High engine temp V8

[CraigH]

Well I suspected the cooling system was not so good when the auxiliary fan was running all the time with the A/C off, the temp gauge was still in the normal range but I know that's not a real indication.
So I had the radiator, thermostat and viscus fan all replaced, but the auxiliary fan still came on. So I assumed it had logged a fault and was keeping it on until it was cleared.
Today I received my Nanocom and went out to have play. There was no faults logged and the reason for the fan coming on was the temp was exceeding 100c. Idle in the driveway and it goes up to 105c, then when you rev it to 2000rpm it drops to 99c. Drive it and it goes up to 104c.
This is really worrying me now as I'm going to tow a caravan at Christmas time.

About the only thing I can think of is the water pump. Do these give much trouble?

Any other ideas on what it might me?

Craig

[BilboBoggles]

Does it go straight up to 100 when you start it from cold? How long does it take? .might be temp sensor.

[CraigH]

Once you start it, it warms up to at a steady pace and keeps going till it hits 100-105c and hovers around there. I've done some more reading since and I'm wondering if it's the themostat that my mechanic replaced is the cause of it.

[Road Stone]

Hi,

All sounds a bit odd.

I'd check if the system has been bled properly and as you state look at the thermostat.

Does your new viscous fan work as it should?

Cheers, Jerry

[CraigH]

Yes, viscus fan is working but what seem to happen is say I'm stationary, temp rises to 105c at idle (A/C on or off doesn't seem to make a difference) then I'll bring the rpm up to 2000, you can here the fan roar the temp drops to 102c fairly quickly and the viscus fan disengages. If i keep it revving it drops a little further to 99c. it If I drive it around the block it hovers around 102-105c.

I'm wondering if the maybe it's the thermostat opening too late to let the water flow to the radiator for cooling.....

Craig

[Pedro_The_Swift]

do water pumps fail internally?
buy some water wetter anyway, it can only help--

[CraigH]

Okay, tried something different. I took it for a run down the freeway 90-110kph. In top gear it sat on 104-105c. Then I dropped it back to 3rd gear, so same speed higher rpm. Temp went to 102c. Tried it with A/C on and off with no real difference.

Then just gently driving around the suburbs 105-107c. Then took it down to a industrial area and gave it a thrashing. It dropped to 100c.
It seems the harder I drive it the cooler it gets!

I'm now guessing it must have something to do with the speed of the coolant flow....

Craig

[Road Stone]

So could it be the water pump?

Just as a comparison, my temps hover around 86/87c when driving normally with A/C on. This rises quite quickly when slowed by traffic to stop start driving, the highest being 92/93.

Up to 95 when in a car park. All this at ambient of 30+C high humidity. My thermo opens at 96, not sure if that is right.

I, for something to do tested to see how good the water pump was and when cold started it up and undid the bleed screw. needless to say coolant shot up in the air. :eek: so took the assumption all was ok:D

I'd still check there is no air in the system first.

Cheers Jerry

[CraigH]

I've had a chat with my LR mech and he is not saying much till he runs a few tests first next week. So I'll wait and see....

Craig

[CraigH]

Well after a double check of things it turns out that it's normal. Spoke to a couple of LR specialists and thats how they are from factory, 100-105c is acceptable...... eek!

It's to do with efficiently and emissions. He said the damage happens when there has been a coolant loss and air enters the system then it boils. The best thing you can do is fit a low coolant alarm. Well I'm one step ahead there.

I know what you guys are thinking and I'm still kind of feeling the same.

Craig

[Road Stone]

Yes you are correct....we are. :(

Still sounds odd. I read that 106C is about the limit and 110C is when you pull over quickly before something goes bust. Does not leave much margin for error and I note you say you will be towing.:confused:

From your note, the viscous fans seems to come on quite late, this is not so in my car where it is working long before even the thermo opens. My condenser fan comes on at 97/98 if A/C (and vehicle stationary, temp then drops to 92C) off or on immediately if I turn on the A/C.

Another little thing to check is did the person who changed the thermo, put the hoses back on in the correct position. Sounds stupid I know but have read of this happening which would cause high running temps.

Are these temps you are recording with the bonnet up or down. If up and stationary then temps will be higher I believe as the fans are less effective.

That viscous fan starting so late look suspisious. But if the LR guys are happy.....

Just my thoughts,

Cheers, Jerry

[clubagreenie]

I find running that high unacceptable. I blew head gaskets, softened heads and dropped liners when I peaked at 104 while on a trip.

New rad, water wetter and coolant and cooler thermostat with soft bypass spring and it sits on 87 constantly now.

[CraigH]

Yes those temps are real world, bonnet down sitting in Drive etc. I put some coolant additive in (equivalent to water wetter) didn't make any real difference yet, but I've only just put it in. I've been watching the readout on the Nanocom for a while and it goes a bit like this. Stopped or slow moving temp creeps to 105-106c, viscus fan cuts in, accelerate and it roars away temp drops quickly to 100-102c and maintains it there while cruising. If I give it a thrashing it may even go as low as 98c. So it seems the harder I drive it the cooler it gets. I may try to borrow my folks van and take it for a test tow for a hour or so and see how it goes. I'm 100% confident it's the thermostat that maintains the higher temps.

