Skip the auto shop - Our mechanics make house calls

Q: The motor starts lurching and my speedometer and tachometer start pegging out, the truck keeps running though

asked by on

As I'm driving along the truck will start lurching and the instruments will start fluctuating, I can continue driving and the problem will stop but it will do it again, sometimes it smells like the exhaust is leaking. I replaced the battery a month ago and there was a starting issue with it, one of the wires to the positive terminal, the one with the fuse link, was sketchy. I would have to jiggle it to get it to start, I replaced the fuse in the link. What's going on with this thing.

My car has 311518 miles.
My car has a standard transmission.

A: Hi there. It would appear, there is a poor ...

Hi there. It would appear, there is a poor electrical connection or wiring issue still present. This would account for the engine lurching (a loss of power or ground to the fuel or ignition system) and erratic speedometer and tachometer. It may be power supply issue and/or poor ground related issue. Taking another look at the replaced fusible link(s), may resolve the problem. It could be, a charging system related concern. A failed alternator diode(s) could create unusual electrical problems. The exhaust smell could be, an electrical smell. I recommend having your vehicle’s engine starts lurching and erratic speedometer and tachometer be diagnosed and repaired by a certified technician, such as one from YourMechanic.

Was this answer helpful?

Need advice from certified mechanic? Get help now!

Over 1000 mechanics are ready to answer your question.
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Ask a Mechanic
(100% Free)

Have a car question? Get free advice from our top-rated mechanics.

Ask A Mechanic
Over 10,000 questions answered!

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing

Get a quote

What others are asking

Q: battery cable replacement

Hi there. If you're trying to change out your battery cables, we actually have a great how to replace the battery cables article that will give you step-by-step instructions. If you read this article and figure out that maybe you...

Q: Truck tugs during acceleration when letting off the brake pedal

What you'd want to do is jack the car up when it acts up like this. Check the wheels and see if they are sticking. If they are sticking, fix that first. If the back ones are sticking, you'll need...

Q: I am having a problem with degraded acceleration/mileage.

I would recommend checking/testing the O2 sensor and the MAF (Mass Air Flow) sensor. When either of these two sensors are not working properly, as you may know, they will send inaccurate signals to the ECM which will then, in...

Related articles

What Causes Hoses to Leak?
While the largest part of your engine is mechanical, hydraulics plays a significant role. You’ll find fluids at work in a number of different areas. Your car's fluids include: Engine oil Transmission...
P0052 OBD-II Trouble Code: HO2S Heater Control Circuit High (Bank 2 Sensor 1)
P0052 code definition HO2S Heater Control Circuit High (Bank 2 Sensor 1) What the P0052 code means This code is seen when the Engine Control Module (ECM) tries to control the...
How Much Does a Mechanic Make in Vermont?
Automotive technician jobs in Vermont have an average mechanic salary of $37k, with some mechanics earning a salary of $53k.