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I just changed out my spark plugs, and a few of them look pretty burned and dirty. If the plugs were numbered as "1, 2, 3" on the back side of the engine, closest to the firewall, and "4, 5, 6" on the front side, the worst looking would be 2 and 5. 4 and 6 actually seemed completely fine.
Sorry, couldn't figure out how to edit my original post to add pics. So I'm adding them into a reply.
Originally Posted by tad2much
Hi all,
Thanks for reading my post.
I just changed out my spark plugs, and a few of them look pretty burned and dirty. If the plugs were numbered as "1, 2, 3" on the back side of the engine, closest to the firewall, and "4, 5, 6" on the front side, the worst looking would be 2 and 5. 4 and 6 actually seemed completely fine.
Simple Diagram to number spark plugs
(firewall)
1 2 3 (driver side)
4 5 6
(front of car)
number "2" spark plug
I was only able to get a look down the plug wells on the front side of the engine. This is plug well number "5". number "5" spark plug well, dirty. number 4 plug well looks nice and clean! =) number 6 is the same.
The ignition pack/coil things that connect to the spark plugs seem fine, no oil on them.
Is this most likely a bad seal/gasket or something? If anyone has thoughts, or better yet links to how to DIY repair, I'd really appreciate it! TIA
Couple of questions: Which car do you have? Are the pictured plugs, the PZFR5F-11 Ngks)? Are these the recommended plug , for your model? Any idea, how many miles, on these plugs? How many miles on the car. Plug well # 5 appears to have a seal issue, easily fixable, replace them all. Correct torque, when installing the plugs, is critical. It insures that the spark plug "washer", is crushed properly, creating a tight seal. Any debris, at the plug seating area, on the head, can also create problems, resulting in leaks. As a side note, are you using a "TOP TIER" fuel?
I have an 01 TL. The plugs are the one's you mentioned, and i think they're the recommended ones. I bought the car used, so can't say how many miles were on em.
I torqued the plugs down to 13lbs, per search here.
Hey tad2much, Thanks for your reply. Still curious, how many miles on the car, and if you are using a (TOP TIER) fuel. If not, you may want to consider it. It's difficult to tell from the pics., but those plugs appear to have had significant use. Checking the gap, should confirm this. As long as there is no "pooling" of oil, in the spark plug wells, and the rocker arm cover gasket is not leaking, you should be good. In the event you want to replace the rocker arm cover, and spark plug well gaskets, and seals, there is a (HOW TO), which is described, in the initial steps, involved in the valve adjustment procedure. You may also want to check the valve adjustment, while your in there.
Without knowing any more I'd say your plugs are extremely old, possibly originals (based on how worn they look). They are probably dirty because they aren't allowing full combustion of the fuel/air mixture in the cylinders.
Switch out to NGK Irridium IX plugs and your TL will have more spring in her step for sure. Also consider your O2 sensor (pre-cat/upstream) if it has never been replaced.
So it sounds like maybe the new plugs with new washer, torqued properly, should solve my issue. But it's possible that my spark plug T seals are bad. Dunno what those are, but a search here indicates I'd need to remove my valve cover to get to them, is that right?
I just did an oil change and noticed that the oil level was pretty low. It had only been about 5,000 miles since my last oil change, and I use fully synthetic oil. Would bad spark plug tube seals lead to oil loss? Any other symptoms to look for?
From your pics above your #5 T (tube) is saturated with oil due to the T seal leaking as oppose to #4 T... Being clean. Also from your pics of the 6 spark plugs, some of them shows oil saturated on the plug's threads/body. Which indicates oil leaking from the T seals.
Likewise, the plugs them selves are firing normal or more accurately the burn patterns are all normal. Which means there is no excess oil leaking into the combustion chamber. Just normal amounts of oil being burn in the combustion chamber. That would explain for some of your oil consumption.
Yes, you have to take the valve covers off to change the T seals. If you're going to change the T seals then you should change all the seals and gaskets on the valve covers to prevent leaks from recycled gaskets/seals.
Makes sense. I want to try to replace the tube seals and the valve cover gasket. I searched and read a bunch of threads here, but haven't found a good write-up. I gather that while I'm at it, I should also clean the EGR (and maybe also the intake manifold and throttle body?).
If anyone can point me to good write-ups for those, that would be great. I found a lot of people asking for write ups but didn't actually find any myself.
05-30-2018, 02:35 PM
