MBP 03

I decided to change the plugs today on my '03 TL-S with just a hair under 100K miles. I am the second owner, but based on the extensive maintenance records, I believe that the plugs are original.


All of the plugs with the exception of the middle one by the firewall (#4?) came out super easy, but that one is fighting me pretty hard. I was able to break it loose without too much trouble and it spun pretty well for a bit, but then it got tighter and I stopped not wanting to damage the threads or break the plug. I am using a 6" long 3/8" ratchet and I'm wondering how much force I can apply to this plug? Can I go with a slightly longer handle? The plug spins both ways just fine and it tightens against the head without a problem, but I need to get it out to get the new one in there!


Right now, I have some penetrating oil sprayed in the plug hole and hoping that this will help.


This is that dreaded location by the firewall with the extra heat build up.


Any tips from people that have run into a similar problem?

EE4Life

The middle spark plug by the firewall is bank 1 cylinder #2.

Other than using the penetrating oil, work the plug back and forth (repeatedly loosening and tightening it) until it comes out. It may take a while. You may hear some creaking noise, which doesn't sound good, but you will hopefully be OK and get it out without any damage. Just be patient.

Good luck!

MBP 03

The old plug is out and the new one went in without any issues. A little waiting time, penetrating oil, and working the plug back and forth did the trick.


I stayed with the 6" ratchet just in case.

01tl4tl

torque spec is ~14 pounds iirc, that's not much , just enough to compress the crush ring and make a good seal

a little anti-seize on the threads will make installation and next removal better

100kmiles is what the book says for plug change! that's crazy!
most here find that 70kmiles is a good time to do it

Note: Use NGK Iridium , Iridium IX or Platinum, $8 each and for a reason!
denso is ok too but cost more and dont last as long
Other brands are total bs and will fail soon!

MBP 03

13 pounds is what the shop manual calls for, so you were almost dead on.


I went with the NGK Iridium IX plugs and they definitely won't be in there for as long as the factory plugs were.


The car idles nice and smooth now.

01tl4tl

change them in 60-70kmiles, they will last that long no problem
Seafoam thru gas tank at 2 oz per gal fuel will not hurt the new plugs in any way
Then the plugs have a nice clean office in which to conduct business

for all:
If not already done, carb cleaner or deep creep the Throttle Body Air Plate
on both of its sides and the edges- use throttle mechanism to open plate for access to rear side of plate
Really dirty ones may require scrubbing with an old toothbrush!
Wipe up the runoff and put all the air snout tubing to air filter back in place
Make sure the hose clamp is tight - air leaks are not permitted!
Start engine, it will run bad for a minute as some cleaner that was still in there runs thru the combustion chambers. Then it will run better~!
affects idle and disrupts airflow when dirty- especially the edge of plate

Googie

I had the same problem recently and my plugs would not go in correctly. I torqued them, but the engine had a horrible vibration to it.

I bought a cheapo thread chaser tool from the local parts store that worked an absolute charm . Apply some grease into the groover, and hand thread it into the socket. The grease looked like mud when it came out.

A second chase into the threads and it could turn by had all the way down and up again. Spark plugs had no problems after that.