Jump to content
SAU Community

Cracking Spark Plug Porcelain Problem

Recommended Posts

Im having this annoying problem on my 26/30 at the moment and i originally thought it was a one off problem and its happened on 3 different sets of plugs now.

The porcelain on the top of the plug keeps cracking away. It looks like its starting to crack from the top down. I assume its heat related but the motor is running with no coilpack cover, afr's are mid 11s and pretty conservative timing numbers too, its only running a pair of stock gtr twins and previously ran a single gt3076r as well. Its got stock 26 coilpacks, and ecu is an Autronic smc. Im also making sure i dont tighten the plugs too tight too as i thought that was possibly the cause, so i have got 2 different people to install them and they all have same problem. I cant remember what cylinders it did last time but it was on 2 of them and this time i found the worse cracked one on cylinder number 1 and then the other on cylinder 4, i dont know if its happening on the same cylinder each time.

any ideas whats causing this? anyone had the same issues? These are BCPR7ES ngk's too

heres a few pics....



Link to comment
Share on other sites

Whoever is installing the plugs/coil packs is breaking them.

They don't just randomly crack like that. They are either being installed incorrectly, there is a problem with the spark plug socket being used, or the coil packs are being pushed down too hard.

Link to comment
Share on other sites

Damn its not that hard to keep the socket straight on the plug...

Maybe get yourself one of those special spark plug sockets with the rubber insert to prevent cracking of the plug.

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

  • Similar Content

  • Latest Posts

    • world's fastest R33 with sunroof, A/C and sound deadening  
    • And lower chances of a divorce, hookers & coke much higher chance, a bit lower are strippers & coke.
    • Been slowly chipping away at it when I've got time. Tried to get the box in with the converter but worked out that the flexplate isn't the correct thickness and the converter pulls out off the pump too much (about 8mm). The flexplate for some reason was setup to use the secondary holes on the converter which had a press in nut to bolt to. I worked with Adamat performance the guys who manufacture the kits and they revised the design and made it suit the factory converter holes and milled up a new one for me and is currently on its way over. Can see the differences between the two compared to the orignal design which is in the post above. Once that's here the box can go in for good. I dummy'd it back up to get tailshaft length and is currently with Hardy Spicer to sort that out. Unfortunately won't get it back until late Jan Have been working in the boot lately getting it all a bit nicer and useable. Painted it with sound deadener and cut out a new boot floor from 18mm MDF so I can put a pram or my tool bag in the back. Have marine carpet coming to stick onto that and then also cut a piece to cover the battery. Once ive stuck the carpet in and all cleaned up ill pop the fuel system back in. Need to order 2 new Walbro 525s to replace the 3x 460s. Should be enough fuel for the new setup and run a bit cooler as well having more volume in the surge tank and less heat.  Have also ordered some sound deadener to put under the carpet. That should be here next week and I'll start putting it down on the floor, doors and roof. Hoping all this effort will make it a nice streeter with ability to daily if I want to.
    • It's only money. This arrived for mine yesterday 
  • Create New...