knoking noise when engine warm PEUGEOT 207 (WA_, WC_)

I had exactly the same with my 207! Turned out to be hydraulic tappets making noise once oil gets thin from heat. Changed oil to 10W-40 instead of 5W-30 and noise reduced by 80%. Check your oil level first though

Could be VVT solenoid issue mate. My neighbour's 207 had similar symptoms – rattling after warmup. Mechanic said the variable valve timing actuator was sticking when hot, sorted it by cleaning and replacing solenoid

@user_105200 check timing chain tensioner! These 1.4 VVT engines are known for weak tensioners that cause knocking especially when warm and oil pressure drops a bit. Not expensive to fix but needs doing before it gets worse

Agree with others but also worth checking oil pressure sensor. I've seen 207s throw oil pressure faults when hot even though actual pressure is fine – faulty sensor gives low reading and you get knocking sounds from lifters not getting enough oil

My 207 did this for months before I finally took it in. Was the timing chain guides worn out. When engine warms up, the clearances change and the chain starts slapping around. You'll hear it more at idle. Got it sorted for about £350 with labour

@trevor_barnes +1 on the timing chain, but don't panic yet. Try an oil flush first and refill with slightly thicker oil. Sometimes carbon buildup in the oil passages causes low pressure when hot and that's when you hear the knock. Worked for my mate's 207 anyway

@alfred_hill The VVT solenoid is a common fault but honestly I'd check spark plugs too. If one's come loose it'll tick like crazy once the head expands from heat. Take the cover off and check they're all torqued properly, takes 10 mins

Had a 207 1.4 for 5 years. That knock after warmup is classic piston slap on these engines. The piston expands when cold and seals properly, but when really hot the clearance opens up again and you get that knocking. Not dangerous but annoying as hell. Mine did it from 80k miles till I sold it at 140k

@user_105200 Before spending money, do this next time it knocks, rev it to about 2000rpm and hold it there for 30 seconds. If knock disappears it's oil pressure related (pump or sensor). If it stays it's mechanical like timing chain or piston slap. That'll narrow it down quickly

@m.ellis19 Good shout on the oil flush, but be careful with thicker oil on the VVT engines. They need proper flow to the actuators. I'd stick with manufacturer spec 5W-30 but use a quality fully synthetic, made a difference on mine

@eric_cooooole Piston slap usually happens when COLD though, not after warmup? I thought it was the opposite – cold piston rattles, then expands and seals when warm. Maybe OP has the reverse situation with worn bores?

@Sebastian.Barnes You're right normally, but on some 207s with higher mileage the bore wear pattern is uneven. So at mid-temps it's quiet but once fully heat-soaked the geometry shifts again and knock returns. Weird but I've seen it twice now includingg my old one