how can I tell if head gasket a small leak i can't see anything obvious temprature gauge showing ok but when parked up can smell heat from engine

What does "smelo of heat" mean? Smell of exhaust gasses, hot oil or coolant?

 

HG failure may have one or more of these symptoms:

- pressure in coolant circuit: pressure valve in reservoir cap often opens on idle, coolant level changes dramatically with removed cap. Engine may consume some of coolant. Gas bubbles may reduce efficiency of cooling and heating.

- leak of coolant into oil: significiant amount of white emulsion ("mayo") of water and oil forms under oil cap. 

- leak of oil into coolant

On 01/10/2019 at 09:16, Papez said:

pressure valve in reservoir cap often opens on idle, coolant level changes dramatically with removed cap. Engine may consume some of coolant.

Can you explain more in detail how the engine consumes coolant due to excessively low level of coolant?

12 minutes ago, RicardoM said:

Can you explain more in detail how the engine consumes coolant due to excessively low level of coolant?

 

Where did I say anything about low level of coolant?

Alright you said the level changes dramatically with removed cap, hence the engine consumes some of coolant.

How exactly does the engine consumes the coolant?

I said that level changes, i didn't say which direction or that it corelates with volume of coolant in engine. 

 

Coolant consumption is another symptom. It can leak either into oil or into cylinder.

1 hour ago, RicardoM said:

Alright you said the level changes dramatically with removed cap, hence the engine consumes some of coolant.

How exactly does the engine consumes the coolant?

It does by burning it and letting it of as steam. 

Sometimes it is not even noticeable. 

3 hours ago, Thefeliciahacker said:

It does by burning it and letting it of as steam. 

I have never heard of an engine starting to 'consume/burn' the coolant due to a coolant level disturbance...

1 minute ago, RicardoM said:

I have never heard of an engine starting to 'consume/burn' the coolant due to a coolant level disturbance...

Ah no I did not actually mean due to low level but rather a HG failure 

1 minute ago, Thefeliciahacker said:

Ah no I did not actually mean due to low level but rather a HG failure 

If you read carefully the topic, you'll see what was the context for my question and comment.

I agree with Ricardo; the only ways an engine can lose coolant are by leaking externally or by HGF between a waterway and an oil way or a cylinder.

22 hours ago, RicardoM said:

I have never heard of an engine starting to 'consume/burn' the coolant due to a coolant level disturbance...

Again, where did I say that engine starts burning coolant due to low coolant level? Or where did I say anything about LOW coolant level?

 

I did say that coolant level might change with removed cap on running engine. PERIOD. Also, engine might loose some coolant. Two different things. Get it?

Edited 3 October, 20196 yr by Papez

On 01/10/2019 at 09:16, Papez said:

- pressure in coolant circuit: pressure valve in reservoir cap often opens on idle, coolant level changes dramatically with removed cap. Engine may consume some of coolant.

For a long time I've seen you are nit picking my posts. You should stop being anal and doing semantics on my posts because I can play the same game too. We are here to help people, not to show off. Got it?

7 hours ago, RicardoM said:

For a long time I've seen you are nit picking my posts. 

 

Where? Certainly I haven't kept repeat something you didnt write just to humiliate you and I definitely didn't mean it as personal attack. We have PM for personal issues.

 

I still don't understand what in my post say that "level change" means "low coolant level"

Edited 4 October, 20196 yr by Papez

7 hours ago, RicardoM said:

For a long time I've seen you are nit picking my posts. You should stop being anal and doing semantics on my posts because I can play the same game too. We are here to help people, not to show off. Got it?

I think you both got carried over by a context mistake. 

Papez did say that engine may consume some coolant. 

This phrase was badly connected with the low coolant level phrase. 

Therefore the meaning deduced by it is that when the coolant is low the egine will consume some. 

But this is not what Papez wanted to say. 

Just an opinion. 

Edited 4 October, 20196 yr by Thefeliciahacker

On 02/10/2019 at 16:24, Papez said:

 Coolant consumption is another symptom.

 

15 minutes ago, Thefeliciahacker said:

 

Therefore the meaning deduced by it is that when the coolant is low the egine will consume some. 

But this is not what Papez wanted to say. 

Just an opinion. 

 

You are right, it was badly formulated and I wrote it right at start of conversation.

 

Also by coolant level change I didn't mean low level. I meant that level in expansion tank might fluctuate and in extreme case, coolant might run out of expansion tank.

 

I had a coolant tank crack. That ultimately lets pressure and gasses out, ultimately those gases contain moisture, or a blokes version of it if not a chemically accurate description...

 

Might be a weeping pipe too.

 

I spotted it visually, but I knew to look as it smelt. Can't describe it, just knew it wasn't the right smell