3.9 overheating - update

A few months I posted a query about my RRC overheating and pressure build
up. To recap, I'd just bought it (it was cheap!) and it started to overheat
on the way home. Needle stayed just under the red all the way. Occasionally
when using it locally it boiled over through the expansion tank. Not good.
When cold, it would start to overheat after about 10 mins.

To date I have carried out the following:

- replaced expansion tank cap
- replaced thermostat (didn't have a toggle-y thing on it like the old one
did, but it was supplied by a LR specialist near to me so it must be ok....)
- replaced both head gaskets
- replaced waterpump.

I used it on a 40 mile journey over the weekend for the first time,
involving motorways and A roads. The temp needle didnt go past half way at
all, however the cooling fans at the front were on, so it was getting a bit
warm but not to the extent it was before I did all the work. And when i was
in the queue for the lights the needle did start to creep up but then once
moving, it went back down again.

The coolant level in the expansion tank is at the same level as I have been
checking it daily after a run (when cold of course!) No cross contamination
that I can see.

Any suggestions as to what could be causing this extra overheating? I
haven't yet tried a reverse flush on the rad because it looks complicated to
remove, what with all those oil coolers etc..

TIA.


--
--
Thanks,
Paul
--------------------
1992 RRC Vogue SE

During stardate Mon, 10 Oct 2005 10:27:05 +0100, "Pacman"
<[email protected]> uttered the imortal words:


>Any suggestions as to what could be causing this extra overheating? I
>haven't yet tried a reverse flush on the rad because it looks complicated to
>remove, what with all those oil coolers etc..
>
>TIA.
>
>
>--

The Rad on my 1990 RR TD was simple enough to remove. The cooler etc
were seperate units so once the cover plate along the top is removed
then I just pulled out the bit I needed rather than the who shabang.

No doubt no I've said that the Petrol version is all in one.

Given the lengths you have gone to I'd whip out the rad and take it to
a back street rad mender / maker /sales. Our local one costs peanuts
and they will know how to sort it good and proper.


Lee D
--
Success is going from failure to failure without a loss of enthusiam.
Winston Churchill

www.lrproject.com
'76 101 Camper
'64 88" IIa V8 Auto
'97 Disco ES Auto LPG'd
'01 Laguna

"Pacman" <[email protected]> wrote in message
news:[email protected]...
>A few months I posted a query about my RRC overheating and pressure build
> up. To recap, I'd just bought it (it was cheap!) and it started to
> overheat
> on the way home. Needle stayed just under the red all the way.
> Occasionally
> when using it locally it boiled over through the expansion tank. Not
> good.
> When cold, it would start to overheat after about 10 mins.
>
> To date I have carried out the following:
>
> - replaced expansion tank cap
> - replaced thermostat (didn't have a toggle-y thing on it like the old one
> did, but it was supplied by a LR specialist near to me so it must be
> ok....)
> - replaced both head gaskets
> - replaced waterpump.
>
> I used it on a 40 mile journey over the weekend for the first time,
> involving motorways and A roads. The temp needle didnt go past half way
> at
> all, however the cooling fans at the front were on, so it was getting a
> bit
> warm but not to the extent it was before I did all the work. And when i
> was
> in the queue for the lights the needle did start to creep up but then once
> moving, it went back down again.
>
> The coolant level in the expansion tank is at the same level as I have
> been
> checking it daily after a run (when cold of course!) No cross
> contamination
> that I can see.
>
> Any suggestions as to what could be causing this extra overheating? I
> haven't yet tried a reverse flush on the rad because it looks complicated
> to
> remove, what with all those oil coolers etc..

Does it have a viscous fan fitted still? If so, all the symptoms of a "soft"
coupling, replace the coupling and it'll be fine. Fans shouldn't have been
on whilst you were actually sitting at speed on your run, how do you know
they were on whilst at speed, or were they on when you stopped? If so, this
is normal as the heat-soak from the working engine has no cooling by ram air
as you slow down to a halt, so the temp rises and the fans come on.
Badger.

>
> Does it have a viscous fan fitted still? If so, all the symptoms of a
> "soft" coupling, replace the coupling and it'll be fine.

It does have viscous fan....also 2 fans other otherside of the radiator..

> Fans shouldn't have been on whilst you were actually sitting at speed on
> your run, how do you know they were on whilst at speed, or were they on
> when you stopped? If so, this is normal as the heat-soak from the working
> engine has no cooling by ram air as you slow down to a halt, so the temp
> rises and the fans come on.

I notice it when I stop and get out. Should the needle move at all when
stationary for a minute or is it expected to rise a little? I'd expect it
to rise if sitting for a few mins, but not half a min....


