Faulty aircon = coolant leak = overheating?

[kapowww]

When I test drove my P38 all was well as there were no leaks and no book symbol on the A/C. Obviously a couple of test drives don't really mean much as you can't possibly do enough real world testing. Anyway the day after I got it I changed some A/C settings and the dreaded book symbol appeared. It would appear a few minutes into driving on certain settings.

Then whenever I drove I'd lose a bit of coolant (up to 300mL at a time) and if I drove for over 30 minutes then I'd lose a whole lot more especially going uphill. Then it would start overheating and I read all the scary threads about head gaskets and new engines, etc.

Took it back to the roadworthy mechanic who fixed a couple of coolant leaks by replacing the radiator cap and heater hose.. Problem still happened after long drives and I couldn't tell there was less coolant until the next day. I kept topping it up and driving it short distances.

One day my wife finally took it for a drive and changed the A/C settings. Since she did that the evil book symbol hasn't appeared, and the coolant has not leaked one drop! No more overheating! Now.. I'm scared to change the A/C settings because I don't want it to leak again, and I don't want to jinx this good run haha.

Old settings: I would usually turn A/C off but seemed to happen with it on too, have the dash and feet blowers, and whatever temperature set.

New settings: A/C on, only the feet blowers, and I've tried a few different temperature settings with various outside temps (hotter than outside, colder than outside).

So what could the problem be? Is there a link between the A/C faulty book symbol and coolant leaking? Not sure if the colder Melbourne weather has helped but I've driven on slightly warmer days with no problems.

[mike 90 RR]

especially going uphill. Then it would start overheating

Symptoms of a blocked radiator....




Basically ... you have a old car.

1: You need to have the Radiator rodded or replaced.
2: The viscous fan needs to be checked for working.


Get this part of the cooling system up to date.

Cheers
Mike

[Hoges]

x2 as above ..plus
FWIW: The plenum chamber in the heating system has flap which moves in accord with temp settings. The (plastic) chamber "box" can get slightly out of shape over the years due to heat. This can cause the blend flap to bind, causing the blend motor to stall and resulting in a book symbol. For example, I get no book symbols during winter when the ambient air temp is less than 17 degC... yet, as the day warms up, the book symbol appears:eek: because the flap gets jammed and won't cycle through its full arc... not saying this is what your issue is, but it's one of several which can cause problems.

coolant flows through the heating system all the time; it's the blend flap which determines the temperature... what colour coolant are you using in your engine?

EDIT: have a careful look at the front of the engine to see if you have any leaks around the water pump. Check for evidence of coolant leaks with an inspection mirror if necessary, around the rear of the heads and also around the head bolts for #1 cylinder (front LHS -passenger side)

[TheTree]

Hi

Also don't forget to check and replace RL7 in the fusebox if you have or have had the book symbol.

This should extend the life of your fusebox

Steve

[kapowww]

For example, I get no book symbols during winter when the ambient air temp is less than 17 degC... yet, as the day warms up, the book symbol appears:eek: because the flap gets jammed and won't cycle through its full arc... not saying this is what your issue is, but it's one of several which can cause problems.

coolant flows through the heating system all the time; it's the blend flap which determines the temperature... what colour coolant are you using in your engine?

EDIT: have a careful look at the front of the engine to see if you have any leaks around the water pump. Check for evidence of coolant leaks with an inspection mirror if necessary, around the rear of the heads and also around the head bolts for #1 cylinder (front LHS -passenger side)


Mine used to do that but book symbol hasn't shown for weeks no matter the outside temp and it has reached 20 and also in traffic where other exhaust heat tends to bump up the temp.

Mine has red coolant. Not sure of the ratio to water and how sensitive a Rangie is to that.



1: You need to have the Radiator rodded or replaced.

2: The viscous fan needs to be checked for working.




1. Yep I realised that and realise I'd probably have to replace the radiator. Been looking at the eBay ones. They any good?

Thing is I don't want to spend money on replacing that before spending money on fixing the leak in case it's something a lot worse.

2. Is that by doing the rolled up newspaper test? I did that and it's all good. I haven't checked to see if it turns on at the right times.

[kapowww]

Hi

Also don't forget to check and replace RL7 in the fusebox if you have or have had the book symbol.

This should extend the life of your fusebox

Steve


Will do.

[mike 90 RR]

1. Yep I realised that and realise I'd probably have to replace the radiator. Been looking at the eBay ones. They any good?.

I prefer copper core radiators ... however tho, anything will be heaps better than what you have.



Thing is I don't want to spend money on replacing that before spending money on fixing the leak in case it's something a lot worse..

