I have a 2000 E320, with 97,000 miles, changed plugs at 30,000 mile. So far car runs fine, Do I need to change the plugs again? The mechanics “recommends” to replace cables too, because they come as a “kit”. Is this real?
What does your owner’s manual say about spark plug replacement intervals? If they say 100K miles, then since the car is running fine, I would go to 130K miles.
The car is 15 years old, and spark plug wires do degrade. So it may be worthy advice.
Most important though, is how long do you plan to keep the vehicle?
Doing the plugs is not a bad idea due to the age to avoid the risk of threads “freezing” in the cylinder head, but not absolutely necessary. Stick only with OEM plugs. I would not do the expensive cables unless you have indications they have started to deteriorate or cause misfiring.
Since you have replaced them already…the answer lies in THOSE plugs.
which plugs did you install ?
paltinum ?
Double paltinum ?
iridium ?
( o.e. was iriduim and could have gone 100k )
The better the electrode material, the longer sevice life.
Plug wires now too ?..yes.
According to the normal maintenance schedule for your car, the plugs are due at 100,000 miles or five years. I would have to bet that since the plugs were replaced at 30k and it’s fifteen years old, the plugs were due five years ago.
I’d do both. The plugs are more or less due and wires degrade over time. You’ve gotten your use out of both, treat the car and to a new set of both. You may see a bit of a mileage improvement.
At 15 years old, I’m sure those plug wires are deteriorating a bit. I’d replace them along with the plugs and be given a little confidence that it is one less thing that you need to worry about.
Besides a set of wires are not that expensive. $50-$75.
Yosemite
They don’t come as a “kit”. However as others point out at this age they are getting ready for replacement, and I’d go ahead and do it. My wife’s Nissan was 16 years old when we replaced plugs and wires.
Plugs, it depends on what you used last time. If they were iron tipped plugs, you are way overdue, so much so that I am surprised the engine is still running. If you used double platinum or iridium, then they are still good. If you used NGK or Denso, you don’t have to worry about them freezing in the hole, if you used Autolite or some Champions and did not use anti-seize, it may already be too late.
The spark plug wires are good for the life of the vehicle.
I stand corrected…these are coil over, but the mechanic may have meant the replaceable boot and contact springs.
Unless he thought that the battery cables were corroded to thge point of future failure. That may be the cables he refered to.
Yosemite
Replacing the plugs and wires is a little involved, as you have 12 wires and 12 plugs, and a shop will charge accordingly
If you’re going for it, get only the exact plugs listed in the owner’s manual. Speaking from experience, this engine does not like cheap champion plugs, for example.
If you’re getting wires, get Bosch. Beru and bremi are inferior, at least for this application
Thanks for all the comments. In summary:
• I would like to keep the car for 5 more years.
• Plugs changed at 30K at dealer, assuming they were original MB parts. Not sure what electrode material are?
• Correct, The plugs and wires are not that expansive, however, the labor is high, at least two hours for $180, and is done in local mechanics, not dealer.
I think I will change both with Bosch, thanks again.
The plugs are either platinum or iridium. I’m leaning towards platinum, because I don’t think iridium plugs were very common in 2000
Many manufacturers are recommending a 100K SP replacement interval these days. Here’s the problem. They are motivated to do that b/c the magazines that rate car affordability take into account the recommended maintenance schedule and how much that work will cost. So the manufacturer can make the car appear less expensive if they push the recommended maintenance schedule out.
They wouldn’t recommend doing it of course if they knew it was going to cause a problem, but if they didn’t know for certain … well … think which side their bread is buttered on, and you decide …
I wouldn’t wait for 100K myself. The spark plugs can get soot built up on them over miles and time, and that can make them difficult to get out. Worse case, they get completely stuck, and removing them could damage the threads in the cylinder head. Think expensive. So it’s more economical to the car owners, at least in my way of thinking, to ignore the 100K recommendation and to replace the spark plugs at no more than 30 K or so.
Ah, ze German engineering… the bill comes due.
I wonder, was Mercedes using iridium in 2000?
Seriously, I’d personally change the plugs.
From what I can find the OE plugs are platinum, I personally would stick with the mfg. recommendation.
Back in the old days, I would buy whatever name brand plug that was on sale and from the cross reference chart, choose the plug listed for my engine. When I was a teenager, we had a 1954 Buick with an OHV V8, a 1952 Dodge flathead 6, a rototiller with a Lauson 4 stroke engine, a,LawnBoy mower with a 2 stroke engine and a 3 HP Evinrude twin cylinder boatmotor. We could use a Champion J8 in all these engines. Some years later when I owned the Buick, I bought a set of Western Auto plugs with the dual electrodes. I learned to stick with name brand plugs. These plugs would cause an engine miss. I took them out of the car and tried them in the lawnBoy. These plugs didn’t work any better there. The last time I substituted plugs by the cross reference chart was the last set I put in my 1978 Oldsmobile Cutlass. I found Autolite on sale at Walmart so I used them instead of the AC that was specified and had no trouble.
However, today’s engines are different. Use the spark plugs specified by the manufacturer. You don’t change plugs that often anyway, so cost is not a factor