RR running hot.

[malibu9]

Since the weather has got warmer my Rangie has been running hot. I have flushed the radiator checked the condition of the cooling fins and they look fine and I have replaced the thermostat. I am running a good quality coolant and I also have a thermo fan on the front as well as the one running off the motor.
Question:
1. If I remove the thermostat will this have any ill affects on the motor?
2. Will it run cooler with the thermostat removed?

[matta]

From what I know it is a definite NO to remove the thermostat. I have read nothing will wear a motor out more than by doing this. Something to do with failing to allow the motor to heat correctly and causing major wear issues....
Check your thermostat is rated at 180 degree. Check the bottom of your rad isn't blocked. Check all your fans are working etc etc Check your gauge is working correctly..

Others on this forum will know heaps more then me....

MATTA GOLD COAST

[DaveS3]

Check your gauge is working correctly..


MATTA GOLD COAST

How can i check this aswell?

I have 2 guages to check heat - 1 aftermarket and factory, and both tell different stories - ie one says its overheating and the other i just below half?

Dave.

[Bush65]

Because of the cross flow design of the radiator, sediment finds its way to the bottom (due to gravity) where it blocks the lower tubes.

Flushing wont clean the sediment from the tubes. The only sure way is to remove the tanks and rod them out

[GURU]

is it using water? hows the waterpump? belts tight ??

[malibu9]

is it using water? hows the waterpump? belts tight ??

No it's not using coolant and the belts are tight.

[up2nogood]

Pull the readiator and get it cleaned. Mine was running hot, did the same.

Even though I had flushed it, and the coolant was clean before and after I flushed, it was still 1/3rd blocked.

That and a new genuine thermostat and she don't run hot no more.

No thermostat causes more dramas than it fixes. Yes, it will run cooler initially but on a long run it may overheat as the coolant will spend more time getting hot in the engine than staying in the radiator getting cool.

[bobtail]

Your clutch fan will be rooted

[malibu9]

The radiator is coming out some time this week for cleaning and rodding.
As far as I know the clutch fan is fine how can I tell if it is stuffed as it is spinning when the engine is on and speeds up at higher revs?

[Maxtd5def]

Stand over the engine idling, get someone else to shut it off, and grab the fan. It should offer resistance. If it spins, its slipping even at idle.

Regards
Max P

[up2nogood]

From take off when the engine is warm (say at a set of lights) you should hear the fan all the way up to third gear if it is working. The whole point is that the oil inside it offers a resistance to the fan free wheeling at lower revs.

It should also not be heard at high speed when airflow does a better job.

A sure way to tell if it's cactus is to see if there's oil leaking from the hub seal where the shaft enters the unit on the engine side.

[Adam]

You guys are all jumping to conclusions. First, check to see that the guage is working. Range Rover sending units have a horrible tendency of going bad and spiking, causing the operator to think the temp is too high. They are cheap and easy to replace, and are one of the first things to do when diagnosing a cooling system.

If you have access to a laser thermometer, you can check the temperature to see how its actually running, by pointing the laser at the water neck where the upper rad hose meets the water pump. This number should be anywhere from 190-210* F when in normal operating range.

In short, don't go replacing radiators and water pumps before you verify that you're actually overheating!

[malibu9]

I had the radiator pulled out and cleaned the other day but it is still getting hot. I have put a new thermostat in and a new temp gauge. It statrts to overheat on hot days when the A/C is on but as soon as I turn the A/C off the temp starts to come down within 1-2 minutes. The clutch fan does have some resistance when cold, but the resistance still feels the same when the it is hot. When I spin the clutch fan it would be lucky to rotate another half turn freely is this not enough resistance?
I am thinking the electric thermo fan on the front may not be sufficient to cool the A/C tank in front of the radiator would it be worth putting another one in so they run side by side(1 on the left and one on the right) as the one that is in there at the moment is on the passenger side. Any more suggestions are greatly appreciated.

[justinC]

Malibu9

Is your RR EFI or carb, if carb, what sort?

[malibu9]

Malibu9

Is your RR EFI or carb, if carb, what sort?

It's carbi CD 175's. It's a 4.6 short motor.

[up2nogood]

Might be running lean. That is, it will be running lean if the carbs are unchanged from being fitted to their original 3.5 engine.

There's been a few other threads on the 4.6/carby/lean/overheat subject fairly recently. Do a search!

[justinC]

It'll be lean allright!
I would be searching for someone up you way who has experience in SU performance tuning.
If you are keen, I would recommend a pair of HIF 6 SU's from a Rover P6b, and fit richer needles to them.
Type SU into Google, the company supplying these carbs from UK is still supplying new kits for rover engines, and may be able to help with needle profile codes so you can alter them yourself.

I can't remember their website, its on my work computer.

Do it soon, before you have liner/ valve problems.

Regards JC

[justinC]

It'll be lean allright!
I would be searching for someone up you way who has experience in SU performance tuning.
If you are keen, I would recommend a pair of HIF 6 SU's from a Rover P6b, and fit richer needles to them.
Type SU into Google, the company supplying these carbs from UK is still supplying new kits for rover engines, and may be able to help with needle profile codes so you can alter them yourself.

I can't remember their website, its on my work computer.

Do it soon, before you have liner/ valve problems.

Regards JC

[p76rangie]

This is probably a stupid question, but what makes you so sure it is running lean. My understanding of a carbie is that the jets control the mixture of fuel to air. The actual mixture of fuel to air required to run a motor I would think should not change from motor to motor to any great degree. However, the larger motor does need more air to run at higher revs. Therefore the 3.5 carbs would strangle the motor in regard to airflow, but I am not sure how this would make the motor run lean.

I ran the 3.5 carbs on my 4.4 before they took the lead out of the petrol. From the exhaust colour I knew it was not running lean. But it would not rev out due to lack of airflow. I now run a 500 Holley and it revs out a lot better.