My beloved JCW has a problem that i cannot track, it exhibits a few symptoms all at the same time and only after prolonged wet & colder days. It started in Feb 2015, by April the problems had gone until this weeks rain! Its been fine all Summer!

  1. Temp gauge doesn't read
  2. Start stop doesn't work
  3. Sluggish at low revs
  4. (this is the weird and perhaps unrelated one) The suicide door doesn't open.

The car can start with this problem then after 30 mins it might go away, also it can start perfectly fine then have a problem while driving! I'm guessing there is some sort of problem with water getting in and stopping the reading of the temperature because the 1st 3 issues can be explained if the engine doesn't think its hot enough, with the door i'm thinking its not unlocking as the handle pulls and works unless the 1st 3 problems persist.
An unrelated issue is a small oil leak from the rocker cover (which im posting for completeness and know i need to get sorted and will in the next month).

Any ideas? im completely lost!