6.5L Vibrations, any ideas what it can be?

[Paveltolz]

Good to hear you’re back on the road. Sucks about the IP.
Regardless of seller, none of the 6.5 parts suppliers rebuilds the IPs they sell. We just have to find a dealer who gets their stuff from reliable rebuild companies. That’s why it’s the fortunate few who ask here first before plunking down $$$.
I went through an IP nut roll a couple years ago and the seller swapped out four IPs with last one being from a different rebuilder. Looonnggg story.
Not defending SS Diesel by any means as when I bought it had a few SSD parts and in my newbieness, it got a few more. Long story short, they got replaced in short order. FWIW, Walt’s in failing health these days.

 

[Scott_2255]

Good to hear you’re back on the road. Sucks about the IP.
Regardless of seller, none of the 6.5 parts suppliers rebuilds the IPs they sell. We just have to find a dealer who gets their stuff from reliable rebuild companies. That’s why it’s the fortunate few who ask here first before plunking down $$$.
I went through an IP nut roll a couple years ago and the seller swapped out four IPs with last one being from a different rebuilder. Looonnggg story.
Not defending SS Diesel by any means as when I bought it had a few SSD parts and in my newbieness, it got a few more. Long story short, they got replaced in short order. FWIW, Walt’s in failing health these ds

Good to hear you’re back on the road. Sucks about the IP.
Regardless of seller, none of the 6.5 parts suppliers rebuilds the IPs they sell. We just have to find a dealer who gets their stuff from reliable rebuild companies. That’s why it’s the fortunate few who ask here first before plunking down $$$.
I went through an IP nut roll a couple years ago and the seller swapped out four IPs with last one being from a different rebuilder. Looonnggg story.
Not defending SS Diesel by any means as when I bought it had a few SSD parts and in my newbieness, it got a few more. Long story short, they got replaced in short order. FWIW, Walt’s in failing health these days.

Sorry you had to deal with injection pump issues too. That's unfortunate to hear the owner of SS Diesel is having heath issues. Seems like replacement staff is failing terribly. I know I'll never buy from them again as they wouldn't even respond to a warranty claim and they kept my deposit for the working injection pump I sent them. I wish I had that one, even with 229k miles on it,it ran better than the one I purchased and then paid more money to have a local shop fix it!

 

[Paveltolz]

Dropped a metric butt-ton of $$ at SSD before I wised up. He was happy to sell parts I thought I needed when I didn’t. First time a vendor talked me out of buying stuff cause they knew I didn’t need them, he had a loyal customer. New owners have been ok but, not the same.

I wish my old IP was on mine as well. It was a new Stanadyne With only 25K on it. Still on the shelf though. The new owners at Heath did me a solid and didn’t charge for a core. That was because at first the pumps were suspect. Oh well. Hang in there. Live, learn and let it go.

 

[Will L.]

SS Diesel needs to sink.
I don’t ever wish bad health on anyone- but if I saw him face to face I would beat the crap out of him. No way would he walk away with all his teeth intact.
Ripped me off big time at a time I couldn’t afford it. Never made it right- like many many others experienced from that crook.

 

[Scott_2255]

Hello again to everyone in the forum. Well I thought things were improving on the vibration issue with this engine but they have not totally disappeared. Since my last update I have made some additional changes unfortunately. I've been daily driving the truck for awhile to put some hours on the engine and the more I drove it the more apparent it became that there was more than a flex plate issue with this vibration problem.

The truck was getting difficult to start, seemed to have lower power and acceleration than the old tired 6.5. Since the injection pump has been a problem since I got the engine back together, had it re-built (sort of) its still not been as good as the engine that was tired. I pulled the trigger and purchased a re-built one from Quadstar. Big improvement! But vibration was still there at certain RPMs, ended up removing the neoprene motor mounts and went back to the stock rubber ones, another huge improvement but the truck still has a pretty serious vibration at 1400 rpm. Above 1400 and below 1280 vibration is not there, It smooths out. Been getting creative in my driving, ha ha.

Pulled the boat this weekend with it and it did ok, lots of steep hills for several miles at higher altitudes. The engine vibration was very annoying to the point I was ready to sell this for what I could get and move on.

I have thought about it some more and have one other idea besides having the rotating assembly balanced which means pulling engine to get that done which I feel would be best but I want to be able to use this thing and hate to make that decision if its something else.

Info on it so you don;t have to read past posts. Truck has a Fluid damper, billet one piece pulley for the belt, a idler puller I added to eliminate belt vibration (vac pump deleted). The idler helped a lot too. the crank shaft is a scat and I failed to have the crank and rods balanced by the machine shop unfortunately.

My question is, could a faulty injector cause bad harmonics at a specific rpm? It starts fine but when cold the truck does shake a bit and seems to smooth out when it warmed up above 140. The injectors are not that old and were in the other engine and they had less than a year on them with probably less than 500 hrs and are Bosch matched (supposedly).

Sorry for the long message just wanted to recap what has occurred since the warped flex plate was replaced. Dont want to replace them if not needed but also want to avoid pulling engine this winter if its an injector.


