When I first got my E36, I had to drive it home for 3 hours down the highway. The speed limit in Ontario is 90 km/h on the highway I was travelling. I typically travel around 115 km/h to avoid getting pulled over by the police. This is common practice in Ontario (they usually pull over at around 120)

I noticed something peculiar was happening. The majority of traffic was still travelling faster than I was, despite my speedometer reading 115 km/h. I got passed by a camper trailer (NOOO).

Upon arriving home, I checked the speedometer accuracy via GPS. I've used the GPS in my line of work (Fish and Wildlife Enforcement) and was familiar with the speed readings given. I had a few shifts of work with the police, and we tested the GPS unit against the police radar for accuracy. The GPS came back in sync with the radar unit.

At this stage, if the GPS was incorrect, I could at least live with being in sync with the radar units (to avoid speeding tickets). I tested my speedometer errors (sorry guys, metric units)

Speedometer Reading vs. Actual Reading from GPS:
20 km/h vs 18 km/h
40 km/h vs 36 km/h
60 km/h vs 54 km/h
80 km/h vs 72 km/h
100 km/h vs 91 km/h
110 km/h vs 101 km/h
120 km/h vs 111 km/h
130 km/h vs 121 km/h
140 km/h vs 130 km/h
150 km/h vs 140 km/h

The key to this problem was the highway speed. I do tons of distance travelling, so I needed to have an accurate speedometer.

After looking around for several fixes, including a device that alters the volatge coming from the speed sensor to your pre-determined values, I decided to try my hand at changing the position of the needle. I'd heard of this working in other cars, so I checked eBay for a backup cluster in case I ruined this one. Good to go, I had a plan B, so off I went tearing into it.

Not only did I correct the problem, but the cluster manages to be correct at all speed ranges (something I'm not quite familiar with as to why, but nevertheless it's correct!). I was hoping for the 100-120 range to be accurate at best, so it was a nice surprise.

Here's what I did. Keep in mind, if you attempt this, I can't accept any responsibility for you destroying anything. I think it's pretty safe to attempt though. You'll need a torx set with the common sizes for pulling the instrument cluster. If you do not have tilt steering, then I can't guarantee that you won't get the cluster out without having to remove the steering wheel. I'm sure you should be able to get it out though, I've watched it happen without tilt.

Cluster in dash:
http://img128.imageshack.us/img128/8403/21025721kg0.jpg

STEP 1:
Remove Instrument Cluster. (2 torx bolts connecting to the top of the dash, use thin object to pry the cluster down a bit, grab hold and pull it out). Unclip the electronic connectors (place a finger from one hand on the release tab, use the other hand to slide the plastic hoop and get it started, slide hoop off of connector - this removes connectors). There are 3 connections. Once they are off, slide the cluster out.
http://img46.imageshack.us/img46/5567/23702078mu2.jpg

http://img138.imageshack.us/img138/336/41664521tw7.jpg

http://img46.imageshack.us/img46/2605/60240254vz0.jpg

http://img46.imageshack.us/img46/4476/21303141wu5.jpg

http://img138.imageshack.us/img138/8107/25606783zd5.jpg

STEP 2 DISASSEMBLE CLUSTER:
Using torx bits, remove backing from instrument cluster. There are 5 screws holding this in. Once they are out, pry the two halves apart using moderate force. Pry on the left and right sides of the cluster, switching back and forth between the two to generate an even force. Once the backing is off, you need to separate the glass housing from the speedometer assembly. There are 3 *finger screws* (plastic tabs based over a pane of plastic glass) that need to be twisted into openings to allow the two parts to separate. You will need some minor dexterity (or if not, a small screwdriver) to twist these into position. Once this is complete, you are left with your speedometer assembly in the open.
http://img128.imageshack.us/img128/13/97452157pi2.jpg

http://img521.imageshack.us/img521/909/59384669zp1.jpg

http://img521.imageshack.us/img521/9884/15412521st9.jpg

STEP 3: CHANGE POSITION OF THE NEEDLE
This is where the challenge comes in. If you have a pretty good idea of how far off your speedometer is (usually 10% at 60mph/100 km/h on E36 models) then you should be okay to estimate from this point.

Grab the speedometer needle and move it around a bit. You will notice that the needle is on a bushing that has some give to it. Using two fingers firmly around the needle (sounds gross, heh) lift up lightly on the needle and move it below the plastic stopper (below zero). The needle shouldn't fall very much further from here.

