Mysterious coolant loss

[Stocky]

Never a dull moment with my new Stag. The coolant level keeps falling with no overflow from the (new) pressure cap (I have one of VMad's header tanks), no hose leaks, coolant system pressure tested, no HGF (block test done, twice), no water in the "V". I'm having to refill the header tank regularly. The only clue I have is white smoke (condensation or steam?) from the exhaust, which is constant.
So, am I likely to have an inlet manifold gasket leak? Would this explain a coolant loss of perhaps 1 litre in a 20 minute drive?

[wilf]

Easy way to tell - Have a look at the plugs.

That amount of water going into one or two cylinders will likely clean them up no end! i.e. they should look very different to the rest.

[ChasR]

From what you are saying it could be the inlet manifold gaskets.

[Stocky]

Thanks chaps. D'oh, didn't think of looking at the plugs! Obvious really.

[Stocky]

An update.
Damn. Plugs OK, rechecked block test for the third time (twice in three days) and the head gasket has gone. I can only assume the leak has been intermittent and the gasket has finally let go. It would explain my mysterious intermittent over-pressurisation I have posted about before.
I now have to decide if this car I've had for 6 weeks is worth keeping/spending the money on. I've never attempted anything more than basic maintenance before, so a HG replacement is daunting. On the other hand I can't afford 2k spent with one of the specialists.
I think I want my TR6 back.

[Goldstar]

Hi Ross,

Sorry to hear your woe. It would certainly be worth sending out an SOS to the Surrey area team, they are very knowledgeable and helpful and I am sure they would guide you through the process.

Paul

[V Mad]

The most recent stag I had this problem with, there was a simple test that confirmed head gasket failure and which side it was. Take out plugs and crank the engine on the starter a few times. Water should spit out of the offending cylinder. Why not try it?

[Staggard]

An update.
Damn. Plugs OK, rechecked block test for the third time (twice in three days) and the head gasket has gone. I can only assume the leak has been intermittent and the gasket has finally let go. It would explain my mysterious intermittent over-pressurisation I have posted about before.
I now have to decide if this car I've had for 6 weeks is worth keeping/spending the money on. I've never attempted anything more than basic maintenance before, so a HG replacement is daunting. On the other hand I can't afford 2k spent with one of the specialists.
I think I want my TR6 back.

Drop a PM to Russ (Kryten) is in you'r area he may be able to help. Graham

[jasper]

Have you tried re touqueing the head bolts ???
Im haveing the same problem as you at the moment
My only thought is should I replace the other head gasket at the same time ?
They were both replaced in 2006 with extra thick gaskets
John

[wilf]

Ross - sorry to hear it wasn't the simpler option. But as someone else has said, if it isn't a serious HG issue, a retorque might just help, and there are cars out there running with Kseal or other treatments in them that has held up for a while. Just thinking of cheaper alternates for you.

[Stocky]

Thanks guys. I'm feeling a bit more positive this evening! Wilf: I got a sealant today and put that in, it has held up so far on a short run. Thanks for the ideas. If this weather continues it won't get much use this winter anyway, so I'll have time to try the simple stuff like retorquing.
And at the end of the day, I have a garage and tools and an ROM and the forum and I'm sure some local help if needed, so I will extend my mechanical skills if needed. Nothing like having a go to build skills and confidence.

[MarkTwo]

Ross,

My Stag deposited a small amount of coolant out of the overflow bottle again recently. Last time, only a few months ago I retorqued the heads and put in some K seal and that fixed it. Once again after less than a thousand miles, spome of the head bolts were loose again and I have retorqued again. This seems to have fixed the problem again.

A question for anyone. With the bolts working loose again, are there any recommendations to fix this? I tightened to 55 ft/lbs. I think I saw someone recommending 60 at one time. Is the only answer to replace the head gaskets? They were last replaced in 2006 - 6000 miles ago, but the heads were not skimmed.

Thanks,

Mark

[Motorsport Micky]

Mark,

There has been quite a discussion on a thread marked Head gasket over the last week, review it and see what you think.

I outlined where I've redrilled my block in the center and now run with 65lbs on the studs, 55lbs on the long set bolts and 35lbs on the short setbolts, did this 9 or 10 years ago and been ok since. This is what I've done and I recount this only to explain what I've done and not to encorouge you to do it, (unless of course you wanted to try it yourself !). I drain the engine and retorque every 2 years after loosening the heads the smallest amount.

Micky

[V Mad]

Mark, I dont think head bolts can work loose when torqued to 55lb, altough new gaskets do need re-torqueing because they compress after a time.

If you find one or two do move a small amount on re-torqueing, this is probably due either to small changes in the wrench, or changes in the conditions (temperature etc) or possibly the gasket is even disintegrating!

Many people are now using a higher value than 55lb with no problems. I usually go to 60lb myself but I know some are using 65lb without any apparent breakages. The higher the torque the greater the clamping force hence less likely for the gasket to leak, but the risk of excessive torque is either stud/bolt breakage or worse, head distortion/cracking.

[MarkTwo]

Thanks Chris and Micky. I will leave them for now and see if the same thing happens - coolant loss and what seems to be a loosening of some of the bolts / studs. Then it may be time for something more drastic!

Mark