Core plug and combustion gasses in coolant?
Core plug and combustion gasses in coolant?
Author
Discussion

Steviesam

Original Poster:

1,346 posts

150 months

Does a brokenl/leaking core (freeze) plug give combustion gasses in coolant?

I dont think it does, but my neighbour insists it does.

Who is right?

Thanks!

GreenV8S

30,915 posts

300 months

All the core plugs I've ever seen separate the cooling jacket from the outside of the engine. Which engine and which core plug in it does your source think separates the cooling jacket from the crank case?

E-bmw

11,176 posts

168 months

GreenV8S said:
All the core plugs I've ever seen separate the cooling jacket from the outside of the engine.
^^^^ Wot 'e said.

I too have only ever seen core plugs on the external block of an engine.

As the colloquial name (freeze plugs) implies, they are a natural weak point should the coolant freeze & will then allow frozen/expanding coolant out rather than do damage internally in the engine.

As such it is not possible for them to allow combustion gases into the coolant.

paul_c123

1,021 posts

9 months

Combustion gases in coolant? Sounds like head gasket failure, albeit it may be a small leak if there's no other obvious symptoms.

Steviesam

Original Poster:

1,346 posts

150 months

Thanks gents.

I did tell him before he bought it (for 200 euro) that the headgasket had gone (basically sold it for scrap) but saw him today and he said it was the core plug. I explained that a core plug wouldnt result in combustion gasses in the coolant, but he wont have it. Still, at least i told him head gasket so after he has removed half the engine to replace it and its still leaking and overheating it wont be my fault!

GreenV8S

30,915 posts

300 months

Steviesam said:
he said it was the core plug
He can prove himself right quite easily by identifying a core plug separating the cooling system from the crank case. With the amount of information freely available online these days I think you'd have to be daft to try to find it by physically dismantling the engine, but if that's how he's decided to tackle it then that's his problem. It will be a learning opportunity either way.

E-bmw

11,176 posts

168 months

Yesterday (07:57)
quotequote all
Steviesam said:
Thanks gents.

I did tell him before he bought it (for 200 euro) that the headgasket had gone (basically sold it for scrap) but saw him today and he said it was the core plug. I explained that a core plug wouldnt result in combustion gasses in the coolant, but he wont have it. Still, at least i told him head gasket so after he has removed half the engine to replace it and its still leaking and overheating it wont be my fault!
Sometimes you just have to remember that you can't educate pork!

Huntsman

8,810 posts

266 months

Yesterday (08:12)
quotequote all
E-bmw said:
As the colloquial name (freeze plugs) implies, they are a natural weak point should the coolant freeze & will then allow frozen/expanding coolant out rather than do damage internally in the engine.
Thats quite wrong.

The cores are moulded and bonded sand and used as part of the casting process to create the cavity, the cores are supported in the tooling and this creates the holes.

stevieturbo

17,799 posts

263 months

Yesterday (08:39)
quotequote all
Huntsman said:
Thats quite wrong.

The cores are moulded and bonded sand and used as part of the casting process to create the cavity, the cores are supported in the tooling and this creates the holes.
What he said was largely correct. But it is not a design feature, it just so happens they tend to pop out if the coolant freezes, which may limit damage to a block.

But as you say, the holes are part of the casting process. Not a built in safety feature of any kind.

E-bmw

11,176 posts

168 months

Yesterday (11:32)
quotequote all
Huntsman said:
E-bmw said:
As the colloquial name (freeze plugs) implies, they are a natural weak point should the coolant freeze & will then allow frozen/expanding coolant out rather than do damage internally in the engine.
Thats quite wrong.

The cores are moulded and bonded sand and used as part of the casting process to create the cavity, the cores are supported in the tooling and this creates the holes.
Correct, but then you are talking about the holes, whereas everyone else is talking about the core plugs.

tr7v8

7,449 posts

244 months

Yesterday (12:41)
quotequote all
Steviesam said:
Thanks gents.

I did tell him before he bought it (for 200 euro) that the headgasket had gone (basically sold it for scrap) but saw him today and he said it was the core plug. I explained that a core plug wouldnt result in combustion gasses in the coolant, but he wont have it. Still, at least i told him head gasket so after he has removed half the engine to replace it and its still leaking and overheating it wont be my fault!
What is it? sounds like head gasket, or could be cracked head or even cracked liner.

Steviesam

Original Poster:

1,346 posts

150 months

Yesterday (18:33)
quotequote all
It’s a Peugeot 3008 1.6 hdi 2012

Steviesam

Original Poster:

1,346 posts

150 months

Yesterday (19:10)
quotequote all
It’s a Peugeot 3008 1.6 hdi 2012

E-bmw

11,176 posts

168 months

Could well be a cracked block.

I had that engine in a Volvo v40 a couple of years ago.

There are many online counts of these engines with cracked blocks.

It starts with a "low coolant" warning occasionally.

Then when the crack gets a bit bigger it will just send a large gulp of combustion gases into the coolant & you get the symptoms above.

ComStrike

444 posts

109 months

They run a split liner setup in the block
More than likely its cracked
Seen it on numerous occasions with that particular engine & setup