Speedometer Problems

[amtrakmatt]

Has anyone had problems with the speedometer not wanting to pass the 125MPH mark. I was trying to catch up to a BMW 540, once I hit around 125MPH it started bouncing up and down. I thought it was go to 140MPH.

 

[Mr Anonymous]

Lemme guess, you have a '98???

Yep, it's a '98 thing.

Cams welded yet?

Welcome to the forum!

 

[multishowner]

mine does it at about 110... it bounces for a few, then drops to zero... the good is that you should never hit the factory electronic speed limit because it uses this input from the system... the bad is you won't know how fast you are going when the police pull in behind you...

Cheers!!

 

[amtrakmatt]

Thanks for the info guys. Yes, it's a 1998, I'm guessing that problem isn't worth fixing, since it's not too often we're going over 120 mph. I had my 98 SHO welding about a month after buying. John Stossel in Los Angeles did a great job welding it. Also replaced all coils after several failures.

Matt
Orange County

 

[SHOZ123]

The cure is though to be a non-'98 ABS controller although it is just theory....

 

[stephen newberg]

I thought we had eliminated that as workable during our session of data collection?

pax, smn

 

[SHOZ123]

It was the PCM that was eliminated. I don't know of anyone who has replaced the ABS controller on a '98 with some other year to cure the speedo problem.

 

[stephen newberg]

Right. Well, all we have to do now is talk someone into giving it a try...

pax, smn

 

[98SF19]

update?

I happened to be researching speedo and/or tach signal problems and found this thread. It's over 5 years old, so is there anything new on the non-ABS controller curing the 98 high end speedo problem?

Thanks!

 

[roland]

problem was the 98 SHO can't catch a 540i.

I didn't know the 98's have this problem, I'm going to look at one tomorrow so that's a good thing to know......

 

[SHOZ123]

The last time I tried to bury the speedo the pug was giving me worried looks.

 

[roland]

Has anyone ever actually gotten to 150 in a 3G SHO?

 

[SHOZ123]

.....

 

[stephen newberg]

Yup.

Had no problem with the last eager 540 I ran across, either.

pax, smn

 

[roland]

What altitude did you push it out at?

 

[stephen newberg]

I think the track on the South Shore of Nova Scotia is about 50 meters or so above sea level. Might be a bit more, but its certainly not very high. Both the car and I were younger then, too. Quite a bit younger, actually...

pax, smn

 

[98SF19]

Soooooo . . .

Stephen and Paul, so you've both defeated the speedo problem (not sure if Paul owns a 98)? Does this mean that you've installed a non-98 ABS controller? I very much doubt that I'll ever take my '98 over 100mph or so (by choice), but in the event that I sell her, it'll likely be to someone already familiar with the issue, and I'd rather not get into the whole argument of the cost of a non-98 unit and the labor needed to install it vs. the difference in the offer.

 

[SHOZ123]

I had a 97

 

[stephen newberg]

Mine is not fixed, the speed and time runs were done at a track and speeds radar indicated.

Though Paul suggested a possible fix some time ago, I have not heard of anyone having tried it.

pax, smn

 

[zach44102]

Has anyone ever actually gotten to 150 in a 3G SHO?

Not driving but riding yes.