xsaras4ever wrote: ↑12 Dec 2017, 10:46
If we understand you correctly - fumes can flow from the rocker cover INTO the air-inlet pipes and turbo - - BUT - will not pass the opposite way.
That is correct
Jim
Runner, cyclist, time triallist, duathlete, Citroen AX fan and the CCC Citroenian 'From A to Z' Columnist...
My understanding is that on most modern pcv systems the valves are arranged to allow air to freely flow into the crank case, but only allow fumes out when the crankcase is under (small) positive pressure.
Negative pressure in the crankcase encourages blowby past the piston rings and reduces the effectiveness of the oil pump.
The need for positive pressure before venting stops the engine from emitting fumes after switch-off.
Been some time since we updated this post...........
We fitted a new cambelt and a new camshaft seal . Problem solved. 100km later it started pi**ing from over at the other end - by the vacuum pump. It flowed out like a river and ran down to drip off the gearbox.
Disgusted - we left it alone for a few months.
We finally bought the seals and fitted them - not expecting it to last too long.
We spoke to our neighbour - a French lad and a mechanic for the last 10 years. You can imagine that as most cars in France are either Renault , Citroen or Peugeot - that he has a lot of experience with the 1.4hdi.
He says that many many of the 1.4hdi engines pi**ed oil even from new. It stops after about 5000km.
At his garage they smother them in silicone sealant when doing head-gaskets etc.
At the moment we have done 350km without a leak - which is a great surprise to us - fingers crossed.
We now have another problem.
When we first got this car and fitted a replacement engine we were amazed how lively it was for a xsara estate with only a 1.4hdi.
Since replacing the rockers , head gasket, and hydraulic tappets it has an amazing flat spot between 1800 and 2300 rpm.
We are right is saying that you do not have to set a valve clearance on this engine ?????
We did a few km with the oil filler removed to test if it was excessive pressure in the engine - but this made no difference.
We disconnected the MAF from the air inlet pipes and were not sure if it made any difference - it might have been marginally better but not great.
Shortly after removing this we got the ANTI-POLLUTION message. We replaced the connection and the error disappeared after about 30km.
Its obviously worse in 4th and 5th gear as its more difficult to pick up speed to hit that magic number where the turbo cuts in.
When the turbo arrived the car is great again.
We suspect its an injector, though its a pig to do a leak-off test as the injectors are at the back under lots of gubbins - not easily accessible.
OK - big guilt here - we opened and closed an injector when we had the head off - we kept it as clean as humanely possible but maybe the spray pattern is screwed ?
Any ideas ???
Jumper 2.5d
406 Phase 2 Estate, Hdi
Fiat 500 (2009)
1997 Audi A3 tdi
Peugeot 205 td
Fordson Major Tractor
Nuffield 460 tractor
JCB 3cx