I own a 1999 VW Golf with 136+ thousand miles. We drive it mostly on surface streets and it runs fine. However, this past holiday we hopped on the expressway and as soon as we got above 55mph it started to stutter. It felt almost as if the spark plugs were miss firing. I’ve since given the spark plugs a once over and they look fine but I’m due for a tune up soon anyway and i intend to replace them. I can’t help feeling though that if the plugs are the problem, the car would be stuttering regardless of speed. Does anyone have any possible causes for this problem?
How about the health of your plug wires? Have you put your hand near them while it was running to see if you get zapped? Also look at the wires at night in the dark…while running…you might get lucky enough to see some voltage leaking…via sparks.
I say do the tune up one stage at a time to see what the culprit was…Fuel filter, Air filter, plugs, wires, oil change if needed…and wires if they are breached. Then see how she runs… If you do it all at once you wont know what the issue was…if you dont care…just do it…if you do…do the tune up in stages…
Spark plugs used to be routinely inspected, cleaned, re-gaped and put back in in the old days at 5,000 miles and changed at 10,000. I don’t see any difference in the gasket design from then.