The 75 and ZT Owners Club Forums - View Single Post - Coolant Leak

TomTheTyke · 26th November 2022, 14:35

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...

26th November 2022, 14:35	#1
TomTheTyke Avid contributor Rover 75 2.5 Connoisseur, MG TF 80th Anniversary Join Date: Sep 2021 Location: Pontefract Posts: 157 Thanks: 12 Thanked 22 Times in 11 Posts	Coolant Leak - what would you do? 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...