1998 Renault Laguna temp gauge up and down but not over heating driving me mad

Could a problem with the gauge itself, you might need a new display. Have you had an Auto-electrician look over it?

Hi I had the same problem, after a while the car would sometime not start, breakdown said it was the alternator, I got a new one still the problem was there. after 2weeks the car would not start at all, my local repair garage could not find the problem so they had an auto spark to have a look at it, he found the problem, it was a loose earth wire in the steering loom,I have had no problems since. After I spent nearly £200 it was a simple thing, oh and I even had the car on a machine and it could not find the problem. hope this is helpful to you, the repair garage said they were glad it stopped altogether as they then knew it was something silly
yvonne

must be a commom fault with renault i have 1.9 dti took it every where but no one could find what it was changed every think and yes it was the earth strap.........