Knock Knock, part 2...

[blueskies]

I finally had some time to get under my car last night, and the temps were cooperating at 55 degrees.

Getting ready...

The pan was a mother to get off, because there isn't much room to pry the seal loose. It took me about 45 minutes of profanity tapestry weaving to get it loose. The pan comes off with out removing the steering parts on the '49-'52 models.

Here's what I found in the bottom of the pan:

Lots of fine metal particles... And, I was surprized to see assembly lube puddled in pockets here and there. I've changed the oil three times since startup, with about 6,500 miles now on the engine.

So I climbed back under the car with a bright light, and thought I'd find an obvious bearing hanging out somewhere. But everything looks fine at first glance.

I tapped the rod bearing caps with a hammer, and they all sound the same, and seem tight. I pulled a random rod bearing cap (#3), for a look. It looks the same as the day I installed it:

I checked out the cam, and it looks new as well. I've been worried for quite a while about using hi pressure RACE valve springs. I had visions of the cam not breaking in correctly, and the extra pressure from the springs eating up the cam. All is well there.

I checked the distributor shaft, and it looks like it clears the crank lobe just fine. And the oil crossover tube is installed correctly too. There is no evidence that anything is bumping the pan at all.

Since there is nothing obvious, I'm going to take the main bearing caps off one at a time, and inspect the bearing halves. If it's not one or more of the mains, I'm going to do the same with the other five rod bearings.

I suspect it's got to be a bearing, because of the metal in the pan. The entire oil system was clean as a whistle when it went together, I used a gun cleaning kit to clean all the oil passages till they were spotless. I'm wondering how clean the passages are now that there's a bunch of grit in the pan... damn.

Can't wait to get home from work tonight and dig deeper...

More to come-

Pete

[bob westphal]

Pete,

Didn't you try to sound out the noise before you dropped the pan? Main noise will have a heavy thud while ehngine is under load. Rods will rattle when throttle is fluttered. Everey time I have dropped the pan on a recent rebuild there has been some metal in pan. This is common. A lot of metal- No!

[blueskies]

Pete,

Didn't you try to sound out the noise before you dropped the pan? Main noise will have a heavy thud while ehngine is under load. Rods will rattle when throttle is fluttered.

Yep, back in the thread Knock Knock, part one, complete with a sound clip for armchair diagnosis . I couldn't really tell where the sound was coming from, and I wanted to change my oil pan gasket anyway. I feel much better getting inside to see what is really going on. I've already dispelled some of my fears, so it was worth pulling the pan just for that alone.

Pete

[Plymouthy Adams]

Have you considered the possibility of a wrist pin knocking?

[Justin Slingsby]

Does a wrist pin knock under load? I think I have the same knock as Pete it comes and goes though it just depends on what mood the car is in..

[blueskies]

Have you considered the possibility of a wrist pin knocking?

Tim-

According to this diagnostic page posted in my other knock knock thread, the wrist pin sound is a rattle sound, similar in pitch to a tappet sound. The sound I hear is a low pitch knock sound, and is loudest under acceleration above idle at about 2100 rpms.

According to this page, my sound fits better with a rod knock, but it's hard to tell. I'm going to inspect the mains first, only because there are only 4 of them and I can get to them all without rotating the crank...

Pete

[blueskies]

Does a wrist pin knock under load? I think I have the same knock as Pete it comes and goes though it just depends on what mood the car is in..

Mine was moody for a while too... It was worse when the engine was cold. when it warmed up, the sound went away for the most part. Now, it's there no matter what the engine temp is... It has steadily gotten worse over the last couple thousand miles.

Pete

[Justin Slingsby]

Okay I have the reverse. I get the knock under temp and when the motor is cold it is quiet and it just shows up when it feels like it. It has been this way for at least 3000 miles. Ever since I blew the head gasket going WAAAAAAAAY too fast..

[Plymouthy Adams]

Here is an interesting read on the subject..good head on approach with finding the problem foremost with less cost for parts/tools eating your budget.

Chrysler mech said that my 2.5 4 cylinder was diagnosied as wrist pin noise..inherent to the design, nothing can be done.....matter of fact they all slap their silly little pistons was the answer..just keep in mind the the silent chain is not always silent.....enough said here...funny how the same pistons, inserts etc just shut the hang up with the new guides and proper tension. Only reason the car was at the dealership was a EGR recall and I mentioned the noise...220,000 miles later...these same wrist pins are still in there...we allhave stories like this I'm sure..any way here is the link......

http://www-personal.umich.edu/~jfarrugi/images/vanagon/engdiagnosis.html

[Plymouthy Adams]

your noise explained in the above could lead you to believe excessive bearing clearance for sure..as you have not yet been able to plasti gage them all..it is still a guessing game..process of elimination is painfully slow and can get costly...hopefully you will find it fast.

As your engine is apart right now..the link I just sent in may not help you at the minute..I do like the use of the timing light to sync the noise as you ground the cylinders.

Sound can travel and amplify...sorta off subject here but I would have sworn I had a nest of squirrels in my den overhead..I mean right in the corner..If I got up to investigate it seems to go away..sit back down at my computer and here they go again...two months later and the babies are still there...I say wait a minute..little trespassers should be grown by now..just by luck I was standing in the doorway opening to the front porch..I have a windsock there..it was barely moving BUT the metal clip was riding on a cast iron bracket right where there was some flash metal...it was resonationg and as it was mounted to a heavy oaken beam that ended about 1 foor inside my den overhead..it was acting as a sounding rod..squeaking like furry little critters. I would have lost money on the bet I would find a nest of varmints overhead.

