Car Mechanics (UK)

FUEL-BORNE AD­DI­TIVES – DIESEL

- Austria · Peugeot S.A. · Ford Motor Company · Volvo Cars · Mazda Motor Corporation

Ad­di­tional chem­i­cals can be added to diesel fuel, which sur­vive the com­bus­tion process and end up in the DPF that en­cour­age soot com­bus­tion at lower tem­per­a­tures, re­duc­ing the risk of block­age. These fu­el­borne ad­di­tives (which are also re­ferred to as cat­a­lysts) can be dosed man­u­ally or au­to­mat­i­cally. Au­to­matic sys­tems are fit­ted to many PSA Peu­geot/citroën/ds cars, as well as var­i­ous Ford, MINI, Volvo and Mazda mod­els, where a cerium-based ad­di­tive (re­ferred to as Eolys) is stored in ei­ther a pouch, or a sep­a­rate five-litre tank. In most cases, an on­board com­puter in­jects the cor­rect quan­tity of ad­di­tive into the fuel tank after ev­ery fill-up. This ad­di­tive needs to be re­plen­ished at var­i­ous ser­vice in­ter­vals and the rel­e­vant ECU reset after­wards.

We in­ves­ti­gated these sys­tems in the Septem­ber 2016 is­sue of As then, we ad­vise that you use gen­uine flu­ids only, be­cause sev­eral after­mar­ket fluid sup­pli­ers would not sub­stan­ti­ate their claims of com­pat­i­bil­ity, when we asked.

Usu­ally, when the owner ex­pe­ri­ences an is­sue with pre­ma­ture DPF soot block­age, fuel-borne ad­di­tives can be bought off-the-shelf and in­tro­duced into the fuel tank man­u­ally to pro­mote soot com­bus­tion. How­ever, you should fol­low dos­ing in­struc­tions care­fully. Cer­tain well-mean­ing own­ers mis­tak­enly be­lieve that using more ad­di­tive is a good thing, but over­dos­ing can cause the soot within the DPF to com­bust too quickly, re­sult­ing in ther­mal run­away, be­cause the DPF can­not reg­u­late the tem­per­a­ture of the burn­ing par­tic­u­lates. Ei­ther the DPF’S internal ce­ramic mono­lith, or the outer cas­ing, will melt. Should the lat­ter oc­cur, red-hot par­ti­cles could ig­nite ma­te­rial on the ground, which could cause a se­ri­ous fire.

 ??  ??

Newspapers in English

Newspapers from UK