Thank you again for taking the time to read this and for all the support and advice I've recieved on this. Its' been amazing and hopefully helps other avoid the same pitfalls I've experienced

 

[Will L.]

The rubber engine mounts aren’t fixing anything- they are masking it.

Verify the vibration when in park/neutral. You have to eliminate everything behind the engine. Taking out the driveline and axles is easy that way.
There is still the possibility of the transmission being at fault- that obviously takes removing it or engine except Unbolt the TC from. Flexplate and slide it back secure it from coming forward using safety wire. That eliminates the transmission from being the cause.

Remove the belt and test. You can run without coolant circulation for a couple minutes at those rpm. If you want to verify balancer and pulley- pop them off and install the stock balancer if you have a good one still.


On injectors- replacing is almost only option. Test the pop pressure is same in all.
You can try cracking up in one injector at a time while the engine is running and listen for differences in how the engine sounds and vibration. Then swap around locations of the injectors, like swapping injector, one and two with each other. See if that alters vibrations. Not as clear but free labor vs $ spent for having the injectors pop tested.
If you do send them in or test yourself- get them to within 25psi of each other.
Unbalanced amount of fuel or how good they are misting will have a huge impact.

 

[Scott_2255]

The rubber engine mounts aren’t fixing anything- they are masking it.

Verify the vibration when in park/neutral. You have to eliminate everything behind the engine. Taking out the driveline and axles is easy that way.
There is still the possibility of the transmission being at fault- that obviously takes removing it or engine except Unbolt the TC from. Flexplate and slide it back secure it from coming forward using safety wire. That eliminates the transmission from being the cause.

Remove the belt and test. You can run without coolant circulation for a couple minutes at those rpm. If you want to verify balancer and pulley- pop them off and install the stock balancer if you have a good one still.


On injectors- replacing is almost only option. Test the pop pressure is same in all.
You can try cracking up in one injector at a time while the engine is running and listen for differences in how the engine sounds and vibration. Then swap around locations of the injectors, like swapping injector, one and two with each other. See if that alters vibrations. Not as clear but free labor vs $ spent for having the injectors pop tested.
If you do send them in or test yourself- get them to within 25psi of each other.
Unbalanced amount of fuel or how good they are misting will have a huge impact.

Thank you Will for the input and suggestions. I agree that the softer mounts only mask it. I'll try unbolting the torque converter from the flex plate again to see if that helps.

I'm thinking it might be injectors as the vibrations between 1300 and 1400 appeared after driving it for awhile. Put a pretty good load on it pulling the boat up several mountains to the lake.

Hopefully it's injection not trans . Separating the flex plate from converter is not too difficult luckily.

I tried turning off one injector.at a time with the scan gauge but I didn't notice anything different which puzzled me.i ran it in park up to that rpm while testing. The only thing it did was drop engine rpm.


Thanks again for the help

 

[Twisted Steel Performance]

That rpm is where the rotating imbalance will show up.

 

[Scott_2255]

That rpm is where the rotating imbalance will show up.

Very interesting, was kind of afraid of that! Going to disconnect the flex plate from converter one more time just to see but considering everything else I've looked at balance seems to be the item that continues to pop up in my mind too. The newer injection pump has made a huge difference, still pretty sore about that entire adventure/scam! Was hoping the vibration was something other than a rotating assembly issue. If it is I guess its pull the engine this winter and start over or walk away from it but I don't want to do that. I've been pretty creative in my driving to avoid that rpm range but that's not a fix either.

Thank you for the info

 

[Will L.]

Worse case scenario is pull apart and rebuild the engine. Imagine if you see a couple things wrong and some parts required- then another balance job- you will have it fixed for under $750. To me, that is worth it because if you sell the truck with the shake- you won’t get full money for it. Now that amount of money buys a different used truck with its own problems.

 

[Scott_2255]

Worse case scenario is pull apart and rebuild the engine. Imagine if you see a couple things wrong and some parts required- then another balance job- you will have it fixed for under $750. To me, that is worth it because if you sell the truck with the shake- you won’t get full money for it. Now that amount of money buys a different used truck with its own problems.

Wil, you're totally correct. I feel the same way, just sometimes the easy answer seems appealing although not smart financially. Pulling the engine out and getting it balanced is a pain but definitely cheaper than buying another used truck with high miles and it's probably for sale due to items needing attention.

Definitely cheaper than 25-30k. Just frustrating as its been a long time due to the injection pump debacle.

 

[dbrannon79]

Am I recalling correctly that you installed a scat crank or am I thinking of another thread here? if so, for whatever reason I seem to recall someone else having issues with the scat crank and balance issues. it's possible that the mfg of the scat crank does do balancing but they do it with just the crank and not with the rods and pistons weight.

 

[Scott_2255]

Dbrannon79, yes you're right. It does have a Scat crank. I didn't think about balancing the crank with the rods unfortunately, big mistake. The fluid damper is supposed to help? It probably is but due to the potential balance issues it's been very interesting. Kinda changed my opinion on a few things.

Pretty shocked how much it vibrates after all the other stuff I have replaced. I did have a warped flex plate and replacing that made a big difference. It was basically undrivable between the crap injection pump from SS Diesel and the warped flex plate.

