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I have an ej251 that previously threw a P0301 and P0420.
There were no real noticeable issues at the time.
Codes were cleared and didn't return for about 6 months. Upon returning engine has obvious misfire and will not idle.
Cleared codes again and they have not returned...but issues remain.
Plugs, wires and coil pack were replaced after the #1 plug wire electrode broke off from the boot.
The original coil tested fine on the primary, but secondary readings were out of spec, so replaced.
Engine runs rough with a mis at low rpm(-1k) and will not idle. The mis is not as noticeable at higher rpm(+1k) but can still be seen using a timing light.
Exhaust smokes a bit and smells very rich upon cold starts, then disapates after warm-up.
Working on getting the numbers...my isp sucks and I've been waiting 12+ hours for SSM4 to download.
Will post detailed stats after running diagnostic software.
Any advice or direction is much appreciated.
After doing a static compression test on all 4 cylinders....I have 0 compression on Bank 1 and ~180-185 on Bank 2.
Prior to the CT engine would start right up and idle only when cold. Still shaky and rough running, but upon unplugging the injector on the number one cylinder it smoothed out just a bit.
The plugs on bank 1 (cyl.1/3) were normal aside from maybe being a bit wet (no carbon) and on Bank 2 (cyl.2/4) they were both dry fouled and covered in carbon build up. (All new plugs gapped at .28 -.30)
My wife had brought the vehicle home exhibiting the p0301, p0420... along with an obvious noisy tensioner bearing, misfire and idle fluctuation.
I cleared the codes and replaced all of the timing components. The issues still remained afterwards, except for the noisy tensioner pulley.
Upon doing the timing replacement, I noticed that the cam pulley on Bank 1 had no resistance when turned. It would pretty much spin freely. Quite the contrast to the bank 2 cam pulley.
All timing marks were lined up properly using the single hash marks and not the arrow stamps. Engine was turned over twice prior to starting again. Had no abnormal resistance and the cam and crank marks lined up properly.
I finally have SSM 3/4 and VX manager downloaded, but have not had the time to install and properly configure.
I would think that if the issue was a blown head gasket on Bank 1, I should still have some sort of reading from the compression test.?.?
It almost seems like the valves on Bank 1 are all stuck wide open....
I would really appreciate some direction as to how to proceed from this point. TIA
When you did the timing belt, did you note if the marks were lined up before you pulled the original belt off? :huh: It's possible that the original belt jumped and allowed valves to bend on bank one. That'd account for the misfiring, low compression and lack of resistance on the camshaft pulley.
If you have a borescope, or can get your hands on one, you could remove the bank one spark plugs and look at the tops of the pistons for contact marks. Or, you could remove the bank one valve cover and inspect the valve lash. I don't know the spec off the top of my head, but valve lash is typically measured in thousandths of a inch. Much more than that might suggest a bent valve.
So I checked both cylinders with a borescope and there are no signs in the slightest of any valve on piston damage.
I haven't had a chance to pull the valve cover and check the lash measurements yet.
I'm pretty sure that I had marked the old timing belt prior to service.
I normally always do....but cant specifically recall as this was several months ago and I had a lot going on around that time so things are kinda hazy.
What would be the corrective action to take if it wasnt marked and happened to be out of time?
Wouldn't the camshafts simply have to be lined back up 180° in the opposite direction?
And shouldn't I at least be able to feel the cam lobes making contact with the valves at some point during a complete rotation of the camshaft pulley?
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