VG30 crank pulley "wobble"

[68Datsun510]

Hey all, long story short I have had a EFI VG30E from an 87 300ZX in my car since August. Among some teething issues, is a mysterious metallic sound on cold starts only, accompanied with what can only be described as a wobbling crank pulley. Bolt is to spec, all woodruff keys were new, etc. 

 

Not terribly easy to view the tiny amount of runout, but heres the noise at least. 

 

Anyone else ever experience this?

 

 

[datzenmike]

The VG30 was used in the Mercury Villager van and it had problems with the nose snapping off the crank. They went to a larger diameter snout. 

[Stoffregen Motorsports]

Cody, that motor don't sound too good...

 

Sounds like a low oil pressure rod knock, or a bad hydraulic lifter (did they use hydraulic lifters?). Either way, it doesn't sound good.

[Stoffregen Motorsports]

Dan sure loves that 1900 you sold him. I bet you wish you had it back right about now.

[68Datsun510]

Im not gonna admit defeat that easily...lol Dan had the connections and money to get that engine where it needed to be. Could I have done the same with the money spent on this engine? Probably... But I am still having fun with it, completely changed how the car drives, all that torque! LOL 

 

The noise isn't (at least i THINK) a rod, as is wouldn't go away once that warms up. And i have thrashed on it quite a bit, kinda need to to feel more confident with it over time. I doubt it will ever be as durable as that 1900 though lol Gonna pull the crank pulley and check the keyway and everything next weekend... Hopefully its just something dumb.... The ticking later in the video is just the injectors. 

 

It sure does sound nice though...lol

 

(freezing cold weather, not head gasket steam)

 

Edited January 10, 2019 by 68Datsun510

[68Datsun510]

4 hours ago, Stoffregen Motorsports said:

Cody, that motor don't sound too good...

 

Sounds like a low oil pressure rod knock, or a bad hydraulic lifter (did they use hydraulic lifters?). Either way, it doesn't sound good.

 

Yes they have hydraulic lifters, and thanks to Mobil1 they dont all tick like old pathfinders lol

[bottomwatcher]

Not too familiar with that engine but the end of the crank usually has some kind of harmonic balancer and they deteriorate over time. Again I don't know if this engine has one. Just throwing it out there.

[Stoffregen Motorsports]

A piston pin knock can sound like that and they do tend to go away once the engine comes up to temp.

 

I couldn't see the wobble in the video, but yes, if it is a vulcanized harmonic balancer, that could definitely be the cause of the wobble.

[68Datsun510]

2 hours ago, Stoffregen Motorsports said:

A piston pin knock can sound like that and they do tend to go away once the engine comes up to temp.

 

I couldn't see the wobble in the video, but yes, if it is a vulcanized harmonic balancer, that could definitely be the cause of the wobble.

 

 This later model engine is supposed to have full floating wristpins so I really hope that's not the issue. The strange thing is if you remove the V belt off the crank all the noise stops immediately.

 

 It does have a harmonic balancer but the pulleys are bolted straight to the actual sleeve around the crank. The balance ring is independent of any pulleys. After some fiddling yesterday it appears that the pulley is actually bent which can definitely give the optical illusion of having a bent crank. the pulley is stamped steel which is bolted to the machine hub around the crank snout.

 

I'm on the hunt for a complete set of 88+ pulleys for it.

[Jesse C.]

I think the crank is toast. Wobbly lower pulleys usually indicate a broken crank. And yes, they can still run like that. 

[paradime]

That noise is external and at a certain rpm at 0:08 you can hear the distinct slight ringing sound of stamped metal, not the deep nock of a bent or broken crank at all. If removing the V bolt stops it, that's pretty much case closed. I say break out the big hammer and get to work.

[68Datsun510]

On 1/15/2019 at 10:02 PM, Jesse C. said:

I think the crank is toast. Wobbly lower pulleys usually indicate a broken crank. And yes, they can still run like that. 

 

Ordered a new pulley/balancer as i found mine to actually be damaged. New bolt as well. Crossing fingers!

 

On 1/16/2019 at 1:54 AM, paradime said:

That noise is external and at a certain rpm at 0:08 you can hear the distinct slight ringing sound of stamped metal, not the deep nock of a bent or broken crank at all. If removing the V bolt stops it, that's pretty much case closed. I say break out the big hammer and get to work.

 

I thought so as well! I looked up piston knock on youtube, and ive heard rod knock before, way deeper and more ominous sounding. Hoping my new parts fix it .

[Jesse C.]

2 hours ago, 68Datsun510 said:

 

Ordered a new pulley/balancer as i found mine to actually be damaged. New bolt as well. Crossing fingers!

.

 

Hopefully that's all it is. Good Luck! 

[paradime]

I may be making assumptions here, but Cody sound like the kind of guy who changes his oil regularly and takes care of his toys, but you never know what the PO did. I have sympathy, because I know that feeling of not knowing a salvaged engine's history.

 

A bent pulley wouldn't be out of the ordinary. I've seen all kinds of damage done by the folks who pull the engines and the monkeys moving, storing, and shipping them. Being that the pulley is low and right out front makes it vulnerable. My SR had the usual crushed oil pan and bent pickup, but for some reason instead of simply undoing the bolts, they used a sawsall to cut the rubber on the engine mounts. Also had a broken CAS cover and the entire fan and clutch assembly was jacked. Looked like it was in a demolition derby by the time it got to my shop. Fortunately the long block was in great shape and after 6 years of thrashing on it, it's still throwing down the HP.  I wish you the same fate. 

[68Datsun510]

18 hours ago, paradime said:

I may be making assumptions here, but Cody sound like the kind of guy who changes his oil regularly and takes care of his toys, but you never know what the PO did. I have sympathy, because I know that feeling of not knowing a salvaged engine's history.

 

A bent pulley wouldn't be out of the ordinary. I've seen all kinds of damage done by the folks who pull the engines and the monkeys moving, storing, and shipping them. Being that the pulley is low and right out front makes it vulnerable. My SR had the usual crushed oil pan and bent pickup, but for some reason instead of simply undoing the bolts, they used a sawsall to cut the rubber on the engine mounts. Also had a broken CAS cover and the entire fan and clutch assembly was jacked. Looked like it was in a demolition derby by the time it got to my shop. Fortunately the long block was in great shape and after 6 years of thrashing on it, it's still throwing down the HP.  I wish you the same fate. 

 

I appreciate your assumptions! I do take care of things as best I can! That being said, this VG was certainly not in BAD condition when I got it... I went through the motor and found almost zero sludge, no water evidence, and even looked to have frequent oil changes! Bearings were mint! But that doesnt mean accidents didnt happen along the way, the pulley damage looks like the typical removal without a puller, so they use a prybar...on a thin steel pulley...SMH. Hoping to have time to tackle it asap.