97x Vibration Issue

[Maverick6587]

The repair saga continues with the 97x...

I am currently getting the following codes-
P0014:
Camshaft Position B - Timing Over-Advanced or System Performance (Bank 1)

P0017:
Crankshaft Position - Camshaft Position Correlation

P0305: Cylinder 5 misfire

P0300: Random/multiple cylinder misfire

Edit: Initially it showed a MAP sensor error code along with the P0014 and P0017. The MAP error code was not listed this morning on my scanner. I'll check the freeze frame data when I get home today as well. I was too tire and it was too late to even think about doing anything after driving through that snow storm.

I have only received the P0305 once in the past few weeks and now it's pretty consistently P0300.

I first started to feel this vibration a few months ago when I replaced the spark plug, intake manifold gaskets, and cleaned the throttle body. The vibration then was so light that anyone else would probably not noticed it. Thinking that the vibration was an engine mount, I replaced the passenger's side motor mount, still getting a vibration. The misfire codes have been happening for about 3-4 weeks now, about a week or so after the spark plugs were installed, but they did happen very frequently. The cam and crank codes have only been happening for about a week or so. When I get the cam and crank codes the vehicle either stalls out or runs very rough, until the vehicle reaches operating temp. All parts that were replaced were AC Delco. The spark plugs were those $7 AC Delco plugs that Amazon had, that had a possibility of being counterfeit. I never took them back out to check the spelling. If it's not too cold tonight I might check those out.

I did an oil change a week ago and have already replaced both the VVT Solenoid and the Cam Sensor. VVT Solenoid is an AC Delco, but the cam sensor is a Standard Ignition sensor from O'Reilly's. They were the only ones who even had a cam sensor in stock this weekend. I have no problem ordering it from Amazon and returning it if it comes down to that being the issue. I did just pull the wiring diagrams for the cam and crank sensors. I'm going to do some electrical testing tonight. My fear is that this is an actual camshaft problem, that I really don't want to mess with right now. I die a little bit every time I think about taking the oil pan off to clean it, lol.

I don't think it's the driver's side motor mount though, could be but I doubt it. The vibration is worse now though. It does vibrate while parked and while in neutral. It will start vibrating around 1000 rpm up to 2000 rpm. It is the worst right at 1500 rpms, while driving/under load. I was driving on the highway heading home yesterday after replacing the harmonic balancer. I noticed that right at 50 mph the rpms drop from 2000 to about 1500. It feels like the engine is getting bogged down, not losing rpms because of a gear shift.

Edit: I did change the driver's side front wheel bearing. It was not AC Delco though, I bought that before I knew how important AC Delco was on these vehicles. I was also thinking that the vibration could be related to a bearing, CV Axle, or drive shaft out of balance.

 

[Sparky]

My bet is the vibration is related to your misfire. Fix that first. Check those plugs.

 

[TequilaWarrior]

ACDelco 41-103 should be the only plugs used in the 4.2. I tried Bosch's and ended up nearly having it towed home. Changed all 6 to 41-103 in an autozone parking lot. Night and Day difference. Bastard's wouldn't refund me for the Bosch plugs though.

 

[Maverick6587]

My bet is the vibration is related to your misfire. Fix that first. Check those plugs.

Thanks sparky. My focus was going to be on the spark plugs and then the throttle body as the next components to look at. I would have went for them first, but I thought it was the harmonic balancer causing the vibration from its wobble. The vibration just didn't feel like a miss/rough running engine until now It was only vibrating.

I'm praying to all the deities that the spark plugs are bad and swapping them fixes all of these problems. lol, I've been fixing this thing since November, I need a break.

ACDelco 41-103 should be the only plugs used in the 4.2. I tried Bosch's and ended up nearly having it towed home. Changed all 6 to 41-103 in an autozone parking lot. Night and Day difference. Bastard's wouldn't refund me for the Bosch plugs though.

I need to be a little more careful next time about good deals on Amazon. I'm going to pick them up from a local store this time. The only reason I bought them was because it said the seller was AC Delco. After I purchased them, it then said sold by: Green Bugs Store. Really lost on rolling the dice on that one. lol

 

[Sparky]

Throttle body would not be causing misfires or vibrations so that would be low on my list of suspect parts. Unless you wanted to clean it, which is never a bad idea if it hasn't been done in a while.

 

[Maverick6587]

The CEL comes on randomly. I drove home with no error codes and no misfires were detected from the scanner.

I changed the spark plugs back to my old champions. I never had an issue with them for the 3 months they were installed. I will change them again to the verified AC Delco 41 103s, but I wanted to verify if the ones I took out were bad or something else is causing all of these issues. Well see if any misfires happen after the spark plug change. The vibration is still there though.

