Water in the Oil

[Mad Mart]

A Sprint came to me with a suspected head gasket failure. On starting the engine you could immediately see bubbles rising in the expansion tank (plastic tank) and a quick check confirmed that the water was getting in with the oil. Cutting a long story short, the head has been skimmed and pressure tested and the block face (deck) has also been skimmed. A new Payen head gasket was fitted.

After starting it up earlier today it was clear that bubbles were still rising in the expansion tank. You will get this for a while after refilling the cooling system but after about 20-30 minutes there was still the occasional few bubbles. I let it cool for a couple of hours (had to watch the F1 GP) then went back out and removed the sump plug. Sure enough approx. half a cup full of water came out before the oil did.

I can't think what else can be wrong so I have posted this thread to see if any of you guys can help!

[matt of the vivas]

Waterpump seal leaking slightly? Might have been damaged by the overheating that blew the head gasket.

[Carledo]

I've been giving this some thought too and the possibility of water pump did occur to me since it is one other place where oil and water come together. But when the engine is running the oil pressure had better be higher than the water pressure in the cooling system or you'd have more trouble than a few bubbles! And in this case you would get oil in the water, rather than the opposite symptoms Mart is experiencing. At least I think so, not being sure how much oil pressure is present at that point in the engine, which is pulse fed off the front of the jackshaft. But even if this were so, it doesn't account for where the air is coming from!

Since you are so far in the hole now Mart, it might be worth grasping at the last straw and re-sealing the water pump, cos the ONLY other possibility (and I am loath to suggest it) is that the block is porous, or more specifically, one of the bores.

Steve

[trackerjack]

Judging by some of the recent slants I have rebuilt it could be a poor seal on the inlet manifold allowing a leak into no 1 (plug will show). But the bubbles rule this out.
A cracked block or could also give same symptoms and an engine with no antifreeze in winter could have cracked bores. I have just scrapped a block that had a 50mm square cracked out. (lucky me found a rebored first class condition one to replace it.

[IncaDolly78]

Other than what has already been suggested I wonder could the head itself be cracked somewhere and water is entering the top of the cylinders? This would produce a lot of steam out the exhaust though wouldn't it? I vote water pump seal then!

[xvivalve]

A TR6 engine was decked as part of a rebuild some years ago and it proved impossible to get a head gasket to seal on that. Eventually, it was determined the decking had not been done perpendicular to the axes of the studs so that a tapered gap always existed between head and block. Obviously harder to check this on a Sprint with angled fixings to start with! Symptoms on the TR also included fluids leaking out of the gasket space.

[sprint95m]

A failed water transfer housing gasket?



Ian.

[Jon Tilson]

If the water pump seal has gone to the extent that oil gets past it into the sump, you get much more than half a cup and a sump full of mayo...

You can clutch at straws on the inlet manifold gasket and retorque the head again properly but I'd say its coming off...

Jonners

[Carledo]

If the water pump seal has gone to the extent that oil gets past it into the sump, you get much more than half a cup and a sump full of mayo...

You can clutch at straws on the inlet manifold gasket and retorque the head again properly but I'd say its coming off...

Jonners

He's had the head off twice now Jonners and it's been skimmed and pressure tested. I'm fairly convinced the head is good - which means the problem is lower down, unfortunately!

Steve

[Jon Tilson]

Steve you have no idea as to the quality or provenance of the work done...any more than I do...
Skim and decking means nothing if the work was badly done. I'm inclined to be suspicious of any work done on a Sprint these days as so few really know what they are doing.

If the top water pump seal is leaking slightly the water gets thrown out of the slot and doesnt normally get past the oil seal and in to the sump. I have only ever known water to get in via the pump when the top seal is badly broken, as in when some clod has whacked the pump with a hammer to get it down enough. This is why I devised the "fit pump without impellor" method in the wiki guide.

So that leaves water jacket to pistons and down bores....again pretty rare. If a gasket is duff it normally blows compression gas into the cooling passages and the bubbles in the expansion tank we all know and hate. It has to be REALLY bad for water to get in to the oil. I have never seen it this bad on a Sprint....only ever seen pressurising.

