

Didn't we confirm that the 96 has a 2.87:1 rear end with a 1:1 4th gear transmission? That might change things slightly...

DslBnz

According to Bergwerks, the differential is indeed a 2.87.

Hehe...Talk about slippage. In my SDL, I can get 2800 rpms in 4th at 40 mph, 2900 rpms at 50 and 60 mph, at 70 3200 rpms, 80 3500 rpms, and every bit past that the TC locks up more and more. The slippage earlier on, is enough to make people in the passenger seat think the car jumped down a gear or two, lol.

The torque in the 3.0 liter OM60x diesel series engines is usually way up high. Thus the slippage.

Here is a dyno sheet of a specially tuned version.....

DslBnz

Oh, and the red-line is torque in nM, and blue is KW.

DslBnz

Here is the Bergwerks link.

http://www.bergwerks.com/different_appli.jsp

E-Klasse

That is strange. What year is your E-Class? There might be software differences. It should track your RPMs.



go here

DslBnz

Notice the extreme lockup effect once 4900 - 5000 rpm is hit.

Here is an example of 60x lockup.

http://www.ejzcars.com/TCLockupOnly.mov

(seems we're diverging into two related but seperate topics in one thread. Thanks for the codes, I think I'll use them next time I give the 119 a run-around).

Green E-300 DT

It matters not what the Bergwerks chart says, or what anyone else says for that matter; It is what gears are actually in the car that counts! :v

According to the official MBUSA charts, this car in question has 3.08s. See:

http://www.mbusa.com/brand/container...45678&menu=5_3

To be sure, anyone can crawl under the back end and read the actual ratio that is plainly stamped on the lower right hand corner of the differential case.

His '96 E-320 four speed automatic equipped car in fourth gear which is direct drive, or one to one ratio, is the same as my '99 E-300 when running in fourth speed. I checked mine this afternoon, and at a steady speed of 70 mph when locked in fourth speed, my tach reads almost 3000 rpm on level ground using the C/R. And mine does have the 3.08 ratio, but the MBZ site has mine listed as having 3.46s. And that is incorrect! The factory does make mistakes. I know of two others like mine that also have the same ratios. Upshifting to fifth gear which is 0.83 (overdrive,) and 3000 rpms is about 83 mph.

Wish mine locked up like the new W-211 E-320 CDI does.

Green E-300 DT

The only way to be absolutely sure of what the ratio is on anyones car is to verify the ratio by reading it off of the lower right-hand corner of the differential case. Then you are sure of what that particular car has, unless of course someone has changed out the gears since the original gears were installed, and that is not likely!

It only takes a minute to check, and you don't need to jack up the car. Simply crawl under the back end with a rag and a flashlight, and wipe off the grim on the flat surface, and read what is stamped thereon.

What could be simplier?