Going to remove the flex plate from the converter to see if it is the transmission or engine. Have a sinking feeling its balance issues on the engine. That was mentioned before but I had other issues too. Now that those are fixed it seems like the only additional thing left.

Vibration is significantly less but there's a specific range it vibrates, not like before but it's definitely noticeable.

 

[dbrannon79]

Try removing the TC from the flexplate like others are saying first and then the engine belt. that part is free to try! after that, if you don't have the OEM balancer, do what I did to locate a GM one using a website called oemcats. I located one at a dealership in my area, called them to verify they had it. it was a bit of a drive but for $100 it was worth it. youll need the GM part number to search that site too. then if that doesn't help matters you will have the GM one to send with the crank and other parts when you are sure the crank needs to be balanced. you don't want to use the fluidamper when balancing the crank. at least that is what I understand.

 

[Scott_2255]

Try removing the TC from the flexplate like others are saying first and then the engine belt. that part is free to try! after that, if you don't have the OEM balancer, do what I did to locate a GM one using a website called oemcats. I located one at a dealership in my area, called them to verify they had it. it was a bit of a drive but for $100 it was worth it. youll need the GM part number to search that site too. then if that doesn't help matters you will have the GM one to send with the crank and other parts when you are sure the crank needs to be balanced. you don't want to use the fluidamper when balancing the crank. at least that is what I understand.

Cool, thanks for the info. Lots to do. Might be a bit but I'll definitely take everyone's suggestions and see what I find. Busy summer, don't always get the time to wrench on it and luckily it's not my daily driver
.

 

[EWC]

The FD website states that you can not use it when balancing . It will need a stock balancer for the machine work or something else ? Maybe Chris can comment .

 

[Twisted Steel Performance]

All cranks are "factory balanced" it is not the same, they use a different way. A true balance starts with ALL things connected to the crank, get each rod balanced , big & small ends, pistons, pins, clips, etc. The 2 forged cranks in house had major weight changes from adding weight where the factory had removed some and removing weight where it was too heavy.

I have the specs and pics of just how bad the assembly was, my machine shop couldn't believe how bad everything was till he saw it first hand.

I hold a 2tenths of a oz tolerance on everything and my shop holds his to 7000rpm spec, same as he does for race motors.

 

[Scott_2255]

All cranks are "factory balanced" it is not the same, they use a different way. A true balance starts with ALL things connected to the crank, get each rod balanced , big & small ends, pistons, pins, clips, etc. The 2 forged cranks in house had major weight changes from adding weight where the factory had removed some and removing weight where it was too heavy.

I have the specs and pics of just how bad the assembly was, my machine shop couldn't believe how bad everything was till he saw it first hand.

I hold a 2tenths of a oz tolerance on everything and my shop holds his to 7000rpm spec, same as he does for race motors.

Very interesting, never knew that. Lessons learned. Didn't even think about balancing it. For some reason I figured it would be fine.

 

[Will L.]

100% YOU MUST BALANCE WITH A GOOD AC DELCO BALANCER. I agree with Chris’ explanation. Usually only race engines get balanced. When they balance a 6.5- they will have a heart attack. They can’t believe these engines stay together- imagine that with all our broken blocks and crankshafts.

Some key points. You must instruct them to NOT make any changes to the balancer or the flexplate/flywheel. Tell them you 100% will be replacing both of them.

Most balances are done for 5-6,000 rpm- jumping to 7,000 is a next level up and not all shops can do it. Usually it is done by doubling the factor-
If you know your normal rpm you run your engine at most of the time- sharing that can be helpful. They will should balance it for high rpm like Chris said- but if you are hot shotting and run down the hiway at 2550 rpm for hours at a time- they can adjust their test and get it fine tuned for that -this is a harmonics thing so 3,000 rpm =1,500= 750= 375. An example is if you have a tire out of balance and truck vibrates at 25 mph and again at 50mph- thats harmonic vibrating frequency - think through the term harmonic balancer…

Wish I had a good balancer to ship you to use. One of the friendly guys here sent me one- and after having mine balanced there was another guy here who needed a balancer and was thin on the wallet so I sent it to him. My fluiddampr is on the shelf awaiting build day in about 700 years. Haha

These engines are not smooth- but they grenade themselves when no noticeable shake is occurring. If yours is noticeable- it is trying to self destruct. This isn’t your DD- so take it seriously and if you can’t find it external…1 option left.


Oh yeah- something that hit me.
Paint marker on flex plate “ENGINE SIDE” and “TRANSMISSION SIDE”. Just like many of us put them on backwards at one time, machinist make errors also. When you assemble you’ll feel better anyways.

 

[Scott_2255]

Thank you Will, definitely a lot of good information here from everyone that will ensure I get it balanced correctly. From everything posted it really seems like balance issues.

Hopefully my mistakes and ignorance with balance on the 6.5 will help someone else in the future. As I don't drive it often hopefully it'll stay together until I can get it balanced. Definitely not wanting to drive it much now until it's corrected.

Lots of other projects taking my time presently. So it'll be in the fall before I can tear into it for balance unfortunately.