Recently noticed when driving my 6n2 16v that I get a loss of power and engine management light starts flashing as well as the manifold glowing red

.

Managed to get a diagnostic done by my uncle who said that everything pointed to the coil pack... He's then spoke to his mechanic friend who seems to think it could be a wire that feeds from the manifold to the engine that can sometimes break. Does anybody know what that cable is? It's not the lambda in case that is the first thought although I may need to change that as the heat may have fried it?

Does anyone else have any idea what it could be?

I have changed the plugs and HT leads so they're not a problem... Also what parts should be changed in what order as I'm guessing its just a matter of trial and error

Cheers guys :)

Edited 3 February, 201313 yr by curty409

Recently noticed when driving my 6n2 16v that I get a loss of power and engine management light starts flashing as well as the manifold glowing red

You have to have been really pushing it to get it that hot surely? Otherwise I'd be thinking weak mixture causing it to run hot. How you have got the mixture weak is another matter. Is this a standard car? Which engine?

Doesn't a glowing manifold point at it overfuelling ?

Wasn't pushing it hard, just driving normally and couldn't get up any hills...

The engine is all standard, with standard exhaust

With my experience I'd say the cat has collapsed but might be wrong

Over fueling can actually have a cooling effect on the engine.

As said, your problem could be down to weak mixture (which has the opposite effect to over fueling), also, as said, it could be down to the cat, however, the first thing that I would be checking is the timing, starting with the valve timing and going on to the ignition.

I can't think of any wire from the exhaust manifold, other than the Lambda cable. Could it be that they are talking about the inlet manifold, which has barometric the sensor etc?

Regards.

Not sure what cable they're on about. I've changed the cat, mid silencer, ht leads, plugs, ignition coil and lambda from cat. Got all fault codes off but still rubbing boggy and getting the glowin red manifold.

How would I check the timing?

Also been told it could be the ECU?

Does it not have the precat on your car? It'd a can like thing welded to the manifold. What can happen is that it will collapse and cause a blockage. This happened on ours, but it didn't glow or nything just had no power. I cut it in half and smashed the shite outta it with a hammer and chisel, then had it welded back up. The thing goes like stink now and there are no error codes etc.plus the mpg is way better now.

Does it not have the precat on your car? It'd a can like thing welded to the manifold. What can happen is that it will collapse and cause a blockage. This happened on ours, but it didn't glow or nything just had no power. I cut it in half and smashed the shite outta it with a hammer and chisel, then had it welded back up. The thing goes like stink now and there are no error codes etc.plus the mpg is way better now.

Is the pre-cat not needed then?

If not I may take it out, just getting a little fucked off with it now haha

Costing me a fortune

Glowing manifold is almost certainly weak mixture, with the aluminium piston in cylinder four at serious risk of melting.

Glowing manifold is almost certainly weak mixture, with the aluminium piston in cylinder four at serious risk of melting.

Would a meted piston show on vagcom by any chance? And I'm guessing if that happens engine is pretty much no use without a decent rebuild?

Also been told it could be the backbox that is blocked?

No, if you melt a piston, you'll seriously fuck your engine. Cannot make this point more clearly.

Don't run it if it continues to do this!

Changing parts randomly is not going to solve this! You need to get it on Vag-com and find out why it's under fuelling. There must be a reason, air leak, whatever. It might show up on Vag-com as a timing pull, or fueling correction factor - this is the engine trying to fix itself.

The engine might have logged fault codes. You could remove the start of the exhaust (from the manifold) and run it. It'll be loud, but it will rule out the possibility of a blockage.

Sounds weak mix or a blocked cat - ignition timing could be too retarded too.

As said, don't use it. Get vagcom on and check suggested things

You know when a piston melts itself, normally the temp pin is somewhere in the red due to the extremes of temperature involved with an engine on the verge of shitting itself.

Diagnosing:

Blocked exhaust: start car stick hand over exhaust tip, do you feel a good flow, No: exhaust is blocked, remove in sections till blockage clears, Yes: exhaust not blocked

Fuelling: Is the fuel filter new, is the pump running properly, is the fuel pressure correct.

VAG-COM: run diagnostic to check for error codes. Report back to here with error codes.

Dont use the car or you will most likely do terminal damage.

You know when a piston melts itself, normally the temp pin is somewhere in the red due to the extremes of temperature involved with an engine on the verge of shitting itself.

Diagnosing:

Blocked exhaust: start car stick hand over exhaust tip, do you feel a good flow, No: exhaust is blocked, remove in sections till blockage clears, Yes: exhaust not blocked

Fuelling: Is the fuel filter new, is the pump running properly, is the fuel pressure correct.

