How JustAnswer Works:
  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site. Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.
Ask Robert Your Own Question
Robert, UK Qualified Car Technician
Category: Car
Satisfied Customers: 4716
Experience:  Fully qualified / self employed garage technician in the UK
Type Your Car Question Here...
Robert is online now

, have got 58 plate citroen relay 100000 miles engine is

This answer was rated:

Hi, have got 58 plate citroen relay 100000 miles engine is really smooth, but belches black smoke , when driving van hard I have noticed van looses power and will only rev to 3000 rpm, when restarted it rev perfectly again


Best place to start ideally would be the EGR valve."exhaust gas recirculation valve".often these tend to stick or get stuck or not operate efficiently due to them getting sooted up internally and thus the valve cant open or close properly under throttle - so that would be a good place to start and the diesel injector cleaner wont help with those but rather just help clear out injectors and as above the egr is the best thing to get taken off and cleaned out - the next check is inspecting the the intake system and air filter aswell the vacuum lines and the intercooler pipe work leading to the turbo unit aswell as check the wastegate lever is able to move freely..I do hope this helps

Customer: replied 3 years ago.

Hi Robert , that is the conclusion that I had come to , do I need to replace any seals after cleaning or just refit


Not far is recall depending on which hdi diesel you have,there are two types of vacuum controlled the other electronic/motor with plug connector - just ensure the metal gasket is back the same way round you removed,sometimes you dont have to replace the gaskets unless you putting anew unit on..but the gasket is suspect then its worth just replacing might get a gasket kit from the when you buy a new EGR you get the gaskets with it - but once you get the valve off then where the valve/flap is you can spray brake cleaner/brush to get the crud out..then before fitting wd-40 the inside etc..and see if that helps..if there are indeed any warning lights when this happens then may a diagnostic test might confirm if there is low flow/restriction at the egr or still if the egr itself is at fault..but try the cleaning first...I note you do mention the wynns cleaner..there another product out there called cataclean..might be worth looking into that..i do hope this helps further

Robert and other Car Specialists are ready to help you