406oc.co.uk

Just lately i have noticed that my 406 v6 auto has been making a bad loud knocking noise. The car has just been serviced and is only on 85716 Miles.
Very confused where why this is happening. Sounds like it is coming from the top of the engine.

I am not overly familiar with the V6 engine, Having said that, the HDi engine can produce a knocking noise which happens when the crankshaft pulley wears out, it usually sounds like a top end noise when it goes, the V6 might have a similar type of crankshaft pulley which could be causing the noise, you might be able to find out if its faulty by grabbing the crankshaft pulley (located behind the drivers side wheel) with the engine off if you can feel any movement in the pulley then it is worn out.

Is this the 194bhp or 210bhp version? The 210 is very prone to top end tapping (not loud knocking though) on start up. Mine's done it ever since I had it back in Mar 2007. A quick blip on the throttle chases it away though and it doesn't return till next start up. My last oil change was done using Total Quartz 5/40 Fully Synthetic and the tapping disappeared for 3 months but has now begun to make a reappearance.
I'm not at all sure if the noise is due to a noisy hydraulic valve lifter or if it's connected to the VVT system on the inlet cams. Either way, it hasn't got any worse in my 7 years of ownership.

If yours is making more than just a top end tapping noise, then it is probably unconnected with the above to be fair.....

Its quite a loud knocking noise really and it does go away when I rev the car past 3000rpm. Mines the 210bhp version. It also happens when the car is warm. I will try to make a video of the noise to show how loud and where it is coming from. The car still drives fine and changes gear smooth. In no way was the car effected by this but is very annoying. Last weekend I drove about 500 miles and back and I was finding the car to be sluggish on gear changes eg. kickdown and changing to higher gears. When driving back the noise grew louder so I am not sure what to do. It goes away when revved above 1500rpm when driving so when on the road it does not make that noise. Its really just when it is idling

A couple of days ago I went to a Peugeot dealer while I was in town and they told me that they would have to replace the pistons and the block at a cost of £1567 or where I am from R25000, which is a bit high for me at the moment. The guy at Peugeot said the car would need it to be done in the next 6 months. That is half what I paid for the car 3 years ago. How long can the car run like this. The Peugeot dealer said the problem was piston slap or that the piston was in clattering around the block. I use my car about 3 times a week and do approximately 420miles a month. The car has a full service history and has only covered 86000miles of 86517 to be exact. How long can the car last with this problem

Peugeot dealers would be rather expensive for that sort of engine surgery, id take it to a trusted independent garage to have it looked at.
Other than that, have you tried the coupe club yet to discuss the problem, there are a lot more coupes with the V6 engine than saloons, it might be worth a try incase someone with a v6 has had issues similar to the ones you are describing

I think you have low oil pressure and the engine would benefit from an oil flushing agent, a fill of cheap oil for a week, then drain and refill with quality fully-synthetic. The oil strainer/pick up in the sump might even be blocked for some reason. If you had bore wear you would be drinking oil at a high rate like 1ltr per week, does it use any oil?

Took it to my local garage. They charged me a couple and had a complete engine flush out and the problem is solved!