I decided to pop the hood and check for bad connections first when i noticed these markings on my coilpacks
Any idea what they mean ?
View attachment 1716182767
Someone was probably diagnosing a misfire and marking coil packs as they went.
Thats a good point, ill see if one of them is missing a the mark
My first guess was that the coils had come frome a junkyard, they tend to mark their parts like that
Those markings could be from the factory...
If the coil pack supplier sent in a bad batch of coil packs to the factory and the engine plant caught them... And they will because they have an online test called 'cold test' where they spin the engine on a dry dyno where it isn't run with fuel, just spun dry to check certain parameters and map specific items, like oil pressure signature and spark to certify the quality of every engine. They can catch missing bearings, defective oil pump, missing oil squirt holes in the rods, too wide or closed gap spark plugs, defective spark plug wires, etc...
So if they caught more than 3 bad/defective parts, then the supplier is called in and the Supplier Quality guy 'spanks' the company for sending in bad parts. They then have to quarantine all of the potential defective parts in the factory and test them and certify they do not have the defect. Sometimes they can send people to the assembly plant to check the parts, if not the quarantined stock gets sent back to the supplier's manufacturing plant and they have to test and certify the parts and sort out all of the defective ones...
Meanwhile the parts that are currently coming off the supplier's line must be certified not to have that defect also... The supplier must come up with a corrective action and implement it to make sure that problem doesn't happen again and fill out all kinds of documentation for it....
All of the certified parts must be marked somehow, usually by a paint mark and the engine factory will be notified how they are marked (where on the part and what color paint mark is used for that particular issue)... The supplier can choose whatever color paint marker and location to mark the parts... The mark must be able to be easily seen so they know the parts were certified and ok to use...
They are allowed to use any color paint marker, except red or any color that may look red (like dark pink or dark orange) because a red paint or red mark on a part in an assembly plant is how they identify no good/scrap parts that are not to be used... All workers in an assembly plant are trained not to use a part with a red mark on it and if they find any defective parts to identify them with red paint and put them off to the side where they will not be used...
The supplier is required to mark the certified parts for all shipments for 90 days until they have proven that they have fixed the problem (established a clean point) and no more defective parts will get through... If the supplier gets caught violating the clean point by shipping more defective parts in during that time, the issue is escalated and they have to add a second inspection/sort to make sure all parts coming in are good and the second inspection will have its own paint mark in another color to signify it was inspected/tested twice for that defect since the original/first inspection didn't catch it and the 90 day clock is set back to zero...
This happens regularly in production, eventually a supplier will ship a bad part in and will have to certify their shipments until a clean point is established and maintained for 90 days, mistakes happen... After the 90 days of no defective parts getting shipped, the extra inspection/certification/marking can end...
This is why you may find paint marks on various parts in new cars...
However it is not a bad thing, because the parts with the marks on them have been certified to be of good quality....
