Slow driving = Hot running

[Burke]

Last weekend while doing some slow 1st and 2nd gear (easy) driving on the beach I glanced at my guages (like I do every few minutes in the 90 :rolleyes ) and the temp guage was just inside the red. I shut it down and let it sit for an hour or so. It was fine when re-started, but got hot again while in the sand, but once I got moving on the road she cooled down. I replaced the thrmostat a few years ago, and have a fairly new radiator. I am wondering if the aux fan is working, fuse, etc? Any other ideas?

[landrovered]

Viscous fan clutch

[Burke]

Thanks Scott, I did a search and found some good info on that, could be. I have been having some temp issues for a few years, not running into the red, but sometimes getting close. Now that I think of it I cannot remember ever hearing the fan kick on at idle. When I get home and start her up, should the fan be always moving, or at a stop until needed? When these fans kick on is it a noticeable sound like most vehicles?

[landrovered]

The clutch is heat activated. When cold it will spin lazily. After the engine warms up it should be quite stiff and spinning in time with the engine. You will hear a bit of roar when accelerating from a stop to about 35 mph. Over 35 the fan clutch should disengage again.

When you go to remove the fan clutch remember the threads are reversed so you should hit the wrench on the drivers side toward the ground to break it lose.

[Ragland]

My experience has been the truck will simply get hot. I don't have a new radiator, but have replaced most everything else (fan clutch, thermostat, water temp sensor, etc). Overall, I have the impression that because Land Rover did not make that many of these trucks with the V8 setup like ours, certain issues like cooling (or the oil cooler lines) were never sorted out well. Perhaps it is the location of hot parts, airflow, and design factors, I don't know. I haven't experienced these issues with Discoverys.

From reading the comments listed by others, I don't get the feeling a radiator replacement makes it all go away, either.

[revorder]

Have you had your truck on the sand before with no issues? I know mine would run hotter just from added drag. I would use low range to give the 4.0 a break if you were in 4H. JP

[MonLand]

Have you had your truck on the sand before with no issues? I know mine would run hotter just from added drag. I would use low range to give the 4.0 a break if you were in 4H. JP
(side note: The 1994 D90 has the 3.9L and 5-spd manual transmission).
This is a good point (beside the fan vicous coupling unit), what happens is you run in low gear (i.e. low speed) and high RPM (let's say 4000rpm) for a while, does the temperature climbs?
How hot was it outside? Typically, on the beach, you have a nice breeze coming from the ocean that cools the air.

[landrovered]

I beg to differ with the "rovers just run hot" premise.

I have trundled around in all sorts of different situations in low range in the summer and my vehicle does not run hot. If the viscous fan, radiator, water pump and hoses are in good nick then you should not have a problem with operating temperature.

Plain and simple....running at 2000 rpms should not overheat your engine. If it does then something is wrong.

[Burke]

So after a short ride Sat morning I let her idle in the driveway while watching the fan. About 80 degrees out. After about 5 minutes the fan never changed speed, and the needle was just to the red. Does that sound like a Viscous fan clutch prognosis Doctors?

[Weldon]

I'm having a similar issue, when driving my temp gauge shows running cool (about 3/8 from C) but after stoping & turning truck off then turning truck back on the temp gauge climbs to just before hot, the odd thing is, if I running truck (drive, truck not sitting) the gauge comes down to about the middle...

Could my fan clutch, thermostat or my water temp sensor be going or perhaps something else going ???

[landrovered]

Replace your fan clutch already!

[revtor]

Maybe an obvious point, but youve checked your coolant levels in the expasion tank and radiator right?

[Burke]

Replace your fan clutch already!


Maybe I should replace my fan clutch? :grin

[Ragland]

I beg to differ with the "rovers just run hot" premise.

I have trundled around in all sorts of different situations in low range in the summer and my vehicle does not run hot. If the viscous fan, radiator, water pump and hoses are in good nick then you should not have a problem with operating temperature.

Plain and simple....running at 2000 rpms should not overheat your engine. If it does then something is wrong.

I bought mine with 24k on the clock, and this has been the case ever since. It's not that I'm happy with it, but this seems to be a common experience. One day soon, I will sort this out. The truck doesn't go above mid range during normal situations. But with bad traffic, extended idling, or slow higher rpm driving, the tendency is there to go hot quicker than other vehicles I've had.

Also, I assume you removed that temperature gauge device in your '93 that keeps it pegged in the middle.

[landrovered]

Yes, I installed a new VDO temp gauge with the matching sender unit so that I would know what was going on with the engine. I actually have numbers on my temp gauge which is useful.

I had to get an adapter machined to accomodate the 1/8th NPT sender on the new VDO unit. It cost me $8 at the local machine shop.

The "signal conditioner" is long gone!

I guess I am lucky, my 110 runs at 190 and will creep to 200 in trying conditions. The AC will add 5-10 degrees but I don't run it very often.

[sflash868]

The only time I haven't seen a rover engine run hot was when it was brand new. (in my experience) My family has 2 90's currently and i just used one to tow a 4500 pound trailer on the highway in 90 degree weather with no temp problem. Come to a traffic light and the guage would pin to the right side of the gauge (past the red). Second I started driving again I could watch it drop right down within a minute. The other 90 gets hot at freeway speed, just below red. Drove it to Moab in the summer time and it sat on the trail idling with the AC on and it never even went to the middle of the gauge. Both cars have had every part of the cooling system replaced including water pump and radiator. The only thing that ever helped my temp issue was popping the hood at freeway speed.