VAG-COM: run diagnostic to check for error codes. Report back to here with error codes.

Dont use the car or you will most likely do terminal damage.

I've not been using it as the car isn't producing enough power to move anyway

I've checked on VAG-COM with the fault codes and eliminated them all by replacing the parts.

From top of my head they were...

Oxygen Sensor

Lambda Sensor

EGR Valve

Multiple Cylinders Mis-firing

and not sure if there was any more.

I did however save the codes somewhere on the laptop i used so will get them up when i get to dads where it is.

The exhaust, really shouldn't be blocked in the mid section or cat as they are brand new and only got fitted monday since then the car hasn't been moved.

Also how do i know if the temp pin is in red bit? obviously i can't touch it or i'll have no fingerprints left haha

Would a meted piston show on vagcom by any chance?

EPIC!

dont take this wrong way but - take it to a garage. it has become slightly apparent that this problem is more serious than the usual stuff asked on here and guessing to what the problem is could be more catastrophic to the car then just admitting defeat and getting a garage to look at it.

Also how do i know if the temp pin is in red bit? obviously i can't touch it or i'll have no fingerprints left haha

I think he meant the coolant temperature gauge would be in the red if you're melting a piston. But it's not necessarily the case anyway, so I'd just ignore that bit!

Also how do i know if the temp pin is in red bit? obviously i can't touch it or i'll have no fingerprints left haha

I think he meant the coolant temperature gauge would be in the red if you're melting a piston. But it's not necessarily the case anyway, so I'd just ignore that bit!

Garage is a good call at minute, think it may be time to buy a new car and get it sorted when weather is a little better and money is looking good

thanks for help though guys, much appreciated :)

I've not been using it as the car isn't producing enough power to move anyway

I've checked on VAG-COM with the fault codes and eliminated them all by replacing the parts.

From top of my head they were...

Oxygen Sensor

Lambda Sensor

EGR Valve

Multiple Cylinders Mis-firing

and not sure if there was any more.

hmmm timing out and therefore fuel pretty much burning in your manifold rather than your engine? would mess up any sensors like the lambda i think too if it is

I've not been using it as the car isn't producing enough power to move anyway

I've checked on VAG-COM with the fault codes and eliminated them all by replacing the parts.

From top of my head they were...

Oxygen Sensor

Lambda Sensor

EGR Valve

Multiple Cylinders Mis-firing

and not sure if there was any more.

hmmm timing out and therefore fuel pretty much burning in your manifold rather than your engine? would mess up any sensors like the lambda i think too if it is

Uncle's coming down saturday to have a look at timing for me but if that doesn't work then i reckon i'll give it up as a bad job.

I've driven on a melted piston and it actually got me over three miles home.

But it sounded like a '71 Beetle with three spark plugs being chased whilst being shot at by an AK47. The cloud of smoke behind me could be seen for over a mile and pretty much cleared the roads behind me. It drank most of it's oil in that journey (blowing the rest out the breather and all over the engine bay) and had destroyed the engine block.

So yeah, if you melt a piston you won't need a diagnostics to tell you something isn't quite right.

Over fueling can actually have a cooling effect on the engine.

As said, your problem could be down to weak mixture (which has the opposite effect to over fueling), also, as said, it could be down to the cat, however, the first thing that I would be checking is the timing, starting with the valve timing and going on to the ignition.

I can't think of any wire from the exhaust manifold, other than the Lambda cable. Could it be that they are talking about the inlet manifold, which has barometric the sensor etc?

Regards.

Check the timing???

I cant see how any of the symptoms would be because of timing, it would be a bit worse than loss of power it would run like shit.

Over fueling can actually have a cooling effect on the engine.

As said, your problem could be down to weak mixture (which has the opposite effect to over fueling), also, as said, it could be down to the cat, however, the first thing that I would be checking is the timing, starting with the valve timing and going on to the ignition.

I can't think of any wire from the exhaust manifold, other than the Lambda cable. Could it be that they are talking about the inlet manifold, which has barometric the sensor etc?

Regards.

Check the timing???

I cant see how any of the symptoms would be because of timing, it would be a bit worse than loss of power it would run like shit.

It does run like shit, it struggles to get off the drive

Could possibly be timing, could do with getting it sorted this weekend otherwise I'm going to have to look for a new car which I don't particularly want to do.

How would I check the timing?

And don't think piston is gone, engine temp is normal, no oil anywhere or loss of oil so really don't know

You need vag-com for the timing.

Even then it cant be adjusted.

Found the thread I was thinking of.

www.clubpolo.co.uk/forum/lofiversion/index.php/t239688.html