Chemical testers for cylinder head leaks?

[AJL308]

I have a suspected fault with a cylinder head gasket - car is difficult to start when hot and I'm told that it may be due to coolant pressure leaking into a cylinder making it hard to turn over.

Someone has told me about these chemical tests which apparently tell you whether exhaust gasses are entering the cooling system indicating a head gasket fault. Do they actually work? If so are any better than others?

https://www.amazon.co.uk/RELD-Cylinder-Combusion-U...

[Drezza]

Yes they do work, I just bought the cheapest one on eBay (less than £10 I think). I had exhaust gasses entering the coolant system and was so bad it was popping the rad hoses off and used one of these kits to diagnose it.

[E-bmw]

Are you losing water/coolant level?

Is there any oil in the water or water in the oil?

[GreenV8S]

They do work. I haven't used a wide variety but it's a simple chemical test and I'd be surprised to find one that didn't work.

[stevieturbo]

AJL308 said:

I have a suspected fault with a cylinder head gasket - car is difficult to start when hot and I'm told that it may be due to coolant pressure leaking into a cylinder making it hard to turn over.

Someone has told me about these chemical tests which apparently tell you whether exhaust gasses are entering the cooling system indicating a head gasket fault. Do they actually work? If so are any better than others?

https://www.amazon.co.uk/RELD-Cylinder-Combusion-U...

So is it actually hard to turn over ? Difficult to start can be from many symptoms. Is that actually one of them ? Rarely would I say a HG issue makes an engine difficult to turn over though.
Unless it's been cooked and half seized...which isn't really the same thing.

Exactly what are the symptoms ?

[AJL308]

stevieturbo said:

AJL308 said:

I have a suspected fault with a cylinder head gasket - car is difficult to start when hot and I'm told that it may be due to coolant pressure leaking into a cylinder making it hard to turn over.

Someone has told me about these chemical tests which apparently tell you whether exhaust gasses are entering the cooling system indicating a head gasket fault. Do they actually work? If so are any better than others?

https://www.amazon.co.uk/RELD-Cylinder-Combusion-U...

So is it actually hard to turn over ? Difficult to start can be from many symptoms. Is that actually one of them ? Rarely would I say a HG issue makes an engine difficult to turn over though.
Unless it's been cooked and half seized...which isn't really the same thing.

Exactly what are the symptoms ?

It doesn't actually feel like it's struggling to turn over. It just does nothing at all. This only happens when fully up to temperature and usually very soon after stopping. After 10 minutes or so it'll starts no problem. A head gasket issue is just something which has been suggested although I'm not entirely convinced. Other options are possibly a bad starter motor not coping with the heat too well - the car is 18 years old and probably it's original starter motor and maybe on it's last legs.

[stevieturbo]

AJL308 said:

It doesn't actually feel like it's struggling to turn over. It just does nothing at all. This only happens when fully up to temperature and usually very soon after stopping. After 10 minutes or so it'll starts no problem. A head gasket issue is just something which has been suggested although I'm not entirely convinced. Other options are possibly a bad starter motor not coping with the heat too well - the car is 18 years old and probably it's original starter motor and maybe on it's last legs.

Makes no sense.

You say it isn't struggling to turn over, then you say it does nothing at all ? but then think the starter is on it's last legs ?

Which is it ? Does it turn over or not ? Does it struggle to turn over or not ? Does it do nothing...or does that mean it just does not attempt to fire ?

And give some info as to the vehicle, and background to this problem appearing. HG seems unlikely given you mention no real symptoms of HG issues.

[AJL308]

stevieturbo said:

AJL308 said:

It doesn't actually feel like it's struggling to turn over. It just does nothing at all. This only happens when fully up to temperature and usually very soon after stopping. After 10 minutes or so it'll starts no problem. A head gasket issue is just something which has been suggested although I'm not entirely convinced. Other options are possibly a bad starter motor not coping with the heat too well - the car is 18 years old and probably it's original starter motor and maybe on it's last legs.

Makes no sense.

You say it isn't struggling to turn over, then you say it does nothing at all ? but then think the starter is on it's last legs ?

Which is it ? Does it turn over or not ? Does it struggle to turn over or not ? Does it do nothing...or does that mean it just does not attempt to fire ?

