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2000 VW Jetta Engine Light & Fouled Spark Plugs

At 165,200 my engine light came on. Was diagnosed as misfiring #1 spark plug. Mechanic indicated there was an oil consumption problem. He suspected head gasket but said if that would be around $1,000 or more and if that wasn’t the problem it could cost a lot to repair or even find what needed repairing. He suggested I start looking for a new car. But in the meantime he said we could keep changing the spark plug and adding oil as needed. that repair got me about 2,400 miles until light came on again, spark plug got changed. Today it came on again after only about 600 miles. I was hoping to get at least another 30-40,000 miles out of that car - after all my previous VW went 215,000 before it started causing me sufficient trouble to replace it. I don’t think it’s dangerous to drive with the engine light on, and I understand I can get it cleared at most auto parts stores, but of course it would come on again without fixing the underlying cause. I haven’t changed spark plugs it since I had a 74 celica years ago, and I don’t really know where they are in this car, but I’m disinclined to spend $83 every 600 miles to have the mechanic do it though… Anyone have any useful advice for prolonging the life of this car or whether it’s worth getting the head gasket replaced and if that cost is reasonable?

I think a head gasket might be a bad diagnosis on a problem like this. The first step in an oil consumption problem is to run a compression test; a dry one followed by a wet test.
If the wet test numbers go up considerably that points to a piston ring problem.

Connecting a vacuum gauge to the intake manifold is also a quick and easy first step that might shed some light on the problem and arguably could be done prior to a compression test.

If the vehicle is going to continue to be used in this condition, then widening the plug gaps a bit on new plugs (say by .005) and adding an anti-fouler to the plug can help keep it going.

JMHO, but I think it’s bad form to have an oil consumption complaint and not perform a compression test then and there. The plugs are out anyway and another 5-10 minutes would answer the question.

I’m assuming your mechanic did a compression and/or leakdown test and verified there’s a head gasket problem. If he didn’t, that’s probably the first thing to do. There’s a couple of things you could do to try to prolong the life of the engine without replacing the head gasket.

  • Have the mechanic retorque the head bolts to spec. That sometimes helps.

  • There’s products sold at auto parts stores for this problem, one is called Bars Leaks or something like that. Tom & Ray said they know of folks who have used these products and got some temporary remedy. Eventually your car will need a new head gasket I expect, but you might be able to secure some more miles if you’re willing to experiment with temporary fixes.

One more thing. If your mechanic will replace the head gasket for $1000, and will offer a guarantee doing so will fix the spark plug fouling problem you are having, that’s a pretty reasonable price. It might make sense to just take him up on it and be done w/it.

As OK4550 said there’s a plug anti-fouler.
It screws into the plug hole then the plug screws into it.
It recesses the plug and keeps oil or whatever from reaching it.
It will reduce compression a bit and slow down the flame propagation.
But it’s inexpensive and might get you some more engine light free miles.

That CEL (check engine light) is just a kid in class waving her hand trying to get you attention because she has the answer. You need to have the codes read. Some places will read them for FREE. Try Autozone or Advanced Auto Parts. Get the exact code (like P0123) not just their translation into English and post it back here.