The other possible way is via the inlet manifold. Again this would also likely ingest down the inlet tract leading to lots of white smoke or steam and a smell of anitfreeze in the exhaust. Also extremely rare. If the gasket fails it usually blows out on the bottom side and tips down the head and block.

Ive never had that back of the head transfer housing fail. I rarely bother taking them off.

By all means have the pump out....and check the thermostat is opening too, but we all know the head is coming off when you find nothing wrong.

Jonners

[Carledo]

Steve you have no idea as to the quality or provenance of the work done...any more than I do...
Skim and decking means nothing if the work was badly done. I'm inclined to be suspicious of any work done on a Sprint these days as so few really know what they are doing.

If the top water pump seal is leaking slightly the water gets thrown out of the slot and doesnt normally get past the oil seal and in to the sump. I have only ever known water to get in via the pump when the top seal is badly broken, as in when some clod has whacked the pump with a hammer to get it down enough. This is why I devised the "fit pump without impellor" method in the wiki guide.

So that leaves water jacket to pistons and down bores....again pretty rare. If a gasket is duff it normally blows compression gas into the cooling passages and the bubbles in the expansion tank we all know and hate. It has to be REALLY bad for water to get in to the oil. I have never seen it this bad on a Sprint....only ever seen pressurising.

The other possible way is via the inlet manifold. Again this would also likely ingest down the inlet tract leading to lots of white smoke or steam and a smell of anitfreeze in the exhaust. Also extremely rare. If the gasket fails it usually blows out on the bottom side and tips down the head and block.

Ive never had that back of the head transfer housing fail. I rarely bother taking them off.

By all means have the pump out....and check the thermostat is opening too, but we all know the head is coming off when you find nothing wrong.

Jonners

Alright Jon, Don't get your knickers in a twist. I would like to point out, first, this is Mart we're talking about and if he doesn't know his way around a Sprint engine, nobody does. Second, the machine shop he uses has been doing his work to a satisfactory standard in the past.
I agree that head and head gasket problems are the most likely source of trouble, but that has been eliminated. I further agree that the water pump is an unlikely culprit for these symptoms. Ditto the water transfer housing and the manifold gasket (which, in any case would have been changed out twice now).

Sherlock Holmes said, "When you have eliminated everything else, then what is left, however improbable, is the truth"

My money is going on the block, yes it's rare, but it IS possible and would give these symptoms, particularly the bit about water in the sump but not as Mayo.

Steve

[Jon Tilson]

No twisted underwear here mate....

Unless you have some knowledge that's not on the thread I'm not seeing any info on Mart having commissioned the work or the head being off twice...

If the head comes off again and shows no sign of gasket failure then I'll agree about the block...as you say its unlikley.

Jonners

[trackerjack]

Having years of playing with Triumphs I am not surprised at anything that breaks or fails.
Years ago a friend had an Essex V6 engine Capri that went like stink and blew gaskets I took the heads off and noticed a grey stain down one of the inlets which was a crack and only leaked when hot.
Cracks sometimes open only when hot and the Sprint block is not the strongest design ever invented and a crack in the bore is what I would stake money on.
Please find the fault Mart and we can add another "watch out for" on our lists of things to worry about

[Mad Mart]

Thank you all for your input. It had me beat for a while there but in the end, and with the help of you guys, I tracked it down. To be honest, I should have picked this up sooner. I suppose it was because I was concentrating more on the head than the block and had pretty much convinced myself that it won't be the block. It was, or definitely looks like, a hairline crack in no.1 cylinder...


Inside Cylinder No.1

Badcyl1.jpg (52.92 KiB) Viewed 1271 times

Badcyl2.jpg (54.73 KiB) Viewed 1271 times

Outside Cylinder No.1

Badcyl3.jpg (58.59 KiB) Viewed 1271 times

Badcyl4.jpg (55.84 KiB) Viewed 1271 times

For those of you who said it was the block, give yourselves a pat on the back. I'm just happy I can now move forward.

[Carledo]

I don't think you should blame yourself TOO much for this Mart, I would reckon the chances of this at less than 1%. I just had a gut feeling from a past experience on an entirely different vehicle. I'll take the back pat, but no more than that!

This looks to me like damage from a car left standing for long periods without antifreeze and I will bet good money that you are not the first person to have attempted a cure. You can draw some satisfaction from being the LAST such attempt however!

Steve