Skoda Fabia MK2 exhaust manifold red glow....??? is that normal

[alenyohannan]

Did anyone notice it????

 

[26DIPP]

We have "only" got a 1.4L petrol BXW engine, but even in the garage after some work with engine on afterwards, ours does not glow red in the manifold. It can happen at a turbo, but your 1.2 MPI is normally aspirated.

If you have a problem with the O2 / lambda system and your fuel is burning too lean, i.e. you have air entrainment into the fuel mix from a punctured / broken hose your gases will burn hotter - a bit like O2 rich welding Check for continuity and damage of all the hoses in the engine bay. Your garage might be able to pressurize the system or put fog into the air intake and look for leaks. This will not show in any DTCs on VCDS unfortunately.

Edited 7 February, 2021 by 26DIPP

[sepulchrave]

An engine won't run if it's that lean, it'll just stall, even a slight air leak makes the idle unstable so whilst your theory is sound, it's practically impossible.

[J.R.]

One thing that will always make an exhaust manifold glow red is retarded ignition timing, very unlikely to be the case on a modern ECU controlled engine but worthy of mention, possibly the cam belt has been replaced & the torsion value setting is incorrect.

 

Were it a diesel with a DPF then the talk of short journeys would make me think that its the effect of post combustion injection to get the DPF up to temperature, does a petrol engine do something similar to get the catastrophic convertor up to temperature?

 

What were the sensors giving the readings and where are they positioned?

[J.R.]

On 22/01/2021 at 22:18, sepulchrave said:

I'm not sure what I said to get the downvote, whether it was the reassurance of normality or the dwarf joke?

It was your gratuitous and totally uncalled for rudeness and sarcasm aimed at a new contributor.

[Breezy_Pete]

7 hours ago, alenyohannan said:

Did anyone notice it????

 

I promise I'll have a look this evening after dark, I have to shuffle cars around anyway before the morning.

 

[sepulchrave]

1 hour ago, J.R. said:

It was your gratuitous and totally uncalled for rudeness and sarcasm aimed at a new contributor.

 

Absolutely not, I was completely serious, there is nothing wrong with the car, there was no sarcasm because it doesn't work in a written context.

 

You have totally misunderstood my post and taken it completely the wrong way which is your fault, not mine.

[26DIPP]

3 hours ago, sepulchrave said:

An engine won't run if it's that lean, it'll just stall, even a slight air leak makes the idle unstable so whilst your theory is sound, it's practically impossible.

An engine will run lean as well as rich. It might not be the most powerful or smooth, but it will essentially run!

Lean and rich relate to above and below Lambda1, which is what your catalytic converter requires. If your engine runs rich, Lambda goes down and lean the opposite. Some engines are designed to run a little richer - like my air cooled bike engine - to allow for the excess fuel to condensate on the cylinder walls and through latent heat of evaporation cool the engine. A lean mix will do the opposite. As there is less fuel to eavaporate on the cylinder walls the whole system including exhaust gases will be a lot hotter.

The crankcase and engine block run a negative pressure and any tiny cracks in the pipes and hoses around the air intake will lead to air entrainment which is not measured by an air flow sensor behind the air filter, but is in the intake air. You may find that the lambda sensor registers surplus air and tells the ECU to enrich, but you may not. If you check the exhaust gasses you might find a higher O2 content.

[SuperbTWM]

3 hours ago, J.R. said:

 

Were it a diesel with a DPF then the talk of short journeys would make me think that its the effect of post combustion injection to get the DPF up to temperature, does a petrol engine do something similar to get the catastrophic convertor up to temperature?

 

 

 

I would't think so, I think running rich/unburnt fuel can kill/melt a cat

[J.R.]

2 hours ago, sepulchrave said:

 

Absolutely not, I was completely serious, there is nothing wrong with the car, there was no sarcasm because it doesn't work in a written context.

 

You have totally misunderstood my post and taken it completely the wrong way which is your fault, not mine.

 

I guess I must be at fault when I read most of your posts in which case.

[Breezy_Pete]

With engine idling, fully warmed up following a twenty minute drive, I looked under the bonnet and removed the engine cover so I could see around the area better.

There was no glowing of any colour, even when I looked from the sides to see under the heatshield.

I took this photo horizontally from just in front of the battery, looking across towards exhaust manifold/cat

:

 

 

Ambient temperature was a chilly 0.5°C though.

Edited 7 February, 2021 by Wino

[alenyohannan]

On 07/02/2021 at 23:56, Wino said:

With engine idling, fully warmed up following a twenty minute drive, I looked under the bonnet and removed the engine cover so I could see around the area better.

There was no glowing of any colour, even when I looked from the sides to see under the heatshield.

I took this photo horizontally from just in front of the battery, looking across towards exhaust manifold/cat

:

 

 

Ambient temperature was a chilly 0.5°C though.

Thnx bro its just solved😁😁💪🏼

[DieselMonte]

On 18/02/2021 at 15:18, alenyohannan said:

Thnx bro its just solved😁😁💪🏼

What was it if you dont mind me asking? Blocked cat?

[MickAshton]

On 22/01/2021 at 19:56, sepulchrave said:

 

Of course it's normal, exhaust gases are extremely hot, they're the product of an explosion which reaches thousands of degrees momentarily. How else would it get that hot, a dwarf with an oxy-acetylene torch hiding under the bonnet?

 

On 18/02/2021 at 15:18, alenyohannan said:

Thnx bro its just solved😁😁💪🏼

 

[MickAshton]

Just now, MickAshton said:

 

 

 

Just now, MickAshton said:

 

 

So Aleyonhannon, don't keep us in suspense- share your solution please?

[J.R.]

Liberal application of small person type gratuitous sarcasm!

Edited 2 March, 2021 by J.R.

[sepulchrave]

I can't believe this, just because the OP didn't see the dwarf with a portapak hiding in the engine bay doesn't mean they weren't there, I thought that people kept an open mind on here, next you'll be telling me that father Christmas isn't real either!

[AmusedMussel]

Can't believe none of you requested a picture lol

[alenyohannan]

On 03/03/2021 at 02:27, MickAshton said:

 

So Aleyonhannon, don't keep us in suspense- share your solution please?

Bro.. injector cleaning will fix this... it's Not much costly... Use liqiu molly fuel cleaner

[sepulchrave]

54 minutes ago, alenyohannan said:

Bro.. injector cleaning will fix this... it's Not much costly... Use liqiu molly fuel cleaner

 

Don't look under the bonnet in the dark then you won't worry about how hot the manicat gets.

[ionutss02]

Sorry for bringing up this topic but i have the same problem. CHFA engine heat the catalytic converter like hell. Runs on idle at 600C degrees and in roll above 800C degrees at 2000-2500rpm.

The engine works and sound great. Managed to do some work, rebuild cylinder head, new head gasket, new valves, new timing chain, new coils and spark, new Lambda sensors, changed the catalytic converter and still does the same. i really don’t know what to do. car runs on aftermaket landi renzo LPG and petrol. both fuels heat up the catalytic converter. exhaust is not blocked. 

 

I really left up of ideas, don’t know what to do next.

[26DIPP]

Very lean mixture? I.e. hot combustion.

[sepulchrave]

Stop looking at it!

 

The cat will be working perfectly.

[sepulchrave]

[ionutss02]

cat box is empty. no catalytic converter at this time, trying to solve the issue. i don’t think its normal to get up to 900 degrees.

36 minutes ago, 26DIPP said:

Very lean mixture? I.e. hot combustion.

that’s what im thinking about but i don’t know where to start