I should have taken the new car.

December 10, 2005 1:30 AM

Car Question. My speedometer just broke. How worried should I be?

A bit more information. The car is a 1996 Honda Del Sol. It is about 3000 miles past due for an oil change. I just drove it roughly 500 miles with about 2 hours (out of 8) in stop and go traffic. (I didn't notice how old the oil was until after I had driven that much.)

The speedometer started acting funny in the last 100 miles, occasionally just falling to zero for short periods of time (a few minutes). Everything else seems fine, though the transmission stutters a little bit when the speedometer needle is either in the middle of dying (or coming back to life).

Finally, the check engine ligth came on just before I got back to my hotel (I'm about 120 miles away from home). It is my understanding that the speedometer thing is not a huge issue. I probably would have just driven the car until I got back to my hometown on Monday but the check engine light has me worried. Would a broken speedometer make that light go off? Should I suck it up and take it to a nearby mechanic? Should I be worried about driving it 10-20 miles?

posted by oddman to travel & transportation (23 comments total)

a) The lack of oil change is probably not a huge deal. Make sure you have enough oil in there, that's the most important part. Oil changes should be every 5,000 to 10,000 miles, depending on a variety of factors. (The 3,000 mile thing is a myth.)

b) The speedometer problem is no big deal. It's obviously an important gauge for driving, and the car won't pass most state inspections without it, but it does not affect the running of the car whatsoever.

c) The check engine light can be a really big deal, but in most cases it isn't. It comes on when some problem has been detected, which can be something minor, like an emission control device (oxygen sensor, EGR valve), to something major (extremely low oil pressure, engine siezure imminent). There are generally ways to get the error code out of the car, using a paper clip, at least on older cars like yours. If you're interested, let me know and I'll help you figure out how to do it. Otherwise, take the car to Autozone (or similar), and they'll generally scan the computer for codes for free, and tell you what's wrong. Then you can decide how you want to address the problem.
posted by knave at 1:35 AM on December 10, 2005

This page has diagnostic procedures and error codes for your car. Your car has OBD II (second generation on-board diagnostics), which generally require a scan tool to retrieve data from. However, the page I linked describes (in very little detail) a procedure to get the code manually. Scroll down to 96-97 del Sol.

Where they say "MIL", it means malfunction indicator lamp, and the idea is this: short the connection they tell you to make (with a paperclip or a wire), turn the key to the "on" position, then watch the check engine light. It should begin flashing. Count the flashes, and it spells out a 4-digit error code. Then lookup that code in the chart to see what's gone wrong. I've done this on Toyotas, Nissans, and VWs, but never Hondas. It's generally pretty simple, a novice can do it if he knows where to short the diagnostic connection.
posted by knave at 1:43 AM on December 10, 2005

More info here, Honda codes might only be 2 digits. (See the MIL column in my error codes link above.) According to this page, it's long flashes for the first digit, short flashes for the second digit. Multiple codes may be stored, and displayed in order. Sorry for the multiple posts, hope it's helpful.
posted by knave at 1:48 AM on December 10, 2005

Knave you rock. I ran the circuit test and got a MIL code 17. It seems the Honda is having some trouble with the VSS. (It turns out the car is a 95, but I don't think that matters for MIL.) This makes sense since VSS (from what I gathered on the net) is like an electronic speed sensor.

I haven't been able to find a lot of information on what the VSS does in a Del Sol. It seems to regulate cruise control (and mine was flaking out) and possibly some safety systems. But I can't find anything definitive. It looks like I should be able to get it home.

Any thoughts?
posted by oddman at 2:42 AM on December 10, 2005

It's not true that the car will necessarily run the same with a malfunctioning speedometer. The ECU ("engine computer") as well as the automatic transmission both take the speedo input as a factor for many decisions. This could very well be why the check engine light is on. The ECU/trans might even enter limp-home mode without it.
posted by Rhomboid at 3:00 AM on December 10, 2005

Obviously he's not in limp mode, or I think he would have noticed. I think the car is perfectly safe to drive, as long as you made sure your oil level is fine (most cars lose a little oil, and if it's been a while since the last change, you might be low). And do get that oil changed when you get a chance.

Rhomboid, can you shed some light on the ECU decisions impacted by the VSS? I could see it being used for a speed-limiter/governer, but not much else. Not implying you're wrong, just curious.
posted by knave at 3:06 AM on December 10, 2005

Ok. I've got 1.5 hours of sleep time left so this will be my last post for a few hours. I don't think I'm in limp mode (which seems to be a sort of emergency setting for malfunctioning sensors?). The car was running fine so long as I didn't use cruise control. Though it is possible (I guess) that it is in limp-home mode and I have driven it enough to notice the considerably poorer mpg.