--
--
Thanks,
Paul
--------------------
1992 RRC Vogue SE

"Pacman" <[email protected]> wrote in message
news:[email protected]...
>
>>
>> Does it have a viscous fan fitted still? If so, all the symptoms of a
>> "soft" coupling, replace the coupling and it'll be fine.
>
> It does have viscous fan....also 2 fans other otherside of the radiator..
>
>> Fans shouldn't have been on whilst you were actually sitting at speed on
>> your run, how do you know they were on whilst at speed, or were they on
>> when you stopped? If so, this is normal as the heat-soak from the working
>> engine has no cooling by ram air as you slow down to a halt, so the temp
>> rises and the fans come on.
>
> I notice it when I stop and get out. Should the needle move at all when
> stationary for a minute or is it expected to rise a little? I'd expect it
> to rise if sitting for a few mins, but not half a min....

If it's just been "worked" and you become stationary it will rise quite
quickly, but if the viscous fan is operating properly it shouldn't need the
electric fans at all. The exception being the std fit aircon fan which will
run regardless of actual engine temp. The viscous fan provides a smoother
temperature control gradient, as opposed to an on-off switch cycling the
engine between 2 different temp values (fan on, 100 deg, fan off, 86deg, for
arguments sake).
If you leave the (warmed-up) engine idling the fans will come on after
aprox. 5 minutes and run for around a minute at a time, settling to a cycle
of approx 1 min on, 1 min off. That seems to be sort of ballpark figures for
twin fans.
The viscous coupling can be checked as follows:- 1st thing in the morning,
before starting, pop the bonnet and try to turn the fan by hand, there
should be some resistance but you will turn it relatively easily.
Free-spinning = knackered, totally solid = knackered. Start up, rev engine
to around 2000, fan will be heard to rev up, and then slow down as you
maintain the revs. No fan speed increase = knackered, no release after about
30 seconds = knackered. With the engine hot enough for the lecky fans to be
on, switch engine off and try turning viscous fan by hand again, if there is
little or no resistance, it is knackered and needs replacing. this is what I
suspect you will find, a free-spinning fan when hot.
Badger.

<great advice snipped>

Thanks for that, I'll give that a go later.

Mr Beamends - how much for a new coupling in case my is bosted?

> Badger.
>

--
--
Thanks,
Paul
--------------------
1992 RRC Vogue SE

so Pacman was, like...
>
>It does have viscous fan....also 2 fans other otherside of the
> radiator..

These aren't the fans for the aircon, are they?

--
Rich
==============================
Disco 300 Tdi auto
S2a 88" SW
Tiggrr (V8 trialler)

In message <[email protected]>
"Pacman" <[email protected]> wrote:

> <great advice snipped>
>
> Thanks for that, I'll give that a go later.
>
> Mr Beamends - how much for a new coupling in case my is bosted?
>
> > Badger.
> >
>

£50.41 inc VAT

Richard
--
www.beamends-lrspares.co.uk [email protected]
Running a business in a Microsoft free environment - it can be done
Powered by Risc-OS - you won't get a virus from us!!
Boycott the Yorkshire Dales - No Play, No Pay

"Pacman" <[email protected]> wrote in message
news:[email protected]...
> <great advice snipped>
>
> Thanks for that, I'll give that a go later.
>
> Mr Beamends - how much for a new coupling in case my is bosted?
>
> > Badger.
> >
>
> --
> --
> Thanks,
> Paul
> --------------------
> 1992 RRC Vogue SE
>
>
Just a little thought on your prob.
I had an overheat problem on my '83 3.5l. RR (now departed).
Changed thermostat- still o'heating.
Replaced vicious coupling- still o'heating.
Pulled out 5-core tropical radiator, opened & cleaned- still o'heating.
Ran some acid cooling system cleaner through the block for 100 k's or so,
flushed & replaced coolant- VOILA!

Might be worth trying.



* * *
TAKE IT BUSH, OR TAKE IT BACK!

On or around Thu, 13 Oct 2005 00:09:35 +1000, "Natalie Drest"
<[email protected]> enlightened us thusly:

>Just a little thought on your prob.
>I had an overheat problem on my '83 3.5l. RR (now departed).
>Changed thermostat- still o'heating.
>Replaced vicious coupling- still o'heating.
>Pulled out 5-core tropical radiator, opened & cleaned- still o'heating.
>Ran some acid cooling system cleaner through the block for 100 k's or so,
>flushed & replaced coolant- VOILA!

most of the chronic overheating problems I've had are down to partly blocked
rads. You can't effectively unblock a rad[1] - the supply of water you can
contrive will flow easily through about 30% at most of the tubes, so there's
no pressure on the others to clear 'em. Same with radflush and the like -
it'll clean tubes which have flow through 'em, but actual blocked ones are
not likely to unblock, unless they're only very slightly blocked. In most
cases, recore or replace the rad is the answer.

Not always, of course. Water ways can get blocked in engines, the pump
impeller can rot away to uselessness, or other esoteric faults.

[1] Not absolutely true, you could take the tanks off the ends and poke a
wire through every tube...
--
Austin Shackles. www.ddol-las.net my opinions are just that
"The great masses of the people ... will more easily fall victims to
a great lie than to a small one" Adolf Hitler (1889 - 1945)
from Mein Kampf, Ch 10