What brand spark plug comes with the car when new.

I want to change them with the same brand.
I don't want to fiddle with it until I'm going to change them.


Thanks for the help in advance.

 

Take them out and look? Either way you have Iridium plugs, but I believe some motors were shipped with NGK and others with another popular brand.

 

yes sir, you would be correct! the plugs at the dealer with the toyota name on them are denso brand, that's the other brand that was shipped from the factory. NGK is the other brand and if you want those it's part no 4589, and you can get those from most any auto parts store.

 

So the NGK is ok,thanks.

I just don't want to burn out Anything like a module or anything like that.

No need to unhook a battery for computer I guess,just a spark plug change.

I'm trying to get rid of a slight ruff idle... Annoying just a bit.

28,000 miles on a 87 tc

 

You can't burn out a module with a spark plug. If you run different style plugs, you would effect the efficiency of your motor to properly output power. Thats really the only side effect.

 

Just want to keep it close to OEM. ... So everything is happy.

I do know autolites in a chevy don't work well.

Only other idea for a slightly ruff idle ?

 

what mods do you have? vacuum leaks, primary o2, and a possible fuel problem usually are what u find when im idling rough. i noticed the tc runs a bit rough at idle as it is. its never been real smooth at idle...all 3 of my motors have ran that way.

 

It's bone stock.

I seem to remember it smoother at idle,it's not bad but I would like smoother,
Just me I guess.

ALSO,guy at work did his plugs and o2 sensor ( nissan maxima)and says it was a night and day difference. ... So that got me thinking again.

 

well only 28,000 miles shouldnt be enough to foul an o2 sensor. but it might be why. they're quite expensive though....id do the spark plugs first, and if it doesnt make a difference do the primary o2.

 

Yea,that's the plan....

Il put NGK plugs in as the came with it and see if it helps,can't hurt.

There's also a rattle at the hatch ____ing me off,like plastic is loose. Il have to find that. It's annoying.

Is there such a thing as unhooking battery and resetting computer ?

 

you can find the fix here for the raddle
https://www.scionlife.com/forums/tc-tech-diy-1818/hatch-rattle-fix-33086/

and yea to reset the ecu, unplug the negative side of the battery for like 20 min, then plug it back in. start the car and it will begin to re-learn

 

Since theres only 28K on it, take it to the dealer for warranty. And can you define "slightly rough idle", what are the rpms on idle? I suggest not throwing parts at it hoping to fix it.

 

It's about 750 at idle. That sounds correct I would think.

il put a set of plugs in it,air cleaner and see how it is.

When I say slightly rough I mean I can feel it in the steering wheel and azz when it settles down at every stop light,not bad but clearly feel it.

 

Il check that link,thanks.

So the computer does relearn after battery is unplugged ok,like some Oder cars I had.

I may get a new battery as it's 5 years old and zero every morning almost here,just for peace of mind,it is about 5 years old. .. Be ready for next winter.

 

Your idle is fine. Air cleaner won't affect your idle. (but not a bad idea if its dirty) I would look at your engine mounts, but it all might be in your head. I had a Grand Prix that I thought had a bad idle, turns out it was all me.

 

I don't think anything is broken. ... In that way,just in need of scheduled maintainance.

Il do basic things,plugs and air cleaner maybe a oxy sensor if it's about $50 .. But I think it's more.


Air cleaner is due,I changed it at 15k miles.

ALSO, I think there's a 30k mile dealer mantainance ..should look into it.

ALSO, fuse box door started to rattle and won't stop,talk about a dum rattle.

 

Iridium spark plugs are a 100K mile replace item. Just an fyi.

 

Yea,that's what they say. ... guy at worked changed his and it was a night and day difference he says, so il try it also.

 

I would remove them and inspect them, make sure their gapped properly. Then buy if you feel you need to.

 

was reading all the posts and it hit me. Have you checked your MAF sensor? it's just upstream from the air filter, on the air tube that goes to the throttle body/intake. This has been well-known to get dirty and can affect the idle quality. CRC brand sells a MAF sensor spray that works extremely well. On the sensor are two sections, the amber bulb (idle air temp sensor) and the MAF sensor are the two small dental floss looking wires. just clean both.

Another thing is after 28k could be time for a fuel injector cleaner. I usually dump this in BEFORE replacing the spark plugs, since I've found it can leave deposits on the plugs. Ran it once, left the plugs in, and it left some deposits on the plugs. The brand I recommend is BG Product's 44k fuel system cleaner. Take the gas tank down to about 1/4, dump in the 44k fuel cleaner, fill up, let it run out, then fill the tank again, run that, then get an oil change. the residue of the 44k fuel cleaner can mix with the oil on the cylinder walls, just being prudent. yeah I know I'm full of instructions just helping ya out

Now between those two, you should notice the idle improve. Only time I had trouble with the spark plus is when I used the denso brand from the toyota dealer. As it was discussed earlier, there are two coming from the factory, denso and ngk plugs. When I used the denso, rough idle, didn't care for it, searched for the ngk and put them in, back to quiet and smooth.

but maf sensor is your first line before an 02 sensor. I wouldn't replace that unless it was throwing a check engine light (CEL). try the maf sensor cleaning first