jds62f

I must have jinxed myself posting a question about it earlier. Can someone confirm I'm on the right track?

CEL has been coming on more often lately. Always:

P1300, P0301, P0303

Used to come on rarely at low rpms with light throttle after the engine warmed up, now will likely come on a couple minutes into the start of a drive. Same codes always.

Results for dry compression test:

#1:200
#2:115
#3:193
#4:200

Wet:

#1:210
#2:125
#3:205
#4:215

Spark plug pictures attached, 1,2,3,4 is the order, I *think* they look ok. Could a problem with #2 be why I'm getting CEL misfires on #1 and #3?

Not leaking coolant, no smoke out the exhaust. I'm thinking I might have a valve issue, do you think I'm on the right track? Is next step leakdown test, valve adjustment? Both? Neither?

grumblemarc

iTrader: (4)

Pull the head.

motegicivic

Number 2 is too low for a valve adjustment. Does it smoke at start up?

For the misfires, how old is the cap, rotor and wires?

jds62f

Cap and rotor are about a year old. No "out of the ordinary" smoke on startup (ie its very light and clears in a minute)

worx

leak down test. i had a similar issue did a leak down test showed a leaky intake valve but in fact my cam journal was eaten up where it wouldnt let the valve close all the way

94EG8

You've got one bad cylinder. Pull the head and see what's up.

jds62f

Pull the head it is... gonna be about 2 weeks before I've got that kinda time so I'm going to do a leakdown test first, next weekend. Will update the thread in a week.

jds62f

well my update is... during the week I realized I didn't do the compression test completely right, I did not have the throttle pressed all the way down when I did the test, so today I repeated the dry compression test with that step in place, and today I got different results:

#1:190
#2:150
#3:188
#4:165

I didn't get a leak tester from amazon b/c they're back ordered, I'm going to do a poor mans leak test by just hooking the hose from the compression test tool (sans valve) to the air compressor and see where I hear a leak

94EG8

It really doesn't even matter all that much if you did the test right or not. cylinder 2 is much lower than the other 3 cylinders. Could be a bent valve, broken/stuck ring, bent rod, blown headgasket, etc.

jbpnoman

Not just 2. 4 is also outside of service limits.

Former User

This^

It's best to know where compression is lost before you pull the head.

94EG8

So it is. Although I'm wondering if it's just the results of that compression test, it was pretty close in the first two tests.

beecee18

Although your crank sensor is shooting the misfire codes not because of missfire, it is because there is a slight discrepency with the rotation of the motor with both those cylinders being out, and the sensor notices this, expecially at idle or low load/thottle applications, so it shoots those codes simply cause the stumbling.
Just like everyone above says, it need to come apart.

jbpnoman

It needs a leakdown test before it comes apart.