Spark plug exploded. Need help!!!
Super Moderator
Joined: Jun 2008
Posts: 19,942
Likes: 192
From: Llandudno, Cape Town, South Africa
late 2009 CLK 350 Coupe Elegance, '65 Jaguar S Type wires
I've raced highly stressed very high BMEP engines with both NGK & Bosch plugs. Both companies make excellent products.
NGK had a few weaknesses in the leaded fuel days but that is no longer an issue in road cars.
NGK had a few weaknesses in the leaded fuel days but that is no longer an issue in road cars.
Super Moderator
Joined: Jun 2008
Posts: 19,942
Likes: 192
From: Llandudno, Cape Town, South Africa
late 2009 CLK 350 Coupe Elegance, '65 Jaguar S Type wires
Guys - It's not even on the horizon. Long before that I would write a book on working in the American oil majors & how not to manage a Corporation outside the US & maybe even inside.
It would bring tears to your eyes or maybe such mirth that you would end up in tears.
It would sell far better than some introspective crap on yours truly.
It would bring tears to your eyes or maybe such mirth that you would end up in tears.
It would sell far better than some introspective crap on yours truly.
Thread Starter
Junior Member
Joined: Sep 2008
Posts: 31
Likes: 0
2006 c280
Mechanics were able to remove all plugs with an easyout. A magnet was lowered into each cylinder and a borescope was used to look for ceramics. Everything looked good so they replaced all 6 plugs (with the exact same Bosch plugs that I originally installed). That was two days ago. Car seems to be running fine. Total cost: $462 (including the tow). Could have been much worse.
Anybody have any additional advice?
Barring any noticeable problems should I get a compression test done? Is it possible for problems to arise a month from now, or is it a "now or never" sort of issue?
Thanks all for working through the issue with me.
Anybody have any additional advice?
Barring any noticeable problems should I get a compression test done? Is it possible for problems to arise a month from now, or is it a "now or never" sort of issue?
Thanks all for working through the issue with me.
Super Moderator
Joined: Jun 2008
Posts: 19,942
Likes: 192
From: Llandudno, Cape Town, South Africa
late 2009 CLK 350 Coupe Elegance, '65 Jaguar S Type wires
Don't worry - You would know if you had a bent valve or worse. Just drive & enjoy. Obviously be vigilant initially for any changes in behavior. I think you are in the clear. Boroscope in competent hands would pick up any damage.
MB World Stories
The Best of Mercedes & AMG
Manual Mercedes? 6 Times Sindelfingen Let Drivers Have All The Fun
Verdad Gallardo
Mercedes SLR McLaren 722 S Is Extremely Rare Example Modified by McLaren
Verdad Gallardo
8 Classic Boxy Mercedes Designs That Have Aged Like Fine Wine
Verdad Gallardo
Flawlessly Restored Mercedes 190E Evo II Heads to Auction
Verdad Gallardo
Electric Mercedes C-Class Unveiled: 11 Things You Need to Know
Verdad Gallardo
Mercedes EQS Gets A Major Update: Everything You Need to Know
Verdad Gallardo
5 Underrated Mercedes-Benz Models That Don't Get the Love They Deserve
Verdad Gallardo
Mercedes 300D Has Pushed Well Past 1 Million Miles and It Ain't Stopping
Verdad Gallardo
10 Most Reliable Mercedes-Benz Models You Can Buy Used
Verdad Gallardo
MBWorld Fanatic!
Joined: Mar 2004
Posts: 1,175
Likes: 24
From: Boston, MA
'14 ML350, '13 C220 CDI, '07 C280, '98 ML320
kastnna, glad to hear that your car is back on the road without the need for major repair.
I guess the consensus is that the root cause of the problem is over-tightening of the spark plugs to the extent the plugs' structure was weekend. No issue with the compatability of the plugs from Autohaus.
Enjoy your ride.
I guess the consensus is that the root cause of the problem is over-tightening of the spark plugs to the extent the plugs' structure was weekend. No issue with the compatability of the plugs from Autohaus.
Enjoy your ride.
Glad it worked out well. Whew.....
Out Of Control!!
Joined: Nov 2005
Posts: 18,677
Likes: 9
From: OC
a quarter mile at a time
Mechanics were able to remove all plugs with an easyout. A magnet was lowered into each cylinder and a borescope was used to look for ceramics. Everything looked good so they replaced all 6 plugs (with the exact same Bosch plugs that I originally installed). That was two days ago. Car seems to be running fine. Total cost: $462 (including the tow). Could have been much worse.