I will definitely check the oil in the morning before starting the car.
posted by oddman at 3:24 AM on December 10, 2005

This happened to me...even though you've got things somewhat figured out already, I'll add my part. When the spedometer on my car started acting funny, the check engine light would come and then it would idle roughly. But it still ran fine, overall. I got it fixed after some time..it was some sensor. (Probably the same one...it was on a Honda Accord.) I think you will be fine driving the car home or wherever you need to go, but you should probably get it checked out when you get back. I found that a broken spedometer freaked me out more than the check engine lights.
posted by jetskiaccidents at 6:54 AM on December 10, 2005

Certainly in the UK, a broken speedometer would make the vehicle "dangerous to drive" and thus unroadworthy and illegal - is this not the case in the USA?
posted by benzo8 at 6:58 AM on December 10, 2005

This happened to me also six months ago - I see you think you know what the problem is already, and I hope you're right that it's something you can drive home with - but I'll just mention my story. I have a '97 Toyota Tercel, automatic transmission. I was driving down the highway to a destination two hours away and my speedometer cut out and dropped to zero, which freaked me out. When I pulled off the highway onto a country route I pulled over, turned the car off, and turned it on again. Not only did the speedometer stay broken, the check engine light came on. But everything sounded fine. I drove gingerly on to my destination and had my aunt's husband look at it there. He said everything looked fine as far as he could see and maybe a sensor had crapped out, no big deal, I should get it looked at when I got home.

So later that day I drove it home. About halfway home, my tranmission died completely. I had to wait a couple hours for a tow truck at the side of a big road with two babies in the car (one was 7 weeks old). Luckily I had my mother with me, but the sun went down while we waited so it was Not Fun. Anyway, I had to get the whole transmission replaced; the speedometer had broken because the transmission was about to go. So. In my experience, a broken speedometer is something to worry about! Not meaning to scare, but in your situation, because of my past experience, I would be more cautious and get it looked at, or at least make sure you have AAA if you run into trouble on your way home.
posted by Melinika at 7:59 AM on December 10, 2005

Driving with a broken spedometer is illegal in Canada and almost certainly the USA as well. But I'm pretty sure, as long as you're not speeding (good luck figuring out if you are or not) any cop that somehow noticed would take it like a broken headlamp. He'd just warn you that it needs to be replaced, add the warning to your record, and you'd have a few days to get it fixed beforfe the next officer gets a bit more serious.

Eventually it might lead to a tow truck if you were being pulled over all the time, but I can't imagine an officer being bothered with a ticket for his...

[FYI, my dad drove for about 2 or 3 years with a broken spedo and the only thing he ever got pulled over for was seatbelt infractions...]

Just don't go faster than other traffic and nobody will care. :D
posted by shepd at 8:21 AM on December 10, 2005

Not to be a smart-aleck, but how would a police officer know that your speedometer was broken?

I mean, it would be reading '0 mph' when he/she has their head in the window, wouldn't it?
posted by Wild_Eep at 8:33 AM on December 10, 2005

This is a super-common problem in Hondas. I even have a friend with an Acura NSX (serious expensive racing machine) which had this problem. Replacing the speed sensor is not that expensive. I had it done for about $100 as I recall, in my old Civic. When it's really dead, it WILL cause your check engine light to go on. You can ignore this if you want; all it's saying is that the car ECU thinks your car is revving much too high for the speed you're going (which it thinks is zero). As long as it really ISN'T revving too high, you're fine. It IS illegal to drive with a broken speedometer, and personally I find it really annoying not being able to know my speed :-)
posted by autojack at 9:34 AM on December 10, 2005

>I mean, it would be reading '0 mph' when he/she has their head in the window, wouldn't it?

Yeah, but I've seen cop cars pull up beside me (and other cars) while driving on highways and take a good look into your car. I wouldn't be surprised if they could see the spedo then. Or, if you were speeding and were dumb enough to mention it, they would probably take a look...

But otherwise, it wouldn't be obvious when stopped unless it got stuck at speed instead of at 0... :-)
posted by shepd at 9:40 AM on December 10, 2005

Wild_Eep - I'd suggest the problem was not "can I get away with it?" but "should I do it?" Driving with a broken speedo may be impossible to detect and may not cause any issues (if you can judge speed well) but should something untoward happen - an accidented unrelated, perhaps, to the speed the car was going - you can guarantee an insurance company would not pay out if the car was deemed unroadworthy and illegal...
posted by benzo8 at 10:41 AM on December 10, 2005

knave scribbled "Rhomboid, can you shed some light on the ECU decisions impacted by the VSS? I could see it being used for a speed-limiter/governer, but not much else. Not implying you're wrong, just curious."

