Stuck lifter?

[RobertISaar]

link? no.

 

ZIP archive of diagnostics? yes.

342..zip

[xtremerevolution]

No offense to you, but those did me no good at all. With the exception of the puttering at idle, before I replaced the heads the engine ran fine. It didn't vibrate excessively, it didn't knock, though it did have the same ticking noise I mentioned earlier in this thread. I have since ignored it since its been going on since October of last year. I would think if the problem was very serious such as cam walk, I would be having bigger issues. I pulled my cam sensor and it was perfectly intact. The clearance between the cam and the timing cover was also perfectly fine.

 

I've never heard of cam walk on a 3800. I hope I never do. Part of this is me being in denial that this could even be a possibility, because if it is, I'm seriously going to order the Jag shipment on Monday, fix the jag, and put the Regal in storage for the next 12 months at least.

[RobertISaar]

that don't help with diagnosing why you seems to keep getting a somewhat random SES light?

 

and let's assume that the heads that were taken off and the heads put on are identical except for fixed exhaust valve issue and the porting. let's also assume that the cam sensor error code is completely unrelated and forget about it temporarily.

 

i believe a sherlock holmes quote goes well here, something about if all probable explanations are exhausted, then the improbable explanations, no matter how likely, must be correct.

[tornado_735]

I say to slap a set of un-altered heads on there and see what happens. I know it's a royal huge pain in the ass, considering you just pulled them...

[xtremerevolution]

that don't help with diagnosing why you seems to keep getting a somewhat random SES light?

 

and let's assume that the heads that were taken off and the heads put on are identical except for fixed exhaust valve issue and the porting. let's also assume that the cam sensor error code is completely unrelated and forget about it temporarily.

 

i believe a sherlock holmes quote goes well here, something about if all probable explanations are exhausted, then the improbable explanations, no matter how likely, must be correct.

 

Ok, lets go through this for a second. The first time I got anything remotely related to this was in October right after I ran the engine at 4600 rpm for 5 minutes straight up the mountain with a very heavy load in the back. Right after I went over the peak, the SES light turned on, and I got an intermittent camshaft signal error. Turns out I was using bad 85 octane gas and my car didn't like it.

 

Since then it did not happen a single time. I drove the car for a while, and it was fine. Now that I changed the heads, I got a code 342 and today was the first time I was able to scan it.

 

I went outside and pulled the cam sensor. I imagine if the cam moved, it would have destroyed this thing if in the scenario you spoke of, it cut out a silver dollar size piece out of the timing cover.

 

From bonnevilleforum.com:

I have never heard of it happening. The cam bolt would have to come loose. that would allow the cam sprocket to move. But the crank sprocket wont be able to move because it's held in place by the oil pump. So the cam sprocket should stay in place.

If I don't get down to the bottom of this in the next 2400 miles, I'm pulling the intake manifold off and checking the entire top end over with a magnifying glass and a flashlight, lifters included, and whatever I can see of the cam with a few crank rotations through the starter.

 

I'll let you all know what happens when I run out of fuel and get a chance to pump a full tank of 93 octane in there.

 

Damn this shit has me scared.

 

 

If I still can't figure it out, I'll lap the shit out of my old heads, port them the same way I did the others, swap the springs over from the newer heads, and put it all back together. At least with those heads, the engine ran without any serious vibration.

Edited April 25, 2010 by xtremerevolution

[RobertISaar]

i occasionally got either a 24X or cam sensor error on the MC... i always figured it was due to a fairly old timing chain that liked to make a bit of instability at idle... never happened at anything more than absolute minimum throttle...

 

there's just so many possible variables here and they could all be contributing for all we know.

[xtremerevolution]

i occasionally got either a 24X or cam sensor error on the MC... i always figured it was due to a fairly old timing chain that liked to make a bit of instability at idle... never happened at anything more than absolute minimum throttle...

 

there's just so many possible variables here and they could all be contributing for all we know.

