MGB: Drops of coolant near #3 plug?

Wife's '73B overheated right after engine reinstalled following clutch job a month ago. Mechanic said just air bubble and all now okay.

Noticed last week that coolant was way low. Filled it and it has not gone down since.

Yesterday, however, car started hard and felt like it was initially running on 2 or 3 cylinders. After a few minutes it ran smoothly.

Noticed a bit of coolant sitting just below #3 plug.

Symptoms of blown head gasket? Or head itself?

That's a common location for a head crack, from the second or third plug hole downward. You need to determine if the drip is from near the plug or at the head gasket. A leakdown test may be in order.

Coolant is above head gasket in plug hole depression. Also, forgot to say that I adjusted valves last week and noticed a couple of coolant drops oozing up from valves in the #3 area.

UH OH, leak down test time.
RS

David I've had the same happen a couple of times to me and each time it was the darn heater control spraying a fine mist in that area. Might be something you want to check before digging in deep :)

Best case - Naomi's heater valve spraying coolant. Worst case - cracked head (more probable considering the coolant also under the rocker cover). Not sure that a leak down test will pinpoint this as the crack is usually just into a coolant passage. Usually you can see the crack if the area is cleaned of all the crud and a strong light is used. The good news is that this can be fixed with a process called stitching and doesn't have to be welded. Stitching is the process of drilling and taping a hole at one end of the crack, screw in a plug, grind it flush, drill an overlapping hole, screw in another plug, grind it flush, etc. until the end of the crack is reached. There is a company that sells the necessary plugs to do this process at home, but I can't find the name and web site right now. If anyone is interested, I'll get the information for them.
Cheers,

Naomi: Pretty sure its not the heater control. Been there-done that before and this time I shielded the plug area from the control with a piece of cardboard. No evidence of spray.

Upon closer inspection it looks like the coolant is leaking (just a few drops) down from the valve cover gasket (!?) into the #3 plug area and then collecting under the plug. After I removed the plug I could see a dribble track underneath a droplet clinging to the gasket. This conforms to the fact that I saw a small bit of coolant around the #3 valve springs when I had the valve cover of to adjust the valves. The tip of the spark plug also seemed wet (not gas). Does this still point toward cracked head or is it possible its just the head gasket?

Dave: My post crossed yours. Cleaned the area below, above and around the plug hole and show a strong light but no crack obvious.

Yes, interested learning about this "stitching" process.

dwhatty Wrote:

Cracked head unfortunately seems to be the consensus. Luckily its her car and not mine as the deal is she pays for hers and I for mine. (Sorry Dear, but I'll do the work for "free" just because I love you.)

Any reliable sources of ready to bolt (hardened valves, springs etc installed) on standard cast iron heads in the US? Bought the last one from Chris at Octarine in UK in 2001 but the exchange rate and shipping costs now seem prohibitive.

So, what exactly can happen to the engine when a head is cracked?

Post an ad on Trader and you may well turn one up quickly. They're not rare, and as you probably know, they can be swapped in a morning as long as you have all of the gaskets on hand.

Might be a little pricey...2 to 500, based on the source and what comes with it.

Follow the Haynes Manual on this one.

I've done a few. Fairly easy job...just takes a little patience.

I would vote that it's cracked as others have said. You've mentioned the telltale items. Don't drive it like that.

Dan

Jimmy Hilton had some heads on Ebay a week or so ago, PM him to see if he sold them , they were ready to go if I remember correctly.

Oh if you want to pin-point the leak a little closer, get your hands on a pump pressure tester, it hoks up the radiator car neck, pressurizes the system with a hand pump, has a gauge on it to tell if you're holding pressure or not, and will always pressurize the leak point and you can probably watch and see the leak's orgin.

...I can't believe no said to try a re-torque first. Could be as simple as a lifted head after she got hot. It sure doesn't hurt to try.

repeat post in error.