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What spark plugs to pick for the e320?

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20K views 26 replies 10 participants last post by  01blackhawk  
#1 ·
I need to replace the park plugs on our 1999 E320. They are long due. Do you have any suggestion which ones I should pick?
 
#7 ·
#4 ·
I just replaced the plugs on my 2001 e320 4matic wagon with 200k miles. I used Bosch 7422 (FR8DPP33) platinum plus plugs. I used the same plugs when I changed them out at 100k miles. When I removed the plugs that I installed at 100k, they were in excellent condition. The gap had increase to about 0.055 in (vs 0.040 when installed) but other than that there were no problems with those plugs. The car started, ran, and drove without any problems and I would recommend these plugs for this engine.
 
#6 · (Edited)
F
#5 ·
My advice - buy Bosch OE equivalents - simplest "old" cross-reference is #7422 - for 12pc set $60 on Amazon:

https://www.amazon.com/Piece-Bosch-...PP33/dp/B005T3ITOW/ref=sr_1_3?ie=UTF8&qid=1509662912&sr=8-3&keywords=bosch+7422

Buy $16 "boot removal tool" used to "pop off" the spark plug connectors

https://www.amazon.com/EWK-Mercedes...EM/ref=sr_1_1?ie=UTF8&qid=1509663326&sr=8-1&keywords=mercedes+boot+removal+tool

Then search for a 5/8" ball socket swivel socket - and needs thinner wall.

A "pea" size dollop of dielectric grease for the top of the spark plug electrode for when you snap the boots back on.

It's a afternoon expereince not to be missed !
 
M
#8 ·
Amazon says it would fit. I have had them for about 4 years now. No problems at all. One of the Bosch 7422 plugs were broken at the insulator when i took them out.

Bought them from local Advanced Auto parts with discount code $35 for 12.

I change the plugs about every 5 years. I make less than 10,000 miles per year on that car so, I do not really care whether the plug is a 100 Kmile plug or not :)

https://www.amazon.com/NGK-7090-BKR...ar=1998|1998&ie=UTF8&n=15684181&s=automotive&vehicleId=4&vehicleType=automotive
 
#11 · (Edited)
No, but if I plan on doing engine mounts I do the spark plugs at the same time. With one side of the engine raised to remove a mount it makes it far easier to get to the back two spark plugs.

Since the replacement of spark plugs and engine mounts go pretty much at the same time, it's a good way to get both done and doesn't add a lot of time to the job.

I realize you already ordered the NGKs, but for the record Bosch 7422s are perfectly fine. Anything else (triple/quadruple platinum, etc.) are a waste of money. They won't make a noticeable difference in economy or performance.

Dan
 
#12 · (Edited)
NGK says proper plug for 98 E320 is NGK (4292) PFR5R-11 Laser Platinum Spark Plug. Equivalent to Bosch F8DPER according to this site: http://de.sparkplug-crossreference.com/convert/BOSCH_PN/F8DPER

https://www.amazon.com/NGK-PFR5R-11...ie=UTF8&n=15684181&newVehicle=1&s=automotive&vehicleId=2&vehicleType=automotive

Cheaper here: https://www.ngk.com/product.aspx?zpid=9913 and maybe elsewhere? But still not cheap!

7090 available in Canada for just under C$50 for 12. (US$38.95)From what is posted above, seems like these would be OK for our 50k km/5yrs E320?
 
M
#13 ·
MBGraham said:
NGK says proper plug for 98 E320 is NGK (4292) PFR5R-11 Laser Platinum Spark Plug. Equivalent to Bosch F8DPER according to this site: Möglichen ersatz-zündkerzen für BOSCH F8DPER

https://www.amazon.com/NGK-PFR5R-11...ie=UTF8&n=15684181&newVehicle=1&s=automotive&vehicleId=2&vehicleType=automotive

Cheaper here: https://www.ngk.com/product.aspx?zpid=9913 and maybe elsewhere? But still not cheap!

7090 available in Canada for just under C$50 for 12. (US$38.95)From what is posted above, seems like these would be OK for our 50k km/5yrs E320?
Click to expand...
Well, before I changed the spark plugs 4 years ago, I had read the spark plug discussions in this forum, ad-nauseum. Apparently, Ohlord, whom I respect his (past) opinions, and suggestions, did his analysis, and concluded that the 7090 is a cheaper and viable alternative to recommended Bosch at that time. What is good enough for Ohlord is certainly good enough for me :). For 50 Kmiles, I do not think there would be any performance difference between spark plugs with the same or similar characteristics (class, gap, resistance, material, etc.). Besides you have two plugs per cylinder which will ignite with varying timing in between, so I do not really expect ignition and combustion issues.

What is more important to me is the quality of materials , mechanical integrity, anti-seize properties, and in-spec gapping.

Few tips to get good performance, and installation to the OP:

1)Use dielectric grease on the plug end that goes into the boot. Not a lot, just a smear will do.
2)Use the special wrench for removing / installing plug boots. Make sure you get a positive click when you push the boot with the tool end.
3) Never use anti-seize on these plugs. The metal already has anti-seize properties, and any use of anti-seize can reduce plug performance (additional resistance on the return path).
4) After removal of the plug cable, prior to removal of the plug, apply some compressed air to the cavity to clean any debris that may be lodged in there, so it will not end up in the cylinder when the plug is removed.

I replace the plugs in every 5 years, because I want to be able to remove them without too much hassle due to seizing over a much longer period of time.
 
M
#15 ·
Excellent value for money :). I kept the old Bosch spark plugs which are in good shape. Just in case, if I have an ignition issue which points to a specific cylinder's spark plug(s), I could use the old ones to replace the suspect ones. This is easier than switching plugs between cylinders, and also less invasive troubleshooting.
 
#22 · (Edited)
Looked through my tools for something to remove boots. I have the plier type but most here say they don't work well. The type most talked about here cost a small fortune once shipping to Canada is added, considering it's likely a one time use for me. So it looks like I will have to make up a lever of some sort.

I do have a large offset box wrench, but don't want to wreck it. I did find this set locally and could cut the end off one:

https://www.princessauto.com/en/detail/5-pc-45-sae-offset-box-end-wrench-set/A-p8343576e

They have a metric set too (pic below)
https://www.princessauto.com/en/detail/5-pc-45-metric-offset-box-end-wrench-set/A-p8343584e

How important is the 17mm size? I have some smaller offset valve adjustment wrenches (14mm)

Maybe just bend a piece of flatbar.

Have to get car in garage and have a look!

Image
 
#27 ·
NGKs are good, I personally like em better than Bosch and feel like I’m getting a tad bit better gas mileage with them but that might be just my imagination. I changed my plugs about a month ago and switched back to NGKs, also changed the wires, half of them were bad. Now sitting at a red light, I have to look at the tacho if the engine is still running, silky smooth.
 
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