mep002a vibration

[sandfantom]

I have been playing around with my new to me 002a and have noticed when it runs, it seems to have an excessive vibration. Almost acts like some thing is way out of balance.

Have checked out a few utube vids and my genny does not run near as smooth as they do. I haven't put a load on it yet as I am still trying to figure out my 24v dc charging problem. I have the front flywheel shroud off of it now.

I doesn't seem like it is missing but I am not sure. I have adjusted the valves and that made quit a difference in the noise that I was hearing. Once I get the dc working and get the shroud back on I suppose I could run some injector cleaner through it to see if that makes a difference. There are few diesel shops around and I should probably have my injectors checked.

I used the search on this forum and really couldn't find anything related to my problem. I will try to post a utube vid in a day or two.

Any advice would be appreciated

thanks

sandfantom

 

[jbk]

the 002 is going to vibrate alot more than the 003, nature of the beast. i was going to suggest adjust valves as this made a big differance to mine. might recheck, if out a little it can make a big differance(vibrate). it will run on one cylinder but will take its time to come to speed. try putting some electric heaters on it, but not through the conv. outlet. if not hitting on one cylinder it will fall on its face with a signnifigant load(5 or 6 kw). i would think it woud have a wet exhaust from the unburned fuel, might even smoke a little. the dc regulators are a comon failure. the stators not so much most of the regulators i had to replace were overcharging 31 plus volts.

 

[Harleyd315]

I have had a similiar problem on some of my sets. What I have found very helpful is an infared thermometer or laser thermometer. You just point it at an object and it gives you the temp. Most of the sets that had bad valve adjustments or bad injectors were hotter than the others. Although no fuel thru an injector would give you a cooler reading. Take off the to shroud cover and use the exhaust manifold on each cylinder to get a reading. Then I put the shroud back on, put a load on the set and raise the shroud cover and take a reading on the head in between the push rods. I didn't record the temps but the ones that were bad were about 150 degs F hotter than the rest. I'm new to the aircooled diesels but with the larger equipment and trucks I worked on, turbo boost and EGT were a good indicator of a good running engine.

 

[RichardR]

Sandfantom and jbk,

My 002 also vibrates a lot more than I expected. It is a fresh rebuild with only a couple hours on the clock, so I didn't expect that at all.

The shaking is worst at the blower/front end, so I looked in that area first. My first suspicion was that the blower wheel was out of balance. I have seen similar effects on other small generators when a fin gets broken off the blower flywheel, throwing the balance off. But my 002 has all the fins still attached.

Things I have tried include:

1. Checked the valve adjustment. They were all very close to spec, but made minor adjustments.

2. Checked the cylinder temps. They were within a couple of degrees of each other.

3. Removed the blower wheel and fired it up. It will run for a few minutes without overheating. This also eliminated the battery charging alternator inside the blower wheel.

Nothing I did made the slightest difference. The front end still shakes. Apparently the problem is not at the front end of the engine, although that is the end that shakes the most.

That leaves only the flywheel-generator coupling, and the generator itself. That end is a lot more work to get into, and I didn't see any varmint nests in that area that could cause unbalance, but it is hard to see clearly into the generator.

I haven't tried it with a load. Maybe it will smooth out with a load?

One other thing that has occurred to me is that maybe the vibration isolator mounts are old/stiff/misadjusted. Is that likely? And what, within reason, can be done to fix that?

And maybe it is just going to shake like it does and still be OK.

Any advice is welcome,
Richard

 

[RichardR]

Harleyd,

You beat me with your post regarding cylinder temps! That should catch both injector and IP problems, and maybe even valve problems. But none of that seems to be my problem.

Regards,
Richard

 

[Gravytrain]

Mine vibrated alot when I was just useing the convenience outlet, in fact it wanted to walk around on the concrete floor I was almost thinking of bolting it down . Yesterday I wired it to the house and put a good load on it and now she runs pretty smooth for a two cyl.

 

[RichardR]

Gravytrain,

Thanks for that report. It sounds like loading the gen is the best way to get it to run smooth(er). I was becoming convinced that there was something seriously unbalanced with mine, but, as jbk said, it's just the nature of the 2-cylinder diesel engine. I suppose that isn't a real problem since it has to be loaded to be useful .

On a related note, I have another MEP-002A that the engine/generator run fairly smooth, but the control box vibrates like it is going to fly off! I am concerned that the meters are going to be destroyed by the vibration. But on that machine, I think the problem must be the control box vibration mounts and the mass of the control box forming a resonant system at the 1800 rpm rotation frequency. I suppose I can "fix" that by changing the vibration mounts or by adding some weight to the control box to change the resonant frequency off of 1800 Hz. Any other advice?

Regards,
Richard

 

[Harleyd315]

Richard, Any updates? I just finished getting another 002 fired up and wow does it vibrate. It does dance around on the garage floor and the control box vibrates so bad its hard to read the gauges. This is also a fresh Tier2 reset with only 9 hours and it has a rebuild tag from an outside vendor in southern NJ. I stepped on a few places of the frame and that seemed to help a little so I may look to see if something on the frame is cracked or broken. Let me know if you found anything new, Thanks

 

[rosco]

An infared thermometer is great, but just placing your hand on the exhaust port, not too long after start-up, will give you a good idea about which cylinder is doing the most work.

I know that you are not supposed to idle (slow run) these machines. BUT, I learned, the only way to really set valves, is when they are hot and running!

