My check engine is light is on and I'm misfireing.

[Blitz]

I've replaced my spark plugs and my car ran fine for a week. I have a lexus es 300 96'. After the first week my spark plugs blew out again. When I had them replaced my engline light was still on. What could be causing my spark plugs to blow out like that?

[green91]

bad coil pack most likely.

[BTLFED]

You need to take it somewhere and get the code read, but I tend to agree with Green91, especially because he is a Toyota Technician lol

[Z U L8R]

your spark plug tube seals leaking oil around the spark plugs, they should come with a valve cover gasket set

[green91]

they do not come with vc set. is your cel flashing? does it always misfire? how many spark plugs were "blown out" ?

[Spektrewing386]

go to napa and get the code read

[Z U L8R]

mountains out of mole hills. whether they do or don't come with the valve cover gasket set is pointless, you need a valve cover gasket and spark plug tube seals they look like little o rings, they keep oil from getting in the tube and filling up with oil around the spark plug which creates misfires.

[BTLFED]

mountains out of mole hills. whether they do or don't come with the valve cover gasket set is pointless, you need a valve cover gasket and spark plug tube seals they look like little o rings, they keep oil from getting in the tube and filling up with oil around the spark plug which creates misfires.

How do you know he even has oil in his spark plug tubes?

[green91]

because it happens all the time on the 3.0.. oh wait it doesnt. lol. plus the 3.0 is a good 6 hour valve cover gasket set job for someone unexperienced.

[BTLFED]

because it happens all the time on the 3.0.. oh wait it doesnt. lol. plus the 3.0 is a good 6 hour valve cover gasket set job for someone unexperienced.

:lmfao:

Toyota Technician - 1
Z U L8R - 0

[SKUNK2GUY]

i sense a timing problem but what do i know i love apc. lol g/l yo!

[green91]

timing is completely computer controlled on es300. there are no adjustments

next!

[speedminded]

I've replaced my spark plugs and my car ran fine for a week. I have a lexus es 300 96'. After the first week my spark plugs blew out again. When I had them replaced my engline light was still on. What could be causing my spark plugs to blow out like that?The problem is you have a 96 foot lexus, when you get one that's around 15.649' (4,770mm) then she'll prolly run fine ;) :D

[Z U L8R]

those motors are notorious sludge motors and the valve covers leaking is a lot more common than you think. the first guess was coil pack after the guy says he replaced the plugs and it wasn't misfiring for a week........if it had a bad coil pack putting plugs in it wouldn't solve it for a week. putting plugs in would not have changed anything at all.

so the 3 plugs in the back are a bitch cause the intake sits right above the rear valve cover....it'd take a NOOB C tech 6 hours. some of those v6's had 3 coil packs and 3 wires, 1 wire coming off 1 coil pack times 3.

anyways, when a person/customer says it's misfiring but he replaced the plugs and it solved it for a little while then came back, it makes no sense to condemn the coil pack FIRST or at all for that matter. it makes more sense - if you understand theory and operation - that the customers car was misfiring. the misfire was because the spark plugs were fouled out, which means most likely the plug was not getting it's ignition current. well if he put plugs in and it was STILL misfiring with no improvement at all then hell yeah i agree on the coil. but since the new plugs helped it, no. it took a week for the new plug(s) to foul out. so it's obvious there's something gradually happening with his engine that it takes seven whole days for the plug(s) to foul out....could it be oil leaking down in the spark plug tube seal? maybe. could it be a blown headgasket leaking coolant into the cylinder? maybe. could it be a burnt valve or low compression on a certain cylinder for whatever reason imaginable? maybe. but ur saying if this customer's car was in your shop and you were the tech doing the diag....your train of thought would start with an intermittent short in a coil pack....btlfed i'm assuming they're leaking, i have no idea if they are or aren't, typically when i respond on general tech i give the most likely, most common thing i see at MY shop, based on the symptom/information provided i understand you're his friend and all. green91 i'm not gonna swing all over your diag because your cosigner says you're a toyota technician. logically it makes more sense to be tube seals than it does to be a coil with an intermittent short. that's my opinion

maturity 1
cosigning 0

[koukis14]

Ok did the guy replace the plugs, fix it, and is bitching cause the light is still on??

[green91]

first hand in dealer experience working on ALOT of 3.0 fwd motors, the coil packs do have aLOT of intermittent failures. Seen it first hand. id say ive had to replace 10 coil packs for each 1 that had the spark plug tubes leaking.

[Z U L8R]

green91 at my shop we've had more tube seals be the issue than the coil packs/boots, so it's all relative.

i will say that in our situations on these 1mz motors where it had no oil from a leaking tube seal that the customer's problem was a bad spark plug boot that was cracking the porcelin on the plug so in that case, since you can't just get the boot on coils, replacing the coil was the remedy, you can however just get the wire if the boot on the wire is cracking the plug on the back though. i just didn't see why I was getting hi beams when we're collectively trying to help Blitz. anyways no harm done :D

blitz, we could use a little more information. you should have 3 coil packs in the front with 3 plug wires going to the back 3 cylinders. have you isolated which cyilnder(s) have the misfire. what is the code stored in the ECU? did whoever changed the plugs mention anything about oil around the spark plugs when they changed them? did they use ngk or denso OE plugs? thanks =]

felpro vs50471r , LIST price $70.45 set includes 2 valve cover gaskets and 6 tube seals. :ninja:

[green91]

well thats why i also asked how many plugs were "blowing out" because i do believe the 96 1mz is wasted spark and 2 plugs would share a coil.