tune up question. .horrible gas mileage lately
Registered User
Joined: Jul 2009
Posts: 46
Likes: 0
[quote=DaveB;6240516]
I disagree for a couple of reasons.
1) I've pulled out OEM platinum plugs on 85-105K VQ motors and the electrodes were heavily warn, increasing the gap dramatically. All these cars were experiencing minor driveability issues and low mpgs.
2) The longer you leave the plugs, the more likely you'll have problems removing them. The last thing you want to have happen is heavy carbon buildup on the plug end getting pulled into the threads, causing a potential cross-threading issue.
3) The heads are aluminum and the sparkplug thread is steel. Chemical reactions take place between these two different metals. The longer you leave them in, the higher the chance of the cross-threading issue to occur.
The maximum I'd ever leave a set of plugs in aluminum heads to 4 years or 60K miles. No more.
The service manual says to wait until 105,000 miles to replace the platinum OEM plugs. Given the aggressive nature of car companies to make money off service, I find it hard to believe they'd recommend waiting so long unless they're absolutely certain it's safe to do so.
60k sounds right for normal plugs. The platinum ones should last a lot longer.
I disagree for a couple of reasons.
1) I've pulled out OEM platinum plugs on 85-105K VQ motors and the electrodes were heavily warn, increasing the gap dramatically. All these cars were experiencing minor driveability issues and low mpgs.
2) The longer you leave the plugs, the more likely you'll have problems removing them. The last thing you want to have happen is heavy carbon buildup on the plug end getting pulled into the threads, causing a potential cross-threading issue.
3) The heads are aluminum and the sparkplug thread is steel. Chemical reactions take place between these two different metals. The longer you leave them in, the higher the chance of the cross-threading issue to occur.
The maximum I'd ever leave a set of plugs in aluminum heads to 4 years or 60K miles. No more.
60k sounds right for normal plugs. The platinum ones should last a lot longer.
[quote=thebonafortuna;6240688]
The service manual says to wait until 105,000 miles to replace the platinum OEM plugs. Given the aggressive nature of car companies to make money off service, I find it hard to believe they'd recommend waiting so long unless they're absolutely certain it's safe to do so.
60k sounds right for normal plugs. The platinum ones should last a lot longer.
I think it is just his personal preference not to leave the plugs in the aluminum head for longer than that time frame. Not necessarily saying that the plug is bad or worn out.
The service manual says to wait until 105,000 miles to replace the platinum OEM plugs. Given the aggressive nature of car companies to make money off service, I find it hard to believe they'd recommend waiting so long unless they're absolutely certain it's safe to do so.
60k sounds right for normal plugs. The platinum ones should last a lot longer.
[quote=thebonafortuna;6240688]
The service manual says to wait until 105,000 miles to replace the platinum OEM plugs. Given the aggressive nature of car companies to make money off service, I find it hard to believe they'd recommend waiting so long unless they're absolutely certain it's safe to do so.
60k sounds right for normal plugs. The platinum ones should last a lot longer.
Using that theory, sell a few spark plugs or a head when you strip the threads; well after the warranty is up? 
The service manual says to wait until 105,000 miles to replace the platinum OEM plugs. Given the aggressive nature of car companies to make money off service, I find it hard to believe they'd recommend waiting so long unless they're absolutely certain it's safe to do so.
60k sounds right for normal plugs. The platinum ones should last a lot longer.
Last edited by 5150DS; Dec 7, 2011 at 03:51 PM.
Thread
Thread Starter
Forum
Replies
Last Post
RemmyZero
V36 DIY
10
Apr 23, 2018 11:13 AM
