TD4 Hesitation @high boost roughly 4000rpm in 5th Gear.

Hi, yes i'm sorry to hear you still have the problem at 90mph, I thought that the hesitation may be caused by the same problem as mine, although mine happens when pulling away after engine running for 20 mins or so. If the egr valve ever opens when it is not supposed to, your turbo boost pressure diminishes to bugger all.ie the boost goes back thru egr valve into the exhaust,instead of into the inlet manifold giving you plenty of ooomph when you press the go pedal.this is why i thought your valve may be opening at high speeds causing the hesitation,but it doesn't seem to be that by the sound of it. incidentally if you want to see if it is the egr valve making the weird noises on shutdown, just blank the vacuum pipe off,and don't reconnect it to the egr valve, just leave it off and blanked, run the car and if the noises arent there it must've been the valve with possibly a bit of trapped wind in it.Sorry i don't know the answer, have you checked all the rubber and plastic ducts and hoses in the turbo / inlet side of the engine for splits or softness, thats all i can come up with at the moment. Best Rgds .

Hi

My Range Rover EFi does the same it's the pump failing (will agree with your mechanic chap one of the pumps are on the way out)

If it were a petrol might have suggested the plugs but it's not so wont.

Charlotte

baldeagle said:

incidentally if you want to see if it is the egr valve making the weird noises on shutdown, just blank the vacuum pipe off,and don't reconnect it to the egr valve, just leave it off and blanked, run the car and if the noises arent there it must've been the valve with possibly a bit of trapped wind in it..

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Hi baldeagle, as a matter of fact, while I was testing things out by opening the hood etc. before shutting down the engine, I also removed the vacuum pipe from the egr valve and the one time I catched the noise and I had the impression it came from the egr valve was with the pipe removed, so ...???

hi all i have just blocked the erg valve on my car, and i am away pulling the caravan this afternoon so it will be interesting to see how it gets on, unlike you guys i used a small plastic g clamp that i got from the local pet shop to nip the pipe seconds to fit and take of if it is no good. they are used to regulate the flow of air to fish tanks from the air pump and they cost about ten bob each

Hard one this, would have thought the stealers could have pinned this one, i go with the zip , but trouble is you have 2 pmps on your model one in the tank and a lift pmp in the front , it is a fair bet that it is most likely the rear one[dont quote me on that]but most of this forum people who have had pmp problems it always seems the rear one, i know this is all guess work and you might go through all that hassle and still have the problem, and yes my td4 will sit on 115 no problem, hope you get it sorted. . . Ming

check this out http://www.bmwland.co.uk/talker/viewtopic.php?t=22351&highlight=egr+valve