birkhoff

 

The oil pressure jumps back up to 40-60 psi immediately after giving it a little throttle. Could the low psi at idle be caused by the conventional oil I'm using? Doesn't seem like a factor to me.

 

Spec is >=14 PSI at 600 RPM and >= 43 PSI at 5000 RPM so you are probably fine. I think a new-ish pump and tight build will show higher pressures (mine did) but you set all the clearances a little loose and even over spec on the mains, so it is not unreasonable that you would see slightly lower oil pressure than stock.

All is good, especially if the next oil change is cleaner.

The cloudiness may be in part due to moisture inside the engine. Depends on your climate but if it was sitting around in a humid shop with temp changes there can be moisture. You didn't run it long enough to drive water out of the oil. There isn't enough to settle out, or it doesn't seem so from the pictures.

Shimmering is another thing. Something you don't really want to see except maybe a little bit in the first oil, but even better not at all.

^ Does StkmltS seem like someone who leaves his banjo filters in place?? Good idea though!

I couldn't bring myself to type 'O-ring' in previous post with respect to oil pressure. Are you sure it is there? I personally don't know anyone who has left it out, and I would expect it to make a bigger difference than 5 psi at idle, but my musings above are kind of far-fetched. A missing or re-used O-ring would be a more obvious place to look.

Why don't you send all of your injectors to Deatshwerks for a cleaning (27$ per injector) preceded by a pre-test($5 per injector)?. If the pre-test results show that they are all in good shape, they will call you to let you know that cleaning is not required. That's what happened to me anyway about a month ago. I was pleasantly surprised. How many miles on them anyway?

I'd be thinking in the other direction: change as little as possible and concentrate on one thing at a time. I sense we agree that if only one thing can be looked at, it should be electrical.

If you start pulling injectors, you may change the electrical and attribute it to the mechanical, when in fact it was the electrical. Does that make sense? I'm not sure I believe it myself!

There are multi-step diagnostics in the FSM for both injector and ignition electrics that involve a multimeter and a little time. Just because the dealer service places follow the FSM (I hope!) doesn't mean the FSM is dumb.

There is an end to this road that we all know, but don't want to say. If no external cause can be found, the engine has to come out and the head come off to look for a crack or other defect that was missed at rebuild time. Nobody wants to do that. Slow and systematic until there are no other options!

At first I thought the same thing, but...

 

When it's missing if I press the throttle and raise the rpm to say, 2500, it continues to detect misses, just at a faster pace.

Low load.

As heiche describes it, the ECU is looking for slight changes in angular velocity, and then tries to match what it sees with a planned ignition event. If all cylinders are working hard and one takes a pause, it may be hard for the system to detect under the higher torque and angular momentum.

I do find it interesting that we typically only see misfires in some combination of low RPM and low load. Kind of hoping someone who actually knows the limitations on these systems will chime in. This is all pure conjecture on my part.

Pictures of oil are hard to read, but that does look pretty dirty for 30 min, as did the previous pic. Does it look graphite-ish? Maybe there was honing material left in the block passages or on the cylinders. It might be a good idea to throw in an extra oil change before 500 miles to see if it is clearing up.

Did you take the oil pump apart? Maybe it didn't align quite the same as before if it is worn to the top end of spec. Most important is to see the pressure jump up to max when you blip the throttle.

I agree that injectors and coils that are having a hard time keeping up at low speed are unlikely to correct themselves under higher speeds or increased load. But I don't think we can say for sure the misfires are not happening at high speed as well.

There are bound to be limitations to the misfire detection system and there may be some engine speeds above which the sensors and ECU are simply unable to confirm a misfire. It may also be load related.

If this is true, at higher speeds/loads you are going to see the effect more in general loss of power and perhaps unburned hydrocarbons in the exhaust stream, the latter if the injection is happening but the ignition is not.

The fact that we often report misfires at low engine speeds/loads may say more about the detection system than the prevalence of misfires.

Just to be clear though, I know for a fact that the max value the counter can report is 99. If it reaches 99, it'll go back to zero right away and keep incrementing if needs be. It happened to me a couple of times with that freakin leaky injector .

 

Personally, if you see this happening, you are misfiring reaaaaal bad

I bet your engine was just scared what you would do to it if it went into triple digits!

Have you tried any "live" tests when it is misfiring? Wiggle the #2 coil plug to see if it stops missing. Wiggle the #2 injector plug to see if it stops missing. Turn on the AC to raise the idle a little. Move the shifter from park, drive, reverse, etc. Just looking for ANY more variables

^+2 for that. OP has honed his senses so well that he can read the OBD codes with his mind. Try to make it misbehave with your hands! Just be careful where you put them while the engine is running.

Has anyone actually followed the FSM diagnostic procedure for the P30x codes? Unless I am reading it wrong, it concentrates on the lines and connectors for the injectors, not the coils. Lines for the coils also have a diagnostic procedure but it is in the 'no start' section around page 64. Weird.

Try 'massaging' the electrics on the #2 injector while you are at it, like heiche suggested.

