Hello guys, I got my 2006 S2000 just last September, and has put on around 2000 happy miles since (odometer shows 89k now). Recently, the check engine light and VSA light came on, so I brought it to a local mechanic shop (in MA greater Boston area) and they told me it's something with the spark plug, and I foolishly paid $285 for that single spark plug change. The lights went away, but after a few days came back on again. Now it's just the check engine light so I brought it back to the shop and asked them to take a deeper look at it. They opened the head and cleaned the combustion chamber and valves for $125, but still the check engine light won't go away. They claimed that cylinder 1 has low compression and is due to bad gas I was putting in it, but I always go for the highest grade at any gas station, either 91 or 93 (though I have to admit I don't always go the big names like Golf Mobil and Shell, and they say that's the issue). They claimed that the only way to fix it is to rebuild the engine or replace it. What do I do now folks? Any help is greatly appreciated! Sorry for the bad English, it's not my main language.

Cylinder 1 pressure:

cylinders #2, 3&4:

 

Gotta know how they did that!

Our cars require a minimum of 91 octane. Just using 91 should not be a problem, there are parts of the country where that's all you can get.

Did I miss the CEL codes? $285 was not just for changing the spark plug. Shop rates of $200/hour are not uncommon. They gotta pay rent, heat, etc. And it takes time and tools to determine the problem.

A local S2000 specialist may be of help. The New England guys will respond soon if they didn't while I was typing.

-- Chuck.

 

I would scope it to see if anything is obvious and then do a leak down. Maybe something damaged a valve seat?

 

Adjust valves regardless. Rule out coil pack and injector is easy enough to do.

 

They did not open the head and do anything for $125. The gasket set is likely a good chunk of that and $125 would not even cover shop labor to remove the head, let alone do anything else and put it back together. I am not sure what they did there. Cleaning out the combustion chambers, I am guessing they ran some sort of cleaner through it like seafoam and that is that.

What was the "issue with the spark plug" ? I am curious there because honda increased the tq spec for the plugs do to some instances of them backing out. When they start backing out, it can ruin the threads on the plug.

I am skeptical of this shop based upon what has been said here. A leakdown test can help identify where the compression loss is occurring. Scoping the bores via the spark plug holes can help to see if any significant cylinder scoring has occurred.

 

He needs to find a good S2000 mechanic.