D15z1 vibrations, frustration running high
 

Here goes,

Short of it is I just put a rebuilt engine (never ran before, got from salvage yard) in my vx and have a vibration that goes into the gear shift knob and the clutch pedal. Its a high frequency vibration that makes my foot feel tingly and hand numb and gets noticeable above 1500. Does no matter if pedal is pressed in with gear selected or in neutral. Just to rule out the trans, I took the transmission off to check flywheel run out (had resurfaced already), looked at the pressure plate fingers for evenness and clutch disc for high spots and release bearing for smoothness (all new components). Trans is freshly rebuilt and shifts smooth with new bearings.

I looked at the crank pulley and saw that it wobbles a few thousandths as well as the bolt. I placed a screwdriver on it while running and there is a noticeable lope. My question is, does this happen on all these motors?

I have not had a chance to get to the machine shop to have them look yet but have a bad feeling they will say its normal. I do not remember the clutch pedal vibrating with my old setup. Getting very frustrated at this point because I even paid extra for the shop to individually balance the complete rotating assembly. I just don't want premature bearing failure.

Need some feedback from VX owners. Thanks.

Re: D15z1 vibrations, frustration running high
 

My vx does not vibrate like you say. I don't know what the problem is, but mine doesn't do that.
By crank pulley I assume you mean the harmonic balancer? Mine is spot on, no vibration/lope at all. It might be the cause of your problem.
B

Re: D15z1 vibrations, frustration running high
 

So the salvage yard pull the engine from a wrecked vehicle and rebuilt it just for you? Do they have a machine shop on site? Did the engine come from a wrecked car?

Ask them if they installed new undersize bearings, if so, I wonder if they reground the crankshaft and didn't have the machine set up properly- so it was not ground true. The crank pulley should not wobble.

It isn't a VX, but my 1987 1.5 liter civic motor has a small amount of vibration above 2400rpm- but not enough to make one's hand numb.

Re: D15z1 vibrations, frustration running high
 

If I lightly start to rest my foot on the clutch pedal while at idle(in neutral of course), I feel a continuous vibration through the pedal. Now, I know my clutch is wearing and needs replacing, but if I got a clutch replacement/ISB replaced as well...and it continued??

...I've always wondered if that was wrong, my first manual so I didn't know either way.

Re: D15z1 vibrations, frustration running high
 

I got the engine from the savage yard with 90k, took home and performed a leak-down test and exhaust valve seats leaked badly. At that point I decided on a complete overhaul. I took it to a machine shop and they did all the work. New bearings, 20 over pistons, I even had them balance the whole rotating assembly including flywheel and pressure plate. I was there when they put the oil pan on so I saw areas that material was removed. The bearings are standard and they polished the crank. I told them to check everything. I would assume that would include the crank if they balanced it but who knows. I paid 1250 for all the machine work so lets just say I'm surprised at this. I have an idea to remove the (balancer) and put the screwdriver on the crank snout and see if there is a wobble. Thanks for the responses. It helps to know that the crank should be absolutely true. Any other ideas are welcomed.

Re: D15z1 vibrations, frustration running high
 

There should be a metal access cover under the trans that will allow you to see the flywheel. It would be interesting to see if the flywheel also wobbles when the engine is idling.

Re: D15z1 vibrations, frustration running high
 

I plan on getting to it on Thursday. I called the machine shop and will have them take a look at it. I will also check the spark plugs to make sure a lean condition isn't causing the rough running. Another thing, if I sit in nuetral and do quick bounces on the throttle around 1700 rpm, it sounds king of like a rock tumbler at the instant the throttle is pulsed. It seems like a resonance of the rotating assembly that is not there much over or under that spot. Anyone experience that?

Re: D15z1 vibrations, frustration running high
 

"Rock tumbler" is exactly how I would describe spark knock in a large-displacement GM V6 or V8. See this post for a video I found that captures the sound perfectly:
https://www.gassavers.org/showpost.ph...4&postcount=59

Re: D15z1 vibrations, frustration running high
 

i've owned several GM V6 and 8s....that noise is quite familiar!

Re: D15z1 vibrations, frustration running high
 

I plan on checking the plugs for any indication of lean firing or detonation. I used a mix of used parts for sensors and such. Three injectors that I had and one from the old motor. I verified function using compressed air and filling the inlet wth penetrating oil, checking the spray pattern. Also plan on checking the EGR for leaks to see if that is the cause of rough running.

Re: D15z1 vibrations, frustration running high
 

Just checked the plugs and 3 out of four are perfectly clean on the insulator. The fourth one is a nice dark tan color. I used 3 injectors from the junkyard motor (the fourth one was stuck closed) and a fourth from the engine that just came out. Im guessing that the injector that gave the good pattern is the one from my old engine. This is exciting because an imbalance in fuel ratio could be the vibration (and spark knock sound) Im chasing.
I will install the 3 other injectors from my old setup and report back. Any votes of confidence that this is the cause?

