Small block water leak query

XenonJohn · Post by **XenonJohn** » Sun Apr 19, 15 10:22 pm

Hi,
273 small block in Aussie VE Valiant. Running fine. No mayonnaise in oil, no white smoke, engine runs just great, however:
Small drip coming from back of engine on right side. It is water, not oil. Cannot see it without dental mirror or something but almost seems to be from back end of cylinder head. Not coming from rearmost exhaust manifold bolt, have checked that.
??Head gasket.
Have had repeated problem with the valve in right exhaust manifold that directs warm exhaust on startup under the carb to warm it up not opening when engine warm. Just wonder if head has got too hot or something. Have not run it for miles and miles like this, just very short test runs and test runs on driveway measuring temp of each part of engine as it warms up with one of those infra red thermometer guns, still recommissioning the car.
Is this leak a known issue?
Have noticed that official Chrysler antifreeze apparently used to contain small dose of a leak/crack stopper so tiny leaks presumably would fix themselves. Thinking of trying older style leak stopper pellets (not radweld or similar but older type pellets made from black pepper among other things).
Any help much appreciated
John

Pete · Post by **Pete** » Sun Apr 19, 15 10:27 pm

There are Core plugs in the back of the block (concealed by the bell housing) and also in the back of the heads. I just had one go on a Big Block motor - the DO Rust through.

Maybe that is your first check....but its a lot of work for a £1 item......

XenonJohn · Post by **XenonJohn** » Sun Apr 19, 15 11:37 pm

That would make sense. seems to be coming from back of the head itself but I thought that could not be possible, clearly it is!
All core plugs had gone in sides of block when it came out of a barn so would make sense. I didn't know the heads had them too.
Need to do something else for a bit while I summon up the will to tackle this one.

Steve · Post by **Steve** » Mon Apr 20, 15 12:46 am

Good luck John and sure you will be fine once you start this job. Maybe you could post some pics as you go along for us to see what you are doing.....great way to learn, especially if, like me, you haven't tackled this before

Gareth · Post by **Gareth** » Mon Apr 20, 15 8:32 am

Yep, sounds like a core plug leaking. Be aware when buying that a lot of core plug sets do not include the ones for the cylinder heads. Brass replacements are worth the extra over steel.

shovelheadrob · Post by **shovelheadrob** » Mon Apr 20, 15 1:30 pm

I think that Pete is referring to the ones in the block within the bell housing, but there are some in the heads too.

XenonJohn · Post by **XenonJohn** » Mon Apr 20, 15 3:16 pm

OK,
Bought me a Rolson dental mirror from Maplin plus pentorch and went investigating.
It is clearly the cylinder head core plug that has the leak. Has corrosion plus a load of gloopy goo oozing from it.
Beginning to think my old Lotus was not so much of a pain in the butt after all - and that's saying summat!

Thanks for the advice everyone.

latil · Post by **latil** » Mon Apr 20, 15 4:14 pm

Probably better to take engine out complete rather than taking heads off to do it,you can then change all the plugs to brass ones including the one at the back of the block. And,yes core plug sets do not have the head plugs included,separate order.

aussie pete · Post by **aussie pete** » Mon Apr 20, 15 4:51 pm

I had repeated problems with core plugs corroding replaced all with brass and no problems since