D15z1 vibrations, frustration running high

[honerscivic]

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.

[benfrogg]

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

[GasSavers_Erik]

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.

[add|ct]

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.

[honerscivic]

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.

[GasSavers_Erik]

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.

[honerscivic]

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?

[theholycow]

"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:
http://www.gassavers.org/showpost.ph...4&postcount=59

[bowtieguy]

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

[honerscivic]

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.