Yet another problem


Ever since shortly after I got my Range Rover it has been using a coolant, always had to top it up a bit every month or so. About Christmas time my car started overheating as I arrived home from work along with messages about low coolant level flashing up. Pulled up asap and opened the bonnet to a cloud of steam. Water pipe out the back of the engine had burst. Ever since that happened there has been the phenomenon of my temperature gauge liking to jump around!

What would happen was the gauge would slowly creep up to about 3/4 the way towards the red (third dash on the gauge). This would then after about 30 seconds drop like a stone back to the middle. Having had this happen I have found that the quickest way to get it to drop back to the middle is to drop it down a gear or two and floor it (counter to what I would be inclined to do). Since this time I have had another water pipe burst on me (while the car was turned off after having just been parked) and this problem seems to be more frequent now.

Along with this the car has gradually over time started using more and more coolant, currently I have to put about a litre into the car every couple of days, but yet there doesn't appear to be any coolant dripping anywhere.

Any suggestions!!

First question is are you petrol or diesel I ask because the expansion tank on the BMW 4.4 petrol is known to split and only leak when the coolant system is pressurized , if so I believe a new expansion tank is not too expensive and is an easy fix DIY . 2008 MY Supercharged
Rimini Red / Jet
four zone climate
remote park heater
and no ugly kid windows.
magnus satis quod turpis satis

If yours is the 4.4 I had the same pipe fail at the back of the engine. It did it just as I pulled onto my drive luckily. Then about 3 months later my header tank blew. I’d been topping up about a pint a month, now since replacing the water level stays constant.

I wonder if you are heading the same way?

I would suggest that you have an air lock somewhere if your needle is fluctuating – it could also be your water pump splines if higher revs ease the problem.

Dan 

I was thinking air lock myself, but iv did everthing I can to bleed the system. The top radiator pipe however never feels like its full of coolant and I believe I can hear bubbles when I squeeze it.

I have throughly checked the header tanks and can't find any leaks but I'll price it and if it's not too expensive I'll replace to see if it fixes anything. I assume a water pump is not so cheap to replace

I have also just ordered a new expansion tank cap as the rubber rings round the current one look a bit worse for wear.

With the engine running top the header tank up whilst constantly squeezing and releasing the top rad hose until it takes no more coolant. You should see loads of bubbles coming through as you do this. Also make sure the heater is on so it runs the aux' coolant pump.... 

Stebo wrote:

I assume a water pump is not so cheap to replace

Cheaper than an engine block!

Get your local independant garage to pressure test your coolant system ...

This should show up any faults on the components that make up the system.

Chances are that if you have had one pipe burst, the rest could be knackered also - if you give it some welly when driving and it appears to breifly rectify the gauge indication level it shows that it may be forcing out the pressure build up when really hot (this ain't doing your engine any good however - and will only be a matter of time before it goes bang! )

If your coolant needs replenishing as often as you say - but you dont notice any puddles when parked up then it may constantly be spraying out of fine mist (from fault area) and evaporating whilst driving/when hot.

dan_uk_1984 has offered great advice with regards to a couple of potential faults that you may have - do what he says with topping up the header tank and see where that leads you first

Looks like getting a pressure test done might provide the solution. I assume this would show up any problems with the header tanks too, therefore better to get this done before replacing the header tank in case it's fine

Stebo

Its definately worth a try - The pressure testing equipment would actually attach to the header tank so the only component that it couldn't test would be your cap with the worn rubber rings.

It will however test every other component from gasket seals to radiators for any gradual loss of pressure - especially the hoses.

Not that there is a lot of room within the engine bay to see too much - but you may possibly be able to spot the build up of a whiteish powdery residue of old leaked engine coolant somewhere within.

ALSO, does the inside of your header tank look clean or is there a lot of scale or brownish discolouring? - I am not to sure how true this is (one of the other forum members may be able to help here) but I have been led to believe - if the inside is grubby - it would indicate a corroded radiator or damaged water pump housing (from bearings)

Good luck with finding the problem

my rangie had a coolant problem it used a fair mount when i got a litre or so a month, however there was no dripe or obviouse leakage, eventualy i had steam out the front during traffic this eventually led to a shagged radiator. the guy who changed it kept it and let me have a look and it is was knackered.

this may also be your problem as the side the radiator you can see easily looked fine how wrong i was apparently they do go after time

good luck with the quest for the truth 02 Range Rover HSE Zambezie silver 4.4

Just to update.

Had a bit of time over the weekend and decided that replacing the coolant couldn't hurt. The coolant that came out was near black with lots of residue in it. I decided that I may as well try that holtz radiator flush stuff and also the sealant that you get.

Spent the day flushing and sealing the radiator and it seems like it may have fixed the problem. The car now raises to the correct temp and sits there. Also the coolant has stopped disapearing. Seems like the problem may have been a several small holes in the system that must have been releasing steam once the system got up to temp.

Stebo wrote:

near black with lots of residue in it.

The waterpump impellers are made of black nylon plastic, maybe they have warn/disintegrated and that's what you flushed out? 

Thanks for letting me know.

It was like black water with what almost looked like black grit/sand at the bottom. I was thinking it was maybe rust/limescale residue but that would make sense.

Seems to be working now anyway, if it starts to go again at lease I'll know what it might be.

It wasn't where someone had already been filling the coolant up with a radweld type product to try and stop the coolant loss was it?

If coolant is changed as specified you shouldn't have any rust as Antifreeze stops it. As far as I know anyway.

My problem was that I was constantly loosing coolant and topping up with water. I always made sure to put antifreeze in during cold weather but there was next to no antifreeze in the coolant I removed. Also because of whatever holes the water was getting out I can only assume that air was getting in (causing the over-heating).

Maybe someone previously had the red organic coolant in there and you flushed out the sludge build up from mixing the types of coolant? Just an idea.

Hopefully now though you'll be trouble free.

I'm going to do a coolant change next month, I have a 25L drum of distilled water (from the condensing tumble dryer) that I will use for the 50% water mix. I also need to get the summer oil in her.