How hot?

[chj]

... is the exhaust between the manifold and Y piece?

I seem to have a slight heat glow noticeable in the dark, particularly on one side when revving up. A bit of a worry - surely can't be right? ... any ideas?

Thanks.

[chrispitman]

blocked or loose small cat in manifold. If there still in cheapest solution beatem out.

[chj]

Okay. Spoke to a couple of garages. One said its probably running rich, one said could be partly blocked cat or slight misfire and one said they all do that at a couple thousand rpm but should be equal each side.

It would be useful to know if others have noticed glowing in dull conditions.

Thanks.

[Alun450]

As first post said I'd suspect carbon build up or blocked pre cat.

[jojackson4]

chrispitman said:

blocked or loose small cat in manifold. If there still in cheapest solution beatem out.

Big hammer time get rid of the pre cats or get a rovergage to tell you what the landers are saying

[ChimpOnGas]

If you have a glowing manifold, you have unburnt fuel reaching it.

If you have unburnt fuel, its not being ignited on one or more cylinders.

If its not being ignited on one or more cylinders, you have an ignition fault.

Change:

1) Plugs

2) Extenders

3) HT leads.

Or better still, get it on a old school Sun Tuner machine to see what's a miss.

That way you'll only replace what's needed.

My money would be on one or all three of the above.

Edited by ChimpOnGas on Friday 19th April 23:03

[jojackson4]

What about a stuck valve?

[Dr Mike Oxgreen]

jojackson4 said:

What about a stuck valve?

I have experienced this once, on an aircraft engine. Shortly after starting up the engine suddenly started running rough and the Exhaust Gas Temperature gauge went up slightly higher than normal. It turned out that an exhaust valve had stuck open, and presumably was allowing unburnt mixture to be pushed back out of the cylinder into the exhaust.

I've never heard of it happening to a car engine, but I guess it's entirely possible. The worry is that if a valve sticks open it unloads the rest of the valve train and bits can go AWOL; alternatively if a valve sticks closed you can end up with a bent rod.

[chj]

ChimpOnGas said:

If you have a glowing manifold, you have unburnt fuel reaching it.

If you have unburnt fuel, its not being ignited on one or more cylinders.

If its not being ignited on one or more cylinders, you have an ignition fault.

Change:

1) Plugs

2) Extenders

3) HT leads.

Edited by ChimpOnGas on Friday 19th April 23:03

Changed plugs, replaced dizzy cap, removed extenders ... problem solved

[ChimpOnGas]

chj said:

ChimpOnGas said:

If you have a glowing manifold, you have unburnt fuel reaching it.

If you have unburnt fuel, its not being ignited on one or more cylinders.

If its not being ignited on one or more cylinders, you have an ignition fault.

Change:

1) Plugs

2) Extenders

3) HT leads.

Edited by ChimpOnGas on Friday 19th April 23:03

Changed plugs, replaced dizzy cap, removed extenders ... problem solved

Great news

Enjoy the sun

[VictorMeldrew]

Dr Mike Oxgreen said:

jojackson4 said:

What about a stuck valve?

I have experienced this once, on an aircraft engine. Shortly after starting up the engine suddenly started running rough and the Exhaust Gas Temperature gauge went up slightly higher than normal. It turned out that an exhaust valve had stuck open, and presumably was allowing unburnt mixture to be pushed back out of the cylinder into the exhaust.

I've never heard of it happening to a car engine, but I guess it's entirely possible. The worry is that if a valve sticks open it unloads the rest of the valve train and bits can go AWOL; alternatively if a valve sticks closed you can end up with a bent rod.

When my engine sucked up debris (engine mount failed, air intake pulled off filter, engine hoovered the road) it bent an exhaust valve slightly, and the result was one header glowing yellow. It also smashed the piston skirt and dropped a liner, but the glowing header was the most obvious sign that something was amiss. When I pulled it apart there was a 3" piece of fibreglass wedged in the plenum, unable to work its way over the top of the trumpets fortunately, but obviuosly some smaller bits had found their way into the combustion chamber.