jcard120

Good Evening Everyone,

I bought a 1990 lexus ls 400 this year and it has only 117k miles on it. So far it has run beautifully but I know It was garaged for quite a while given the age and low mileage.

Because I am about to order a new set of tires I also was wondering how beneficial it would be to replace the spark plugs with NGK iridium IX plugs and NGK Spark plug wire set. When I had it looked at a few months ago they said it had titanium spark plugs which were in mediocre shape and factory wires, but I was wondering whether it would be wise to go ahead and upgrade the plugs and wiring to help improve how it drives and improve engine life.

I have also read wonderful reviews about Tufoil 8 oz engine treatment, and was hoping you guys could confirm the quality of this product before I order it.

Any suggestions from experience would be greatly appreciated. I love lexus and support all lexus owners..I just want to do my part to keep the engine driving smooth and lasting for years.

jcard120

any feedback?

Schnitz

iTrader: (5)

Are they the original plugs? If so, then hell ya change'em.
Never heard of the Tufoil. Did you try a search?

jcard120

According to the service records the spark plugs were replaced at 60k miles..and I am approaching 120k miles.

I also am wondering if I should drain and refill the transmission fluid as it was changed at 90k miles..but thats been almost 5 years ago..Does TF degrade over time when it's not used??

Also, I would assume I would need to change the diff oil also at the same time right?

7schulz

I like to baseline a car or turck when I get one, (mine had dealer records from 94 to 2010 so I know where mine sits) I would do the spark plugs and wires maybe cap and rotor while you are in there. Drain the 2 qts of ATF and replace with Mobil 1 Syn ATF and start the drain refill process every oil change for a while. Changing the diff is def a good idea if it hasn't been done or might as well do it anyway. Then you know where you sit and don't have any questions.
http://www.lexls.com/tutorials/

3UZFTE

Plugs, you can goto the dealer and pay a little more, or goto a parts store and get them for a little cheaper, I don't think you need to go platinum. I would just replace the plugs, the wires rarely mess unless you have a noticeable misfire. Stay away from the engine treatment, you only have 115k on it, thats like still breaking it in. Just my thoughts as a Toyota tech. If you want to prolong the life, change oil and filter at 3k, and make sure there are no leaks or anything and everything should be good to go.

PureDrifter

iTrader: (10)

factory plugs are platinum, keep it that way unless you dont mind changing plugs every 10-12k miles instead of every 100k-120k miles...

7schulz

Spark Plugs - OEM
http://sd.autohausaz.com/autohausaz/...0@Spark%20Plug

Also I like the lucas oil product that you put in your gas tank to clean your injection system. I put in the 2-3 oz or whatever it says the next full take of gas after an oil change. I get the quart size and use it in all my vehicles.
http://www.lucasoil.com/products/dis...el%20Treatment

Banshee365

I vote for OEM plugs and OEM wires only. Especially on the wires. The OEM plugs for my '96 are some Denso iridium. Call up Carson Toyota out in california. You may want to also think about replacing your caps and rotors at the same time you do the plugs. Also clean the throttle body, you should notice a difference.

j stuff

iTrader: (5)

i got the oem densos and ngk plugs from sparkplugs.com i believe.

jcard120

Can you explain why you suggest I drain 2 quarts of Type-IV and replace em with Mobil 1 ATF..I think its in the Lexus Bible to use IV only lol.

Aside from that, it would be nice to know the best way to blow a few hundred to improve the car. New Speakers? Sparks and Air Filters/Hoses?

After that it's tint, 18 inch lexus wheels, and head unit..hows that sound

PureDrifter

iTrader: (10)

the Mobil 1 ATF is one of the few that is spec'd to meet T-IV requirements, and since T-IV isn't a synthetic, many feel that it would last longer. personally, T-IV can be had cheap enough that i prefer to just use it unless ur really pushing the car and wanna actually splurge on some redline or Amsoil/RP trans fluid for heavy duty track use.

sam12345

iTrader: (1)

7shultz, I use the lucas fuel additive also. I had read people adding about 1 to 2 ounces of 2 stroke oil to their tanks to lubricate above the oil rings but did not want to risk fouling my engine. I have been using the lucas on all my cars and swear that for a while the cars ran better and better with each tank full. Now they have plateaud. I think over time it cleans out all the carbon. I put it in nearly every time I gas up. I figure it will help the valves last longer as well as the rings since it is essential like the 2 stroke oil.

7schulz

That Lucas Oil stuf does make a difference. Make sure when you get the Mobil 1 SYN ATF that it says T-IV on the back.

Bill Dowd

Denso iridium plugs are the best I just put them in my 1990 lesus at 220,000 and I got 1-2 miles better mileage I don't know why, but they will last 120k at to platinum plugs I ran mine 102,000 miles and they still looked good at that mileage my last car a toyota went over 529,000 miles I ran mobil 1 products in everything and no failures on anything