ah shites, well i had somewhat of a similar problem twice, and by that i mean the way it manifests itself.

first time, it was when the driveshaft was knackered, or to be more precise, the joint on the driveshaft, one closer to the gearbox, not the CV. it was caused by the broken engine suspension, the rubbery part holding the engine on its right side. its a bit tricky to get to as the air filter has to go off. get that checked, before you end up with broken driveshaft like me

and 2nd time, it was caused by... gasp... lack of oil in power steering pump. :| yeah, i didnt believe it myself. i had a tiny leak on power steering pump and the oil was slowly dripping for months, at one point i started having exactly the same symptoms, i checked the oil, but it looked normal, except bit bubbly. that was right after i turned the engine off, but after half an hour, and oil having settled, i could see that it was way below the min. level.

so i suggest check the 2nd one first, easier. and then the first one. good luck

 

Just been out and checked power steering level - well above the maximum, and car hasn't moved for 2 days so well settled. Power steering was one of the things the mechanic mentioned he had checked.

I too have asked about driveshaft/CV joint, but he reckons if it was the CV joint then it would be clicking, and not just this knock now and then.

I've asked them to check the driveshafts to be sure, because as you say, I don't want them broken.

 

Its not actually driveshaft problem itself, but the engine mounting bracket gives up which puts additional strain on the inner side joint of driveshaft.

Mine had the left bracket give way, but it can be either really. So its worth checking them, being that im not really good with the mechanical terms, heres a picture.

So i guess both left and right side should be checked, in red. One way you could check is open the bonnet, take a step back, and look at the engine, does it look tilted either left or right? even a slightly bit. thats the first thing i noticed, but i had no idea what was broken, and even if that might be normal. only once they took out the driveshaft to replace it and once new one was in, knocking sound was back as the actual cause of the problem was not solved.

 

The engine looks level.... tried to check with a spirit level, but such slight movements affects it

Will be one of the things I'll ask them to check :thumb:

I've topped up the power steering fluid (out of curiosity) - it was above the max before, but now its a good inch above - the tried and tested Peugeot way for electric power steering :lol: I can't quite see the relationship between power steering and the knock, but will see if it makes any difference :thumb:

 

OR PROBLEM WITH PRESURRE valve in PIPE

 

How could the power steering create a knock as I've described?

 

Any resolution?

Hi,

I wonder, did you ever get to the bottom of this?.

I recently brought a 407 SW 2.0 HDI Estate and have just noticed a knock that happens in very similar circumstances that were mentioned in the OP.

To add though, I have noticed mine happen sometimes when the car comes to a standstill as I'm approaching the end of a road I need to stop at before pulling away or traffic lightsm certainly not everytime though.

I had a good look last weekend to see if I could find anything loose, by getting the fronts up on Axle stands but couldnt spot anything.

 

Droplinks JM? frip joints or upper ball joints. I would look at these even though you had new frip joints not so long ago. Also roll bar clamp bushes

 

The dealer never really found what the cause was, however, after being back in with them again (costs covered 100% by them) it seems to be 99% OK. I have heard it perhaps once or twice in the last 2 months, so nowhere near what it was like.

When in with them, they checked everything to do with suspension, steering and driveshafts. There was absolutely no play in any of it, including all the suspension joints... which the lower ball joint was my first suspicion after the noises I had experienced before. However, they checked the torques on the upper ball joints, and did something to the subframe... not 100% sure what, but something to do with adding washers somewhere, lubricating and torquing it up. Whatever they did, it is now 99% fine and vastly improved from before, even though no parts were ever replaced. They experienced the knock, but after referring to Peugeot's known faults, the washers and torquing of the bolts was the only possible things to try (based on the fact there wasn't any play in any of the parts they checked).

Sorry it might not be a definitive answer, but it seems to have worked.

Davidireland on here, also Paugeot tech, also recommended to me that it could be the subframe creaking and would be ok by undoing and redoing the bolts... perhaps this is what they did that helped.

 

Sounds like the lower hub carrier bush to me as ive had both sides go and you only get the knocking around bends not on bumps. Bad news its either £350 for a new hub carrier or a pattern bush that ive tried that arnt very good see here for details

 

Could be inner joint of steering rack. My mechanic could not find the knock for about 2 months. I decided to replace my LH one (just in case) and it solved the problem!