2004 Acura TL (3.2L V6, Automatic, 156,300 miles)

Replaced spark plugs on 2/6/24 with 152,700 miles on car. Haven't even driven 4k miles on the new plugs yet. But as you can see in the pic, quite a bit of corrosion has happened in 7.5 months. FWIW, I live in Florida and there's plenty of humidity in my garage. The previous spark plugs were 10 years old, 62k miles on them and looked much worse with corrosion. But they performed really good imo. They were getting 25-26 mpg.

I only decided to check the plugs because I have a valve cover gasket leak which has been getting worse lately. As far as I can see, there's no oil on the plugs. And from my limited knowledge, I don't think oil is causing the corrosion. The new plugs are getting the same mpg as the previous plugs. The engine does feel a little smoother with the new plugs. I am really happy with the performance of the engine and transmission.

Can anyone tell me what is most likely causing the corrosion? And if it's not causing performance problems, how important is it to fix it? I've had this car 20 years at the end of this month. I'd like to keep it as long as I can easily maintain it myself. If it gets expensive, I will opt for a newer car.

 

where did you get the plugs from??

 

Shipped by Amazon
Sold by Purchased Dec 2023

 

fake fake fake

 

I was mistaken, the Amazon seller when I purchased was G.P.S. - .

 

lots of fake stuff on amazon. even if amazon is the seller, I would not risk it. Amazon combines parts from all providers into 1 bin for fulfillment. ( see attached post).

https://acurazine.com/forums/3g-tl-2.../#post16941527

before putting in genuine plugs, you might want to clean threads in the cylinder to prevent rust getting on new plugs. some posters will recommend anti-seize but if you use it, adjust your torque specs.

 

Real NGK plugs come with a coating that resists corrosion and should be good for a long time (like 60K to 120K miles!). I think you got fake ones, esp judging by the brown near the wrong side of the ceramic....

 

Really disappointed to find out the plugs are likely fakes. I went ahead and replaced the pcv valve and both valve cover gaskets. Will do the camshaft cover seals next.

Do you think I need to replace the spark plugs now or wait until I notice performance problems?

 

depends, do you like to be proactive or reactive?

 

I like to be on time.

 

Thanks for the advice. Seems reasonable to think that if the genuine NGK platinum plugs that were in there before (for 10 years) got corroded, I should have cleaned it out before putting in new plugs.

 

I would not buy spark plugs or oil filters from Amazon who is known to be guilty of commingling, especially when selling what is termed a fungible product. Here is an example of commingling. Let's say I give Amazon 100 counterfeit Honda oil filters. Amazon also buys direct from Honda of America 100 copies of the genuine filter for sale under the conditions “filled and shipped by Amazon”. All the filters, both counterfeit and genuine, at any given Amazon warehouse are placed in the same stock bin and the computer simply handles who made the purchase and a robot (most likely) draws the filter from the bin at time of purchase. But in this example, you have 50/50 chance of getting a counterfeit filter.

Amazon regards the products as fungible (it's an actual legal term), meaning that a filter made by brand xyz and labeled as Honda, is the same regardless of who is selling it. Further, if a warehouse in Brooklyn runs out of stock of the filter, the order may be filled from a warehouse in Harrisburg PA, again regardless of who has supplied the filters in any given bin.

So the buyer needs to use caution in purchasing these small commodity items; you may not know what you get, until you get it!

Honda of America at the Corporate level purchases thousands, perhaps millions of filters every year, and they purchase them direct from their source in Japan. They are then disseminated downward to the individual dealers, Honda parts suppliers, etc. based on the Honda inventory system. There isn't any unknown middle person, the filter is supplied from Honda (Japan) to Honda of America to the local Honda dealership. The odds are much higher in this scenario to get the genuine Honda filter.

This was well documented back in 2014 by many sources, one at The pros and cons of commingling for Amazon merchants. Whether it holds true today, and specifically with respect to Honda filters, remains an unknown. But buying the filter from a dealership or from the online dealer related vendors seems to be a better path.

 

Thanks, John from PA. Appreciate the additional detail on Amazon. I was not aware of how they handle the same item from different sellers. Unacceptable.

I had been purchasing most of my Acura OEM from Acura Parts Warehouse. I get annoyed about how much they charge for shipping and handling, especially if I want to get something small like an o-ring. But it seems I will continue to have to go with one of these smaller parts vendors or raise the counterfeit risk.

 

Your local dealership may price match the online dealership. But you'll have to go in and ask them. Might be cheaper than shipping.

 

Thanks. Worth a try.

 

Has anyone replaced rear camshaft cover seal on a TL? I did the front seal but the rear is much harder to access on a 2004 TL.

 

Definitely worth a try! In my case my Acura dealer is about an 18 mile drive but a Honda dealer is about 5 miles. For the most part things that are engine related are common to the two vehicles and the parts guy tells me he can get virtually any Acura part in a day or two. On most items I go armed with the online price (screen shot).