Re: D15z1 vibrations, frustration running high
 

Vote +1

Not only could the pattern be bad, but the injector size could be incorrect. Are you sure you are running four 190cc injectors? Many other models use 240cc injectors and that would 100% cause a problem.

Re: D15z1 vibrations, frustration running high
 

I ended up puting all 4 injectors from my old motor back in and no difference in running except peace of mind. I took it to the machine shop and they said the engine seems to be fine but the noise (knocking) Im hearing is from the distributor area. This is a unit I never ran before so willing to try it but doubt full that it could produce a sound. He said the vibration in the clutch is most likely the throw out bearing but that is new as well. I will let you know when I change the distributor.

I plan on posting a different thread on how to tell the difference between injector types because I was aware of the different flow rates. The only identifying marks are in four holes on the left side of the injector body. Mine read 2HA7 and 2HA8. There is usualy a little smear of white paint here and there is sky blue paint around the injector body as well. I have another random set that read 5JCW with a smear of yellow paint

Anyone care to report the alphanumeric on the side of the D15z1 and the rest (lx-EX)? I looked in google for these numbers and would like a way to tell with all of these loose injectors.

Re: D15z1 vibrations, frustration running high
 

A couple of ideas-
Possibility of the timing belt being off a tooth? Worth checking out, it would cause vibration/ lack of power, etc.
Ignition timing way too advanced.... which could be related to a timing belt on the wrong tooth....

I doubt highly noise could be coming from the dizzy. I suppose vibration at the pedal could be the throw out bearing, but you had it replaced.... so....

After those ideas, I'd start to think about faulty bearings/machine work. It's possible the new bearings had problems before going in. They could have been defective from the factory. It still seems terribly unlikely since the shop should have noticed that after assembly.

How's the idle? (rpm, smooth, etc) How does the engine feel in terms of general power? Did you replaced all plug wires/dizzy cap/rotor etc when doing the rebuild? Bad plug wires could cause some vibration, me thinks.

B

Re: D15z1 vibrations, frustration running high
 

Timing is set to middle notch. Checked that twice. Talked to the machinist about mabe cam timing and he said it would not run as smooth as it is had it not been right. I checked it three times when setting up the motor but did it with the damper pulley on the cam cover because I did not notice the index on the crank gear. I thought I could have put that on backward but figured if the damper matched the 0? mark on the cover, should be good right. That is the only anomaly I can think of.

I reused the wires from my old setup because they are new. Cap and rotor from new dizzy had brass inserts so I decided to keep using them. Put the old dizzy in and same noise. I will have to make a vid of the sound but next thing I could do is replace the entire cam/rocker assembly with the known good setup. The machine shop said they could check the cam for straightness. What a pain.

Re: D15z1 vibrations, frustration running high
 

I really don't think that a bent cam would cause as much engine vibration as you described.

How did they determine that the head/dizzy was the source of the noise/vibration? The only way that I know that works is a long screwdriver pressed to the ear.

Re: D15z1 vibrations, frustration running high
 

We used a mechanics stethoscope and I kept bouncing the rpms in the noticeable range 1500-2000. I listened and it was loudest on the distributor housing but I suggested that maybe the hollow chamber in the dizzy actually resonated the sound making it louder there. I guess I was on the right track because it was no help. The noise is so dense sounding that its hard to point out. After listening to rod knock vids on youtube, it almost sounds that way but it only happens with quick revs in neutral or when shifting and I happen to change gears at that RPM. Machine shop says I should get knocking on cold start and I dont. I really think that whatever is causing that noise is also sending the vibes through the input shaft and release fork. Need to get a vid posted.

Re: D15z1 vibrations, frustration running high
 

Have you been able to view the flywheel while it is running? If the flywheel is wobbling it would definitely transmit this motion through the release fork. If you manually push on the release fork with the engine idling, does it shake?

I have heard that a rod knock will get louder when the spark plug wire for that cylinder is removed- you could try that.

Piston slap makes a rattling noise that is worse when the engine is cold and gets less noticeable as the engine warms up (maybe they got the piston to bore fit a little loose).

Re: D15z1 vibrations, frustration running high
 

Any chance your tranny input bearing is bad and is causing the noise? Is it still noisy when the engine is reved when the clutch pedal is pressed?

Re: D15z1 vibrations, frustration running high
 

+1 on the flywheel. Also check the cooling fan. Both could be close but clearing ok under most conditions, but a little bit of flex in the engine mounts could make the difference under certain conditions.

