Chuff, chuff, chuff, chuff, chuff...

[Dr Mike Oxgreen]

Accelerating up a slip road on my way home last night, my engine suddenly starting making a "chuffing" noise. Still pulling well with no vibration.

I think it's probably an exhaust manifold gasket gone. Is there anything else it might be?

[K4TRV]

Loose spark plug(s)................??? Difficult without aural interweb?

[Dr Mike Oxgreen]

I guess it could be a plug, but the engine was still pulling smoothly and there was no vibration - so I don't think it was misfiring. A loose plug would result in little or no compression, and no power from that cylinder. But I'll check anyway, thanks!

[pb450]

Blown exhaust gasket is more of a ticking/clicking noise. I wouldn't say it was a chuffing noise... IMHO.

[mr shifty]

Although I hope it's something less severe in your case, my Chimaera did exactly this on a slip road a couple of weeks after I first bought it. I called the RAC who recovered it to a friendly garage and it turned out to be a blown head gasket (compression->air).

[Dr Mike Oxgreen]

I hope so too!

The temperature gauge didn't move, so I'm hoping that reduces the chance of it being OMG HGF!!!

I've booked it in for a service at Str8Six, and I used the word "chuffing". Jason thought it sounded like exhaust gasket failure, so I'm hoping he's right too!

Mark's coming to collect it on Monday, so we'll find out next week...

[QBee]

I had a sudden and serious chuffing noise years ago on a newly serviced 9 month old Renault in the middle of Chelmsford. Pulled over and called the AA (1980s, they still knew what a spanner was then). Geezer turned up, asked questions, took cover off engine and handed me a spark plug. It was completely out of its seat. He told me that if it had been left loose at the service it would slowly unwind and then pop right out.

So it depends how chuffing your noise was......

Slight = manifold gaskets
Loud = head gasket
Full Flying Scotsman = plug out

[Mr Supercharged]

I've had a chuffing sound too, towards the end of last year when I finally SORNed the car ready for winter upgrades. I found that several of the exhaust nuts were loose on the off-side bank so I removed the exhaust completely and have refitted it. Hopefully this will cure the issue. I also had the manifolds re-welded and precats removed due to there being a leak in the centre of the 4 into 1 collectors and fitted a cat free Y piece, re-packed the silencer too. Trouble is it now sounds a bit too loud on the drive.

[zacherynuk]

I had chuffing like that on a Renault GT turbo circa 1993 - I ended up welding all the spark plugs in place. Sorted.

[pwd95]

Experienced the head gasket blowing out the side on my old Wedge.....



Makes a big 'knocking' noise at speed. (just dropped a cog to pass someone on a local dual carriageway)
More of a 'chuff' at idle.

[Dr Mike Oxgreen]

The car has now gone off to Str8Six - it was due a service anyway, so I've just brought that forward slightly.

No diagnosis yet, but I'm just wondering... If this does turn out to be a head gasket, what other jobs should I get done at the same time?

[QBee]

Dr Mike Oxgreen said:

The car has now gone off to Str8Six - it was due a service anyway, so I've just brought that forward slightly.

No diagnosis yet, but I'm just wondering... If this does turn out to be a head gasket, what other jobs should I get done at the same time?

Don't know your car's spec, mileage etc

Are you decatted?
Do you want to be?
And the car?

If the heads are off, is it worth checking the cam?
Any oil leaks in that general area?

[Dr Mike Oxgreen]

Currently a bog-standard 450. I don't really have any desire to mod it, although removing precats might be a sensible improvement to reduce temperatures.

A peek at the cam shaft might be a good idea, especially given the slight reduction in power observed recently on the dyno. The valley gasket was replaced about 3 years ago, but I guess that's a possibility too.

[Mr Supercharged]

What are the inner wing heat shields like? Possibly the bulkhead one too?

[QBee]

Busting to know what the Chuffing turns out to be

[pwd95]

QBee said:

Busting to know what the Chuffing turns out to be

. Me too.

[Dr Mike Oxgreen]

Turned out it was the exhaust manifold gaskets.

As a bonus, the very slight "tappety" sound that this engine has always had is now gone! So I'm guessing it has always had a slight exhaust leak.

It now sounds better than ever!

[macdeb]

Dr Mike Oxgreen said:

Turned out it was the exhaust manifold gaskets.

As a bonus, the very slight "tappety" sound that this engine has always had is now gone! So I'm guessing it has always had a slight exhaust leak.

It now sounds better than ever!

Excellent result
we can all too often expect the worse.

[K4TRV]

Dr Mike Oxgreen said:

Turned out it was the exhaust manifold gaskets.

As a bonus, the very slight "tappety" sound that this engine has always had is now gone! So I'm guessing it has always had a slight exhaust leak.

It now sounds better than ever!

So the title says it all.........Chuff'ed

[QBee]

K4TRV said:

Dr Mike Oxgreen said:

Turned out it was the exhaust manifold gaskets.

As a bonus, the very slight "tappety" sound that this engine has always had is now gone! So I'm guessing it has always had a slight exhaust leak.

It now sounds better than ever!

So the title says it all.........Chuff'ed

Does this make you the new Chuffmeister?