Hi Folks,

I am new around here so please pardon my ignorance. I have a 1998 D1 with it seems several issues. First one is overheating. I have tried to purge all of the air out of the cooling system numerous times but I absolutely cannot get all of the air out and can still hear a slight "Waterfall" sound behind the fire wall. Any tips of getting it all out? It will overheat after going a short distance and if sitting at say a red light or heavy traffic but the temp drops dramatically when you start moving over about 55 MPH but is still running high normal in motion. Thermostat is new and I do not see any signs of head gasket failure (white smoke from exhaust, water in oil cap, frothy oil etc...) Also, when the vehicle is at idle when hot, the oil light will come on but will go out when the engine is revved slightly. The oil light is accompanied by a clicking noise at idle, but will diminish when the engine is revved. Oil level is normal. Could this be a lifter or pending oil pump failure? I appreciate any responses to point me in the right direction. Thanks.

 

1. Consider the heat gauge an approximate view of what is happening. At 50% it can be 225-230F. A scanner or Ultra Gauge can show you what is really happening and if you are making progress. Plugs into OBDII port.

2. The viscous fan clutch impacts heat at idle and slow. Not at 55 mph. Test by spinning fan by hand and releasing when cold (engine off). Should feel stiff. Test again after warming up. It should stop spinning in less than one revolution. If it freewheels, the clutch has lost the internal fluid. A replacement clutch is from a 2000 Chevy Express van, 4.3 liter, w/o AC. About $60.

3. The radiator could be sludged up with calcium. You can check temps across fins of rad top to bottom. More than 10F makes you think lower rows are blocked. Your rad can be removed, and taken to a small indy rad shop. They can unsolder a tank, and rod out the calcium. Plus hot flush. About $75 near me in farm country. Aluminum replacements are about $235.

4. I run a 180F stat in my 97, idles at 180-183, up to 187 ish at freeway speed. If you put stat in backwards, bad things happen. Spring end goes inside the block.

I'd bet you have more than one problem.

 

Your oil light coming on when running hot is because the oil is to hot to do its job and is thinning out to the thickness of water, thats why you get the clicking noise, the engine is running dry.
Increasing the RPM moves the oil fast enough to cool it off just enough to thicken back up.
Check your belt routing, there is a link in the tech section.
If you have a stubborn air pocket in the heater you can reverse the heater hoses and drive it for a day or so until the air is purged., then swap them back, or leave them.

 

Maybe the cap on your coolant reservoir isn't sealing properly and is letting excess air into the system. Could also be a very slight leak on a hose or something letting air in.

 

As stated, overheating, based on your description, is likely either the viscous clutch (https://landroverforums.com/forum/di...02/#post331068) for the fan, and/or the radiator. At the age of your Rover I'd figure on both.
If the radiator is beyond saving with a roding you can get a heavy duty recore if the tanks are good. It costs more than one of the Al jobs, but you'll have a better product.

What temp thermostat did you put in? If you got it at an auto parts it's probably a 195 which is too hot. You should have a 180. There's a sticky on a good stant.

 

Thanks everyone for pointing me in the right direction. The thermostat is a 180, so I will look at the other things pointed out here. This has been a great Rover with very few unscheduled trips to the shop. But at 148,000, I am sure it is time for things to start breaking/clogging. I appreciate all of the helpful information.

 

BTW - if oil is getting that hot, engine is way too hot, but the heat gauge will allow you to be under-informed. A scanner or Ultra Gauge will show the true temperature.