RRGS

Hi everyone,

This summer my 1998 GS300 needs to get a timing belt service. I'm looking for an OEM kit with all the required parts for my timing belt change. I found this 22 piece OEM kit on eBay: NEW LEXUS GS300 1998 TO 2000 FULL FACTORY TOYOTA 22 Pcs TIMING BELT KIT W PUMP.

However, I can get the parts cheaper if I order them separately. I'm looking at the AISIN TKT031 timing belt kit from RockAuto. To be sure, this kit is OEM right? I'm asking this because I've read that Mitsuboshi and Aisin are OEM, but what about Koyo? Currently my car also has a Mitsuboshi timing belt which was placed by the Lexus dealership. Also, does the water pump from Aisin have all the required gaskets and rings? The eBay kit says the Aisin water pump is a 5 piece kit but I'm not sure if the one from RockAuto is the same.

Next to the timing belt kit, I want to order the following parts separately (all OEM):

V-Belt: 99366-D1930
Front Cam Seals (2x): 90311-40020
Front Crank Seal: 90311-46001
Thermostat: 90916-03093
Thermostat Gasket: 16325-62010
Valve Cover Gaskets: 11213-46030 & 11214-46011
PCV Valve & Grommet (2x): 12204-46030
Oil Filter: 90915-20003
Drive Belt: 99366-D1930
Upper & Lower Radiator Hoses: 16571-46200 & 16572-46210

I also want to change my spark plugs together with the wires, but I'm not sure which one to pick. First of all, I can choose between NGK Iridium and NGK Ruthenium spark plugs. I believe I have the Iridium plugs right now, but has anyone tried the Ruthenium plugs? RockAuto says the Ruthenium plugs provide maximum durability & ignitability. Secondly, I'm not sure which wires to pick. I can pick this Denso Wire Set from RockAuto (which is about $35), or buy the OEM Toyota wires separately which will cost me about $70 (parts 90919-15317, 90919-15456 & 90919-15457). Denso is also OEM right, so I guess there is no difference?

Finally I will do the regular service things like changing the oils, replacing air filter etc.

Can you guys please help me out with this? To sum it all up, I've got the following questions:

1. Is the timing belt kit from RockAuto good (OEM?) and does the Aisin water pump come with all the required gaskets and rings?
2. Are the parts mentioned above all the required parts for the timing belt service or am I missing some parts?
3. Which spark plugs do you guys think are the best to pick? The NGK Iridium or NGK Ruthenium? Also, should I go for the Denso Wire Set from RockAuto or for the OEM Toyota wires (which will cost me twice as much as the RockAuto Denso Wire Set)?

Thank you!

Kind regards,
RRGS

firelizard

iTrader: (1)

https://www.clublexus.com/forums/gs-...-belt-job.html

RRGS

Ah thanks, I didn't see that topic.

However, I'm still wondering which spark plugs to pick. Has anyone tried NGK Ruthenium spark plugs on a GS300 already? I've read that someone has tried them in his LS400 (this topic) and was really satisfied with them. I'm not sure how they will perform on a GS300 since the engines are different (maybe someone has tried them in a GS400?). Do you guys think it's safe to go with the Ruthenium plugs?

TrueGS300

NGK BKR5EKPB11 is the OEM plug. Double Platinum. You should use what the engineers decided on. As far as satisfaction from an iridium or this new roofie plug.. satisfied in what way? That it doesn't misfire? A copper plug will satisfy in the same way. I've read all the sales pitches on iridium etc. It doesn't make sense to me. A good condition engine running it's OEM plug is not suffering from incomplete burn. An iridium plug isn't going to make things better. The hype is that they last a long time. I'd still rather replace plugs every 30-40k miles. 100k is a long time for even an iridium plug. I replace them in customer cars from misfires well before 100k quite commonly.

RRGS

I agree with you that you should use what the engineers decided to, but I thought the new NGK Ruthenium might be a better option since it's using new technologies etc. The topic that I was referring to is from someone who has tried them in his LS400 and he mentions points like faster cold-up starts, lower cold start idle, noticable throttle response improvement and some other small things. It all sounds nice but I agree with you and I'm going for the OEM spark plugs. Maybe I'll upgrade to the Ruthenium plugs in the future when more people tested them out.

One thing, you mentioned NGK BKR5EKPB11 as the OEM plug but the Lexus Parts list says that 90919-01196 (Denso) is the OEM plug. I don't know about the difference, I took a look at several topics and people say that both NGK and Denso plugs are OEM...

Anyway, I'm going for 6x 90919-01196 (spark plugs) and new spark plug resistive cords (90919-15317 (NO.1), 90919-15456 (NO.2) and 90919-15457 (NO.3)).

KTGS300

If I remember correctly, Lexus switches their recommendation to the Iridium in the later model. In theory, both the Platinum and Iridium plugs will work fine. I have '02 and it came with Denso Iridium spark plugs from factory. I replaced them with NGK (3764) BKR6EIX-11.

firelizard

iTrader: (1)

That LS400 thread is all butt dyno, and not a valid comparison. Replace used plugs with any new plug meant for the engine and you'll see a restoration of performance.
The claims that it somehow makes the transmission shift better...
Save your money. Or don't. Unless you test a full set of each plug against the other, on a (real) dyno, you won't know which one (if either) improves performance. Anecdotes from people who switched to a new kind of plug when replacing old plugs are useless.

TrueGS300

Makes sense, mines a 98 so double plat is what comes up for it. If the op's calls for iridium, I'd put them in. I've been there and done that will plugs on so many cars. I've leaned just to put whats called for from the factory in. Works best every time. Unless there's the occasional TSB for an updated plug or gap of course.

YODAONE

What you meant to say is: "But I dunno because I haven't actually installed a set of Ruthenium sparkplugs".

So Butt Dyno...Here's toilet paper for you...

Several OEMs are already using Ruthenium.

And...a link to the LS400 post referenced:

https://www.clublexus.com/forums/ls-...ark-plugs.html

....

813GS3

I am going to be doing a tune up on mine within the next few weeks or so and also curious about these plugs. Did you go with them? Or did you stick to Iridium?

TrueGS300

After many plug related discussions and looking into it, with all the changes over the years, NGK 4589 IFR6T11 is the plug I consider best for the 2JZ-GE VVTi engine now.

Here is the last discussion about it. Anyone can feel free to agree or disagree and give reasons. This is just what I think is best at this point.
https://www.clublexus.com/forums/gs-...-99-gs300.html