Perkins engine noise (rattle)

[gcyeaw]

My Kohler 12.5 kw generator with a Perkins engine is very noisy. It makes a ratteling sound (not a rod knock, more like loud preignition on a gas engine). I have been told that this can be a faulty injection pump or injector. (The valve lash is correct). I took off the fan belt and fired it up and there was no difference in the sound, so it isn't the water pump or idler pulley.

Any suggestions will be appreciated.

[iamflagman]

Originally Posted by gcyeaw

My Kohler 12.5 kw generator with a Perkins engine is very noisy. It makes a ratteling sound (not a rod knock, more like loud preignition on a gas engine). I have been told that this can be a faulty injection pump or injector. (The valve lash is correct). I took off the fan belt and fired it up and there was no difference in the sound, so it isn't the water pump or idler pulley.

Any suggestions will be appreciated.

Gardner,

The Perkins engine is just naturally noisy, but I'm not sure about the injector Pump, but I have heard a knocking sound similar to a bad lifter sound on a gasoline engine, that was caused by a bad fuel injector on a big truck diesel engine. Here is a video of a similar sound to what I am talking about, on a GM Diesel engine in a pickup.

http://www.youtube.com/watch?v=YCvj7...eature=related

Like the guy in the video suggests, use a stethoscope, I use one of these that I got at Harbor Freight http://www.harborfreight.com/cpi/cta...emnumber=41966

Or you can also use a long shank screwdriver with the plastic handle held up against your ear and then with the metal end move it around the area that you hear the sound coming from to help isolate it, or real inexpensive method is using an old piece of rubber hose. Check out;

http://www.pbase.com/iamflagman/image/99832498

DO YOU HEAR WHAT I HEAR.jpg

CAUTION, BE VERY CAREFUL DOING THIS AROUND ANY MOVING PARTS, OR ELECTRICAL CONNECTIONS

I had my injectors on the Perkins rebuilt by Superior Diesel in Charleston, but I had it done because they were leaking.

[Turbokitty]

Dear Gardner,

I too have a rattling sound with my Perkins. As the guys have said, it seems to be the nature of the beast. My Kohler/Perkins genset has over 8000 hours on it. The injection pump is rather new as well as the voltage regulator. The rest is pretty much original.

My nickel bet is the valve train gears are causing the rattle.

My generator also leaks alittle oil as most all do. I would not sweat the rattle too much. Unfortunately a lot of the noise comes through the grill. Good luck!

[gcyeaw]

It sounds like I need to make a soundproofing purchace from Stephen, however, my VISA needs some R&R before I do that. Nothing like a new vintage Bird to get the old VISA on a roll.

And yes, the Perkins does leak a bit of oil, a bit too much for me. I think the first thing I would like to do is install a swing door like John Finn did to make it easier to work on things. But once again, I need to wait for the VISA to recover a little. I won a Xantrex Freedom 20 inverter/charger on e-bay which I didn't expect. Usually someone out bids me at the last minute.

[iamflagman]

Originally Posted by gcyeaw

It sounds like I need to make a soundproofing purchace from Stephen, however, my VISA needs some R&R before I do that. Nothing like a new vintage Bird to get the old VISA on a roll.

And yes, the Perkins does leak a bit of oil, a bit too much for me. I think the first thing I would like to do is install a swing door like John Finn did to make it easier to work on things. But once again, I need to wait for the VISA to recover a little. I won a Xantrex Freedom 20 inverter/charger on e-bay which I didn't expect. Usually someone out bids me at the last minute.

Gardner,

Reinsulating the generator compartment made a big difference in the sound, but like you said modifying the radiator to lay down adding a downdraft style fan exactly like the later model 'Birds use and adding the swing door that eliminated the sound leak through the stand up radiator grill, also made a big difference.

Going a step further and adding sound proofing Auralex Acoustics Foam blocks made even more of a difference http://www.pbase.com/iamflagman/image/74863033

AURALEX FOAM JPEG.jpg

There are always some that can be found on eBay http://tinyurl.com/6qppmq

When choosing an Acoustic Foam to install in the generator compartment, it is very important to purchase the type that has the FIRE RETARDANT chemical blended into the foam during the manufacturing process, rather than sprayed on, like the less expensive type, which eventually will wear off. http://www.auralex.com/auralex_acous...dancy_faqs.asp

If you want to use a type similar to what is used in the later model 'Birds, you can purchase SONEX Acoustic Foam http://www.sonexfoam.com/sonex_soc.html which is more expensive.

[RAGster]

I am hearing a "rattling" noise. The noise I hear was more of a metal vibration type noise. I originally thought something in the generator frame was vibrating. Upon further investigation, the noise seems to be coming from the Racor fuel filter system. I'm not sure if there is a fuel pump in the filter or feeding the filter and transfering the noise. The noise comes and goes at times. The frequency would match up to a fuel pump...

Is there a fuel pump inline before the Racor or could the noise be transferring from the generator?

Thanks,

Glenn Allen
1986 PT-40
Marietta, GA

[thomase]

I've got the same rattle from my Perkins. I swear it's louder than it used to be. I recently rebuilt the injectors but the noise persists. It will also overheat in this Texas weather if you don't keep an eye on it.

On the rattling I had an old mechanic suggest I go to a thicker oil such as 20w50. He thought that should quiet it down some.... I haven't had a chance to try it yet.

Anybody tried pulling the perkins out and replacing with a kubota or yanmar engine? I'm not willing to scrap the whole thing as the gen head is fine.

Thomas Eastham
Houston, TX
83 FC35 SB

[Bill Pape]

Hey Gardner,

We need a new Avatar, with the new Bird......
Any Pictures of the latest addition ??
We want to see why the Visa is full.

[Randy Dupree]

hey guys,i drove an 84pt40 for 10 years,same old ratteling perkins.
i tried different things to quiet it down,and one thing i did that worked was to retard the injector pump timing,it really helped.
The downside was it smoked like mad when cold,and when in winter weather it smoked acloud so big you couldnt see the bus!

there is a lot of noise transfered through the injector lines too.
theres just not much you can do to quiet those old engines down.

I think Johns is about the quietest FC out there,Woody may disagree!
Randy

[gcyeaw]

Bill,
When I have time and want to punnish myself I will tune up the new avitar.


Do you really have to ask why the VISA is strained? I just won a Xantrex Freedom 20 inverter charger on ebay, there was no inverter in the new coach and it has an Iota charger that doesn't get the charging voltage up high enough. You can't go out in public with rusty lug nut covers, and tire covers are a must with $2500 worth of new rubber. Of course, 'fill her up' was a real killer when I bought it, and then there is NJ sales tax, registration, insurance, inspection, etc.

This time I am keeping more accurate records, and it is pretty scary how much I have spent already on little things. I still need to find a transmission temperature guage, hopefully one that matches the rest. The dump valves need new paddles, and on and on.

But it is a winner, rides great, runs great, and it is amazingly quiet inside. (but one side of the stereo is burned out)!!!!