Club 80-90 Forums

I did a bit of a search to try and diagnose my coolant leak and I think it may be a corroded core plug.

I have a very slight drip that seem to come out where the exhast pipe connects to the manifold on the right hand side of the rear of the engine. I have no overheating problems, no oil in my coolant and no coolant in my oil (as far as I can tell). This leak it quite slow. I have to top up the coolant every couple of months, but I only drive the van once or twice a week for a few miles, so it may be worse if I went on a longer trip.

My questions:

Am I right in thinking this is a core plug problem, and what are the other possiblities?

How can I get to the core plugs to check, do I have to remove the manifold?

How likely is it that the core plug will "blow" releasing all of the coolant at once (i.e. should i stop driving immediately)? Bearing in mind, I think I have had this leak for the last year, and nothing has really come of it.

Thanks for the help.

JCE

I have been digging a little deeper on my coolant drip problem, and I am wondering if this may not be a core plug problem (still can't find any info on core plugs). Is it possible that this is a leaking head gasket? Here are a couple of pics of the leak. One is from the top looking down and the other is from the bottom. The location is where the exhast pipe connects to the cylinder head...





I am getting a bit more concerned about this problem as I noticed that it has been dripping all night and did not stop when the engine cooled down. Maybe cancelling the easter trip

JCE

Ask Jed he has just been through this himself.
Rob.

Its difficult to tell from your pics but it looks like the head bolt seal may be leaking. Try to clean around the area as much as poss and it may become clearer.

Have a look in the wiki. Theres a few articles about water leaks and a product that may help.

Good luck with it. Hope you dont miss out on an easter trip.

Hi scottishdave - thanks for the reply. Forgive my ignorance, but could you tell me what the difference is between a head bolt seal and the cylinder head gasket? How would one replace a head bolt seal?

cheers,

JCE

Dry all around the area then stick some kitchen paper over it to see where it originates, looks like the head nut from the pics but hard to tell, hope it ain't coming out the zorst. Core plugs are on the underside above/between the push rod tubes, not on the head.
When I installed my wbx water dripped from the zorst at the same point, was coming from the water pipe joining onto the water jacket just above and to the left of the zorst manifold. I Tightened it up a little and leak was cured.

The WBX does not have a traditional head gasket.

The seal that people often think is the head gasket is in fact a water jacket seal but in your pics the leak does not look as if its coming from that area.

The bolts that hold the heads on to the block run through the water jacket and need to be sealed during assembly. Its a risky proposition taking the bolts out to try to re-seal them as they can snap when you try to undo them.

Sorry it does not sound very positive but without laying eyes on it I cant be much help.

Hi John

Just a quick note before anyone picks up on it and pionts out my mistake

Out of habit I refer to the fixings that secure the cylinder heads as bolts.

A bad habit that I need to get out of.

The fixings on this engine are actually studs and the heads are secured by nuts that have the mating face coated with sealant.

Sorry if I confused you by this.

Thanks for the input guys. I can tell from looking at it that the coolant definitely originates where the exhast connects to the head. If this is indeed the case, what would the source of that coolant be? Would it be a leaky head gasket (water jacket) leaking from inside the head? I appreciate all your help with this.

JCE

Sorry to keep banging on about this, but I am really hoping to get a better idea of what I am up against.

If I am getting a slow drip of coolant from the cylinder head where the exhaust connects, what is the likely source of the leak?

Thanks for the help.

JCE

i would say its one of the "o" rings below the barrels, or a cracked / holed head, the head gasket isnt anything to do with the water on a wbx as such.

are you also getting lots of condensation on start up from that port, or a wet plug if you turn the engine over without starting it?

take the spark plug out of the that cylinder , check if the plug is wet and the cylinder isnt full of water , you could also take the exhaust off and have a look .. but don't blame me if the exhaust bolts snap

if it is coolant like you say then either the top sleeve seal has gone or its the head .. sorry

Any luck locating the leak yet?

I was looking at your pics again and it looks like the top of the joint between the exhaust and the head is damp. If it is, bear in mind water/coolant will not flow uphill (unless its under pressure). Sorry if Im stating the obvious but it does look damp up there.

Thanks for the replies. You've given me a few more things to check out. I'll let you all know what I find out.

cheers,

John