My truck has piston slap when cold and it doesn't sound like rattling to me, it sounds like a general diesel engine idling sound (not the clattering portion of that sound but the smoother portion).

AFAIK rod knock always gets louder under heavier load.

Re: D15z1 vibrations, frustration running high
 

I have heard of removing the plug wire to each cylinder to tell if removing 1 compared to any other 3 that are still connected, would make a difference.

If there is ticking, sound resonating...and it's related to a spun bearing, you'd figure the one with the spun bearing(if there is one), would reveal a difference in the idle sound when that one suspected cylinder is not receiving spark compared to when 'healthy' cylinders are continuing to receive spark.

...by the way. I TOO had ticking sounds top-end that I couldn't quite determine where it was. It sounded like it was below the dizzy. I do have a worn clutch, and whatever related parts that may be allowing for extra 'noises' associated with such, that's been my hope for now as I hope replacing that will get me home free moving forward.

ADDED: With the mention of the ISB, which of the following is it in the following link?

https://www.hondaautomotiveparts.com/...CLUTCH+HOUSING

I see a few bearings of the Main-Shaft and Counter-Shaft, I'm trying to identify which bearing is the ISB. I'm guessing so far it's p/n 9? Right at the Maintshaft meeting the clutch housing?

Re: D15z1 vibrations, frustration running high
 

Yep, #9

Re: D15z1 vibrations, frustration running high
 

Thank you. Not trying to hi-jack your thread.;)

Noob mechanic here. Just trying to plan ahead the best C.O.A. to replace the ISB when I get the clutch done after tax returns in the spring.:D

Re: D15z1 vibrations, frustration running high
 

Check these out
https://www.youtube.com/watch?v=iATYUS_CNy8

https://www.youtube.com/watch?v=l-ckNka5mkU

https://www.youtube.com/watch?v=3wKXT48NOWI

descriptions in the title.

I think Im closer after removing the spark. Did not have time to drop exhaust to check flywheel.

Re: D15z1 vibrations, frustration running high
 

Definitely sounds like a rod knock or some sort of internal engine noise, IMO. Is it for sure rod knock? I don't know. Great videos though.

By the way, any reason you chose to unplug the injector on cylinder #1 when you removed the spark plug wire for #1?

Re: D15z1 vibrations, frustration running high
 

This is worth watching. You may want to get an oil pressure gauge and see what actually the oil pressure is.

https://www.youtube.com/watch?v=8f2fcbTh5yw

Re: D15z1 vibrations, frustration running high
 

Manually pushing the clutch release lever forward with you fingers while idling will tell you if the flywheel is wobbling.

Are you sure that you don't have any exhaust leaks around the manifold or cat?

I think a rod would be knocking all of the time, not just in a particular rpm range.

I wonder about really bad piston slap- almost like the pistons are really loose and rattling/tilting back and forth at a particular rpm. I get piston slap around 2000 rpms on cold mornings it is loudest under a slight load and it gets fainter as the engine warms up.

A loose wrist pin(s) might be another possibility.

If the vibration and noise are correlated, then I think it may point to a piston issue. If the crank was unbalanced, then the vibration ought to get more severe as the rpm increases more and more.

I wonder what the machinist would say if you asked to have the original pistons back- this would prove that really did put new pistons in the engine.

Re: D15z1 vibrations, frustration running high
 

I unplugged the injector because I did not like the idea of so much unburned fuel going into the cat being that these maniverters are hard to find.

No exhaust leaks to speak of, I have been under with the engine running.

I also think rod knock would get worse with rpm or be noticeable on start up
Piston issues seem more likely.

I delivered the pistons myself and saw them in the block before the head was torqued. I did notice that while I was spinning the crank by hand while doing the timing belt that there was a clunking noise when the pistons changed direction but the shop said that is normal piston rock and assured that the piston to wall clearance is good.

I will check the flywheel and try to get the oil pressure but its looking more and more like I just need to drive it until something gets louder. If I'm pulling it back out I want to be sure.

Re: D15z1 vibrations, frustration running high
 

Did they give you a warranty? Most junkyard engines have a 30 day warranty. With all of that machine work you ought to have at least a 90 day warranty.

If you have a warranty, you might as well drive it until it gets louder/fails or proves itself.

A quick and dirty way to check hot oil pressure is to get the engine nice and warm and stall the engine in 5th gear while stopped. If you can drag the engine down to 50 rpms and the oil light is still not coming on, the bearing clearance is pretty tight. After killing it while hot, unplug the injectors and crank it over. With a nice tight engine, the oil pressure warning light should go off at cranking speed, even with the engine oil hot (thinned oil somewhat).

