2011 GLK350 ENGINE VIBRATION
when my plugs were done the plug boots broke, and a coil. It fired on 4 cilinders.
Last edited by Mmr1; Dec 26, 2022 at 12:09 PM.




I'm a member of a couple motorcycle forums (been riding 50+ years, no, no Harleys here). There are countless posts about folks complaining about the engine running bad shortly after a a plug change. The 1st question asked is, "are they NGK plugs"?
Do a Google search for "fake NGK" ... you'll get COUNTLESS articles and YouTube videos about this. Even the NGK website has a webpage dedicated to this, with lots of details.
This mostly occurs if the plugs were ordered online. If bought at a local reputable auto parts house, probably okay. However, if you rule out other potential causes, might pull a plug and check it. 👍
Last edited by calder-cay; Dec 27, 2022 at 03:26 PM.




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I have a w212 Sedan that's flex fuel, when I run E85, the car runs smoother with more power at all RPM
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Last edited by Chris1979; Jan 9, 2023 at 04:50 PM.
So when you have vibrations on your SUV and you change a belt tensioner with the pulleys make sure the belt is routed right to avoid confusions about the vibrations or noises.








Thanks for the follow-up!!




So if the belt was originally routed (incorrectly) over the water pump, vs under it, then that means the pump was spinning "in reverse", which in my mind, based on water pumps I've seen (during my personal experience with engine teardowns), that pump was NOT truly pumping the flow of water.
Amazed the engine didn't fail 👍
So if the belt was originally routed (incorrectly) over the water pump, vs under it, then that means the pump was spinning "in reverse", which in my mind, based on water pumps I've seen (during my personal experience with engine teardowns), that pump was NOT truly pumping the flow of water.
Amazed the engine didn't fail 👍




I think the takeaway from this is that the serpentine belt can actually be threaded wrong and still appear to be right at quick glance. I don’t remember any other time I have seen this. When the belt is installed wrong it’s usually so loose the tensioner can’t tighten it or so tight then tensioner won’t retract far enough to catch it.
I keep belt routing diagrams for all my cars at the front of my maintenance records folder.
I think the takeaway from this is that the serpentine belt can actually be threaded wrong and still appear to be right at quick glance. I don’t remember any other time I have seen this. When the belt is installed wrong it’s usually so loose the tensioner can’t tighten it or so tight then tensioner won’t retract far enough to catch it.
I keep belt routing diagrams for all my cars at the front of my maintenance records folder.
Used to work on high-power R.F. transmitters that put out 10,000 watts by means of a water-cooled klystron tube. The coolant pump to the heat exchanger was a large three-phase motor. If you got the phase wiring wrong the pump impeller would spin backwards but you wouldn't know it until you looked at the water flow guage in another room. Instead of the normal, and required, 21 or 22 gallons per minute it would only show about 13 g.p.m.




M272 directional water pump
Last edited by calder-cay; Jan 20, 2023 at 07:29 PM.








