CruzinGS

So it is finally time for me to do some long-overdue maintenance on my '98 GS300. I've been pretty good about oil changes, but I always planned to have the pros do the bigger stuff and put it off ... but when I looked for someone who could do *just* the things I wanted, I didn't find anyone reasonable (I asked for a quote for spark plugs, valve cover gaskets, and drain / refill coolant and came up with quotes that were >$1k). Anyway, since I'll be tacking the stuff myself, I wanted to make sure I get all of my ducks in a row before turning wrenches. My GS300 has 133k on it, and as far as I know hasn't had the plugs replaced. I've owned it since about 95k miles. It has had the timing belt replaced (but not the water pump). I live in a pretty mild climate so things here tend to wear a little longer. Anyway, here is what I'm planning on doing:

- replace cabin filter
- replaced air cleaner element (already done)
- clean MAF
- clean throttle body
- replace spark plugs
- replace plug wires
- replace ignition coil connector clips
- replace valve cover gaskets
- replace VVTi oil control valve (OCV) filter screen and crush washers

With the removal of the throttle body, should I be replacing any gaskets there? Also, I'm a little unclear about the ignition coil connector clips. I can't tell from the pictures and the write-up if these clips hold the low-voltage wiring (the wires that tell the coil when to fire and supply power), or the high voltage (the 3 plug wires). And if I replace the plug wires, do the clips that hold them in a neat bundle usually break (so should I be replacing those too?) ... If it's the low-voltage side, I think I'll plan to have the clips on hand but perhaps not remove them unless necessary or they break. Seeing the kits on eBay that have connector clips, seals, and terminals makes me think I won't really understand how the whole thing works and what the failure points are until I can disassemble things and get eyes on the whole thing.

Any suggestions or comments would be appreciated.

justim

I just replaced the plugs on my '00 GS300 with 297,000KM on it. The plugs had about 100,000KM on them so it was time to replace. It runs so much better with new plugs.

My throttle body gasket was fine so I left it.
My plug wires were in perfect condition. No noticeable wear, no corrosion.

The low voltage ignition coil wires are a different story. I broke 2 of the 3 that go into the ignition coils so I had to order replacements from the dealer. I think it was $12 each for part number 90980-11246. I removed them from the ignition packs when I changed my plugs but if you remove the screws holding the wires and leave them connected to the packs you can probably do this job without any damage.

I also broke one of the two clamps that hold the high voltage ignition wires together so I ordered a replacement for that as well... The plastic in there was so frail.

I'll be replacing the low voltage connectors this weekend. If theres any specific photos you want I'll take a couple as I go.

CruzinGS

If you could post some pictures of the coil pack where the low voltage clip goes, that would be awesome. Looking at eBay, I see that the coil pack clips are often sold as a set of 3 and sometimes include terminals and seals. I'm not sure if that is more a Supra thing, but it also isn't totally clear to me if the terminals are included in case the wiring harness somehow fails when you pull the connectors off the clips, or if the terminals go between the clips and the coil pack. I haven't worked on anything that had an external clip setup for the low voltage wires, everything I've put hands on just plugged directly into the coil.

And answering my own question, it looks like between the throttle body and the "Y pipe" there is a rubber gasket / isolator, and that isn't listed as a replace-if-removed part. Between the "Y pipe" and the upper intake manifold there is a thin gasket that is listed as a replace-if-removed part, and the "Y pipe" did need to be removed to replace the intake side valve cover gasket in the guide I was looking at. So for just plugs, no gasket needed, but when replacing the valve cover gasket, it does call for a replacement Y-pipe gasket.

On the plugs that you replaced with 100KMs on them, where it make a noticeable difference, were they the OE-spec platinum plugs?

Thanks!

justim

I called the dealer and they weren't able to get my parts in by the weekend, so I won't be able to get you any pictures until sometime next week.

I think both the supra and the GS300 parts are identical when it comes to the 2JZ engine it's self. If you haven't seen it yet you can check this thread out:
https://www.clublexus.com/forums/gs-...onnectors.html

The pictures don't provide a very clear view of the coil packs, but it covers what the low voltage wires look like and how to replace them. In step 11 the red arrow is pointing at a low voltage wire plugged into the top of a coil pack. Right above the red arrow is the gasket that sits between the intake (on the left) and the Y pipe.

I replaced with OEM platinum plugs part number 90919-01196. The car used to hesitate a little, after replacing them I don't notice any hesitation at all.