Re: D15z1 vibrations, frustration running high
 

Great follow up by Erik. I can see the logic now pointing towards top-end instead of rod knock, sorry for giving false-direction. I'm curious as to how this turns out, and do agree it's not worth pulling unless you can confirm what it is.

It could be wrist pins, it sounds terrible either way.

Re: D15z1 vibrations, frustration running high
 

That knock sure sounds like a rod bearing to me. Could be a wrist pin but it's more likely the shop did not check the bearing clearances with plastigauge.
I've had rod knocks in engines that only occur at particular RPM ranges. In the cases I've investigated I found the rod journal to be egg shaped. In other words if you put a caliper on the journal or plastigauge it on the less worn sides and then it may appear to be OK but you need to measure the journal for egg shaped out of round and left to right.
There should be no clunk sound when you rotate the engine by hand as you mentioned.
I'd pull the plugs and rotate the engine by hand again to see if you can repeat that clunk. It may give you another clue as to what is wrong.

Re: D15z1 vibrations, frustration running high
 

rbhollanbaugh makes some really good points.

Do you know if they used Honda rod bearings or aftermarket rod bearings?

To get the rod clearances perfect on these Honda engines, you have to look at the stamped codes off the rods and crank and get specially sized/color coded bearings to fit nice and tight. I rebuilt an 87 Civic 1.3 liter engine that I picked up from the junkyard. When I was putting it back together, I noticed that the aftermarket rod bearings were a little bit too loose, but still within the service limit so I went ahead and used them to save money. I used mostly aftermarket main bearings, but there were two that were too loose when I plastigauged them so I had to get the special color coded ones from Honda. BTW- the machinist that inspected/measured my crankshaft said it was not worn and the original bearings were in pretty good shape.

Here's a link to the engine rebuild section of the 92 Civic factory service manual where it addresses bearing clearance. On the next page you will see the color coding that I was describing: https://www.redpepperracing.com/techn...6/aaf.png.html

Re: D15z1 vibrations, frustration running high
 

Yes, I agree 100% with Erik. When I replace bearings on a Honda I use only the correct size of bearing based on the color and letter/number stamp (rod and main bearings are coded differently and it's been a while). As far as I know only replacement Honda bearings use this scheme. If you use the "standard" aftermarket bearings you may get one that is loose or possibly too tight. Since they only come in one size.
If you don't know what the originals were you can calculate it and I think there's a table in the honda manual of measurements and colors.

The other possibility is what happened to me once. I plastigauged the rods and main bearings. All was within spec. Then took it all apart to clean off the plastigauge and oil the journals before tightening the caps down to spec.
After assembling the engine I was turning it over by hand and noticed a very slight clunk. I pulled the pan off and by grabbing each rod bearing and wiggling I found the loose one and that a spec of something had gotten between the mating surfaces of the bearing cap and rod. Cleaned it up and all was well.

Re: D15z1 vibrations, frustration running high
 

these are all great suggestions and I want to try them all. I work a 12 hour schedule and have 3 kids so it may take a few days. I will report back so thanks for sticking with me.

Re: D15z1 vibrations, frustration running high
 

And so what are you doing with those other 12 hrs of free time per day? ;)

Re: D15z1 vibrations, frustration running high
 

Yeah well, if you dont watch out, free time can cause more kids! Anyway, I tried the coast down method in 5th and the oil light never came on but just before the point of stall I can hear the rhythmic knock. Its looking more and more like a tear down every day. I was afraid of damaging the pressure plate springs because I read on there website that lugging can do that.

I still need to feel the clutch for and spin the engine over by hand with the spark plugs out.

Re: D15z1 vibrations, frustration running high
 

I can't imagine how low RPM or lugging could damage, of all things, pressure plate springs. I don't suppose you have a link to that? I'd love to read the explanation, there could be something for me to learn.

Re: D15z1 vibrations, frustration running high
 

^Could a partial clutch failure(yet still 'operable') cause the engine to lug more, conversely?

Re: D15z1 vibrations, frustration running high
 

I will be taking the engine out this week. I have taken time away from this project lately hence the lack of posts. I will report back the findings from the machine shop ( and there better be some).

As for the clutch system damage due to lugging, I read about it in here;

https://www.schaeffler.com/remotemedi...ose_pkw_en.pdf

It was example 18 in fail type D. It is a good read none the less.

Re: D15z1 vibrations, frustration running high
 

Ah. That's not the pressure plate, that's the clutch disc. The springs in question, named "torsion damper" in that document (I've always wondered what they're called), take up excess torque gradually to reduce shock to your drivetrain and engine when you dump the clutch too harshly.

For those springs to fail from high torque makes sense, although I doubt low RPM is required.

Cool file, I'm going to read the rest of it. Thank you! :)