Bosch or Beru if you can find them, never heard any info on NGK GPs.
1st year of the om606 engine IIRC. Read and re-read as many of the howto's and experiences here, peachparts diesel discussion forum and anywhere else before you get into this. Depending on your experience/skills and wallet size maybe better to have a pro do it. Patience and a case of your favorite pentrating oil/spray(not WD40) to start.
PS if they are working fine, dont bother till you need to, personal opinion of course.
1st year of the om606 engine IIRC. Read and re-read as many of the howto's and experiences here, peachparts diesel discussion forum and anywhere else before you get into this. Depending on your experience/skills and wallet size maybe better to have a pro do it. Patience and a case of your favorite pentrating oil/spray(not WD40) to start.
PS if they are working fine, dont bother till you need to, personal opinion of course.
