My oil and water temp kept dropping down to cold when wires on coolant temp sender broke.
The car ran lumpy as well because ECU thought engine was cold.
New coolant temp sensor fitted and water temp juust over half and oil temp at half all the time when warm.
I dont have the 'modine cooler' in mine any more as it sprung a water leak, so i bypassed it.
Hope that helps?!
Cheers
Kevin