Cylinder Misfire - 986 Forum - The Community for Porsche Boxster & Cayman Owners

sharper410 · 02-01-2025, 09:56 AM

This is regarding a 2001 base 2.7 Boxster. I got a check engine light warning and clear loss of power one morning. The error code read misfire on cylinder one. My assumption was it is probably a coil pack, but to be sure I swapped the coils between cylinders one and two. I cleared the code and then started her up to see if it threw a code for cylinder two. And of course I got no code and the engine sounds like it is running just fine (I didn't drive it as it was up in the air with the wheel off). The only difference from when I go the code and today is that it is warmer outside now. The wire was still tightly connected before I removed it as I've seen others mention that is a problem. Just seeing if others thought my assumption about the coil is still valid and either the temperature or moving them around made it work again. I don't like throwing parts at a problem and praying so wanted to get other opinions. Your help is appreciated.

JFP in PA · 02-01-2025, 11:40 AM

Pull the suspect coil and look for ANY signs of cracking, if you see cracks, can it. Test it for resistance (terminal 1 to terminal 15 should read 0.3-0.7 ohms), if it doesn't, toss it. Using an indictive pickup, test each coil for voltagne output on a scope with the engine at idle for uniformity of the voltage wave form; any low peak or irratic peak coils should be canned.

sharper410 · 02-02-2025, 07:59 AM

Maybe the question is what else could cause a misfire on just one cylinder that I should look into first.

Starter986 · 02-02-2025, 10:24 AM

Quote:

Originally Posted by sharper410

Maybe the question is what else could cause a misfire on just one cylinder that I should look into first.

See #2.

PS: From here forward you'll want to heed JFPs advice. If it's any consolation... He's saved me thou$and$.

tcoradeschi · 02-03-2025, 03:43 AM

Quote:

Originally Posted by sharper410

Maybe the question is what else could cause a misfire on just one cylinder that I should look into first.

The 24 year old coils that JFP is telling you to look at.

llonman · 02-08-2025, 09:35 AM

Which terminal is 1 or 15? I see there are three terminals on the coil pack connector.