Unfortunately ... You cannot identify "something a lot worse" until you eliminate the radiator .... If you don't, then it is guaranteed that you will overheat the motor and then your up for 4 to 6k for a reco motor.



2. Is that by doing the rolled up newspaper test? I did that and it's all good. I haven't checked to see if it turns on at the right times.

All sorts of tests available .... Another way is to compare the resistance of your viscous to a new 1 ...



Cheers
Mike

[Nomad9]

Hi Lapowww,
The two P38's I've had have both had green coolant in them.

[TheTree]

HI

You can always go this route :p

http://www.aulro.com/afvb/p38a-range-rover/198925-cooling-system-upgrade.html

Steve

[TheTree]

HI

I believe the Bosch models had red coolant, but if you do get a copper core radiator you MUST use green coolant

Steve

[kapowww]

Unfortunately ... You cannot identify "something a lot worse" until you eliminate the radiator .... If you don't, then it is guaranteed that you will overheat the motor and then your up for 4 to 6k for a reco motor.

But what I'm saying is that now it isn't overheating anymore since the aircon settings were changed and the book symbol doesn't show up. No more leaking and the temp gauge stays in the centre. If it is the radiator then could you explain the link between the radiator and aircon fault coz I have no idea?


HI

You can always go this route :p

http://www.aulro.com/afvb/p38a-range-rover/198925-cooling-system-upgrade.html

Steve

So hardcore!


HI

I believe the Bosch models had red coolant, but if you do get a copper core radiator you MUST use green coolant

Steve

Ok if I get copper then I'll remember this.

[mike 90 RR]

But what I'm saying is that now it isn't overheating anymore since the aircon settings were changed and the book symbol doesn't show up. No more leaking and the temp gauge stays in the centre. If it is the radiator then could you explain the link between the radiator and aircon fault coz I have no idea?

The reason for basis of a blocked radiator is due to the bit where you say ... "overheats when climbing a hill"
When a radiator is blocked .... running the heater helps keep the temp of the motor down ... basically "assists" the radiator. It is winter time and that hides all the problems of radiators.

I'm just providing you with the likely suspects that you need to way up in resolving the matter.




When you have a read of Hoges response ....
It could be suggested that the overheating and test book symbol are 2 separate problems and not related.


Also that Temp gauge ..... LR in their wisdom, designed it so that they never move until the coolant is about to boil ....

Cheers
Mike

[kapowww]

The reason for basis of a blocked radiator is due to the bit where you say ... "overheats when climbing a hill"
When a radiator is blocked .... running the heater helps keep the temp of the motor down ... basically "assists" the radiator. It is winter time and that hides all the problems of radiators.

I'm just providing you with the likely suspects that you need to way up in resolving the matter.




When you have a read of Hoges response ....
It could be suggested that the overheating and test book symbol are 2 separate problems and not related.


Also that Temp gauge ..... LR in their wisdom, designed it so that they never move until the coolant is about to boil ....

Cheers
Mike

Yep I understand the radiator may have a problem.. but.. I mentioned that I only had this problem when there was a leak. Now that there's no more leaks I can go uphill and it's fine. It doesn't overheat at all anymore now the leaking stopped. May be coincidence, but the leaking only stopped when the book symbol stopped showing up that's why I want to know if there's a connection.

That's why the radiator being blocked doesn't concern me at this stage. The leak worries me more.

[Hoges]

But what I'm saying is that now it isn't overheating anymore since the aircon settings were changed and the book symbol doesn't show up. No more leaking and the temp gauge stays in the centre. If it is the radiator then could you explain the link between the radiator and aircon fault coz I have no idea?



So hardcore!



Ok if I get copper then I'll remember this.

Good advice... however, the problem here is that 'traditional' green coolant is NOT optimal for aluminium engines. So while it may be kind to brass fittings, it is not necessarily a good thing for engine block and head.

IIRC some manufacturers have confused issues by putting green dye in aluminium-compatible coolants and red dye in what are essentially "green" chemistry coolants (e.g. Toyota)! Nulon etc have good products. Personally I use the ("red") organic acid technology coolant concentrate from the local Holden dealer as specified for the LS1 V8... see also http://bioengr.ag.utk.edu/Extension/ExtProg/machinery/Articles/engcool.htm for a simple overview.

[TheTree]

Hoges

Good point, you can't trust the colour these days!

OATS or not is the key

Steve

[TheTree]

Hi

To get back to the original question, I don't think the two issues are related.

Steve

[kapowww]

Hi

To get back to the original question, I don't think the two issues are related.