Push on the needle so that the position of the needle changes from it's previous position. You are trying to remove 6mph/10km/h from it at this stage, so you are turning it backwards (down). Give an approximate guess (or you can look at the reverse side of the needle and where it sits, and use that) for your speed deficit. The needle will spin on it's shaft after some prodding. Don't be afraid to damage it, there is nothing securing it to the base.

Once you think you have it, you will have to re-assemble your cluster to test it out. Put it all back together, take the car out on the highway and test it out.

If you over did the reduction in needle position, disassemble, and instead of putting the needle on the other side of the plastic stopper, turn the needle all the way clockwise until you feel it stop. At this stage, the same rule applies - spin the needle on this shaft until it matches up to where you want it to be. Replace and test again.
http://img138.imageshack.us/img138/3804/10hz7.jpg

http://img138.imageshack.us/img138/4438/11to7.jpg

Showing the needle returned to it's original position after changing the position:
http://img521.imageshack.us/img521/4523/12ca0.jpg


To bring the speedometer to read higher:
http://img138.imageshack.us/img138/2673/13dm8.jpg


STEP 4: FINE TUNE AS NECESSARY
In my case, I am able to remove and disassemble the cluster in under 3 minutes. Once I test it on the highway and find it to be incorrect, I would pull over on the side of the road (on a side street), disassemble the cluster, adjust the needle, re-assemble and test again. I did this until I got it right:
http://img232.imageshack.us/img232/5355/16oe5.jpg
(This image is showing 103 km/h while the GPS is showing 101 km/h. The GPS did not catch up to speed as it was not placed with a clear view of the sky. I can verify that it is correct, though). Yes I need to check my engine, get off my nuts. I used a Garmin 76s. My max speed listed on the GPS is 222 km/h, and yes the speedometer is accurate that high up! I've had it to 235 km/h with no GPS, but I'm confident that it is correct!

All the tools you'll need:
http://img521.imageshack.us/img521/2536/14su9.jpg

Basically, I did this awhile back, and the needle has not changed position since the fix, making it a permanant solution. On my cluster, I had moved it around enough that the needle started to lose some of it's rigidity against the post. Although this has occurred, it still hasn't changed position.

And like I mentioned before, all speed ranges seem to be correct now.

Now go be like me and get some speeding tickets. No more life in the slow lane:
http://img46.imageshack.us/img46/2231/winter6qh1.jpg

Nice writeup! :buttrock I will have to try this soon.

Once you do, let me know how it works out for you. I'm very interested to know!

Is this a fairly common problem on e36s?

It is fairly common on all BMWs as far as I know.

Many BMW's exhibit the same problems. They've tested E39 M5's, E46 M3's all with "optomistic" speedometers (car and driver).

Do a search on google for this. You'll hit many BMW forums where this is discussed. Many people don't even know if their speedometers are off or not, as they don't think to test them.

Volkswagen/Audi are another bad bunch for this.

I could live with 4-5km/h @ 100, but 10? WTF.

Might have to do this on mine.

This is actually good for you and everybody else on the road. This will save you from tickets and speeding.

I don't think this is a problem. They are made that way, because of your own and other people safety as qidm67 said. Many cars are like this.

It becomes redundant if you are aware of the error and mentally compensate. This is something I did to keep me from mentally compensating. If I am fully aware of the speed I drive, then safety for overestimating my speed is no longer an issue.

+1 to that, I'm always mentally compensating for the speed.

I don't have a GPS thing (might be able to find someone that I can borrow from), but I could use the OBC to read the speed by resetting the avg. speed (this is how I check now when on the highway). How accurate do you think it is? It's definitely closer than the speedo, not sure how much though.

+1 to that, I'm always mentally compensating for the speed.

I don't have a GPS thing (might be able to find someone that I can borrow from), but I could use the OBC to read the speed by resetting the avg. speed (this is how I check now when on the highway). How accurate do you think it is? It's definitely closer than the speedo, not sure how much though.
roarf,

Never had that function on my OBC (coming soon - I can report back once I upgrade to the 18 button). I know it is *closer* to the actual speed, but I'll need someone with more experience with this to chime in...

It may seem like the OBC is more acurate, but it gets the same information as the speedometer. I feel that using the OBC is not a way to compensate for this issue. Using a device that isn't in the vehicles internal wiring is the best way to test. Thanks, Jake

Well, the OBC in my car definitely reads a different number than my speedometer, and it's usually approx. 5 mph slower than what my speedo says around the 55-70 mph range.

does it mess up anything by unhooking the cluater like the manual says has to be recalibrated

does it mess up anything by unhooking the cluater like the manual says has to be recalibrated
Never had a problem yet! Just don't turn on the ignition while the cluster is unplugged, I believe that will trigger some lights (airbag).