Misfire count.

It cannot be that it counts until it gets to some number and resets since we are reporting all sorts of different values at reset. It is events per time interval.

OP posted logs with misfire counts earlier in this thread. It resets 3 or 4 times during the log. Time interval between resets, reading from this log, is 7904 and 7954 msec for the first two full intervals. I didn't bother checking the others.

Anyone want to bet that the count is NOT per 8 second interval?

 

I haven't tried swapping in a new/used MAF sensor (I have cleaned it though), but that wouldn't explain why the miss only happens in #2. Other than that I don't know what to do other that test the wiring in 1,000 places.

 

--- snip ---

 

My crank sprocket looks good, and I haven't tested the sensor.

I'll try the terminal-twist trick next time I'm in there.

Now we're talking. If it isn't specific to #2, it should be passed over for now. MAF is a good example. Checking again for vacuum leaks another.

A sloppy crank gear should give intermittent problems with timing in all cylinders, and I don't see how a bad crank sensor could isolate to a misfire on one cylinder. Two cylinders maybe. More likely all four.

Wiring section of FSM has a testing procedure for the ignition leads. It also shows pin-outs at the major connections for the power, ground and trigger leads. That's the next step after cleaning and tightening up the connector.

No rebuild and install is without hiccups. Scary stuff in the oil, rough running, leaks of all types are possible and at least some are probable. The key is to arm yourself with all the new information you have so you can focus your efforts!

Cyl #2 was the problem before, right? There was never any evidence of a systematic problem with any other cylinders. Now cylinder #2 again. This cannot be a coincidence even though your mind may wander into that territory. You have to concentrate on things that didn't change during the rebuild. For example, you have all new pistons (isn't that lucky) so you can eliminate that thought. It is inconceivable that you built the exact same problem back into the motor due to sloppy assembly, or incorrect valve clearance or any other things like that. Maybe new problems, but not the exact same one!

I think you are bang-on to concentrate your efforts on electrical, but only things related to cylinder 2. Rereading your introductory post, there was a lot of effort on injectors, coils, vacuum system bore scope and whatnot and you really don't want to follow that path again. Electrical seemed to take a back seat, in retrospect.

Did you thoroughly check the coil connector for #2. Did you try cleaning and gently crimping the contacts?

If you check the wiring diagram, all four coils share the same ground point, and the same power wire (except at some point they separate in the loom and head to the coils). If you have any reason to suspect the power wire or gnd in #2, you could jumper over from an adjacent coil. And/or set up a direct ground for that coil.

Each coil has its own trigger wire back to the ECU. Could you bridge the trigger for #2 just in case there is an intermittent break somewhere in the loom?

Except for checking the connector, none of these are terribly simple steps but they are at least consistent with what you know, after the rebuild.

The misfires are in cylinder 2 and they appear to only be occurring at idle. The log this morning shows roughness getting as high as 36.

The misfire code for cyl#2 is still disabled in my ROM

. . . snip

Something that high will need to be looked into, but it is not going to damage anything in the short run, and it may go away on its own.

Break the engine in. You may be drawing oil up past the rings just enough to drop the flash point below threshold at idle.

And the good news is, checking oil every morning after sitting overnight is not going to draw any attention around the household I wouldn't do anything beyond that (oh, and watch your coolant level, of course) until at least the 500 mile changeout.

What did you see in the 10 minute oil? Any metal? Dirt?

That motor's not broken in yet!

Give it some time. You can expect slightly wonky compression until the rings seat. Misfires even, maybe.

You also want it to use a little oil. At this point, I think the single most important thing to monitor is oil consumption. Check it carefully every hundred miles or so.

Everything else can wait while you confirm that the bottom end is solid and tight.

Typically, the first sign that the rings aren't seating is continued oil consumption. In the old days, you could almost watch them seat as the blue cloud on high vacuum slowly disappeared over a few hundred miles. Our modern cats do such a good job of scrubbing, you'll never see any blue.

About the only thing we do different from the factory manual is to not open up the AC circuit. You can bend the hoses and strap it to the LHS firewall. Ditto the PS pump and associated hoses. Don't forget the ground straps under the engine -- one on each side. Sometimes separating the block from the belhousing goes hard if the engine has not been out before.

Once you have it out, if it is going to be a long time out (and rebuilds ALWAYS take longer than you expect) untangle the PS and AC hoses to take the kinks out and hang the accessories safely in the engine bay. Also, pick up a new red o-ring at the dealer for the low pressure feed line to the PS pump. They almost always leak when you manhandle them like that. Simple insurance against a messy and sometimes hard to diagnose leak later. Nobody has yet found a generic replacement.

Good luck. There are at least 3 rebuilds going on here at any time so lots of experience.

Have you built a motor by yourself from the ground up before? Maybe I missed it earlier in the thread. Also, you normally pull these motors as a package rather than stripping down in the engine bay -- one of the easiest pulls you will find.

Given where you are at, you may not have looked at the factory service manual yet. Suggest you do. It explains all this. A few places we do things a little differently, but mostly it is reliable.

