car idles rough and smell gas once in a while
2007-08-22 05:48:05 · 7 answers · asked by fanofzep1 1 in Cars & Transportation ➔ Maintenance & Repairs
Do them one at a time, so you don't mix up your wires, make sure the gap is correct. HAND TIGHTEN, do not over tighten. be gentle & you won't cross thread them. Change your air filter at the same time, & if you have a manual, try to find the gas filter too. All of that will help the rough idle, & the gas filter may help the gas smell, or you have another problem!
2007-08-22 06:08:13 · answer #1 · answered by fairly smart 7 · 0⤊ 0⤋
The potential to screw something up is always there. You could cross thread a spark plug or gap the plugs wrong. If this guy has a clue, he should be able to handle it. The idling rough and fuel smell I bet has to do with something besides the plugs.
2007-08-22 06:00:13 · answer #2 · answered by Nc Jay 5 · 0⤊ 0⤋
Just as ncjay says, you can cross thread the plugs, and you can get the plug gap wrong either too wide or too narrow. You can also crack the insulator, or over torque the plugs in the head.
Start the threads by hand, and spin the plugs in until they are hand tight. They should go in easy. Tighten with a socket and be careful not to overtighten. Be sure that the plug wire is reinstalled and seated firmly.
good luck.
2007-08-22 06:06:25 · answer #3 · answered by Fordman 7 · 0⤊ 0⤋
It is easy to change spark plugs. Most backyard mechanic should be able to handle it.
What is the worst thing that could happen? The spark plug may split inside of engine (usually happens when previous spark plug install makes mistake and forget to lube the plug thread with oil or anti-seize) OR he himself forget to lube the thread and the plugs gets seized with the engine. In which case, the spark plug splits in half as you try to take out and you have to drill them out (and drop all the metal craps in engine cylinder to shorten the life of the engine piston rings)
Or while installing, you can re-thread the spark plug hole (you really have to be a stupid idiot to do something like that) but apparently they do exists because I do run into re-threaded cylinder head time to time.
If most cases, you can just shoot plenty of WD40 and pull it out without any problem.
2007-08-22 08:40:02 · answer #4 · answered by Sang K 4 · 0⤊ 0⤋
Make sure he even has enough tools to work on a mercedes. I would look at something larger than plugs causing the problem. Air filter, fuel pressure, dirty injectors,
2007-08-22 05:56:31 · answer #5 · answered by Anonymous · 0⤊ 0⤋
New plugs never hurt. They might be the easiest thing to install on a car. Just make sure he gaps them correctly or else you may not get the desired effects.
2007-08-22 05:57:48 · answer #6 · answered by Anonymous · 0⤊ 0⤋
theres really nothing you can screw up, and long as you put the right plugs back in the right holes. dont try and take all 8 out at once, take one out at a time and put it back when your done, you dont want to get the firing order messed up or youll have bigger problems
2007-08-22 06:01:27 · answer #7 · answered by Anonymous · 0⤊ 0⤋