The 75 and ZT Owners Club Forums - View Single Post - Couple of theories on the diesel cool running problem?

HarryM1BYT · 6th January 2016, 05:32

I agree with the diesel being very thermally efficient, so there is very little heat being generated. What small amount of heat there is, can be lost through the airflow around the block and head.

However, keep in mind that a considerable amount of what little heat there is, can be dissipated in warming the cars interior via the heater matrix. After getting the car interior and the engine up to full temperature driving - I had to wait around for 30 minutes in close to freezing temperatures. to keep the car warm, I kept the engine running, but the car interior and the engine cooled down quite rapidly.

The radiator itself is far too big for the engine, but that should not make much difference to the warm up cycle of the engine, if the stat is working properly.

The only way for the 75 diesel to stay at temperature in cold weather conditions is for it to be working hard and be supplemented with an FBH. Even opening the windows can dissipate enough heat via the matrix, to bring the engine temperature down.

6th January 2016, 05:32	#4
HarryM1BYT This is my second home 75 Contemporary SE Mk II 2004 Man. Sal. CDTi 135ps, FBH on red diesel, WinCE6 DD Join Date: May 2010 Location: Leeds Posts: 17,273 Thanks: 2,160 Thanked 2,061 Times in 1,586 Posts	I agree with the diesel being very thermally efficient, so there is very little heat being generated. What small amount of heat there is, can be lost through the airflow around the block and head. However, keep in mind that a considerable amount of what little heat there is, can be dissipated in warming the cars interior via the heater matrix. After getting the car interior and the engine up to full temperature driving - I had to wait around for 30 minutes in close to freezing temperatures. to keep the car warm, I kept the engine running, but the car interior and the engine cooled down quite rapidly. The radiator itself is far too big for the engine, but that should not make much difference to the warm up cycle of the engine, if the stat is working properly. The only way for the 75 diesel to stay at temperature in cold weather conditions is for it to be working hard and be supplemented with an FBH. Even opening the windows can dissipate enough heat via the matrix, to bring the engine temperature down. __________________ Harry How To's and items I offer for free, or just to cover the cost of my expenses... http://www.the75andztclub.co.uk/foru...40#post1764540 Fix a poor handbrake; DIY ABS diagnostic unit; Loan of the spanner needed to change the CDT belts; free OBD diagnostics +MAF; Correct Bosch MAF cheap; DVB-T install in an ex-hi-line system; DD install with a HK amp; FBH servicing. I've taken a vow of poverty. To annoy me, send money.