What's plugs for celica 2zz-ge engine

juno_first · 27 Dec 2015 at 10:21

Recently had my yearly service and I told the garage it needed some iridium plugs as its approaching 120k miles but they disagreed and put normal plugs in instead.

I've been noticing some 'knock' at low revs too lately, could this be down to possibly being the wrong plugs?
I've always used tesco super unleaded specifically to avoid any 'knock' and get another 1% performance increase lol.

Oh, do I need to use higher octane in the celica or will the timing retard itself to any octane down to 87 RON?

The car is a bit odd too as its badged up a tsport and on v5 but as its a pre facelift gen 7 it don't have a rear spoiler or traction control, so should be a 190 I guess. Never had any 'lift' issues in 3 years so must have the newer engine head?

juno_first · 27 Dec 2015 at 11:53

Problem solved

Just bought 4 Denso's at £48 so the garage had better put them in for free.

DB_SamX · 27 Dec 2015 at 14:35

juno_first said:
... it needed some iridium plugs as its approaching 120k miles

Just picking up on that point; is that in the owner's manual? Think I'll be on 120k on my major service next autumn.

juno_first · 27 Dec 2015 at 14:51

I read somewhere the spark plugs need to be changed at 60k so presume at 120k too.

ShakenNstirred · 27 Dec 2015 at 16:37

Even 60k seems a lot of miles between changing them
my 23 year old polo felt better changing them after just 25k

jono_astra · 27 Dec 2015 at 18:03

juno_first · 27 Dec 2015 at 18:58

If I take the car back to the garage that did the service do I have a case to demand they replace for free the normal plugs with the iridiums I just bought?

Can the car get by with normal plugs if changed every year?

adam cool dude · 27 Dec 2015 at 19:21

I normally use copper plugs and replace every other oil change. Iridium is no better than copper they just last longer. With any high compression engine I would be using the highest octane fuel I could get my hands on.

Kaeo · 27 Dec 2015 at 21:01

Generally change oil twice a year and plugs yearly myself. D:

Dogbreath · 27 Dec 2015 at 21:23

adam cool dude said:
I normally use copper plugs and replace every other oil change. Iridium is no better than copper they just last longer. With any high compression engine I would be using the highest octane fuel I could get my hands on.

They are better in the sense that the very small centre electrode means a lower voltage is needed to start ionisation.

juno_first · 28 Dec 2015 at 10:58

Getting plugs changed now. They put like for like platinum plugs in so the previous owner must have put the wrong plugs in. I already had the plugs and they're exchanging without charge, whether or not the original service would have been more expensive is probably yes but I'm just happy it's got the right plugs in now. Oh, will the mpg or performance be any different?
Dumb garage and a right racist guy here moaning about the car wash next door.

Hxc · 28 Dec 2015 at 11:05

If you notice a difference, it's probably a placebo.

juno_first · 28 Dec 2015 at 11:51

These are the double platinum plugs they put in with just 2000 miles on them. I presume it would have been OK to leave them in but at least now it's got what it should have.

Kaeo · 28 Dec 2015 at 12:07

They look absolutely fine.

juno_first · 1 Jan 2016 at 12:03

Noticed idle speed has increased from 850 to 950rpm as per OBD report & less of a 'jolt' when high profile cams engage.