And give some info as to the vehicle, and background to this problem appearing. HG seems unlikely given you mention no real symptoms of HG issues.

Engine is a W12 in a 2003 Phaeton.

If you start it when hot it usually does nothing at all; doesn't sound like it's struggling to turn over or anything. Just doesn't do anything. Give it 10 minutes and it'll always start. This leads me to think that it isn't a head gasket issue but something else. It's been suggested that it may be the starter motor on it's way out and possibly not performing due to the heat or something?

Starting when cold is always fine.

[stevieturbo]

AJL308 said:

Engine is a W12 in a 2003 Phaeton.

If you start it when hot it usually does nothing at all; doesn't sound like it's struggling to turn over or anything. Just doesn't do anything. Give it 10 minutes and it'll always start. This leads me to think that it isn't a head gasket issue but something else. It's been suggested that it may be the starter motor on it's way out and possibly not performing due to the heat or something?

Starting when cold is always fine.

you're contradicting yourself. You say it does nothing at all, but then say it is not struggling to turn over. So clearly it is not doing nothing if it is turning over. Because it is doing something, it is turning over.

And if it is not struggling to turn over...how can it be the starter ?

At what rpm is it turning during cranking ? both in a non start scenario, and when it starts ?

Have you even checked basics ? does it have fuel ? air ? spark ? I'm sure it would even start pretty easily on 6 cylinders let alone 12.

[AJL308]

stevieturbo said:

you're contradicting yourself. You say it does nothing at all, but then say it is not struggling to turn over. So clearly it is not doing nothing if it is turning over. Because it is doing something, it is turning over.

And if it is not struggling to turn over...how can it be the starter ?

At what rpm is it turning during cranking ? both in a non start scenario, and when it starts ?

Have you even checked basics ? does it have fuel ? air ? spark ? I'm sure it would even start pretty easily on 6 cylinders let alone 12.

I'm not contradicting myself. When hot it just doesn't do anything - doesn't attempt to turn over (hence not "struggling" against any sort of resistance), nothing. It is NOT trying to turn over when it's hot. Leave it a few minutes, however, and it'll start as normal.

[UpTheIron]

Are you losing coolant? In the HGF scenario you refer to coolant will be leaving the cooling system via the exhaust. I agree with other posters this doesn't sound like the issue here.

If I've got this right:

Engine cold: car starts absolutely fine
Engine hot: starter doesn't engage/turn over at all

I'd say the issue is the starter is knackered.

[E-bmw]

stevieturbo said:

AJL308 said:

If you start it when hot it usually does nothing at all; doesn't sound like it's struggling to turn over or anything.

you're contradicting yourself. You say it does nothing at all, but then say it is not struggling to turn over. So clearly it is not doing nothing if it is turning over. Because it is doing something, it is turning over.

And if it is not struggling to turn over...how can it be the starter ?

At what rpm is it turning during cranking ? both in a non start scenario, and when it starts ?

Have you even checked basics ? does it have fuel ? air ? spark ? I'm sure it would even start pretty easily on 6 cylinders let alone 12.

Sorry, but you were contradicting yourself.

If someone were to say to me it "Doesn't sound like it is struggling to turn over" that would tell me it is turning over fine.

If someone were to say to me "it does nothing at all" that tells me it isn't turning over, which is not the same thing.

Especially when you add in "if you start it when hot".

However now you have explained it in a slightly different way we understand.

[stevieturbo]

AJL308 said:

I'm not contradicting myself. When hot it just doesn't do anything - doesn't attempt to turn over (hence not "struggling" against any sort of resistance), nothing. It is NOT trying to turn over when it's hot. Leave it a few minutes, however, and it'll start as normal.

Finally you're starting to explain properly.

So when it does not turn over, but you are requesting a start.....check for power to the starter solenoid trigger.


Blood....stone....

[GreenV8S]

If the starter doesn't engage when the engine is hot, you have a dodgy starter motor or problems with the electrical supply to it. Starter motors usually live in a hot, dirty environment and can fail mechanically. These problems often show up worst when things are hot. If it's a mechanical problem you may find that if you simply hold the key in the cranking position for a few tens of seconds the solenoid will eventually overcome friction and spring into life. Physically tapping the body of the starter while you do that can help too - with due regard to hot moving parts and live cables in the vicinity.