Luck to you Pete..sure you will find it..not that much moving down there when you stop and think about it...

[blueskies]

your noise explained in the above could lead you to believe excessive bearing clearance for sure..as you have not yet been able to plasti gage them all..it is still a guessing game..process of elimination is painfully slow and can get costly...hopefully you will find it fast.

Thanks for your input Tim... As for painfully slow, yes... As for expensive, it's just my time and whatever parts I find that need to be replaced. I got so much damn money into this motor, I don't even want to think about it. That's why I have to figure it out... Can't let that pile of cash just sit there, it needs to be ripping up and down the road!

I'm going to plastiguage all the bearings as I inspect them just to be sure...

Pete

[grey beard]

Pete,

If all the bearing clearances plastigague okay, just about all there is left is wrist pin clearance problems, since that is all that reciprocates internally. You installed new pistons with new pins. What was done with the wrist pin bushings during your rebuild? Were the rods reconditioned?

If all the rest of your bearings look as perfect as the one you photographed, you've eliminated the rest of the reciprocating mass. Flywheel's not loose, is it?

LOL

[Normspeed]

Could be a cracked piston. A while back someone here posted a photo of a fresh rebuild with a broken piston skirt. Pete, I'll keep my fingers crossed that it's not something that damaged the crank or block.

[blueskies]

Pete,

If all the bearing clearances plastigague okay, just about all there is left is wrist pin clearance problems, since that is all that reciprocates internally. You installed new pistons with new pins. What was done with the wrist pin bushings during your rebuild? Were the rods reconditioned?

If all the rest of your bearings look as perfect as the one you photographed, you've eliminated the rest of the reciprocating mass. Flywheel's not loose, is it?

LOL

Dave-

The rods were professionally recon'd by Vintage Power Wagons, and the machine shop that did my block work checked them out and said they were well done... I used new pistons and pins too. I'm hoping that it's not the wrist pins... but I doubt that it is.

Pete

[blueskies]

Could be a cracked piston. A while back someone here posted a photo of a fresh rebuild with a broken piston skirt. Pete, I'll keep my fingers crossed that it's not something that damaged the crank or block.

Norm-

From what I can see from the bottom, the pistons look fine. There aren't any chunks missing anyway... And they sure look better than what came out the first time-

Pete

[Don Coatney]

Pete;

Was any of the stuff you found in the bottom of the oil pan magnetic? This may help you identify the source.

[Don Coatney]

Whoos There?

[blueskies]

Pete;

Was any of the stuff you found in the bottom of the oil pan magnetic? This may help you identify the source.

Thanks Don, hadn't thought to check... I'll find my trusty magnet and have a look-see...

Pete

[blueskies]

Whoos There?

???

Pete

[blueskies]

I didn't have much time last night to dig much deeper, but I did pull the rear (#4) main bearing cap for a look.

Squeeky clean... I plasti-guaged the bearing, and it's the same as when it was installed during the rebuild.

This is making me feel like I'm on a goose chase, maybe the noise isn't in the bottom end at all. I have not checked the other five rod bearings, but if it's not the rods or mains, it has to be in the valves or fuel pump? I was hoping for an obvious problem... with an easy fix...

Pete

[grey beard]

Pete,

Did whomever built your motor ever check the deck height from the cylinder head to the valves, before assembly. Everything about your motor job appears completely above reproach, so I'm searching for something that may have changed since assembly that might cause a tap. Wonder if a loose valve might be hitting the head. As I remember you have an aluminum head that may be pretty close to the piston domes. Just wondering . . . . . .

[blueskies]

Pete,

Did whomever built your motor ever check the deck height from the cylinder head to the valves, before assembly.

Well... that would be me... I've done all of my engine rebuild with the exception of the machine work to the block, and installation of the complete valve train. And no, I didn't check the valve to head clearance (doh!). This could definitely be a real possibility... That said, it would seem to me that if the valves were hitting the head, wouldn't they do it at all rpms? The noise seems to come in at around 2100 rpms, or at least is much louder at this rmp range. My valves are noisy though, and they were set at .014" cold for intake and exhaust. I've been wondering about this for quite a while acutally...

I really didn't want to pull the head, but it may be necessary if all else fails to turn up an obvious problem.

Everything about your motor job appears completely above reproach, so I'm searching for something that may have changed since assembly that might cause a tap. Wonder if a loose valve might be hitting the head. As I remember you have an aluminum head that may be pretty close to the piston domes. Just wondering . . . . . .

Thanks for all your input, it keeps me thinking...

Pete

[Niel Hoback]

Pete, would you do me a favor? I see what looks like a missing lockwasher on one of your flywheel bolts. Just for grins, would you check all your flywheel bolts and clutch cover bolts for torque? It just keeps bothering me that you are tearing into a lot of good work, possibly in vain.

[Don Coatney]

no, I didn't check the valve to head clearance (doh!). Pete

Thought you did so? I did;)

[blueskies]

Thought you did so? I did;)

Boy, I'm sure to catch hell if my valves are touching the head...

Pete