 

You're absolutely right. There are so many variables that its stupid. I suppose I don't have much that I can do until I star tuning and see if somehow that's causing my problems.

 

I have a noise coming out of the engine bay that's a bit unusual. I heard it before but didn't pay attention to it. I'll take another video of it when I can.

 

For now, try to listen to the engine at idle, not while its being revved. Let me know if you hear anything unusual. Sounds almost like a diesel.

 

[video=youtube;m-C4lXnz5ho]

[RobertISaar]

i certainly do hear the diesel-like noise... it would be nice if the OBD1 MAF systems used a MAP sensor as well to make tracking vacuum easier...

 

if you pull, let's say 5* or more on 87 octane fuel, and this knocking issue still exists, then i would be leaning toward a mechanical issue, rather than one of recalibration... with better fuel, that number should be less, but considering the PCM wanted to pull ~6* out at times, if removing 5* doesn't at least severely reduce it....

[xtremerevolution]

i certainly do hear the diesel-like noise... it would be nice if the OBD1 MAF systems used a MAP sensor as well to make tracking vacuum easier...

 

if you pull, let's say 5* or more on 87 octane fuel, and this knocking issue still exists, then i would be leaning toward a mechanical issue, rather than one of recalibration... with better fuel, that number should be less, but considering the PCM wanted to pull ~6* out at times, if removing 5* doesn't at least severely reduce it....

 

Well here's the other thing. The PCM didn't retard timing during idle; only at WOT. I'm also leaning toward a mechanical issue myself, but the lifters are the only legitimate thing I can think of. The sound persists repetitively as you rev the engine.

[RobertISaar]

if the algorithm of that PCM works the way most GM OBD1s do, it ignores the knock sensor at idle(and close to it) since almost always it's pretty tough to cause true knock at idle. so it's more or less a sanity feature/potentially an indicator for false knock...

[alec_b]

I'm gonna follow this daily also, as your problems are basically the same as what my car is having, other than the SES light. I have the SAME ticking at idle, the SAME puttering in the exhaust that you had, the SAME occasional rough idle, yet it runs great, has tons of power, and gets great mileage. The only other symptom I have, on occasion, is a long cold crank. Warm crank is always a hit the key and go, but once in a while cold i have to crank her just a bit longer. I've tried priming the fuel system by cycling the key a couple times, it made no difference. I'm almost convinced my front exhaust manifold has a crack in it, it's just hard to hear where my tick is coming from. I can hear it really well with the hood closed and sitting in the car with the window down, but as soon as I get out and open the hood the rest of the engine sounds drown out whatever is ticking.

 

I know you're a perfectionist and I give you mad props for chasing this down as much as you are, because as far as I'm concerned with my car as long as it drives and the only symptom I have is a slight lope at idle, then that's just fine. Like I said I'll be following along closely.

[WrathOfSocrus]

Wait, if you just recently changed heads I'm guessing you have fresh LIM gaskets that went with it? If they are new you should be able to reuse them after removing the LIM. You would only at worst be out time by taking out the lifters, cleaning them, and putting them back in. At best could eliminate your problem. You already have 10 days invested in this thread and have come full circle back to the lifters.

[xtremerevolution]

Finished the compression test. All numbers are with throttle wide open.

 

1: 190

3: 186

5: 190

2: 189

4: 186

6: 190

Edited April 25, 2010 by xtremerevolution

[RobertISaar]

that's not bad at all...

 

alldata specifies 100PSI minimum for good numbers... and they're all within a couple of PSI, so there certainly isn't any significant leakage in either the intake or exhaust valves on any cylinder...

[xtremerevolution]

that's not bad at all...

 

alldata specifies 100PSI minimum for good numbers... and they're all within a couple of PSI, so there certainly isn't any significant leakage in either the intake or exhaust valves on any cylinder...

 

 

Right, but those are pretty high compression numbers. I've been reading around, and while I don't know exactly how all engines differ, a 190 PSI compression seems pretty far up there.

