Tachometer Jumps Around
#1
Tachometer Jumps Around
I did a search, but didn't find exactly my problem. First off, I have a 98 Civic LX with a standard transmission. Every so often (becoming more frequent) my RPMs jump around. The video I linked to below shows it jumping up, but it also drops down to nothing too. It's not just the tachometer malfunctioning because the car surges and coasts according to what the tach is doing. When it drops down to zero, the car coasts and pressing on the pedal has no affect. Typically it happens at higher speeds (between 60 and 75 ish), but it's so random that I wouldn't count out other speeds also. And it doesn't matter if it's raining, dry, cold, or hot outside. So far it only happens after driving for a little while. This morning it was after about 40 minutes, but usually it's closer to an hour. It also only lasts a few of seconds, then everything is back to normal. It might happen once during an hour+ trip, or it might happen several times. I mostly drive with my cruise set and when it drops down it doesn't even kick the cruise off (which is weird). But it also happens when the cruise is not set. Recent repairs since summer: Tune up with plugs, wires, and distributor cap, timing belt and water pump, new (used) transmission. But it was happening before all those repairs too. Had the check engine codes read last night and got: misfires on all four cylinders and catalytic converter (Can only assume they are related to this problem, but I don't know for sure.) Took it to my mechanic when it first happened, but he couldn't reproduce the problem so he couldn't do anything. Not sure what else you might need to know. If anyone can help, it would be much appreciated.
https://vimeo.com/145991836
Thanks,
Scott
https://vimeo.com/145991836
Thanks,
Scott
#2
I did a search, but didn't find exactly my problem. First off, I have a 98 Civic LX with a standard transmission. Every so often (becoming more frequent) my RPMs jump around. The video I linked to below shows it jumping up, but it also drops down to nothing too. It's not just the tachometer malfunctioning because the car surges and coasts according to what the tach is doing. When it drops down to zero, the car coasts and pressing on the pedal has no affect. Typically it happens at higher speeds (between 60 and 75 ish), but it's so random that I wouldn't count out other speeds also. And it doesn't matter if it's raining, dry, cold, or hot outside. So far it only happens after driving for a little while. This morning it was after about 40 minutes, but usually it's closer to an hour. It also only lasts a few of seconds, then everything is back to normal. It might happen once during an hour+ trip, or it might happen several times. I mostly drive with my cruise set and when it drops down it doesn't even kick the cruise off (which is weird). But it also happens when the cruise is not set. Recent repairs since summer: Tune up with plugs, wires, and distributor cap, timing belt and water pump, new (used) transmission. But it was happening before all those repairs too. Had the check engine codes read last night and got: misfires on all four cylinders and catalytic converter (Can only assume they are related to this problem, but I don't know for sure.) Took it to my mechanic when it first happened, but he couldn't reproduce the problem so he couldn't do anything. Not sure what else you might need to know. If anyone can help, it would be much appreciated.
https://vimeo.com/145991836
Thanks,
Scott
https://vimeo.com/145991836
Thanks,
Scott
Thread
Thread Starter
Forum
Replies
Last Post
swamped
Mechanical Problems & Technical Chat
2
08-29-2010 06:41 PM