Even on my ancient 89 Caravan, 2.5L Turbo Automatic, the speed sensor input is used by the SMEC to control: cruise control, torque convertor lock up, suppress cold temperature radiator fan engagement, control idle air when shifting from park/neutral to drive/reverse, and to modify fuel maps. On a Chrysler product with the 4AOD transmission the speed sensor is also one of a few inputs used to set shift points.

Unless the last 3000 miles were at burning man or Indy or something you've got lots of safety margin on oil life so don't sweat that.

Don't sweat the legallity of driving with no speedo either, I've never even heard of someone getting a ticket for that. I'd bet anyone who has got a ticket for it also got a ticket for doing something stupid at the same time. Just don't volunteer it as an excuse if pulled over for speeding. Just get it fixed as soon as you can.

If it really is as common on Hondas as autojack says and it is easy to replace I'd carry a spare. I could replace the speed sensor on my van in about 10 minutes on the side of the road with nothing more than a 10mm wrench.
posted by Mitheral at 10:51 AM on December 10, 2005

benzo8 scribbled "an accidented unrelated, perhaps, to the speed the car was going - you can guarantee an insurance company would not pay out if the car was deemed unroadworthy and illegal..."

How are they going to prove it wasn't caused by the accident if oddman doesn't volunteer that information? OBDII doesn't record anything but instanteous status. It's not like he's driving with no brakes. As long as he maintains a safe distance and keeps up with traffic he'll be fine. I drove thousands of miles with a vehicle not even equipped with a speedo and never once had any problem because of it once I passed the intial inspection.
posted by Mitheral at 11:02 AM on December 10, 2005

I have a '97 Toyota Tercel, automatic transmission.

They only made automatics that year, I have a CE as well :)

Driving with a broken speedometer is illegal in Canada and almost certainly the USA as well.

Not only is it legal, it's a valid defense for speeding in most states. By the way, all traffic laws are state laws in the US, you can never really make a blanket statement about traffic laws in the USA.

Also, when my Speedo broke I bought a GPS receiver to see how fast I'm going. My new speedometer is still off by a few mph.
posted by delmoi at 11:03 AM on December 10, 2005

Er, and if it is illegal it would probably be an 'equipment' violation, the same class as having a broken taillight or whatever.
posted by delmoi at 11:07 AM on December 10, 2005

I had a Windstar with a flaky speedometer -- OK up to 30 m.p.h. or so, but essentially useless at highway speeds as it would either read ridiculously high (120 or so) or just bounce around over a 20 m.p.h. range. The odometer, cruise control and everything else seemed fine, so I never bothered to get it fixed and just used my GPS when I went on trips. Actually easier to read, if anything, than the real speedometer and definitely more accurate.

The only time I got stopped by a cop, was of course for speeding -- no interest was paid in the fact that my GPS was plugged in or that the speedometer was broken. Her radar gun was obviously accurate, because her report of my speed matched the readout on the GPS. Luckily she let me off with a warning.
posted by Quinbus Flestrin at 3:51 PM on December 10, 2005

Thanks to everyone for responding. I drove it around today and had not troubles (I kept it off cruise control). I'm going to get it home and have someone look at it in a day or two.

For the curious, I can track my speed pretty well with the tachometer. 2700 RPM corresponds with about 65 MPH, while 3000 RPM is just about 75 MPH. I checked this before the troubles began. It is sort of like having a bizarre speedometer.
posted by oddman at 3:55 PM on December 10, 2005

In addition to what Mitheral said, the torque converter lock-up could be a major thing. If you habitually leave the speedo unconnected/not working, the trans will never signal the TC to lock up and this will cause a significant decrease in mileage and trans life. Most auto trannies have a set point around 35 to 45 MPH under which the TC will never lock, so if it thinks you are always going 0 it will never happen.
posted by Rhomboid at 7:50 PM on December 10, 2005

Driving with a broken spedometer is illegal in Canada and almost certainly the USA as well. But I'm pretty sure, as long as you're not speeding (good luck figuring out if you are or not) any cop that somehow noticed would take it like a broken headlamp. He'd just warn you that it needs to be replaced, add the warning to your record, and you'd have a few days to get it fixed beforfe the next officer gets a bit more serious.

I had the same thing on an older Toyota. I drove like that for ages (I generally only drove to work and back, so I just kept pace with everyone else). Once, when driving later than usual, I got pulled over.
I was given a "ticket" that said I had three business days to get it fixed, have the mechanic sign off on it, and return it to the police station. No fines or anything if I did that. If I didn't get it done it would have been a fine.
posted by Kellydamnit at 3:10 PM on December 11, 2005