P38A Coolant leak at rear of engine.

James Rogers · Apr 13, 2018

Hi I have a v reg p38 with a V8 petrol engine. Its the later bosch engine.

A coolant leak has appeared and has gotten worse quite quickly. It is at the rear of the engine but I cannot pinpoint it. To give an idea of location it is running down the nearside. Down the fuel pipe and down the side of the engine/Bell housing. It's a steady flow and it drips a reasonable amount of coolant.

When the engine is revved the coolant becomes frothy.

So its running down the fuel pipe which goes over the gear box and into fuel tank. Also down the side of the engine directly where the gearbox bolts to the engine. I can' s where its coming from. I've used a mirror and light. I've even take the nsf wheel arch out but can't see anything.

Any ideas would be appreciated.

Many thanks
James

DanClarke · Apr 13, 2018

Rear Core Plugs corroded?

James Rogers · Apr 13, 2018

I dont know what they are

Saint.V8 · Apr 13, 2018

Little discs that are placed into openings in the block during manufacture that cover the openings that were created during casting....

DanClarke · Apr 13, 2018

They are these delightful little devils.
https://rimmerbros.com/Item--i-RB7105
Basically, there are machined holes in the engine block castings and core plugs block these holes.
Some core plugs are on waterways and some are in oil-ways.
There are (I think) 3 at the rear of the engine, Its a gearbox off or engine out to get at these ones (again., I think) and the failed core-plug would need to be bashed-through and yanked out and then a new one inserted (with a bit of the appropriate sealant ,maybe). The plugs cost nothing, the time and effort to do the job is not trivial.
I read somewhere that leaking/weeping waterway core-plugs is a sign that the coolant mix has not been changed as it should and maintained at the correct mix either.
I hope you find your leak and are able to fix it.

brianp38dse · Apr 13, 2018

These are core plugs they are fitted in the block to close of manufacturing passage ways

here is some at the back of the block and there are ones on the side as well

Saint.V8 · Apr 13, 2018

Could also be a leak on the rear of the Valley Gasket.

James Rogers · Apr 13, 2018

Surely if they were leaking the water wouldn't be coming from above the bell housing? And it wouldn't be running down the fuel pipe?

James Rogers · Apr 13, 2018

Saint.V8 said:
Could also be a leak on the rear of the Valley Gasket.

What's involved in replacing that?

James Rogers · Apr 13, 2018

And also its worth noting the leak has come in quite quickly so surely a corroded plug would start off light and slowly get worse?

PPP38vouge · Apr 13, 2018

I'm with Saint, rear valley gasket.Easy enough job, few nuts and bolts. Few hours work at an easy pace, need a torque wrench for the inlet manifold.

James Rogers · Apr 13, 2018

PPP38vouge said:
I'm with Saint, rear valley gasket.Easy enough job, few nuts and bolts. Few hours work at an easy pace, need a torque wrench for the inlet manifold.

OK so remove manfold a it' under there?

Mark Piercy · Apr 13, 2018

A makeup mirror and torch may help to pinpoint?

Saint.V8 · Apr 13, 2018

The picture above of the core plugs in the rear of the engine - the Valley gasket is the large gasket held in place by the metal strip with a bolt in it!

James Rogers · Apr 13, 2018

Saint.V8 said:
The picture above of the core plugs in the rear of the engine - the Valley gasket is the large gasket held in place by the metal strip with a bolt in it!

The bolt at the very top right?

Saint.V8 · Apr 14, 2018

James Rogers said:
The bolt at the very top right?

James Rogers · Apr 14, 2018

OK so after some research and by looking at the rave guide it seems a very do able job. I will have another look on Monday to see what if I can find the leak. Maybe take the coil packs off. Is this what it is do we think? It does make sense.

James Rogers · Apr 14, 2018

And thanks for the picture. Made it much clearer.

James Rogers · Apr 16, 2018

OK so I've had a look and there's a little puddle of coolant just below the Valley gasket clamp. But above the gearbox. So I'm assuming it's the Valley gasket. Is there a kit I can buy to do the job. I know I need the 2 seals that go either end and the Valley pan Gasket. I'm assuming I'll need one for the throttle body and inlet manifold upper. New bolts too. If someone could share a link or maybe list the bits I will need.

martynv8 · Apr 16, 2018

Get a kit from Turner engineering, some of the other aftermarket valley gaskets are crap & dont fit / leak.
I'd also put some threadlock on your lower intake bolts as mine had a habit of backing off on the outer 4 bolts.

P38A Coolant leak at rear of engine.

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