But the LR specialists guys seem to be reluctant to experiment with thermostats, sighting it's in normal range. I've read that the temp gauge doesn't move off half way until approx 115c and turns on the red led at 121c and off at 118c.

I've read some guys have gone to a softer spring stat but in some cases has had the opposite effect, the harder you drive it the hotter it gets. I guess it won't hurt to experiment with a different thermostat.

Jerry which thermostat are you running?

Craig

[Road Stone]

Hi Craig,

I have the standard unit in place. It opens at around 96C, then there is a dramatic temp drop. I do have the other type here but have not installed it as there appears to be no reason too ;)

That Viscous fan coming on at 105/6c sounds far too late to me, but I'm no expert. On top of that, only coming down to 100ish, then that is still too hot.

I'll check tomorrow at what temp my fan comes on, I have Hawkeye.

Did they check the water pump was doing what it's meant to do, and no air lock?

Will get back to you with my figures.

Cheers, Jerry

[CraigH]

It's a brand new viscus fan. Problem is they say it's normal. I asked if the water pump gives trouble and they say they either leak or they don't. Maybe it's just this thermostat. I've looked broadly at forums from the USA and they all talk about similar operating temps. I think I may need to try to experiment with different thermostats.

Cheers

Craig

[CraigH]

Convinced its probably the thermostat I had a close look at it today and it's a non-genuine stat. I've contacted my local LR dealer who has a genuine one in stock, so I'm going to grab that tomorrow and swap the stats out. See how it goes.... Fingers crossed!

[Road Stone]

HI,

I hope it works.

Right my figures today as promised. This morning at an ambient temp of 26c:

Viscous fan came on at 48c :eek: Never checked before, so a bit surprised.

Highest temp reached in a 20klm drive was 92c. that was at a standstill, lowest and at a steady 87c when driving.

So we had a hot day today so at 2pm I checked again. Ambient temp 36c.

No difference in the running temps all the same. A/C struggled a bit though and the car external temp gauge was ready 40c at one stage.

Not sure about humidity but it would of been high.

As stated I hope the change of thermo does it for you, as there seems to be an issue....Good luck :)

Cheers Jerry

[Pedro_The_Swift]

You'd have to be happy with that Jerry:cool::cool:

I take extra note of the ambient to rad differences. Good to know the extra external temp doesn't add to the rad temp.

[CraigH]

Well I put the genuine thermostat in today and success ! Now sits around 92c when driving (not 103c). I sat in Drive with a/c on idling for 10 min with A/C on max it went no higher than 97.5c (not 107c). Looks like the calibration of the other stat was out.
Thanks for all the temp figures Jerry, I appreciate it.
Cheers

Craig

[Road Stone]

Great news Craig, doing that may have saved your engine :twobeers:

Really pleased to see you got it sorted.:)

Cheers, Jerry

[clubagreenie]

Which thermostat did you end up with ? The std one or the freelander one?

[CraigH]

The standard one

[Pedro_The_Swift]

I've been waiting to get my bluetooth dongle working,, and now that it does--
one ten minute drive and

:eek:

97 while moving and over 100 when stopped.(ambient was around 25 and raining!)

:o:censored:

this is with new everything. rad, pump, hoses,

so this is what LR designed the V8 to run at.

:eek::censored:

I'll start with some water wetter, but can see a new thermostat in my future---:(

[Pedro_The_Swift]

Went for a quick run out to Oakey and back to set some sort of benchmark,,
around 93 with clean air at 100kph,
following a petrol tanker at the same speed with a two to three second gap added 5deg instantly.
a two minute idle in the driveway saw 101.

[ozscott]

Mine with block flush and all new cooling system...ALL..is av of 88 tooling along and up to 94 in traffic on the scangauge. Standard thermostat.

[CraigH]

Pedro's, very similar to what I'm getting using my OBDII wifi scanner. 93-97c when driving. At idle in traffic in Drive A/C on it occasionally tops 100c but quickly drops when I accelerate away. Today I wanted to test it towing for the first time with a 2.2t caravan. Up a long climb on the freeway foot to the floor speed topped at 65km and the temp dropped to 91c. The harder I drove it the more cooling was applied. After a lot of chatting to various LR specialists, this is exactly what these engines run at . They have all told me the best investment I made was fitting the engine saver low coolant warning. Cheers Craig

[Road Stone]

Pedro, You may want to try the lower temp thermostat, cant hurt and could save a lot of money, having said that it is within agreeable limits.
Cheers, Jerry

[ozscott]

It could have air in the system. My v8 from factory never had temps that high even towing 2 tonn up the hills of Paddington in a 38 degree summer day. It only started those temps when I had cooling system failures and later when I had a head gasket gowing and overpressurising and overheating the water jacket.
Cheers

[ozscott]

A lower temp thermo may not work per one of the posters above but also may just mask a problem that when it does get worse will do do quickly and spectacularly.

[ozscott]

Checklist. ..header tank cap; rad; water pump; thermostat; hoses; flush; thermo fan hub; bled properly per RAVE; check for exhaust gas in coolant.