If the speedo is incorrect, what about the odometer?

Good question, however from my experience it seems to be a needle positioning error. The speed sensor in the OBC is closer to accuracy...

I've done the test in Manitoba over a measured kilometer, and the odometer is extremely close to accurate, from what i can tell.

If not... then we are getting screwed on resale value!

The OBC function AVG Speed, as long as you reset it the moment you want to see your speed, it is very accurate. I tested it against one of those "Warning Your Speed: ____ , Speed Limit 35" signs that they posted near the school in my neighborhood to tell speeders to check themselves. I was driving 45mph, turned on cruise, checked the OBC, and thats what showed up on the sign measuring my speed.

Definitely, some speedometers seem to be fairly accurate, while the majority do not seem to be so.

With the average function, used in the method you just described, it's now spot on, putting it in line with the GPS for accuracy (just upgraded to the 18 button OBC the other day).

Bumpage. Looks like you got a chance to upgrade to an 18 button OBC, have you checked to see how accurate the OBC can read your current speed? Either by holding a constant speed w/ cruise control and hitting reset on the avg. speed menu, or by using the instantaneous speed hidden menu. I've got some time this week since I'm on spring break, I think I'm finally gonna bite the bullet and try to fix mine. I'm not sure I'll be able to get a hold of a GPS unit though.

News to report:

my OBC matches extremely closely to the GPS (OBC=101km/h vs GPS=100km/h) and the speedometer reads 100. I was SHOCKED to see it that close!!

Some OBC units are not all that correct from what I've read. That's the problem, they vary substantially, but one thing is reasonably certain: they are more accurate than the speedometer!

Thanks for the update! I would venture to guess that my OBC is pretty truthful, when my speedo reads 70 the OBC reads ~65-66. I think that's about the general consensus on how optimistic our speedos are, yeah?

Oh yeah one other thing I need to do while I have the IC apart, I think my odometer readout is loose. Sometimes the rightmost edge of the last number on the right gets covered up. Other times it's all there. :dunno Did you happen to notice how this piece is secured to the instrument cluster?

Is it really possible to get the cluster out w/o removing the steering wheel (no tilt)? I sure don't see how. Any tips? How much of a pain is it to remove the steering wheel?

edit: Geez, I finally got it! Whew! I had to wiggle and wiggle and crank the wheel almost 90 deg. clockwise before it came out. I sure hope I can get it back in. :no:shifty

Success is at hand! :alright:alright:alright

On the first try, my correction was too much by about 2-2.5 mph. Second try looks good. At 40ish or less mph the speed is slightly below the OBC, no more than 0.5 mph. But at 60 mph it is dead on. :buttrockGood enough for me, that's when I check the most anyways, when I'm on the highway. I don't check so much in the city, just keep with traffic.

Notes:

1) I don't have a tilt steering wheel. It is a bitch the first time you try to get the cluster out w/o a tilt wheel. I had to wiggle mine like crazy and turn the wheel almost 90 deg. clockwise to get it out the right side. It does take some force. It may be possible to get it out the left also, but looked less promising in my case. Oddly enough I got it back in right away on my first try.

2) It was easiest in my car to unplug the rightmost plug first, then do the other two. Reattach in the opposite order.

3) I did not disconnect my battery. I also had to unlock my steering wheel a few times during the process. Despite trying to keep from turning the key all the way to the first position (acc.) I accidentally did. I did not throw any check lights when I was all done reconnecting the cluster, so it seems to be safe enough to have the key at the acc. position to keep the wheel from locking. Do not turn the key any further though.

Glad I finally did this. Thanks for the guide beskhu!

:urtheman

Great news, roarf! Was skeptical to see if you'd ever come around to attempting it, but I see it has worked well. It's a great feeling to fix an inherent flaw in your car so easily.

From other's I talked to, removing the cluster without the tilt wheel (and steering in place) is difficult, but can be done - and once a routine established, it actually becomes easy.

As for # 3, I've done the same thing, as I stopped roadside to disassemble the cluster to get the needle position exact. Never disconnected the battery, and actually goofed and turned the ignition (now that I recall back), with no ill effects.

Congrats, hope this gets others to attempt this. It's not all that difficult!

looks like tire size issues to me.

just install bigger tires

The fact that I'm using the following sizes:
205/60R/15 - OEM size = 24.69 inches in diameter
225/40R/18 - Very close aspect ratio = 25.09 inches

To compensate for the 10% difference, I would have to run tires in diameter of 27.16 inches, increasing ride height over an inch all the way around, and allowing for super-size sidewall heights.

