geordi, thank you for the excellent explanation of the function of the Viscous Heater. If the 2.8 thermostat has failed in the 'open' position, can you share your opinion for an improved replacement for the OEM thermostat?
We are picking up our 'first ever" 2005 KJ 2.8 CRD later today.
I have read the Noobie Guide and hope to learn the quirks of the 2005 Liberty Limited CRD quickly.
Thanks to all for contributing to the GREAT resource LOST JEEPS.
geordi wrote:
If the engine is still assembled, then you aren't looking at the timing belt, you are looking at the serpentine accessory belt.
The timing belt is hidden inside a cover (the black metal behind the belt is the outer cover) and cannot be seen without disassembling the accessories. If your CRD has not had the timing belt replaced though, you are WAY overdue on age of the belt. The actual water pump is driven by the timing belt.
To answer your questions though: The top pulley / device on the serpentine system is either the alternator or the viscous heater. You can tell the difference between them because the heater will have hoses going into the top of it. There is a plug on the side of this device that you can unplug without causing any error codes, and that will disable the heater. It is possible that your engine is struggling just at idle because it is getting air in the fuel or the filter is close to needing to be replaced - most filters only last about 10k-12k miles.
This device does put a significant load on the engine and will cost you quite a bit of fuel mileage if your thermostat is failed open (most have) and the engine never gets up to temperature. The gauge should be straight up or just a hair lower than dead center, if it is down around 1/4 on the temp gauge, then that is the sign your thermostat has failed and the viscous heater is working overtime to heat up the water. You don't need it to do this, but you do want to replace the thermostat at some point. The primary point of the viscous heater is to rapidly heat up the water on a cold start so you get warm air in the cabin sooner. It has no purpose for the engine's performance.
The timing belt is hidden inside a cover (the black metal behind the belt is the outer cover) and cannot be seen without disassembling the accessories. If your CRD has not had the timing belt replaced though, you are WAY overdue on age of the belt. The actual water pump is driven by the timing belt.
To answer your questions though: The top pulley / device on the serpentine system is either the alternator or the viscous heater. You can tell the difference between them because the heater will have hoses going into the top of it. There is a plug on the side of this device that you can unplug without causing any error codes, and that will disable the heater. It is possible that your engine is struggling just at idle because it is getting air in the fuel or the filter is close to needing to be replaced - most filters only last about 10k-12k miles.
This device does put a significant load on the engine and will cost you quite a bit of fuel mileage if your thermostat is failed open (most have) and the engine never gets up to temperature. The gauge should be straight up or just a hair lower than dead center, if it is down around 1/4 on the temp gauge, then that is the sign your thermostat has failed and the viscous heater is working overtime to heat up the water. You don't need it to do this, but you do want to replace the thermostat at some point. The primary point of the viscous heater is to rapidly heat up the water on a cold start so you get warm air in the cabin sooner. It has no purpose for the engine's performance.
