Changing The Plugs

[Kelraine]

I've just bought myself a set of Denso plugs off eBay and would like to fit them... problem is that I have only managed to find two plugs that don't appear to be buried under random bits of engine.

Has anybody changed the plugs on a 2000 Mark II GS? Where are they (I'd never have imagined I'd own a car where I couldn't actually find all the spark plugs!) and what's the easiest way to get the throttle body out of the way?

Any help much appreciated - I'm beginning to feel a bit disheartened!

Oh yeah - I bought a set of IK20s (which the Denso part selectory thing seems to think are the right sort for that age of GS300) - but have since seen that IK16s are recommended.. Anybody know what the difference is and whether I'm likely to have any problems?

[maneesh]

Not a straightforward job, since you have to take the throttle body off (I'm not sure how to).

IK20s are the right plugs. I think the difference (but not sure if I'm correct) is with regard to the design of the tips? Single versus double perhaps?

[Mr Morse]

The IK16's are the recommended plug for the 2JZ-GE engine.

And yes.......most of the TB needs to come off to get to the plugs!

[Kelraine]

Oh dear. Any idea what's likely to happen if I run with IK20s?

[Kelraine]

This is odd:

Denso plug selector (GS)

It looks as if they recommend IK20s for most vehicles. Is this wrong? Hope not...

[Mr Morse]

The IK20's will work......but the slightly colder IK16's work better, especially if the engine has been fettled.

[MacRS200]

The IK20's will work......but the slightly colder IK16's work better, especially if the engine has been fettled.

Other way around Mike :D The IK16 is a hotter plug than the IK20. AFAIK the IK16 is recommended in the States and the IK20 in the UK for the IS300. Probably due to the fact that in general the US speed limits are lower and traffic is heavier so there would be more chance of fouling with the colder plug.

TBH I would not worry about the difference between the IK16 and the IK20 they are only one grade different, not significant enough to give major problems like electrodes melting or fouling.

[Kelraine]

Cheers for that - appreciated. I'll have a go at installing them this weekend...

[Kelraine]

Well, I got the TB off (not hugely difficult, just frustrating...) - and then totally failed to change the plugs because I couldn't figure out how to remove the igniters.. I think a step-by-step guide with photos (by somebody who knows what they are doing...) would be really helpful!

I reassembled the throttle body - any views on how important it is to replace the gaskets (I didn't..) - and does anybody know how much torque to use? (although it's slightly acedemic as there's no way my torque wrench is fitting in the gap)

It's funny - it seems one of the most obvious things to want to replace - but 'alldatadiy.com' and some dodgey 'Lexus' service manual I got off eBay both fail to tell you how to change the plugs. It can't be that difficult, can it?

[P4UL T]

Is this any good?

http://www.clublexus.com/forums/showthread.php?t=116654

[Kelraine]

Cheers! That's spot on.

Think I'll have another go - looks like I'd done the hard part..

I got cold feet when I managed to break the retaining clip for one of the igniter leads (they get very brittle..) hopefully Lexus will sell replacements for Not Very Much (although I can imagine them insisting on selling an entire new lead)

Right - that's a job for next weekend, then.

That article seemed to have a very negative view of Denso iridium plugs - they seemed convinced that Torquemaster plugs made a big difference.. I've got NGKs in at the moment and am a bit worried that the Densos I've bought are going to turn out to be a load of rubbish.

Surely there can't be that much variation between manufacturers, can there?

[Mr Morse]

am a bit worried that the Densos I've bought are going to turn out to be a load of rubbish.

Surely there can't be that much variation between manufacturers, can there?

Someone please correct me if I'm wrong, but don't Denso manufacture most of Toyota's OE plugs?

[Kelraine]

I believe they do - Denso seem to manufacture most of the electronics in the Lexi too.

Called Lexus Hatfield today to ask about the price of a cable clamp (the small plastic clip holding the ignition cable onto the top of the coil pack). They wanted just under £20 each.

TWENTY POUNDS!

For a tiny piece of plastic.

They're usually very helpful but on this occasion I do believe they should have been wearing masks..

Anybody know where I could get these at a reasonable price (not much more than the 3p it obviously costs to manufacture them for example)? I tried Halfrauds but they reckoned it was a dealer only item.

Oh dear.

[Kryz]

Not a straightforward job, since you have to take the throttle body off (I'm not sure how to).

Just spoke to the Lexus Garage, they do not carry the throttle body gasket in stock. Thus when they change the spark plugs at the dealer they reuse the same gasket!!!

Just so everyone know.

I have ordered a new one for £3 from Lexus. Well worth replacing

[Kelraine]

Interesting.... do you reckon a new gasket would make much difference to performance / fuel economy?

Strangely enough, when I asked about the cost of anti-squeal shims when I replaced my brakes, they told me they would have to order them in... I reused the old ones in the end (they cleaned up nicely) - although the service manual is adamant that they should be replaced with the pads.

I wonder what else they don't do? I notice that the fuel filter is supposed to be replaced at the major service - I'm willing to bet they don't bother.