w210 spark plugs replacement

[Car Nut]

Should I change the plugs? It is 4 years old with 65000 miles. It runs very smoothly. I don't want to do anything stupid to mess up a perfectly working machine. Is it difficult to replace? The space around the engine V8 is very tight. Do you guys have any tips?

Car Nut
1999 E430 Sport

[Gilly]

The recommendation on a 99 is 100,000 miles or 4 years, I'd replace them.
"Have a good selection of tools" is about the only recommendation I can tink of.

Gilly

[3star]

I just had the plugs replaced on my 1999 E320 with 55,000km (34,000 miles). I thought it was running smooth before the plugs were changed. At first I didn't think it would make a difference but it is actually running smoother now.

I'm following the manuals maintenance schedule for service time intervals regardless of the number of miles I put on it.

3 star

[vince]

I actually thought access was good when I did them on my '99 E430. I took off each coil unit from the valve covers. I took out the air cleaner housing. The only tight spot was the left rear set of plugs, but a 4" extension is just right and makes short work of that set. To pry off the boots at the plugs I used a peg board hook. I bent the two prongs that fit into the peg board for a snug fit on the boot and slid a length of 1/8" pipe over the opposite end as a lever. Worked like a charm.