 

Obviously my vibration is not a result of a weak cylinder. There's something else going on here.

[RobertISaar]

they're not abnormally high, if that's what you're thinking... they are indicating failry good ring and valve sealing, though a leakdown test is more accurate.

 

and yes, it certainly seems like there isn't a weak cylinder causing issues.

[xtremerevolution]

For some reason I'm still leaning toward the tune being the problem.

[RobertISaar]

could be.

 

i assume you're familiar with the concept of dynamic compression?

 

for anyone else reading that isn't, it's one of the reasons why we need more than just a set amount of spark advance. when you have a car idling, the throttle is completely closed. the only air coming in is through the IAC. now, what happens when an engine that displaces 3.8 liters of air every revolution tries to suck it all through a VERY small hole? you get a decent amount of vacuum because of it. it also creates throttling losses due to the engine having to "struggle" to pull the air in. now the air that gets pulled in at idle, it's in a vacuum(duh), and due to the way thermodynamics interact with how the air/fuel charge burns, it will burn at different speeds.

 

now the way GM OBD1 MAF systems calculate load-based spark advance is based on a few variables, namely MAF reading, RPM and IIRC, throttle position. it knows the size of the motor, and a decent idea of how volumetrically efficient it is through a couple of settings and tables in the tune. through equations too complex for me to try to explain on a sunday evening, all of these things contribute to a value refered to as LV8. LV8 means "load variable 8-bit". a low LV8(say 20-30) would indicate near idle load on the engine due to an idling engine speed(~800RPM) and an idling MAF reading(~4 grams/sec). a high LV8(180-200) would indicate fairly hard acceleration through a high MAF reading(~130) and high RPM(~5000RPM). near 0 readings is what would be considered overrun(higher engine RPM with little/no throttle and subsequently low MAF readings). a LV8 near peak(255) would indicate that the engine can't possibly be working any harder(let's say the car has a manual tranny, is in top gear and at like 1200RPM and has the throttle wide open).

 

now the spark table is based on two things: RPM and LV8. if you're just out of idle and are looking at say 1600 RPM and a LV8 of 32, and are getting knock, you'll need to retard timing(in almost all situations. in the RARE chance that it's pre-ignition you're dealing with, you'll actually need to advance timing. crazy, i know, but starting the spark earlier means that a hot-spot in the combustion chamber that would otherwise ignite the air/fuel charge before the normal flamefront gets to it won't have the pressure and temperature necessary to ignite on it's own.).

[xtremerevolution]

Interesting you posted this, because I was going to post something similar on my own.

 

How far can you possibly advance timing before your timing advance itself creates knock? On the Jag, I know I was talking to people and they advance it between 4-10 degrees. My advance at WOT is between 10 and 16 degrees WITH 6 degrees of KR, while at cruise its around 25 and at idle its as high as 35.

 

Are you saying that if my timing at WOT was advanced 5 degrees, that I would have a chance of preignition simply as a result of the high pressure in the cylinders? At what point is the advance too high and you're detonating as the piston is still on its way up? I thought the idea was to spark just barely before TDC.

 

Still a bit confused here as to why the timing is advanced so far. It sounds counterproductive when you consider that you'd start knocking if you advanced it too far.

 

What's the difference here before knock, preignition, and predetonation. I'm not sure I'm following you here.

 

I imagine that if in the rare case that is pre-ignition, that a hot spot is igniting my fuel, I could run a higher octane fuel and be alright. If that is the case, I'll be kicking myself for not smoothing out the combustion chamber.

 

Man I'm learning a lot here.

[tornado_735]

 

Man I'm learning a lot here.

 

You and me as well.

 

If you didn't have any mechanical problems (like cam walk) before, I venture it a safe guess that you don't have it now. So lets say the tune is the problem. What is the issue here, tuning OBD1.5? If that's the issue, why not make this a good time to swap to OBD2? Then you could tune all day long. Or is it a matter of, no matter what you're telling the computer to do, do the components like the MAF have a limited range within which they can operate?