I replaced the cam sensor and the VVT exhaust cam sensor. I have not replaced the crankshaft sensor yet. I think that might be next, since it is one of three error codes. I only unplugged the battery while changing the VVT sensor and cam sensor.

Do I also need to run through the manual case relearn or would the battery unplug be enough for those 2 parts being replaced? I don't have access to a Tech 2 and I know the places around here charge $100 for any computer work.

I do have a new belt squeal that could be causing some vibration. It's either coming from the idler pulley or the ac compressor. I'll check those tomorrow.

 

[Mooseman]

For the crank sensor, you will need a CASE relearn.

Have you checked your SAIS valve? It has been known to cause misfires. Best recommendation for that is to remove that whole system, block off the port in the head with a block off plate from an 02-03 and have the codes deleted with a tune. Or just insert a piece of sheetmetal between the valve and head to block it off. It's a useless system.

The P0014 could also be caused by a bad cam phaser. Once everything else checks out, this might be the source of this code and possibly the misfires if the exhaust cam is really out of whack.

 

[TequilaWarrior]

The plugs currently in the engine could be "good", but the 4.2 just might not like them.

 

[Maverick6587]

Update:

I forgot to post this in my previous post: "Oh... How I missed you cylinder 6" - said no one ever.

I didn't have time to test drive it last night. On the way to work this morning there is definitely way less vibration at 1500 rpms. The rpm drop off at 50 mph has changed to drop off at 45 mph as well. I'm inclined to think that if I switch to AC Delco and do a voltage check on all of the ignition coils, I might just get rid of all of the vibration. The voltage check would mainly be for cylindar 5, since I did receive the P0305 code, but I'll check them all while I'm there.

There were no misfires listed on the scanner this morning. It does still vibrate when in park and in neutral. The vibration is not noticeable at all while at idle though, only when I press the accelerator. I attached the live data log from this morning after the drive into work, so it was at operating temp. The fuel trims are slightly elevated. I'm doubting I'll get to zero, but are those numbers pretty standard? Fuel trim and engine temp are the only two that I for sure what the numbers should be for an engine, still learning. Is there anything else I need look into from that chart?

The plugs currently in the engine could be "good", but the 4.2 just might not like them.

Thanks TequilaWarrior. I totally agree with you. I'm just sick of throwing parts at this thing. I wanted to make sure there was a change before gambling another $30-$60 on parts. I'm ordering the AC Delco spark plugs this morning.

For the crank sensor, you will need a CASE relearn.

Have you checked your SAIS valve? It has been known to cause misfires. Best recommendation for that is to remove that whole system, block off the port in the head with a block off plate from an 02-03 and have the codes deleted with a tune. Or just insert a piece of sheetmetal between the valve and head to block it off. It's a useless system.

The P0014 could also be caused by a bad cam phaser. Once everything else checks out, this might be the source of this code and possibly the misfires if the exhaust cam is really out of whack.

I have never heard of the SAIS before. After a little research last night I do agree that it seems ridiculous to have a system run for 30 seconds on a cold startup, to help with emissions. I need to go to the junk yard tonight anyway, so I'll grab one of the block off plates as well. I do not have any codes as of right now. I cleared them yesterday morning because it barely started and they have not come back yet. If I removed the SAIS and add the plate, would I still need a tune? I would assume yes, since the PCM will not be receiving a signal from SAIS and then I will probably get an SAIS error code.

 

[Mooseman]

Looking at your last post, I wonder if you have the same issue as I do:
Very Slight Miss at Idle

I have yet to replace the O2 or crank sensors. It still does it if I let it idle and the CEL comes on if I let it idle for too long. It usually clears itself after a few normal drives. It has a very slight vibration at idle.

 

[Maverick6587]

Looking at your last post, I wonder if you have the same issue as I do:
Very Slight Miss at Idle

I have yet to replace the O2 or crank sensors. It still does it if I let it idle and the CEL comes on if I let it idle for too long. It usually clears itself after a few normal drives. It has a very slight vibration at idle.

Ha. It does look like yours, but opposite in nature. Mine only vibrates under load now. Not sure on the misfires yet, with the "new" plugs installed.

Question to anyone. I did look at the engine as I was revving it up last night. I do see a very slight shift to the right (viewed from the driver's seat) when revving. Is that normal or should there be no movement at all? Just trying to gauge the state of the motor mount.

 

[Sparky]

There will always be some movement. What you do not want to see is side to side wobble or vibration. But a bit of twist from engine torque when revving is normal.

