jhalski

Hey Guys,

My GF has a 2008 Scion xD with 196k miles on it. Recently it threw a Cylinder 1 misfire code and has a rough idle only when in drive or the A/C or engine Fan turns on,
then the rpms drop from about 800 to about 500 and the car shakes pretty bad. Below are the troubleshooting steps I've taken so far.

Before we start this, looking at the engine from the front, Cylinder 1 is on the far left correct?

1) Changed all spark plugs (they all seemed okay, Cylinder 1 was a little rougher than the others, to be expected)

2) Check coil packs - engine running, I removed them one by one, they are all working, I swapped Coil pack #1 and #2 just to be sure, I did NOT get a cylinder 2 misfire, still Cylinder 1. Coil Packs seem okay.

3) Replaced Fuel injector on Cylinder 1 - I thought it began to run better (I forgot to turn the A/C on, maybe that's why) then i noticed it started leaking fuel out of it, the O ring broke, so i replaced it, and we're back to square one. Same Cylinder 1 misfire.

I read somewhere someplace that unhooking the battery, then letting it idle for 10min worked for someone...gave that a try, no change.

I'm not sure what else to try here. Working on it tonight with my headlamp i did notice a bit of what i think is an exhaust leak around cylinders 1 and 2.
Could that be causing an issue? I did see an O2 sensor code thrown once, but i cleared it all and it hasn't come up again.

The engine idles/shakes much rougher whenever the engine fan kicks on or I turn the A/C on, soon as i take it off it idles much better.

Anyone have any thoughts or ideas to help me out? It would be much appreciated, thanks!

EDIT: After doing some more research, that leak in the exhaust, that seems like it could cause some compression issues and maybe cause the cylinder to misfire....does that sound correct?

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DAlex

No. Cylinder #1 is ALWAYS on the Driver's side. Numbering of cylinders is always done from Driver's Side to the Passenger Side, and also from Front to Back. The Cylinder on the left, viewed from the Front, is Cylinder #4.

Since you had the Cylinder numbering backwards, what you did was swap #3 and #4. You also replaced the injector from the wrong cylinder (#4, not #1).

You need to take it to a mechanic, before you damage it more.

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jhalski

Damage it more? How am i damaging it more exactly? Swapping working coil packs and working fuel injectors damages what......?

And are you sure? After some searching i cant find EXACTLY a 2008 Scion xD but other scions show the cylinder order from left to right as 1-2-3-4 when looking at it from the front. There's definitely some goofy juice goin around. Regardless.....

I actually swapped the far right 2 coil packs as well. I basically made sure i had a working cylinder, tested each coil pack, made sure it was working, then put them back. All of the coil packs worked correctly and i only got a slightly "off" response on that cylinder where i changed the fuel injector (far left, #4 from what you're saying), but i'm not getting a "cylinder 4 misfire" code...

Its actually at a shop today and they're not sure either. They're thinking it might need a valve job or something, i'll know more tomorrow.

If the repair is crazy expensive then i'm just going to change that #1 cylinder (far right) fuel injector and see if anything gets better.

Thanks tho?

DAlex

If the shop is thinking that it needs a valve job, I would assume that they have performed a compression test (which would've been what I would've done after checking plugs and coil packs, BEFORE spending money on fuel system parts). I'm assuming they've found a lack of compression, probably a failed valve tappet (hoping it's not something worse). Did you hear an audible clatter when it ran? 200k on a 1.8l motor is rather high mileage.

jhalski

EDIT: Actually they found that the compression was not Ok, it was at 30lbs, which is low. They said no blue smoke, no bad noises (i never heard a clatter when it was running). So who knows. Blown head gasket? Needs valve work?.....blah

jhalski

It may not fix it, but it looks like im going to replace the head gasket. If a head gasket were blown, would coolant not be leaking into the cylinder causing white smoke to come out the exhaust? Never saw any of that, nor an sounds that would be a valve......not sure.

I think im willing to try a $50 gasket and hope that it fixes it. Other than that her parents are thinking of just selling it and maybe getting a grand if they're lucky.

DAlex

No, a blown head gasket is not the problem. If you do not have a bad tappet, then the only things left are costly; broken valve, broken valve seat, broken ring, etc. About the only thing that replacing your head gasket is going to do is give you a chance to look at all these items up close. My guess is that you will need to take the head to a shop for work when you get it off (at which time, you'll need to replace the head gasket, anyway).

Good luck.

jhalski

Reading through the online Chilton repair manual it looks like the engine has to come out to get the head off? If thats the case i'm not going to be able to do this myself. oh well.

sajo69

Hi Jhalski! I am having the same issue with my 2008 Scion xB.

Have you found out what the issue is?

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nightmare509

Hi Guys,

I got a Scion IA 2016, around same problem with misfire and cylinder 3 code when cold started, tried today the premium gasoline it working in the cold start at morning 6am, now tried again same problem, did change brand new ignition coils and spark plugs, still same problem.. idk guys.. any help?

Dzldust

I’m having a cylinder one misfire as well,swapped coils to #2 and the misfire moved so I guess I need a coil,only prob I have now is no power to OBD2 port,fuses are good so dang not sure what to do now