Spark plugs changed after 195k miles, and 15 years, Mercedes S500

[GON]

Vehicle background- 2005 S500 Mercedes, was a 2017 Hurricane Harvey (Houston) flood salvage vehicle I purchased from Copart with 145k miles. I have driven it as my daily driver since purchased- I have put 50k miles on it. I knew was in need of a tune-up, but have nine vehicles and four trailers, so I had to wait until I had a opportunity to replace the plugs and wires.

Replaced the OEM original plugs and wires on a 195k mile 2005 Mercedes S500. Here is a picture of the OEM NGK plugs. The came out without issue. I did make sure the car sat 12 hours before removing the plugs. Like some of the plugs, the Bosch wires also had corrosion from what I suspect was flood damage. Surprised the S500 ran so well with so much wear and tear on the plugs and wires. I get 25 MPG on the highway, which includes going over two major mountain passes per day (four total mountain passes round trip). I drive on average 110 miles per day. The V8 S500 has two plugs per cylinder.

 

[Hall]

How do you know they were the original plugs ?

 

[GON]

Good question. I don't know for sure, but vehicle was dealer maintained for a large part of its life, and its service history from Mercedes does not show plug replacement. After it left mercedes for service, I doubt many shops or individual maintainers will go to the dealer to by OEM plugs, which they are, when exact replacement are easier to purchase at a significant savings.

 

[Jetronic]

I suppose with 2 plugs per cylinder you half the chance of misfires... These are well done anyway

 

[slacktide_bitog]

With how much the wires alone cost, they better last 200k miles and a flood!

 

[loneryder]

How did it run with the new plugs? Notice a difference? Dealers usually just record the vehicle was serviced without listing what they did.

 

[Amkeer]

Yikes! Amazing the condition of those plugs. Have any other issues with salt?

 

[GON]

How did it run with the new plugs? Notice a difference? Dealers usually just record the vehicle was serviced without listing what they did.

Was having a slight miss at idle under load (stop light). The plug and wire change appears to have corrected the slight miss. The miss was not large enough for a misfire signal, or any issues a Mercedes factory diagnosis system could identify. I own a copy of the Mercedes factory diagnosis system, called SDS.

Mercedes keeps a very accurate service record. Very exact. I have the full MB service history.

 

[GON]

With how much the wires alone cost, they better last 200k miles and a flood!

Yes, the wires are very expensive, if you use the OEM (Bosch). But they are super high quality, and every plug gets a very exact sized wire. The plugs are not so expensive as it is a high use, competitive item. I purchased a set of Bosch wires, but could not find them. So I purchased an alternate set of NGK wires. Then ended up finding the Bosch. The difference in quality, and even labeling is huge, Bosch so much higher end. I do have to say the NGK could of been counterfit, as I purchased them from a Canadian Ebay Seller.

 

[Astro14]

I think you’re correct, those were the original plugs in the car. For my S-class, I got replacement NGK plugs at sparkplugs.com - and they were genuine...not sure I would trust an EBay seller... as expensive as the coils and wires are, it’s a good call to go with genuine or Bosch parts.

How’s the car otherwise? Any water intrusion in the cabin? Particularly under the front passenger seat, where the SAM Power supply and CANBUS wiring is housed, water causes corrosion and eventual failure. Another susceptible/vulnerable area is under the rear passenger seat, where the rear SAM is located.

I think what’s impressive is the car has served you well despite being flood damaged and running on 200,000 mile plugs.

 

[bbhero]

Was having a slight miss at idle under load (stop light). The plug and wire change appears to have corrected the slight miss. The miss was not large enough for a misfire signal, or any issues a Mercedes factory diagnosis system could identify. I own a copy of the Mercedes factory diagnosis system, called SDS.

Mercedes keeps a very accurate service record. Very exact. I have the full MB service history.

I have had spark plug wires cause a miss at idle and running.... Changed my rotor, distributor cap and plugs in my 95 Nissan Sentra... Ran better but still had a noticeable miss. Changed the wires and it got the car running right.

Like Astro said... It's impressive the car has run has well as it has for you to this point.

I hope it continues to run good for you for a good long while.

 

[slacktide_bitog]

Yes, the wires are very expensive, if you use the OEM (Bosch). But they are super high quality, and every plug gets a very exact sized wire. The plugs are not so expensive as it is a high use, competitive item. I purchased a set of Bosch wires, but could not find them. So I purchased an alternate set of NGK wires. Then ended up finding the Bosch. The difference in quality, and even labeling is huge, Bosch so much higher end. I do have to say the NGK could of been counterfit, as I purchased them from a Canadian Ebay Seller.

Yes, NGK has a lot of problems with counterfeits on eBay. Most NGK spark plugs on eBay are counterfeit, so the wires being fake wouldn't be a surprise, either.

Expensive items are very prone to being counterfeited.