 

[Maverick6587]

Gentlemen (and ladies).....!

Here is the best example of both stupidity and the AC Delco reliance of the 4200 Atlas....!

In the past 2-4 months of dealing with this horrendous vibration issue with the 97x... I have learned so many new thing from so many people on this, I want to thank all of you so much!

Short story: Last night... I fixed the vibration issue with a mother f'ing rubber hose!

Longer story: back when I replaced the intake manifold gasket, cleaned the throttle body, and replaced the spark plugs (with the fake AC Delco brand). I also replaced as many rubber hoses on the engine as I could to fix any vacuum issues.

In doing so... The hose from the intake manifold to the brake booster could not be found anywhere, locally. So I purchased the generic rubber hose from autozone and tried to match the U shape of the original, that's about 10 or so inches long. The next day I looked at that hose and noticed it had a kink in it. So I decided to cut it to cut it to about 6 inches, so that it was in a straight line from the intake manifold to the brake booster.

In trying to reverse everything I did that weekend back to what it was. I went to the junk yard last and picked up 2 of those brake booster hoses (just in case one had a hole in it). I installed that hose last night and that engine runs buttery smooth now. No misses and no vibration at all!

I did still have a long crank time last night. The past 3-4 days it takes about 3 seconds to actually start. I think that is from the non AC Delco cam sensor I put in this weekend. I ordered and AC Delco cam sensor yesterday though. We'll see how that plays out.

Looking at your last post, I wonder if you have the same issue as I do:
Very Slight Miss at Idle

I have yet to replace the O2 or crank sensors. It still does it if I let it idle and the CEL comes on if I let it idle for too long. It usually clears itself after a few normal drives. It has a very slight vibration at idle.

You may want to check that vacuum line as well. It was quite mind blowing that the length or shape of that line caused so many problems for me.

 

[Maverick6587]

So, I've been thinking about how that hose fixed the issue for the past few days now. I just can't seem to figure out what happened. Just trying to figure out what else could be affected by my tragic mistake of cutting that hose.

I assume with the straight hose that it possibly created a vortex of air cause higher vacuum pressures. I would have thought that it would only affect the engine was actually braking though, or maybe not.

With the extra pressure (assumed) what could it have been affecting to cause such strong vibration in the engine, the VVT solenoid?

 

[Mooseman]

The CPAS/VVT is electrically operated so that shouldn't be affected by air/vacuum.

 

[Maverick6587]

Maybe the break booster itself, moving the plunger?

 

[Maverick6587]

Vibration aside at this point. I finally got the camshaft position sensor error to go away. I bought an Standard (make) cam shaft sensor at that last moment, from a local store. It brought back the cam sensor error, even after clearing the code a few times.

swapped it out for a new one under warranty. Gave me another cam sensor error. Bought an AC Delco version online, haven't had a cam sensor error since. I returned the Standard version back to the store.

I am still getting the crankcase error. I bought the AC Delco crankcase sensor. I'm just trying to figure out if I put that in, will the manual relearn procedure actually work or not (below). Has anyone tried manual case relearn before. I'm working on getting the money around for a Tech 2, but all these parts are killing me right now.

The MAP sensor error came back this morning. I pulled the wiring diagrams for them this morning. I'll check them again tonight. If they're good, I'll order the MAP sensor tonight.

Right before I get these two errors the engine starts to misfire pretty bad. If the crank sensor and MAP sensor do not fix the misfiring. How long could I wait if it is in fact a bad cam phaser?


NOTE: If the Crankshaft Variation Relearn is not accessible through your scan tool (some truck applications 1998 & later), perform the relearn in the following manner:

1. Turn off all of the accessories. With the Air temperature sensor and Coolant temperature within 5 degrees (Centigrade) of each other, start the engine and let it idle in Park or Neutral for two minutes.
2. Accelerate the vehicle to 55 mph at part throttle. Cruise at 55 mph for 8- 10 minutes until the engine reaches operating temperature.
3. Cruise at 55 mph for another 5-6 minutes.
4. Decelerate to 45 mph without using the brakes, and maintain 45 mph for 1 minute.
5. Perform 4 deceleration cycles, without using the brakes, of 25 seconds each where no specific speed is necessary. Returning to 45 mph for 15 seconds in between deceleration cycles.
6. Accelerate to 55 mph and cruise for 2 minutes.
7. Stop the vehicle and idle for 2 minutes with the brake applied and the transmission in Drive (automatic trans.) or Neutral (manual trans.) with the clutch depressed.

 

[Mooseman]

That will not work. You need the Tech 2 or other high end scanner with that capability. Most shops can do this if you don't want to fork over the money for a Tech 2.