Paul Kemp
Expert Member
- Joined
- Jan 4, 2021
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I’ll see once it gets proper cold again. Also noting that was my previous diesel last winter. Nothing really indicated that the thermostat was faulty though. Came up to temp just fine, they just take more time than petrol cars as you noted.That's pretty odd, and I'm going to say perhaps your water pump is getting weak and it can't keep up enough flow through the heater core when the engine is idling. Does the situation improve if you rev a bit?
Spent an evening tuning this one a while back and the tuner noted how difficult it was keeping diesels hot on the dyno on cold nights.

