Dallas temperature sensors DS18B20 in vehicle noise reduction

I'm not sure this is in the right category for this forum, so I may need some grace here, but here is my problem:

I am using 2 Dallas DS18B20 temp sensors serialized with the oneWire library on a Sainsmart Nano 3.0 with a uLCD32-PTu for displaying the live streaming temperature data and a 2 channel relay board for switch controls.

I am using this setup in my car, getting power from the 12v and the GND wires that went to a cigarette lighter jack. I'm knocking the 12v down to 5v with a regulator and capacitors to reduce noise on the circuit and connecting the 5v to my vin pin and GND to GND. I am repeating the 12v to 5v regulator setup for my LCD and the 2 channel relays as well so they each have their own individual power supply to reduce noise and strain on the Arduino.

This setup seems to work fairly well as it is, but I am consistently seeing in consistencies in the controller's behavior while driving the car. Voltage fluctuates in cars due to the alternator and stress coming off and on the engine, so naturally I expected a few bugs along the way...

What's happening is that my sensor data sometimes freezes on my LCD display and regardless of the actual temperature, the temperature readout on the LCD stays the same until the Arduino is reset. What is also happening usually during acceleration is that the LCD will display red Xs in place of the data, meaning the arduino is receiving an unreadable digit from the sensors. This also usually persists until I reset the arduino.

Ok, now here's my question: How should I go about fixing this problem? My device is virtually useless in this state and I need to see consistent temperature data along with no data freezes for functionality purposes.

I am planning on replacing my standard 3 strand wire (5v, gnd and data) with a shielded wire and grounding the shield to the frame of the car. Hoping this will reduce the noise from the engine bay and solve my problem, think it will work? I can post my whole arduino code if necessary, but I think this is a hardware issue

Gustermaximus:
I am planning on replacing my standard 3 strand wire (5v, gnd and data) with a shielded wire and grounding the shield to the frame of the car. Hoping this will reduce the noise from the engine bay and solve my problem, think it will work? I can post my whole arduino code if necessary, but I think this is a hardware issue

It might. I think these sensors can be fussy about the quality of the cable, and you don’t need a car to find that out.

It seems like there are a lot of "ghosts" in the system here and based upon the way a car radio can play alien noises through the radio, it may have something to do with the weird bugs in my device. Going to install a new shielded and grounded to the frame of the car wire tomorrow morning and see how it does.

Are there any other commonly used method to increase sensor reliability other than get a good strong cable?

Show us the code. At least the freeze doesn’t look like a hardware problem. I would bet for memory problems.