Steve

Cool thanks. When I looked through RAVE I couldn't seem to make a connection either. Only close thing was the aircon condenser fans sitting by the viscous fan coupling and radiator.

I'm just happy it stopped leaking coolant which lead to the overheating. I'll change my aircon settings to see if I can bring the aircon fault back and from there I'll monitor the coolant levels just in case.

It's just weird that after a couple of months of the aircon fault and coolant leak consistently coming hand in hand that they'd both stop on the exact same day without any intervention besides changing the aircon settings. I know outside temperature could play a part but the problem also happened in colder weather than now.

[derpomz]

I am only a new owner, but i have been told if the pollen filters are blocked, it can cause all sorts of A/C problems.

I checked mine when i got it home and it looked like they had never been changed, they were black and choked up with all sorts of crap. I cleaned and replaced them, waiting for new ones, and the difference it made to the heating and cooling is amazing.

[kapowww]

Yep mine were filthy when I first got it and ordered some from the UK immediately. It did make a huge difference in airflow.

[kapowww]

Anyways I've been changing Aircon settings and it's been all good. Still no leaks at all for the past 5 weeks.

[benji]

I've been thinking about this problem of yours and it's got my stuffed. ..

I could imagine turning the ac on it would put more thermal stress on the coming system; but yours doesn't seem to be doing that. ..

By deduction the face, screen, floor sir vent setting couldn't possibly make a difference.

What were the settings when it was leaking, and what are they now? We're you using the auto setting or ac off buttons at all?

It's a common myth that blocked cabin filters causes the blower motors to work harder, more amperage, more heat etc. However in testing the opposite is true. A blocked air intake makes it easier on the fan. So it doesn't actually cause any problems except poor performance.

Sent from my GT-I9305T using AULRO mobile app

[kapowww]

I never really used the Auto setting but did regularly use the A/C off button. That's the only button I haven't tried again. Changed the blowers and still fine, no faults.

[redandy3575]

Funny i'm reading this post, as i've experienced a similar issue going up Mt Donna Buang today.

By the time i got up to Mountain turn off about a third of the way up, she overheated. It seems to me that either the Radiator cap is possibly faulty as i've had for nearly 3 years and seems to prematurely release the coolant under what appears to be the normal pressure. I'm thinking possibly the fan clutch could be cactus, as again it only overheats when the engine is under load going uphill. The Radiator is vitually new, about a year old

Could it also be the thermostat? Or could it be the Nulon Radiator stop leak causing this when i detected the leak in the heator core elbow?

Sorry, don't mean to hijack the thread or anything, just a similar problem.

[TheTree]

Andy,

The cap would be a good place to start if it leaks fluid under pressure.

You can test the fan clutch by holding some newspaper in it but I think this is a better way before you use the newspaper

how to test a visco fan clutch - Pelican Parts Technical BBS (http://forums.pelicanparts.com/bmw-6-7-8-series-technical-forum/512843-how-test-visco-fan-clutch.html) :cool:

Good luck

Steve

[TheTree]

Hi

A thread here with some suggestions for overheating

Help Overheating (http://www.rangerovers.net/forum/7-range-rover-mark-ii-p38/119338-help-overheating.html)

Steve

[redandy3575]

Another thing. Should there be like a chemical smell come out of the expansion tank when you turn the cap and release the pressure when cold?

[TheTree]

Another thing. Should there be like a chemical smell come out of the expansion tank when you turn the cap and release the pressure when cold?

Hi

I don't think so but it depends on the coolant you are using I would imagine

I use the Burson Brand OATS coolant and there is a very faint chlorine like smell when I open the tank, not strong at all

Steve

[TheTree]

Hi

Another thing which happened to me was I had problems with my old cap so I bought a new cap, britpart .

It leaked coolant fairly badly, so I bought another one, AllMakes, after a week or so one of the little tabs which hold the plunger in broke :angry:

So i bought a genuine cap and it still leaked though not as bad

In the end I replaced the expansion tank with a new Britpart one and it all seems to have settled down, I hope !

Steve

[redandy3575]

Hi

Another thing which happened to me was I had problems with my old cap so I bought a new cap, britpart .

It leaked coolant fairly badly, so I bought another one, AllMakes, after a week or so one of the little tabs which hold the plunger in broke :angry:

So i bought a genuine cap and it still leaked though not as bad

In the end I replaced the expansion tank with a new Britpart one and it all seems to have settled down, I hope !

Steve

Yeah, i've ordered a new cap today. I'm thinking maybe the expansion tank might need to be replaced too as the cap after checking today seems to screw on somewhat crooket.