Coolant Leak - what would you do?

[TomTheTyke]

Hello all,

I replaced my V6 thermostat which was leaking (they all do that sir) this time last year.

I couldn't get hold of a metal version at the time, so went for a plastic item from DMGRS.

So far this has held up fine until I was doing weekly checks this morning. Coolant seemed slightly low, but then the car was on a slight slope I thought hopefully! But no, a check in the V with a torch showed the telltale pinkish puddle!

However, having taken off the engine cover, as far as I can see, the only places with pink residue are where 2 of the hoses enter the thermostat and also the bottom expansion tank hose, all 3 right on the end. This stands to reason as although the thermostat is plastic, I have probably done less than 10,000 miles in the year.

This suggests that the hoses did not like being moved about for the first time in 2 decades last year, and that re-using the original clips was a mistake.

I have checked DMGRS, and the metal thermostat kits are imminently available and I have pre-ordered one, so that will either go on the car or on the shelf to go on in due course.

But while it is cold outside could I get away with a short term fix? Could I just pop the hoses off and fit better hose clamps, having removed the airbox / throttle body? Obviously would then need to top up coolant and bleed.

Or is it a case of get the manifolds off, and change the thermostat for a good long term solution as soon as the metal kit arrives?

The leak as it stands is very small, but it's also the first time I have noticed it. The car is in daily use so for the next week at least I will check every couple of days to establish the rate of loss. I will be annoyed at spending part of 2 consecutive Christmas holidays removing and refitting inlet manifolds, but I suppose that is the joys of an older car...

[FLYING BANANA]

My coolant loss was due to 3 hose clips that were past there best of life. All 3 replaced and it’s been ok ever since.

[TomTheTyke]

Interesting, thanks for that, I’d seen a couple of other posts suggesting it wasn’t unheard of when searching on here.

In the long term the Kaiser thermostat will definitely go on but just don’t want to get into that in December if I can avoid it, especially as the Rover is too big to work on in the garage.

[Mr Toad]

You need to check exactly where the coolant is leaking from. If it is from the hoses it is definitely worthwhile replacing the hose sprung clips for jubilee ones. If you have the original spring clips you should be able to remove them but it may be a little difficult without the special tool. It is also possible to replace the hose clips with jubilee ones although it can also be difficult as there is not much room but it is doable. You have to be careful when removing and replacing the hoses from the thermostat and pipes, too much movement may displace them.

If you have to replace the thermostat this can be done without removing both manifolds, just remove the front one.

Martin

[TomTheTyke]

Thanks, sound advice.

I'm fairly sure it is only the hoses. The leak is small and I had the airbox off for a closer look on Saturday. Tiny bit of bright pink residue around the hoses but nothing anywhere else.

Fair point on the manifolds, I was thinking of the upper and lower part as opposed to the rear inlet.

[TomTheTyke]

Just to update on progress with this.

Continued losing a small amount of coolant. Topped up last Sunday as was doing 150 motorway miles or so in the day, and it had dropped slightly on my return.

Was off work this week so when doing an oil / air filter service decided to take the battery box & throttle body off to get at the hoses to the thermostat / elbow pipe which seemed to have signs of leakage.

Replaced these clips and one other clip which had the same residue with worm drive types and bled up.

Have driven over 100 miles to Manchester and back over the last couple of days and *touch wood* seems to have lost no coolant. Hopefully this will tide things over until delivery of a metal thermostat housing which I have on back order, at which point I’ll probably replace the rest of the clips and maybe a load of hoses as well, they are over 21 years old after all.

[planenut]

Thanks for the update. Certainly when up to temperature, pressure could force some coolant escape at weak joints, however, on the 1.8, when cold, there is a chance of coolant escaping a weak inlet manifold gasket. These things are certainly sent to try us.

[TomTheTyke]

Yes I think the clips had weakened with age, and when fitting the new thermostat last year I had not got them back in their original position on the hoses, meaning they were trying to compress a ‘thicker’ bit.

These things certainly do try us and there’s always something (see my post in Items Wanted as I’ve lost a D post badge today). But - I’ve now done well over 10k miles, this is my everyday car so I commute about 110 miles/week. In addition it’s been up to Scotland, down to Dorset, the Lakes and lots of other places in between. Touch wood nothing major has gone wrong at all.

[SD1too]

Originally Posted by TomTheTyke

Replaced these clips and one other clip which had the same residue with worm drive types and bled ...

Hi Tom,

I offer below my experience of the KV6 cooling system which you can ignore if you wish.

The original factory spring steel hose clips get a bad press because they are so difficult to handle without the specific tool. Their advantage is that they apply a fixed, predetermined pressure to the hose so cannot be under or over tightened.

Worm drive clips corrode and either seize or strip the "thread". The rotating part is bulky and annoyingly slips around the hose away from the tightening tool.

Like many other people I used to routinely replace the sprung type with the worm drive design but no longer. Instead I bought a pair of hose clip pliers which remove and replace the original factory clips in seconds. I'm not exaggerating!

Regarding the thermostat housing, so long as you correctly position the serrated clips on the straight pipe and have used genuine parts (including the 'O' rings), the plastic components will be fine.

My hoses are 23 years old and I haven't replaced a single one. Old age doesn't automatically translate into unreliability. In fact quite the opposite can be the case. If it ain't broke, don't fix it.

Simon

[TomTheTyke]

All fair points. Interestingly mine weren't too hard to remove with ordinary pliers, suggesting maybe they were no longer exerting the right amount of force.

Would potentially be happy to back to spring clips if I have the hoses off again, but would need to get the right size.