Anybody have any additional advice?
Barring any noticeable problems should I get a compression test done? Is it possible for problems to arise a month from now, or is it a "now or never" sort of issue?
Thanks all for working through the issue with me.
Anybody have any additional advice?
Barring any noticeable problems should I get a compression test done? Is it possible for problems to arise a month from now, or is it a "now or never" sort of issue?
Thanks all for working through the issue with me.
Good to hear your car is back on the road! $462 isn't bad considering how much worse it could have been IMO.
MBWorld Fanatic!
Joined: Jun 2002
Posts: 7,265
Likes: 169
From: So. Oregon Coast
C230 Sport Coup + 2006 W164 ML350 + 99 Ford Escort RIP
Being left on the side of the road, watching the blue light shorting from the metal surface
to the ceramic after < 1000 miles, was enough for me. Bosch sux!
Last edited by C230 Sport Coup; Sep 3, 2010 at 12:32 PM.
Super Moderator
Joined: Jun 2008
Posts: 19,942
Likes: 192
From: Llandudno, Cape Town, South Africa
late 2009 CLK 350 Coupe Elegance, '65 Jaguar S Type wires
Todd - you can't blame the plugs & if you had a plug that was tracking I'll bet it was dropped & had a micro crack in the ceramic. NGK was our sponsor in the Honda team & I used to get our racing plugs in polystyrene blocks. People think you can bash plugs around - you can't. In the team if a plug was dropped it got ditched.
Bosch make some of the best plugs around. Try Champion if you want crap & some of the other dubious brands.
Bosch make some of the best plugs around. Try Champion if you want crap & some of the other dubious brands.
Last edited by Glyn M Ruck; Sep 3, 2010 at 12:56 PM.
Senior Member
Joined: Jul 2007
Posts: 389
Likes: 4
2002 E430
Wow sorry to hear. Never seen anything like it. Just did plugs on my Z and didn't use torque wrench. I just hand tightened them. Torque wrenches can go against you if you rely too much on it. Recenty pulled my plenum and I torqued the bolts using regular ratchet. I'd like to 'feel' how tight my bolts are. With torque wrench I couldn't do that. Of course if I'm rebuilding an engine I'd use a good torque wrench but for relatively small jobs regular ratchet will do just fine.
Newbie
Joined: Sep 2014
Posts: 1
Likes: 0
jeep grand Cherokee, Chevy avalanche
having similar issue
Our jeep seized up and we can't figure out why. Why we pulled the spark plugs we found something no one has ever seen.... So now we're more stumped. Any help would be great.
Super Member
Joined: Jul 2009
Posts: 938
Likes: 53
From: Montreal, Canada
2005 C240 2011 R350
I realize this is an old threat but here is an intersting video from NGK regarding torque vs tightening angle. Maybe both should be observed. I have an R350 and a C240 Just doing the R plugs now.
The shop manual says 23NM (17 ft-lbs) Most shop torque wrenches we have are for bigger stuff. Perhaps it is easy to overtorque when a 140ft-b wrench is set to 17! Observe the tightening angle. it is on the NGK plug box.
The shop manual says 23NM (17 ft-lbs) Most shop torque wrenches we have are for bigger stuff. Perhaps it is easy to overtorque when a 140ft-b wrench is set to 17! Observe the tightening angle. it is on the NGK plug box.
Super Member
Joined: Jul 2009
Posts: 938
Likes: 53
From: Montreal, Canada
2005 C240 2011 R350
seems that is a common question. Try pulling one plug to see what came from the factory.
either would be ok
see this thread too.
https://mbworld.org/forums/c-class-w...at-choose.html
as for resistor plugs. seems impossible to get aftermarket. If you are really **** on this get them from the dealer. at 3x the going rate...
either would be ok
see this thread too.
https://mbworld.org/forums/c-class-w...at-choose.html
as for resistor plugs. seems impossible to get aftermarket. If you are really **** on this get them from the dealer. at 3x the going rate...
Newbie
Joined: Jun 2018
Posts: 1
Likes: 0
2012 Honda CR-Z
Exploding spark plug
So yesterday i was driving my 2012 honda crz to work i shifted from 5th to 6th gear and as soon as i left off the clutch and started accelerating i heard the loudest bang in my life sounded like a shotgun in my ear i immediately pulled over car died after idling for 5-6 seconds got it towed and they said my 2nd spark plug literally exploded its nowhere to be found, so im in a similar situation but i just got my car 2 months ago and didn't change the plugs
MBWorld Fanatic!
