Lavrishevo

iTrader: (1)

On small stuff you can get away with guessing the torque but with any kind of suspension work and many of the engine bolts it's very smart to get it right the first time. something many mechanics are lazy to do including those at Lexus. Like the lower ball joints. Super easy to replace yourself but you would be screwed without a wrench that will do at least 120 lbs.

http://www.lexussouthatlantaparts.co...227150042.html

airchomper

What digital torque wrench do you use? And do recall whether the torque wrench hit the proper torque within 1/2 a turn or so of the plug seating?

I don't have a particularly accurate torque wrench, so I just use NGKs and turn 'em a bit after the seat.

Would you recommend your digital torque wrench?

Also, it seems our cars are really easy on spark plugs. The only reason I changed my early (75k or so?) was because they were getting old (13 years) and I didn't want to fight them to get them out. If I ran on the freeway all day, I'd run my plugs to 120k miles or so. The only issue being removal.

Lavrishevo

iTrader: (1)

I got just a regular one at Sears. I did not want to wait and order one. It's a good wrench and easy to use.

http://www.sears.com/craftsman-micro...2&blockType=G2

But Amazon is usually my go to.

http://www.amazon.com/s/ref=nb_sb_ss...we%2Caps%2C213

It's smart to do the plugs when you are doing the timing belt / water pump. You are right there doing all the work and after 90k miles the carbon is evident. The gap and dirty plugs don't burn as much fuel which contribute to more carbon in the engine and exhaust.

KawiLex

I've used foaming tire cleaner in the spray can on the engine bay with excellent results.. just spray and watch it work.

Bocatrip

I have not read through this entire thread. My 01 has 118,000 miles and runs, accelerates, and idles like a top. Can anyone attest to changing the plugs will actually improve my gas mileage significantly?
I do 90% city driving with 13+ and highway probably in the the low to mid 20s but never really checked as I don't care all that much. I was just curious. Thanks all.

Lavrishevo

iTrader: (1)

No, not significantly. Especially since the car was not misfiring before. But you should clean the intake system for ideal efficiency. This includes a clean Denso air filter, clean the maf sensor, clean the throttle body, and replace the plugs. Use a good product to help clean the injectors and burn carbon out. I like the Dura Lube Severe Fuel System Cleaner. Anyway, I can easily get 27 - 29 mpg if I choose to slow down. Like 55 - 65 mph. At 80 - 90 mph I still get 21 or 22. It's worth doing. Car runs better. Makes it too easy to hit 100+ mph. Just passing people if you need too. I don't know about yours but my car seems like it likes to be driven at 90 mph.

XJSFan

I have a 2006 LS 430 with 83K miles and am still on the original plugs. At 70 mph, I get around 28 mpg per the dash read out(I have seen 30 mpg at a steady 65) . I do have my tires set at 35PSI and use 93 octane fuel.... I also do mostly highway runs with this car.

ancdmd

Lexus dealer inspected my car recently and told me I needed new plugs. The plugs have approximately 60-70k miles on them. I have developed a noticeable engine pinging in the last month or two, and the upstream O2 sensors, engine coolant temp sensor, MAF, TPS, knock sensors, and cats are all new. I always use top tier gas. Maybe the plugs are indeed fouled, but seems a little premature, no? Could they be causing a noticeable pinging? I'm picking up the car today from an independent shop that recommended replacing the ECU. UGH.

911LE

How many miles are on it? Mine has 110k and when I disassembled the intake and heads I found a lot of buildup on the pistons. These deposits retain heat and can cause pinging. You might try a couple of cans of Seafoam through the intake and in the fuel tank before you start replacing things.

ancdmd

The car has 177k miles on it. I think I'll try the water injection method of cleaning the combustion chambers just to make sure.

BradTank

Sounds really fishy to me, especially the part about needing a new ECU.

It could be a lot of things, but properly installed, factory plugs shouldn't be causing pinging at that mileage. And if it's truly pinging, modern on board diagnostics should be easily able to pick that up. You should be getting a check engine on at the very least, that's what the knock sensors are for. A good auto scanner (not a code reader) can go deeper and get readings to tell a tech why something isn't working properly.

Considering all the parts you've already replaced, I would personally take into a Lexus dealership and let them put it on their $10,000 scanners and give you a diagnosis. A real shop with the right tools should be able to tell you exactly what's going on.

BradTank

I'd really recommend against that.

If you want to put some SeaFoam in the gas tank, that would be a much safer.

If you pour water down too quickly, you can hydrolock the engine, just not worth the risk.

911LE

The design of the intake manifold makes that almost impossible. You would need over a gallon of liquid in the lower intake before there was any threat of it being sucked into a cylinder. Even then getting enough volume to hydrolock would be difficult.

ancdmd

I understand the hydrolock risk with a large volume of water. I'd only introduce a spray with a spray bottle, either directly into the air intake or through a vacuum hose. Might even install a nipple on the black plastic intake hose. I'm just not convinced the Seafoam does anything.

BradTank

I think there's better/safer ways to address carbon buildup, but if you feel you know what you're doing, carry on.