C4 2005 1.6 petrol red glowing manifold

[mahmoud_911]

Hello There,

can anyone please help me on what may cause the manifold to get red hot till the car went on fire, I did fixed the burnt parts and got all back to normal with no fault reading, Timing is perfectly sat. I've been through this for about 4 months now, and now repair shop can find out the problem with the car, everything is perfect!!!!


ah.. it goes red glowing after speed of 100 KM/h for 5 minutes, it caught fire when i was driving at 160 km/h for 20 minutes
a night photo for my glowing manifold attached, the red goes after the catalyst converter, P.S. I did change it with another used catalyst as we thought that it might be clogged, but nothing changed

thanks for all the help



the image caught after driving at 120 KM/H for 3 minutes


any ideas??

[rabenson]

usual cause of high exhaust temperature is weak mixture but I would have thought that this would have been picked up by sensors and corrected

[isisalar]

Can't offer you any advice I'm afraid, other than to make sure you're carrying a fire extinguisher and be very very careful.
Car shouldn't be driven really.
Someone will be along to help you soon I'm sure.

[Gibbo2286]

Retarded ignition timing or adulterated fuel, both should show noticeable performance loss though.

[sparksie]

Yup
I'd go with timing, too.
Is there a "knock sensor" and is it mounted properly?
Another possibility is valve clearances too tight, not letting exhaust valves close fully when hot, or even cam timing a tooth ahead of where it should be.
I'd imagine a sensor should pick up on the cam timing, on a car as young as that, though.

[Mandrake]

On most (all ?) modern ECU controlled petrol engines if the knock sensor is faulty/unplugged the ECU will detect a fault and permanently retard the timing map by many degrees (5-10) to protect the engine from detonation. This will not necessarily light the check engine light on the dashboard - I know it doesn't on my Xantia V6 for example, although newer ECU's probably will. It WILL cause a fault code that can be read by a Lexia or scan tool though, so I would try to get the fault codes read.

Power and efficiency is dramatically reduced in these conditions, so driving the car hard (and I think 160km/hr for 20 minutes counts) with the timing permanently retarded will work the engine a lot harder to produce the same power so could possibly cause overheating.

Regarding lean running - if there is a problem causing lean running it won't necessarily be corrected for depending on the cause - for example if there is an injector flow problem or fuel pump delivery problem the oxygen sensor can correct (to a point - up to about 15-20%) under closed loop conditions - eg light to medium throttle cruise, but under hard acceleration and/or wide throttle openings the ECU will run in open loop mode where the fuel delivery is pre-calculated, so something reducing fuel flow under these conditions will cause lean running and probably won't set the check engine light either. (I'm battling with just such a problem on my Xantia V6 at the moment - it runs lean in open loop under WOT, but normally in closed loop mode, no check engine light, no fault codes logged!)

In this case you want to look at fuel trim numbers which a 2005 year model should be able to provide on a scan tool. It will be pretty obvious from those if there is a fuel delivery problem, and very likely a code will be set as well. I know you said your garage couldn't find any problems but are you sure there were no fault codes found ?

Also if the oxygen sensor is faulty the car will be running in open loop all the time using pre-calculated values, and it could easily end up running lean all the time if there is a second fault with fuel delivery. No oxygen sensor - no ability to compensate for mixture errors. A faulty oxygen sensor doesn't necessarily set the check engine light either! (Again, it doesn't on the Xantia V6)

Another possibility is a stuck open fuel injector that is dumping a lot of raw fuel through one cylinder that is igniting in the hot exhaust system. This would cause a misfire though - are you sure there isn't a misfire, and is the engine performance normal or worse than it should be ? I would have thought that most things that would cause the exhaust to overheat would cause an obvious loss of power and/or a misfire.

[Lighty]

I would imagine a blocked cat or exhaust , had this on a 307 petrol once .

[mahmoud_911]

I would imagine a blocked cat or exhaust , had this on a 307 petrol once .

both changed and still glowing

[Mandrake]

I would imagine a blocked cat or exhaust , had this on a 307 petrol once .

both changed and still glowing

You still haven't said whether there is any noticeable misfire or lack of power - does the engine seem to run completely normally without misfiring or loss of power ?

Also have you been able to get the fault codes read and fuel trim checked to see if the engine could be running lean ?

[mahmoud_911]

I would imagine a blocked cat or exhaust , had this on a 307 petrol once .

both changed and still glowing

You still haven't said whether there is any noticeable misfire or lack of power - does the engine seem to run completely normally without misfiring or loss of power ?

Also have you been able to get the fault codes read and fuel trim checked to see if the engine could be running lean ?

no, the car is running perfect, no loss of power at all, about the fuel trim, i don't know so much about the diagnoses tools and I don't have one, but the repair shop which has "Peugeot planet 2000" said that nothing faulty appear.
btw, i did buy a fuel pump 6 months before the car went on fire, in this period, the car was not walking long distances on high speed, then i noticed that the car doesn't get over the speed of 140 km/hr, so i headed to the repair shop and got the Throttle body cleaned, after a week, i hit the high road again and it reached 160 for the 20 minutes then..... Fire
so my question is can a faulty new Fuel pump send more petrol than it should and keeps the car running perfect at the same time??
I'm thinking of replacing the fuel pump and test!
another guy also told me that it happened to his car and turned out to be a blockage of the head gasket?

[Gibbo2286]

I note your location is Egypt, if that's correct I would be querying the quality of the petrol that you are using, is it the correct octane rating?

[mahmoud_911]

Yes, i'm from Egypt and using octane 92

[sparksie]

Hmmm
Gibbo may have cracked it.
European standard unleaded is 95 octane and there's also a "Super" unleaded, which is 98 octane.
Lower octane fuels tend to flash quicker, causing knocking (aka "pinking"). It's an uncontrolled detonation, rather than a shaped burn.
If the knock sensor detects knock, the ecu will retard the timing to try to correct it. If it didn't you could burn holes in the pistons.
But, prolonged running at high speeds, with severely retarded timing, causes all manner of problems. Usually the engine will overheat, but if the cooling system can cope with the excess heat, the next thing down the line will suffer. You may well have burnt exhaust valves already, or probably soon will have.
What does the driver's handbook say about low grade fuels? It may suggest additives, or modified driving style, or both!

[Mandrake]

Another point is not all petrol engines actually have knock sensors...even some modern ones don't. The engine could be designed for the lowest available octane in the market it was originally sold in, assume that you're running on at least that, and have no way to adapt to something lower.

Anyone know whether this specific engine has a knock sensor ? If it didn't prolonged running on low octane fuel at high speeds could cause detonation and serious engine damage, not just overheating...knocking/detonating is also a much higher risk in a hot country like Egypt than a cold country like the UK.

The next step might be to try running it on at least 95 octane and driving rather conservatively until the current tank is used up...!

[mahmoud_911]

Another point is not all petrol engines actually have knock sensors...even some modern ones don't. The engine could be designed for the lowest available octane in the market it was originally sold in, assume that you're running on at least that, and have no way to adapt to something lower.

Anyone know whether this specific engine has a knock sensor ? If it didn't prolonged running on low octane fuel at high speeds could cause detonation and serious engine damage, not just overheating...knocking/detonating is also a much higher risk in a hot country like Egypt than a cold country like the UK.

The next step might be to try running it on at least 95 octane and driving rather conservatively until the current tank is used up...!

No cooling problem, no detonation/ knocking, i'm using octane 92 as i used to my ex VW golf and citroen C3 also