I went to bed around 4:30 and apparently about 4 hours is all my mind wanted me to sleep. I'm like a kid waking up super early on Christmas morning.

 

Before I crashed last night I pumped about 5 quarts of oil into the crankcase via the stock oil pressure switch location. This morning there's a small wet spot right under the center of the motor. I held off crying until I got under the car... it was just a slightly loose oil drain plug. Excuse me while I go change my pants.

So let me guess, no torque marking on that plug, right?

Can't wait for the all's clear post!

 

I've left the plugs in all my rebuilds for priming. I take the oil pump apart and pack it with Clevite bearing guard, then reassemble and loctite the screws. The grease in the pump creates instant suction and primes right away. It ran with no pressure after start up for a second maybe. Outfront taught me that one!

If I rebuilt engines for a living, that is what I'd do too. I'd have maybe one bad day in a hundred so no big deal. But what if you forget to install the o-ring in the oil pickup? Easy enough to do for any one of us.

I DO think we should be left alone to decide on this for ourselves. It is a white knuckle point in the process and who am I to tell you how to do it.

However . . .

Personally, I want to know two things, for sure, in this order: (1) does the pump prime and pull oil from the sump and (2) does it build pressure, or is there an open galley plug somewhere?

I will add (3) specifically for our cars -- do I have oil pressure at the CRH on the turbo?

Packing the pump with heavy oil and using a mechanical gauge are no brainers.

Pre-priming may be related to some of this, but it doesn't really answer any of the questions on its own.

As soon as the engine is mated to the bell housing and you can get the starter in there, install your mechanical gauge, fill the sump the usual way, crack the banjo bolt at the turbo CRH and have a helper watch for trouble while you crank with the plugs out. No fuel lines, accessories in the way, etc.

If you get pressure of any sort, that settles (1). If moments later you are spraying oil over your nice clean engine bay, or not, that settles (2), and within 3 or 4 seconds you should see oil at the pipe joint above the turbo; that settles (3). Close it all up and complete the install and first startup. If any of these don't happen as expected, you'll need to investigate, but nothing will have been damaged and it will be (relatively) easy to pull the engine if you need to.

Full disclosure: on my recent rebuild I waited until pretty much everything was done before checking for oil pressure (as above). It was fine, but it was a dumb thing not to get out of the way earlier. Some years ago I rebuild a diesel and left a galley plug out. What a mess! Everything had to come out in that fiasco, but that was a long time ago and maybe I didn't learn my lesson!

I'm jumping up and down like a giddy school girl right now!

Another image that's going to take a while to clear from my head, after FJuan's post #646 . . .

You seem to have plugs and coils installed. What is your plan for priming the oiling circuit? Goes a lot easier if you can crank at speed with no load on the bottom end.

It appears things have just evened out, got a horrible misfire, and it turns out the crank gear is missing a tooth.

 

The race to 250 starts tomorrow!

Crank gear is the most stressed part of the whole timing system. I replaced mine just to make sure the tooth profile was up to snuff. Mine was kind of polished, but o'wise it looked pretty good at 180K or so. Replacing is cheap insurance IMO.

Yes, that was exactly my thinking at the time. I have a little description in post #45 in my rebuild thread

I recall the difference in bore diameters was around 1 thou, so not a lot, but any misalignment will show up on the running surface for the seal which, if large enough, could pound out the seal in the long run. Checking the bore alignment with an old cam nose would probably work but it was easy to make a fixture that was a firm sliding fit on each part. I went that route.

If anyone has a spare cam gear assembly they would like to donate to the cause, I'd be interested in taking the gear housing and cover to an industrial hydraulic place and see if we can make a custom O-ring by splicing. I'm kind of dubious about this, 'cause the guy at OutFront that I talked to wasn't able to source replacement seals; they cannibalize old units when they need a seal. I'd expect they already thought of splicing.

IMO I wouldn't mess with the gears unless you are willing to suffer an additional delay and possibly the expense of buying two new gears. You had no metal to metal failure on that engine and it was reasonably clean on teardown.

Those formed O-rings are unobtainable. When I took mine apart they were stubbornly stuck to the cover plate and I ended up slightly tearing one even though I was being really careful. They were also quite hard and flattened and I worried about getting them to seal again on assembly. Finally, there are no dowel pins to centre the cover plate. The big dowel you see in the pics only serves to index the orientation. I ended up making an alignment fixture to make sure the cover plate was not off centre with respect to the housing. If any of these issues arise, the only quick solution is to buy a new gear. (Outfront M'sports offers a rebuilding service, but that is not a quick solution.)

You can see all of this in my thread. In the end I left the second gear untouched. The one I did take apart was pretty clean inside.

Mine wouldn't budge either. I bolted the m'fold to a strong wooden table, cut off the cable and put a deep socket on what was left. Still needed a LOT of breaker bar action to get it out. Be prepared to chase the threads before you put a new one in.

Crowfoot wrenches (which I had) and cutaway sockets (which I made) all sprung long before I could get the thing to move.