 

[RichardR]

Harleyd315,

Sorry, but I haven't had time to dig into my shaking MEP-002A any further yet, but I have thought about it some. I am convinced that the shaking isn't caused by imbalance in the blower wheel or one of the cylinders working harder than the other. And since the shaking is most prominent at the blower wheel end, I don't think it is an unbalanced flywheel (at the generator end), the generator coupling or the generator itself. That doesn't leave much.

Unless I am wrong and there is something on the generator end (most likely the generator coupling out of alignment), that leaves only the internal engine parts. I don't have a lot of confidence in the quality of the rebuild work that gets done in a Tier 2 Reset, or the testing that gets done afterward. Maybe one of the pistons or rods was replaced with a newer version that shouldn't be mixed with the old ones, or something of that nature. I suppose it is a testament to the ruggedness of these machines that there could be something pretty bad wrong and it would still work OK for a long time.

Then again, it may be that it just takes that special touch that only the original engine builders developed putting together lots and lots of units, and the rebuilders aren't as good at it. I just don't know.

The only thing I can think to do at this point is recheck the valves. I probably ought to take a closer look at the mounting hardware and rubber vibration isolators. Maybe the rubber is old and hard.

I am convinced that the problem I am having with the other MEP-002A with the wildly shaking control box is caused by old vibration isolators or, less likely, by a crack in the mounting framework. The control box itself certainly isn't to blame. I'll take a closer look at it when I get a chance. Hope you get your dancing MEP-002A calmed down.

Regards,
Richard

 

[storeman]

An infared thermometer is great, but just placing your hand on the exhaust port, not too long after start-up, will give you a good idea about which cylinder is doing the most work.

I know that you are not supposed to idle (slow run) these machines. BUT, I learned, the only way to really set valves, is when they are hot and running!

Roscoe,
Do you mean you pull the valve covers while "running" and adjust the valves? A bit hard to envision.
Jerry

 

[storeman]

Harleyd315,

Sorry, but I haven't had time to dig into my shaking MEP-002A any further yet, but I have thought about it some. I am convinced that the shaking isn't caused by imbalance in the blower wheel or one of the cylinders working harder than the other. And since the shaking is most prominent at the blower wheel end, I don't think it is an unbalanced flywheel (at the generator end), the generator coupling or the generator itself. That doesn't leave much.


Richard,
Try measuring the width of the support frame at several places. It may be bent and creating an unbalanced 3-point situation if it has been damaged by a forklift or damaged in an airdrop. I have seen this in three of mine. Some with no obvious damage have been torqued an inch to 2 inches. That is why I move them immediately to 6" casters.
Hope this helps.
Jerry

 

[Harleyd315]

Jerry, Good point I'm going to check mine today. When the unit sits on the ground it does seem to teeter a bit if I step on one end or the other. How did you measure it? Strait edge, string line? Thanks

 

[storeman]

Just a regular tape measure from side to side at several points on the frame. A little variance won't matter unless frame is distorted. Shouldn't matter on ground, but more obvious on hard surface such as concrete. One of mine had been pushed in almost 2 inches. Nothing to do about it but go to 4 casters.
Jerry

 

[ETN550]

The most common vibration problems with skidded equipment that has no apparent balance issues are:

1) Not having a uniform load distribution on too hard a surface. If must be on a hard surface find the light corner and shim it up.

2) Rubber mounts hard from age, torn, or loose / soft from oil or fuel degradation.

3) A mount is loose or jammed or the flat faces between mounts and frame are distorted or raised up or a burr is keeping from full contact. Even a paint run between the parts can be suspect. Where multiple bolts are on a flange they must be drawn down evenly, like doing lugnuts on a car wheel.

4) the driver and the driven unit are misaligned. (not likely for our close coupled units. More likely where there is a flex coupling or driveshaft.)

Suggest running the unit on soft ground, then checking all the mounts and mount areas. Loosten the mounts and see if there is significant frame distortion such that the mounts are not sharing the load equally.

 

[wauto]

A very cheap and easy fix for setting a skid mounted gen on concrete would be to use a couple asphalt aligators. The tread off a truck tire that ends up on the hiway. These things are easy to cut down to size and eliminate the walking across the shop floor . And the local dot workers will love you for doing thier job.

Mike

 

[W1IM]

Harley,

Did you ever figure out the vibration issue with your 002? I think I saw that you have the unit described on ebay right now.

 

[Harleyd315]

There really wasn't an issue with the unit just where I was running them. I moved off the blacktop driveway and now run the gensets on the grass or on my wood decked trailer. The area I was using wasn't exactly level and if I put the generator a certain way it would rock a little when off and vibrate terribly when running.

 

[storeman]

Makes sense.

 

[ArnieLerma]

A very cheap and easy fix for setting a skid mounted gen on concrete would be to use a couple asphalt aligators. The tread off a truck tire that ends up on the hiway. These things are easy to cut down to size and eliminate the walking across the shop floor . And the local dot workers will love you for doing thier job.

Mike

Kudos to you Sir!

I cut up 4 x 5 " pieces of tire tread off an old golf cart tire, with my skill saw... and placed them under the skids at the bolt holes.

The vibration is now minimal, my gauges are not being shaken to death and I can read them and the noise level is SUBSTANTIALLY reduced. AND the unit no longer wants to walk around on the slab.

Thank you so much for the cheap fix.

PS: I also checked cylinder temps by finger and both feel as hot as the other