Yes, I know - Not another temperature thread

This one is more of a report just to share information.

I have a 2002 DII with 186k mile on the clock, that I picked last year with 177k miles. I am the 3rd or 4th or 5th or #X owner. The P.O. had the head gaskets done at 155k miles (I have the receipts for the head gasket kit from AB and the heads where taken to a machine shop).

Last week I had to take extended drives to see some customers - 200 mile commute one day followed by 100 mile trip the next. During the 200 mile trip I noticed a faint coolant smell. Checked it out when I got back home and found the expansion tank had lost coolant - overflowed. Let it sit over night. Filled it up and bled the air from the hoses. Drove it for the 100 mile trip. Same result.

Plugged in the Code reader to watch live status and had commute temperatures running 194°F - 205°F, with peaks up to 212°F. Same temps that I've had since I bought it. I had already replaced the fried Aux fan last year and it comes on as designed. Decided to replace the expansion tank cap. Figured its original and, at only $18, should be replaced anyway. Drove it two days and no more coolant loss. Third day I made another extended trip - only 80 miles - but at the end had lost coolant and had temperatures spike up to 227°F. Not good - very-very BAD!

After it had cooled off, I checked out the operational condition of the fan clutch. Grabbed hold of the blades and found that the whole assembly wobbled.

Ordered a warm weather thermostat, water pump, new water pump bolts, fan clutch, and new fan blade assembly (broke a fin off the original one getting the old fan clutch off), and picked up a few bottles of fresh green 50/50 coolant.

The thermostat is Britpart #PEL500110 advertised as a 82°C / 179.6°F. I found that the internal Thermostat ring is actually marked 78°C / 172.4°F.

The water pump I replaced was not the original - no clue how long ago it was installed, but the shaft was wobbly - tells me that the fan and fan clutch were most likely original.

Spent a few hours under the hood after work yesterday, and aside from smacking myself in the noggin with the fan wrench (it slipped and my fat head was in the way) the entire project went well.

This morning’s trip the temps stayed between 84°C - 91°C / 183°F - 196°F. Result !


The primary point is if you are going through the trouble of replacing your OEM thermostat with a warm weather unit, it's a good time to change your coolant and check the condition of your water pump, fan and fan clutch. Don't just replace your water pump and put the old fan clutch assembly back on - replace them both. If your fan blade assembly is original - check its condition. It there are cracks or bits of fin missing - replace it.

I spent $360 for all the bits. Cheap compared to over cooking my engine.


Rover On!

 

Good job! Stay cool this summer!

 

Its been about two (2) months since I performed the worked detailed in post #1 above. It has finally warmed up enough here in the Mid-Atlantic area to check on the effectiveness of my work.

Went out for a 30 minute drive at lunch today. Air temperature is about 86°F. Second photo shows the engine coolant temp after the drive and parking outside my office for about 5 minutes.

So far - so good.

 

I see your truck is displaying temps in Centigrade. If you would like to have Fahrenteit temps displayed press and hold the recirculate button (far right) and then immediately press and hold the On/Off button (far left). Hold for three seconds until you hear a beep and then release the buttons. The display will then be switched to Fahrenheit.

 

Appreciate the tip.

The display units are purposely in °C.
I do the conversion in my head to figure out the °F temperature equivalent. °C x 2 - (10%°C) + 32 = °F . Keeps me from getting bored on long drives.

Its also fun to change the odometer to KM before visiting the stealership or other repair shops. They are usually amazed to +300,000 displayed on a Disco.