Joined: Jun 2002
Posts: 7,265
Likes: 169
From: So. Oregon Coast
C230 Sport Coup + 2006 W164 ML350 + 99 Ford Escort RIP
Ha, had that happen on my 78 Toyo pickup.
In my case, it was like some kind of miracle, the plug was just resting
on a bracket for the bumper, after shooting out the motor
and bouncing off the inside of the hood.
I screwed it back in, albeit with some force since the thread were bunged, and drove off, lucky me as I also happened to have tools and a flashlight.
I was driving 55+ on a rural backroad when it happened with farm fields on both sides.
Never woulda found it.
In the end I had to use a tap and helicoil to repair the threads to
replace the plug.
In my case, it was like some kind of miracle, the plug was just resting
on a bracket for the bumper, after shooting out the motor
and bouncing off the inside of the hood.
I screwed it back in, albeit with some force since the thread were bunged, and drove off, lucky me as I also happened to have tools and a flashlight.
I was driving 55+ on a rural backroad when it happened with farm fields on both sides.
Never woulda found it.
In the end I had to use a tap and helicoil to repair the threads to
replace the plug.
Super Member
Joined: Apr 2015
Posts: 604
Likes: 51
LS400
An example that DIY doesn't always save $. If a person is not a mechanic or tech, and doesn't have a clue about how a certain torque "feels" this sort of thing can happen. I've seen examples all over the various forums of people reading a torque spec of say 50 in lbs and using a foot pound torque wrench set at 50 ft lbs. It may surprise many but on some fasteners professional mechanics don't use a torque wrench, and the reason is sometimes the time or the space needed to use it.
Newbie
Joined: Jan 2023
Posts: 1
Likes: 0
Crown Victoria
Hi guys,
Changed out my spark plugs the other day. Used a torque wrench set to 20nm, no diaelectic grease, and the OEM bosch plugs were pre-gapped, but I double checked them anyway.
Anyway, after changing them, I cranked the car, got no CEL or skipping or anything, and gently revved the engine to 2500 rpms. No problems. Turned the car off and went to bed.
Yesterday, I crank the car and drive a mile down the road to the nearest highway. As soon as I hit the acceleration ramp, I go WOT. a second later, I hear a sound like a shotgun, followed by a repeated knocking noise, and a squeeking noise that sounds like a belt slipping. CEL begins flashing and the car has almost no power (I'm guessing it is in limp mode). CEL is now solid and car stalls at idle. I barely made it the mile back home.
I open the hood and begin removing coilpacks. Turns out the middle spark plug on the driver's side bank has exploded. Maybe I cracked it when installing, but like I said, I used a torque wrench. Anyway, the plug threads are stuck in the cylinder and I recovered most of the plug internals and ceramic coating but I've got no idea if anything fell into the cylinder.
What the hell do I do now? It's 60 (interstate) miles to the nearest dealership. Is it safe to drive? Should I even start it? I'm afraid to even drive to autozone to have codes read.
Thanks
Changed out my spark plugs the other day. Used a torque wrench set to 20nm, no diaelectic grease, and the OEM bosch plugs were pre-gapped, but I double checked them anyway.
Anyway, after changing them, I cranked the car, got no CEL or skipping or anything, and gently revved the engine to 2500 rpms. No problems. Turned the car off and went to bed.
Yesterday, I crank the car and drive a mile down the road to the nearest highway. As soon as I hit the acceleration ramp, I go WOT. a second later, I hear a sound like a shotgun, followed by a repeated knocking noise, and a squeeking noise that sounds like a belt slipping. CEL begins flashing and the car has almost no power (I'm guessing it is in limp mode). CEL is now solid and car stalls at idle. I barely made it the mile back home.
I open the hood and begin removing coilpacks. Turns out the middle spark plug on the driver's side bank has exploded. Maybe I cracked it when installing, but like I said, I used a torque wrench. Anyway, the plug threads are stuck in the cylinder and I recovered most of the plug internals and ceramic coating but I've got no idea if anything fell into the cylinder.
What the hell do I do now? It's 60 (interstate) miles to the nearest dealership. Is it safe to drive? Should I even start it? I'm afraid to even drive to autozone to have codes read.
Thanks
Proof
More proof
