Loosing a little coolant. No leaks no issues so far and tested need opinions ????

Ok so Iv got an issue with my td5 on 103k

It is using a little amount off coolant currently topping it up after a two week period and 350/500 miles not a huge amount maybe 10-15mm

I have no apparent leaks as checked all over and pressure tested the cooling system which I pressured upto 15psi and after 20 min this sid reduce down to 10psi so somethig is passing so where

I have been out on two pay and play days so engine has had a good seeing to so to speak never overheating or running issues and not pressurising any more than normal in the hoses. No white on oil cap.

I'm thinking against head gasket due to all of the above but am I wrong ?

I have been told there is something for the heating behind the block that oil and water passes through can't remember what what it was sorry. Any ideas? Could this be it?

I would like to get it sorted before it gets any worse

What's your thoights?

Thanks in advance

its not uncommon for landies to lose a little coolant over time especially as cooling system ages ,yours doesnt sound like hg yet, check rad gets hot all over

You are not gonna like that but when mine had that symptom i was a crack in the first inlet port, the coolant simply burns out in the chamber ... let's hope your's a vanishing leak, get that kit UV Dye & UV Torch Kit Leak Detection Dye For Cooling Antifreeze System RLD2 Ring | eBay and if you'll not find traces of leak it's time to pressure test the head

Check the weep hole on the water pump. A small leak their can go undetected.

Even if you suspect a HG or cracked head, 100ml loss per 500 miles (say) isn't necessarily an existential threat to your engine (in the absence of oil contamination).

Suggestion: monitor it, record replenishment amounts, dates and mileages. If the rate keeps increasing, you have a deteriorating problem, and you should Probably Do Something.

If not, chill out, enjoy your landy, don't worry about it, just keep an eye on it.

Personally, I'd eliminate the possible causes in order of repair cost.
Cheapest first, replace the coolant tank pressure cap .... 6 or 7 quid.
Work upwards in cost from there.

Another place to check is the blanking plug for the head which is well hidden behind the exhaust manifold.
Griff

I have ordered a new expansion cap today. This may sound daft but As I'm fairly competent at mechanics and fixing things just new Landy not familiar with the td5. Where can I locate the water pump? And where abouts is this blanking plug ? Thanks

water pump is on the back of the power steering pump(driven by aux belt) which is to the front right of the head. the plug is between the exhaust manifold on the head. the manifold needs to be removed to remove plug. i have done both of these in my quest to stem water loss.

I have a similar very slight leak on mine at 132K miles, also no obvious trace, gonna replace cap first.
Would it be prudent to consider replacing radiator and hoses at this age? (11)