My espace the race is back on the road after a six month lay-up with a blown rocker cover gasket . It was interesting to note that the gasket had worn from the inside out on the back edge of the second air inlet also of interest is the top edge of each inlet had more build up of soot and oil than the bottom edge/inside curve of the inlets.
I have a suspicion that the soot from the EGR process is abrasive and may have caused the failure of the of the gasket, basically a turbo powered soot blaster !.
So having received my machine back from the garage with a new rocker cover gasket and 4 new injectors I was determined to protect it from the ravages of EGR soot .I have removed the the pipe from the exhaust manifold to EGR valve and blanked off exhaust end , the EGR housing/throttle body has been removed there is now a straight run of 73mm diameter pipe in its place ( sorry Roy !).
Annoyingly on testing there was a bit of turbo lag and moderate amounts of black smoke on heavy acceleration plus strong over fuelling smell at idle. Air filter is new but I tried a quick run with it removed with no improvement , next I unplugged MAF still no improvement or difference , a search of the forum lead me to an observation by Renaultbiler about intercooler leaks and overfueling/loss of boost. A poke around with the torch revealed oil on the intercooler fins at the inlet end...intercooler was removed from the top leaving aircon rad and engine rad in place ( remove front grille and left headlight split rads in place and lift out IC).
I filled intercooler with water and pressurised with an aquarium pump but there were no leaks ! , After lots of head scratching it was obvious the inlet pipe hose clamp was not tight enough and was blowing oil onto the IC fins . Working my way back to the turbo I checked all the hose clamps (8 altogether I think) they were all loose and had small amount of oil seeping underneath hose ends .
After putting it all back together and double checking hose clamp tightness I went for a drive...slight grey haze under heavy acceleration no lag ! Something I was wary about having disabled EGR system was engine temp but after half an hour of hard driving the temp did not get above three bars on the display.
We do not have emission testing in New Zealand but a smoking diesel will fail MOT , so disabling EGR is legal also re-directing blowby breather from rocker cover is legal too (into a catch can) . please note that the g9T engine does have a blowby breather that is connected to the air inlet pre-turbo this will make it seem like the turbo is leaking oil from the bearing seals , the pipe work and intercooler plus the EGR valve WILL have a film of oil on them this is ok but silly I recommend installing a catch can if its legal in the UK/Europe , it stops oil getting in the intercooler and it greatly reduces soot sticking to your EGR valve and inlet manifold plus I'm pretty sure it makes for cleaner emissions.
I run my vehicles on bio-diesel I make myself to do my bit for the environment also I love my espace and want it to last forever so I don't feel guilty about removing the EGR also I have six children so I can't afford to have major repairs frequently , I have two other vehicles that I have removed EGR from and installed oil catch cans (Nissan TD27 and Bedford bus with Isuzu truck engine) they both run better getting cool clean air and the traffic behind me doesn't get lungfulls of soot if I hit the turbo !
Hope you guys enjoyed my rant ! , The matra espaces are a marvellous car I think and I am happy to have discovered this forum .
Regards from New Zealand .