This would make my tire sizes:
205/75R/15
235/50R/18

In other words, Ford Explorer tires.

In other words, never.

thanks for diy beskhu3epnm' I did it today.. and didnt even have to take the steering wheel off, no tilt for me.... it's really not that difficult. but had to take it out about 6 time to get it right, but know my speedo is right on with my GPS... I'm soo happy :) :),,, thanks again.

can you leave the plastic cover off until you get it set so you can make adjustments easily without removing it then do a complete install once it is correct? ill be trying this very shortly after i get my 225 summer tires on. no problem running slower in the snow of winter anyway

can you leave the plastic cover off until you get it set so you can make adjustments easily without removing it then do a complete install once it is correct?

It might be hard to get the cluster back out if you didnt put it back together.... And the plastic is a part of the housing and doesnt remove from the housing i belive..

Excellent, so we are 3 for 3 on this modification. roarf, myself, and rize. Anyone else?

Not to jack the thread but, beskhu, how did the red gauge needle mod turn out for you? I'm thinking about doing that too and getting some silver gauge rings. Those look pretty hot in the DIY.

4 for 4. i did mine thursday. it works great runs about 1 MPH over at lower speeds and then is spot on at 80MPH which is what i wanted.

BTW i did remove my steering wheel to do it. much easier and only 2 screws and main bolt pretty easy and makes much more room to work on things.

Not to jack the thread but, beskhu, how did the red gauge needle mod turn out for you? I'm thinking about doing that too and getting some silver gauge rings. Those look pretty hot in the DIY.
Took some tonight roarfster... will have em up sometime tomorrow for you. They look great, and I got photos of both day and night shots.

russom, great to hear of the success, welcome to the club!!! Keep the streak alive... 4/4 it is!

As per request (and subsequent threadjack):
http://img338.imageshack.us/img338/9465/bfcredneedles1gq8.jpg
http://img443.imageshack.us/img443/4515/bfcredneedles2ra3.jpg
http://img338.imageshack.us/img338/2327/bfcredneedles3qx3.jpg
http://img338.imageshack.us/img338/3883/bfcredneedles4wz7.jpg
The mod was surprisingly easy to execute, and the results were fantastic. Make sure it's a genuine sharpie, as that's the only thing I can confirm will work (it's what you see here).

I've had it up since February, and have had tons of hours on the car, and there are no signs of fatigue or fading of any kind.

Chrome cluster rings I don't need but want at the moment. I think it would set off the cluster nicely.

You can compare the white needles at the beginning of this thread to the red ones you see here. My ABS light is on, leave me alone about it.:buttrock

Nice! :buttrock How many "coats" did you put on the needles? Gauge rings would definitely set it off.


Oh, and your Brake Pad and Airbag lights are on too. :shifty

Brake Pad Light = Broken wire/bad sensor as I have about 60% left on the pads.
Airbag Light = Drivers side seatbelt tensioner.... repaired with no way to reset the light. Goes out after a minute or two.
ABS = who knows.:redspot Came on at the same time as the brake pad light though, so I imagine I have some sensor wiring issues under the car.
TCS = because ABS.

I used one solid coat on the needles. Once applied it goes on pretty heavy... almost like paint. Also, the fuel economy needle has to be done redneck-style. Just that you have to hold the needle out and reach under the gauge a bit so that no white shows.

Give a few to dry, and you can touch up as necessary. Overall, gives a clean look.

can this mod be applied to the fuel mileage maker too, or possible to take it off and reposition it? for some reason when I installed my HIDs the position of the needle was changed (I don't know how this happened), it reads about 15mpg off where it should be. For example when the car is stopped it sits at the 15pmg mark instead of 0 :(. My OBD still reads correctly.
Evan

can this mod be applied to the fuel mileage maker too, or possible to take it off and reposition it? for some reason when I installed my HIDs the position of the needle was changed (I don't know how this happened), it reads about 15mpg off where it should be. For example when the car is stopped it sits at the 15pmg mark instead of 0 :(. My OBD still reads correctly.
Evan
Sounds more like a function of improper voltage going to that portion of the cluster, given the surge of power experienced by the car with the HID system?

The needle can be moved, as it has a pivot. But it would be hard to access as it's behind the tach. Give it a shot!

I'll give it a shot here in the next few weeks when I have some spare time to tear it all out (my wheel doesn't tilt). I know it was caused by a surge by the HIDs, I did a little research and I believe they are on the same circuit as the headlamps. When turned on it actually drains the power from the gauge cluster that they need to turn on. Since it still moves and works, it just is off position I was hoping I could reposition it. Thanks for the input.

Evan