Spark plug wires popping off?

Interested in what others have to say. Now and then I have to press down on my extenders and 3-4 of them will "click" indicating they have lifted a bit off the plug. I assume it is the brand of extenders (unknown; installed by PO) and plan to change them out. Not sure if this is the same thing OP is talking about...

 

Do you have the correct length spark plug extenders? Haven't looked for the details, but know that there are different lengths for different models.

 

I have been using the correct OE parts and in over 40 years never seen it happen.

I see all manner of combinations of incorrect, often low quality aftermarket parts have issues. Just use the right stuff from respected suppliers. It is not inherent to the cars.

 

Try a search on the 115647 part number for prior threads. Yours could be fine, but Superformance isn't an official supplier, and any company can make an error.

Another thought might be the spark plug wire end caps that fit into the spark plug tube. There shouldn't be any gas pressure in the spark plug tube as you noted, but I believe they added some venting features to prevent the heating and cooling cycles of the gas inside the spark plug tube from "pumping" the spark plug wire caps off of the tubes. Just a thought as maybe those have been replaced.

 

Also the big umbrella covers have a fair bit of springiness to them. If not positioned far enough up the wire and installed in a compressed state they may act to pull the connector up off the plug. I would imagine it would also require a loose fit on the plug. The connectors should be a tight enough fit it nearly requires a pair of pliers to pull them off.
I have no idea what parts Superformance is selling. I have never once used them as a supplier. I don't know any professional quality shops that do.

 

Generally Ricambi or T Rutland.

 

If you are not a professional and just want correct , high quality parts every time Ricambi is the best choice. T Rutlands and AW are great suppliers but I have to pick and choose a little on their products. Not every single part offered is something I want to use. They are all friends so there is a price to be paid for saying this. But they both have availability on some things Ricambi does not.

I am in business and happily pay a little more for a quality part the 1st time. Its why these 3 get 99% of my business. Opening up a box and finding the wrong part or a **** part is way too expensive.

 

2 thoughts - the clip on the bottom of the extenders that goes over the spark plug can be different from the various factory vs aftermarket extenders - the set you've got might have weak spring clips! Just to mention the other part of that connection, what spark plug brand/model are you using? (Shouldn't make a difference, but you never know)

Aside from OEM supplier vs aftermarket manufacturer, there is a difference in length between 308 and 328 extenders - the 328 extenders are longer, 107mm long - the 308 and QV use 100mm extenders. An easy way to spot the difference is that the 328 extenders have 3 flats on the top of the red part of the extender, the 308 extenders (either red or black) have completely round top parts.



Here's a thread from last year discussing the differences in extenders: 328 Spark plug lead extensions???

I posted part numbers for the different versions and links to the TAV diagrams in a post in that thread:

Gordon

 

I have the taller extender for my 328, and never ever has one popped off