Codes p0304 and po316

[95 marty]

I have a whippled 18 with a stage 2 kit. Having a misfire o. Cylinder 4. Checked plugs and it was black. Oily kind of. Car only has 7000 miles on it. What do you think the problem is? I tried replacing the plugs and also switched coil packs no luck.

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[SolarFlare]

compression test is a good start.

 

[sigintel]

You had changed your oil not too long before thus happened?

 

[95 marty]

I changed my oil about 2000 miles ago. Has to be one of the three. Bad injector, blow bye, or valves not closing.

 

[Ruiner46]

Did you gap the plugs?

 

[sigintel]

I changed my oil about 2000 miles ago. Has to be one of the three. Bad injector, blow bye, or valves not closing.

Leaking valve guide
Oil pooled in intake from high rpm/ aeration after slightly high oil level. On accel, cylinders 8 and 4 get slugged.
Oil blow by damaged ring land on intake stroke
Oil weeping head gasket

Id say grab a beer and pull in the garage to check compression.

Will cross fingers for ya

 

[95 marty]

Bringing it to a shop tomorrow. We will see. Plugs looked the same as I took out with the gap. Using iridium so I dont think you can gap those with out taking off the iridium

 

[Ruiner46]

Bringing it to a shop tomorrow. We will see. Plugs looked the same as I took out with the gap. Using iridium so I dont think you can gap those with out taking off the iridium

Whipple install manual says to gap them to .028". You can gap the iridium plugs, and if you don't close the gap, you will get misfires. Default plug gap on the NGK plugs is almost twice as big as Whipple recommends.

 

[95 marty]

Ok I will try and gap them. Thank you

 

[kcc0521]

Leaking valve guide
Oil pooled in intake from high rpm/ aeration after slightly high oil level. On accel, cylinders 8 and 4 get slugged.
Oil blow by damaged ring land on intake stroke
Oil weeping head gasket

Id say grab a beer and pull in the garage to check compression.

Will cross fingers for ya

I agree. In most cases the misfire codes are the kiss of death in forced induction cars.

 

[95 marty]

Yes your right the kiss of death. No compression on cylinder 4. It just sucks.

 

[sigintel]

Yes your right the kiss of death. No compression on cylinder 4. It just sucks.

Sucks = pulls vacuum?
So trashed exhaust valve/seat/guide?

 

[95 marty]

No I meant it sucks that I have to replace the shortblock after only 7087 miles. There goes 10,000.

 

[sigintel]

No I meant it sucks that I have to replace the shortblock after only 7087 miles. There goes 10,000.

Uhh. Ill swap it for $3k labor plus long block cost.
Damn, your in CA.
Call Chris White Bear Lake n get a long block quote?
Was that Whipple tune? Which revision?
91 octane?
Maybe someone on forum has CA mechanic hookup?
Some dealer techs into modding and active in community will do side work so ask around?
Totally hoping the best for you. Been there and spent $xxxx on 2015 long block and two weekends in garage after breaking a crank above 8k. Lol. So much shrapnel.

 

[engineermike]

What cal, fuel, pulley, and exhaust are you running?

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