 

I hope those questions make sense...

[xtremerevolution]

You and me as well.

 

If you didn't have any mechanical problems (like cam walk) before, I venture it a safe guess that you don't have it now. So lets say the tune is the problem. What is the issue here, tuning OBD1.5? If that's the issue, why not make this a good time to swap to OBD2? Then you could tune all day long. Or is it a matter of, no matter what you're telling the computer to do, do the components like the MAF have a limited range within which they can operate?

 

I hope those questions make sense...

 

Well I can tune with OBD1.5. It just takes longer because I can't use the data cable to tune directly to the ECM. I have to pull the chip, burn the new tune, and try it again. It would cost me a lot more to convert to OBD2. If I'll spend that kind of money, I might as well put a series 2 3800 in there.

 

Right now I just have to confirm the list of parts I need to tune, order those parts, and get to it. Whatever it is that is wrong, I'll still need a tune. Knowing that I have excellent compression on all cylinders makes me feel a lot more comfortable with the situation.

[RobertISaar]

spark advance is most likely the most conusing aspect of anything engine related... mostly due to how incredibly confusing it can get. as to WHY so much advance: everyone knows what Grand Nationals are, right? turbo 3.8. well, guess what: they run UP TO 50* of advance, depending on RPM and LV8. now if you try to run 50* of advance at WOT, don't blame me when your heads blow through your hood. when there is a lot of vacuum, it takes a lot of time for the flamefront to travel completely through the cylinder, which is why at high RPM and a lot of vacuum, you have the most advance(since higher RPM means less time for the flame to travel and high vacuum means it takes longer for the flame to travel).

 

now let's get to the other extreme: boost. let's say 14.7PSI of boost at 1600RPM. now, when air is packed in, it takes even less time for the flame to travel. so in that area, you normally see stuff like 6-9* of advance: the reason is twofold: it doesn't NEED that much advance due to the advantage of having a lot of O2 and fuel molecules being packed together. reason two is that detonation or preignition could happen if cylinder pressure rises too rapidly due to the. BTW, a good primer on the difference between detonation and pre-ignition is found on wikipedia... http://en.wikipedia.org/wiki/Engine_knocking#Pre-ignition more or less, detonation is a second flame front caused by a second source of ignition, and when the fronts collide, shit breaks. pre-ignition is due to rising heat and pressures causing pretty much the entire air/fuel charge to blow the fuck up before the spark plug has a chance to light it off. neither is good, but preignition can kill rod bearings within a second due to the massive amount of pressure that gets put on the piston in the exact opposite direction of the one it's traveling in.

 

what'd i miss?

 

all of this applies to ALL gasoline powered engines, be they MAP/MAF/OBD1/2/3/CAN/direct injection/etc...

 

a lot of theory goes into it obviously, but it certainly makes you wonder how people got by with vacuum-advance distrutors for so long... and why we are able get MUCH better driveability out of our cars today. there's a LOT of driveability/power/economy/emissions in the main spark table alone.

[xtremerevolution]

Man I made an absolutely brilliant discovery today. I feel like freakin Einstein.

 

You put the car into drive while parked, and the car vibrates. That's what I've been complaining about. You put the car into Park and it vibrates a little less. You put the car into reverse and the vibrating is practically gone and the car feels normal...

 

How the hell many engine mounts can you possibly go through in 12 months?

Edited April 26, 2010 by xtremerevolution

[RobertISaar]

DID I NOT CALL THAT SHIT LIKE 5 PAGES BACK!?!?

 

i will have my chuckle now.

 

EDIT: page 2!

 

http://www.w-body.com/showthread.php/46056-Stuck-lifter?p=906945&viewfull=1#post906945

[xtremerevolution]

My L27 has a GODLY amount of torque. Better recognize.