The mystery of the disappearing water

[straylight]

The sprint is dumping water somewhere. Lots of it.

Car is running fine, not blowing white or blue smoke. I've replaced the temp sender and can now see the engine temp and no signs of overheating. I leave the internal heater on so I can tell when the water has run out (it blows cold air instead of the insanely hot stuff). In the space of about 80km the water goes somewhere. I get back home and the top radiator hoses are empty, the expansion bottle is empty. Little water left.

It first happened when I was bringing the car up to Adelaide last December and I've just got around to having a look and getting it back on the road. I feared a head gasket had gone as the car lost power when I tried the final leg after a 2 week hiatus, but I think I've traced the lack of power to a fuel line blockage. Running fine now.

Several runs around the big city block and the water is vanishing again.

No mayo in the oil or under the rocker cover. No water coming out of the expansion bottle lid or overflow hose. No signs of leaks under the car, no steam from under the bonnet. As I said, the engine is pulling like a champion.

what's the best guess ?

stu

[Larry 1300]

The water must be going somewhere. I would run the engine and while the water is under pressure I would check every hose for a leak. Also check for a leak near where you put in the new temperature sender.
Good to hear from you in Australia. Its starting to get very cold here now as the Winter starts. What's the weather like with you?

[GlenM]

Get it pressure tested at garage, that often shows up leaks that are often difficult to trace otherwise.

[alolympic]

Leaking around the water pump? Mine was and tricky to spot as water falls onto block and evaporates...

[DoloWIGHTY]

.

[soe8m]

I think it is the overflow bottle leaking by a faulty cap. should be a 13 lbs one but a 15 or 18 will also do. You can check by putting the overflow hose in some bottle to see if it's going in there.

Jeroen

[Jon Tilson]

Err this is Stu we are talking to here....

He would surely know to look at the slot behind the alternator wouldn't he....

Caps do leak but surely you would see evidence of that.

Core plug behind the flywheel is your worst case scenario....

Jonners

[Robert 352]

In acknowledging that it is indeed Stu who is asking for comment I have to say that I too had a similar problem.

It was as Jeroen suggests, the pressure cap. I twigged to it when someone a great deal smarter than me down here suggested that I should change said cap. I coupled a piece of tube onto the outlet of the pressure tank and ran it into a bottle for a day or so. That was where the water was going.

Stu, cross your fingers, it might just be something simple. The pressure cap perhaps.

Robert

[straylight]

it might be stu (me), but I can also be a doofus when it comes to sorting stuff out

thanks for the suggestions. I'm open to any and all ideas.

I'll have a careful look at the overflow, the overflow bottle does have water left in it, which seems like a good sign. The expansion bottle cap is tight and snug.

No water flowing from the slot in the block under the water pump. No water on the ground, which is annoying as that would immediately point to a leak.

A core plug would be annoying. Thanks Robert But surely I'd hear the escaping steam ?

very perplexing and with summer coming up, too warm to be taking chances on the road. Btw, this is the second sprint, first is running like a charm after the repair to the clutch cross shaft lever.

thanks for your help everyone.

stu

[trackerjack]

Might be an easy fix Stu, try the inlet manifold gasket. It leaks into number one cylinder and the car actually runs better but be aware if too much water is getting in it erodes the alloy.

If you have a crack in the block the water will seep into the oil and the level of oil will rise until the pump sucks it up and ruins the engine.

Good luck with the search

[straylight]

ah, okay, thanks Jon. I'll whip off the inlet manifold and have a look. I recall the water injection thread from a while back.

stu

[Keith CANSDALE]

I presume you have the correct recovery type of radiator cap? Regards KC.

[Toledo Man]

Another possible source of a leak is the bypass tube from the inlet manifold to the water pump. This often happens when the inlet manifold has been removed and refitted.

[Jon Tilson]

If you are ingesting water via the inlet manifold I would first look at the plugs and see if number 1 looks any different.

I think you will be looking at a cleaner less sooty appearance especially after the 1st five minutes running. Wouldnt
you also expect a steamy looking exhaust when cold? Steamier than expected anyway.

It is a worry because most external leaks should be visible. I'd always go with the principal of eliminating all the cheapest
and easiest fixes first...so that puts the expansion bottle cap at the top, followed by plug analysis.

Jonners

[sprint95m]

Another possibility is a leak from the cylinder head transfer plate.
There was a thread some time ago where somebody (from Luxembourg..?) had a Sprint with a coolant leak there.






Ian.