Don’t Anti-Seize the Day

Don’t Anti-Seize the Day

Hello 93636,

Two weeks ago, I had a 2000 Jeep Wrangler with a 4.0L engine come into the shop with misfire codes. When I walked out to greet my new customer I could hear his Jeep running poorly. Joe was referred to us by a “Big Box” automotive repair chain. After questioning Joe, I raised the Jeep’s hood to investigate. I saw lots of expensive new parts so I knew there was more to this story.

He told me the “Check Engine” lamp was on before he went to a corner Quick Lube Station to have his oil changed. While the Jeep was being serviced, the service advisor retrieved trouble codes P0301 (misfire cylinder #1) and P0302 (misfire cylinder #2). After some discussion, Joe decided to have the corner Quick Lube Station replace his spark plugs. After the work was completed there was no improvement in the Jeep’s performance and the “Check Engine” lamp returned. Now, instead of trouble codes P0301 and P0302, P0304 (misfire cylinder #4) and P0306 (misfire cylinder #6) replaced them. The corner Quick Lube Station threw all those new parts at the Jeep but they could not solve the problem. I have told you guys many times, the most expensive diagnostic strategy is replacing good parts with new parts. The most cost efficient diagnostic strategy is testing and replacement of only the defective part(s). Several other shops attempted to fix this Jeep but also were unable to solve the mystery misfires.

Before I ran my normal diagnostic routine, I searched Jeep’s Technical Service Bulletin (TSB) library hoping to narrow my search. I discovered a TSB that matched the symptoms of Joe’s Wrangler. The TSB talked about carbon buildup on the engine’s valve stems and especially if the vehicle is not warmed up properly before driving and/or if the Jeep is mainly driven around town. The carbon buildup causes improper closing (sticking) of the valves.

I decided to remove the spark plugs so I could send a camera through the spark plug hole into the engine to verify carbon build up. As it turned out I didn’t need the camera. The corner Quick Lube Station exacerbated the original problem by adding anti-seize compound to the spark plug treads when they installed the new ones.

Do it Yourselfers: When you do a tune up and replace your spark plugs, put them in dry. NO ANTI-SEIZE!!!

Anti-seize on spark plug threads creates resistance in the secondary ignition (high voltage) ground path. The high resistance restricts the flow of electrons to ground. Instead of 15,000 volts jumping across the spark plug gap on their way to ground, maybe only 4,000 volts make it across. That’s not enough voltage to convert ALL the fuel in the cylinder into pressure. By the way, the secondary ignition voltage that does not jump the spark plug gap finds an alternate path to ground. That can also cause misfires.

Make sure you install your new spark plugs when the engine is at ambient temperature and torque them. If the engine is warm, the metal is expanded and it’s easier to overtighten the spark plugs. When the engine cools down, metal contracts and the spark plugs can become too tight and seize. Anti-seize may reduce seizing but it certainly is a hindrance to secondary ignition performance. Also, if you are going to save money by doing it yourself, make sure you use the manufacturer’s original spark plugs only. It doesn’t matter how well you do your job if you use inferior parts. The quality of your service or repair is NO BETTER than the parts you use, PERIOD. Make sure you check that the spark plug gap is set to the specification on your vehicle’s emission label which is usually located on the hood or fan shroud area.

Once my secondary ignition grounds were clean it was time to find the original cause. Since I had the spark plugs out I installed a pressure transducer into the cylinder #1 spark plug hole. When I cranked the engine over the compression waveform showed a variation in compression by up to 30 percent from compression stroke to compression stroke. That’s the smoking gun I was looking for. I’m now convinced the valves are sticking as Jeep’s TSB indicated.

I followed Jeep’s TSB recommendation and performed a fuel system cleaning. Before I completed the BG Fuel Injection System service, the engine was purring like a kitten. Because of Joe’s driving style I recommended the use of a can of “44K” in the fuel tank every six months or so. I’m not a big fan of “mechanic in the bottle” stuff, but BG Systems has some very powerful additives that work well.

OK everyone, I hope this helps.

It’s gratifying to know that so many of you recognize my name and read this column. What ISN’T so gratifying is that EVERYONE seems to think my NAPA Auto Care Center is located in the Madera Ranchos. Complete Car Care is located in Fresno, three miles south of the San Joaquin River on the 99 freeway. I am located on the east side of the freeway across from Island Water Park. We are the closest official NAPA Auto Care Center to the Madera Ranchos, just a short 15-minute drive.

As always I’m looking for ideas to write about. If you have specific or general questions about your vehicle or the automotive industry, give me a shout at complete_car_care@hotmail.com or on Facebook at Complete Car Care.

God Bless America and God Bless 93636,

Warren Parr
Two-time California NAPA/ASC
Technician of the Year
2013 National NAPA/ASC Technician
of the Year Second Runner Up