T25 - 1985 - Coolant leak from engine head

[adebutter]

Please can you help me with 'how bad' this is?

I have a leak on the offside head, a few drips, clearly water/coolant/antifreeze mix. So I first thought, engine out, or head off, and replace rubber seal which I guess has cracked/dried/etc.
In order to understand more I looked at photos, my books and a few nice videos on you tube. I had a question as to how the studs could be sitting in coolant, and how this was isolated from the piston and chamber.... Now I see that each piston chamber/housing has another gasket each to seal the pots within the surrounding water...
This being the case, compared to say my Renault Modus where the gasket has cracked meaning water is in the cylinders, as well as leaking out. The renault has no choice but to be fixed.

In the case of the T25, am I right to think that a leak out, doesn't mean a leak in to the pots? The two are un-related. As such I could leave it as see how she progresses, keeping an eye on water/coolant levels. (And making sure the coolant is good coolant).

Meanwhile there has been no smoke, no overheating, no exhaust pressure blowing back to the coolant sump etc....

Does any of this make sense (I much more at home with wiring)? Thought appreciated.

Adrian

[itchyfeet]

yes you are right the barrels are sealed seperately to the water jacket so you can leave it for now
its only time though before the leak will get worse.
Also air inside the system will promote corrosion

[adebutter]

Thank you, appreciated.

Is there a worse case scenario here - drips become a stream - or a total loss of seal and coolant gushes.... I guess what I mean is can I get away with topping up, and can she 'fail' such that everything is lost.

I mean this as a 'too close to holiday to fix'. Not intending to leave forever

[captain Byrne]

I had an identical problem when I first got my van a few years ago. I ended up slapping a load of araldite around the offending area. It worked for a while but then eventually coolant started to seep through.
If it's just a small drip at the moment I'm sure you'll be fine but as you say it'll have to be sorted eventually.

[itchyfeet]

if it's a holiday just go for it
the seal won't just fail totally but the leak may get worse.
check your coolant level sensor works and check regularly.

[adebutter]

Thank you both.

Can I assume that if I keep the expansion bottle inbetween max and min, this means the engine is full up?

[itchyfeet]

Main tank in engine bay with pressure cap must be brim full, a leak may mean it doesn't pull extra coolant back from top up tank so keep an eye on the main tank level ( don't open hot)

[nicq]

if it's a holiday just go for it
the seal won't just fail totally but the leak may get worse.
check your coolant level sensor works and check regularly.

I am afraid they do. I had a leak for a year then one day it just gushed out so bad you could not drive it.

[what2do]

As itchy knows, mine has leaked since the day I bought it (3 perhaps 4 years ago, I forget), no better or worse to this day. Coolant is cheap and for me the risk us worth the alternative.

[itchyfeet]

if it's a holiday just go for it
the seal won't just fail totally but the leak may get worse.
check your coolant level sensor works and check regularly.

I am afraid they do. I had a leak for a year then one day it just gushed out so bad you could not drive it.

I meant if wont just fail in the short time of the holiday, to suddenly fail you would most likely have had corrosion of the head having left if a year.

[nicq]

if it's a holiday just go for it
the seal won't just fail totally but the leak may get worse.
check your coolant level sensor works and check regularly.

I am afraid they do. I had a leak for a year then one day it just gushed out so bad you could not drive it.

I meant if wont just fail in the short time of the holiday, to suddenly fail you would most likely have had corrosion of the head having left if a year.

No I had the engine rebuilt, no corrosion around the seals faces. They just split at the point they had been leaking.
Runs perfect now without leaks.

[itchyfeet]

You still left it a year, op was asking was it ok to go on holiday.

Thanks for the info though seems you can't just leave it then as so many do.

[crazyhorse]

Mine had a leak for 2 years, kept topping up but got progressively worse then M5..... coolant gushing out. Happy days.

I suppose it's down to how bad it drips at the mo, is there a pattern on how often you have to fill it up again, and then ultimately if your confident it will make it. I suppose you cant argue with a confident man. Other than that make sure your in with recovery service. Just in case, (speaking from experience of course)

[itchyfeet]

If it's not corrosion around the leak it could be air in the system turned to steam and the steam venting thats killing the seal eventually.

[nicq]

If it's not corrosion around the leak it could be air in the system turned to steam and the steam venting thats killing the seal eventually.

That is what happened to mine. It was a small leak at the top of the block. Got hot and split the seal right across the top. You could see it all hanging out.