Rock Auto should be legit, as they source from the same distributors/warehouses that real auto parts stores use. Real NGK wires should be no problem at all.

NGK supplies the OE plugs, so you should be able to trust them with the wires, as long as you cna also trust the seller ou get them from!

 

[nthach]

Whoa, those plugs look gnarly.

Just when I thought I was bad with my old car, a 1991 Lexus LS400 that still had the factory Denso(then known as Nippondenso and had the old ND markings) PK20R-11 when the car was built in 1990. That was back in 2004 and with 162K on the clock. Of course those were replaced with another set of Densos.

 

[meadows]

Did you measure the gap of the old plugs?

 

[Wolf359]

While those look rough, the tips don't look that bad. If it went to the MB dealer they probably got done. Not sure what the interval on an S500 would have been, maybe 100k? Or the owner went to an indy. Could still have been covered by a service package, you could buy them up to 80k and get a 3pack or a 4pack and the plugs were included in the service pack. The newer cars get them replaced every 60k now. But that's due to their multi spark system which fires up to 5 times per cycle.

 

[Hockeypuck]

I can not believe you had the cajones to by an S500 that had been flooded.. . All the electronics....jesh.

 

[GON]

I can not believe you had the cajones to by an S500 that had been flooded.. . All the electronics....jesh.

You are correct. Never buy a flood vehicle, the only bigger risk is buying a vehicle that was vandalized at auction. Vandalized vehicles are most likely a vehicle with major prior issues such as a flood, poor major repair, or mechanical. They vandalize the vehicle doing cosmetic things, so you keep you attention on the cut seats or smashed windshield, not the deep issue the vehicle has.

I have purchased and rebuilt two S-class Mercedes flood vehicles. Both are still on the road as daily drivers. I was more lucky than good. But the luckiest I was - a 2006 S500 with 43k miles for $350- it had a reported engine fire with pictures to match.

Here is the thread on one of the flood vehicles:

2005 S500 Houston Flood vehicle reserection thread

www.benzworld.org

Here is the thread on the fire vehicle:

2006 S500 4matic external fire reserection thread

www.benzworld.org

Should point out tried to purchase another 2006 S500 at auction today. It was optioned in a way I really desired. I suspect the car was worth up to 1,000 USD. I really wanted it, my final losing bid was $1800 USD. I had the parts to fix, so was willing to go above and beyond. at $1800, out the door not including transport is about $2500. And another $300 plus dollars in transport cost plus three days travel, and can only pickup during normal weekday business hours. I lost the auction, it went for $1900 before fees.

On the auction front- people have money. I am seeing salvage vehicles, with no buyer inspection, sell at auction for prices that can compete with private Seller sales. 99 percent of vehicles sold to individuals at auction are not worth what was paid after fees. One has to work extra hard to find the one percent, and then be more lucky than good that another person did not discover what one found.

Auction business is a tough way to get a vehicle. I simply like the challenge of trying to fix em......

 

[Yah-Tah-Hey]

Vehicle background- 2005 S500 Mercedes, was a 2017 Hurricane Harvey (Houston) flood salvage vehicle I purchased from Copart with 145k miles. I have driven it as my daily driver since purchased- I have put 50k miles on it. I knew was in need of a tune-up, but have nine vehicles and four trailers, so I had to wait until I had a opportunity to replace the plugs and wires.

Replaced the OEM original plugs and wires on a 195k mile 2005 Mercedes S500. Here is a picture of the OEM NGK plugs. The came out without issue. I did make sure the car sat 12 hours before removing the plugs. Like some of the plugs, the Bosch wires also had corrosion from what I suspect was flood damage. Surprised the S500 ran so well with so much wear and tear on the plugs and wires. I get 25 MPG on the highway, which includes going over two major mountain passes per day (four total mountain passes round trip). I drive on average 110 miles per day. The V8 S500 has two plugs per cylinder.

Thanks GON. I'm concerned about removing the plugs from my 04 V6 Camry. I've read that NGK plugs have a tin coating on the threads to aid in removal. Did those plugs come out of an aluminum cylinder head? Regards and have a safe long weekend.

 

[GON]

Thanks GON. I'm concerned about removing the plugs from my 04 V6 Camry. I've read that NGK plugs have a tin coating on the threads to aid in removal. Did those plugs come out of an aluminum cylinder head? Regards and have a safe long weekend.

YTH, plugs came out without any issues. The only thing I made sure of was the engine sat the night before removing the plugs- engine was as cold as could be for summer time job. Read somewhere to remove plugs when engine is cold- and it worked.

 

[pezzy84]

I think I am honestly more surprised that a mid-2000's top of the line Mercedes still has plug wires vs coil on plug, guessing the dual plug arrangement caused this.

How could MB could not engineer a proper flame propagation in one of their flagship engines? Well any engine for that fact.