Detonation maybe?

[mrlullabye]

I purchased a used Farmtrac 360 about 3 months ago during the hottest part of the steamy Alabama Gulf coast summer and it ran great. It did make a funny noise for maybe 5-10 taps that sounded like a ping or detonation the first time we went to test drive it and promptly stopped, the sound did not return.

that is until this weekend. It is still warm, but probably 10 degrees cooler than when we first got it. The noise I don't know how to explain it, but I will try. Basically after mowing the grass for about 2-3 hours running in the 2400 rpm range, I was done mowing and needed to do some FEL work. So I turned off the PTO lowered the RPMs and started pushing stuff around. Within a few minutes it started the tapping/pinging/detonation noise.

I have rebuilt engines before so I know what all the parts look like, but I really don't have much experience with actual engine troubleshooting I am just a take it apart and replace everything that is out of spec guy.

Anyways if I had to guess it sounds like what I would expect a collapsed lifter to sound like. A hard TAP sound. It sounds sort of like someone is whacking some part of the engine with a ball-peen hammer. Now that said it is very obvious that it does not occur every RPM. if the engine is turning 2000 rpms the tap does not happen that frequently. It happens pretty fast but I could almost snap my fingers as fast.

If I turn the engine off and check the oil, by the time I crank it back up the noise will be gone. The noise probably won't return for the duration of the work. I did notice once it started tapping when I had driven the tractor up on the brush pile and it was at an angle that made me think it may have been a lubrication problem, but I backed it off the pile and the noise continued. I turned the tractor off counted to 20, restarted and the noise was not there.

So I am wondering is this maybe caused by a hotspot in the engine causing "detonation"?

I am running street deisel, because I have gotten aggrivated with the questions I get when I try to buy offroad deisel. For some reason the clerk always gives me a snoody look and ask me what I am putting the deisel in which really just gripes me.

So I was wondering if anyone else has an idea what this problem could be?

Does it sound like fuel related detonation?

Is it ok to use street deisel or should I be buying offroad deisel?

What should I try?

I want to reitterate this problem has only occured when the engine was ran at a continuous high rpm for a while then the rpm lowered.

 

[carpenter383]

I'm no deisel engine expert, but I've never heard of detonation with a deisel. Deisel engines being compression ignition engines basically run on detonation or more accurately "pre-ignition"...
I would'nt think street diesel vs. off road would make a difference because I believe the only real difference is the dye in street diesel?
Since you say it happens after running at high rpms, have you changed the fuel filter recently?
Is there any chance it could have water or air in the fuel system?
You could try cracking the injector lines while it is knocking and see if the knock changes.

 

[Richard]

I'm by no means an expert so disregard 99% of what I say and avoid reading the other 1%

First... I'd speculate that the diesel might rather appreciate running in cooler weather than warmer weather? (in general) as the cooler air would be more dense and the temperature differences (inside combustion chamber) and outside would be greater.

Dunno...just speculating out loud.

On the tapping, having had a situation where ALL three bolts that hold the drive head to a fuel pump worked loose, I'd wonder if it's possible that you might have something inside the engine that has loosened up?

Initially, I too was thinking collapsed lifter but...I doubt you have that since your machine is diesel.

My guess is something is loose?

Let us know if you find out.

 

[Soundguy]

how many cyl engine? can you isolate it to one cyl by cracking injector lines one at a time.. it.. get to rpm range it is making the noise.. then go down the line.. etc.

start good cold? startup good hot?

soundguy

 

[Treemonkey1000]

Can it be starving for fuel or oil if a filter is getting clogged? I am not a diesel mechanic at all so I am tossing that in. Also the road diesel now is being mixed with other stuff like french fries or some darn thing verses real diesel from the Farm store. Your motor might not like it. It might like the high cholesterol fuel.

 

[RalphVa]

Twice in the life of our 1983 Benz, it had a pinging at constant speed. I cured it both times by putting some Chevron Techron additive into the tank. First time was when we first bought it with 22k miles on it and one year old after it had sat on the dealer's showroom floor for a while. Second time was after being stored for 4 1/2 years.

Not sure what the cause of the pinging was, but the Techron stopped it both times.

Ralph

 

[cedarbend]

I would guess a weak injector.The only difference in your street diesel is tax. You don't pay tax on diesel for farm use.In Iowa they dye farm diesel so they can tell if your trying to cheat the goverment out of your money. Rocky

 

[dodge man]

Well I'm not an expert either, but diesel has a cetane rating. You could try adding power service to boast that cetane rating some and see if that helps. Do most diesels have hydraulic lifters? I don't know but there is a procedure for adjusting the valves. Maybe the valves need adjusting?

 

[LBrown59]

There is no difference betweeen on road and off road fuel.

I'm no deisel engine expert, but I've never heard of detonation with a deisel. Deisel engines being compression ignition engines basically run on detonation or more accurately "pre-ignition"...
I would'nt think street diesel vs. off road would make a difference because I believe the only real difference is the dye in street diesel?
Since you say it happens after running at high rpms, have you changed the fuel filter recently?
Is there any chance it could have water or air in the fuel system?
You could try cracking the injector lines while it is knocking and see if the knock changes.

I purchased a used Farmtrac 360 about 3 months ago during the hottest part of the steamy Alabama Gulf coast summer and it ran great. It did make a funny noise for maybe 5-10 taps that sounded like a ping or detonation the first time we went to test drive it and promptly stopped, the sound did not return.

that is until this weekend. It is still warm, but probably 10 degrees cooler than when we first got it. The noise I don't know how to explain it, but I will try. Basically after mowing the grass for about 2-3 hours running in the 2400 rpm range, I was done mowing and needed to do some FEL work. So I turned off the PTO lowered the RPMs and started pushing stuff around. Within a few minutes it started the tapping/pinging/detonation noise.

I have rebuilt engines before so I know what all the parts look like, but I really don't have much experience with actual engine troubleshooting I am just a take it apart and replace everything that is out of spec guy.

Anyways if I had to guess it sounds like what I would expect a collapsed lifter to sound like. A hard TAP sound. It sounds sort of like someone is whacking some part of the engine with a ball-peen hammer. Now that said it is very obvious that it does not occur every RPM. if the engine is turning 2000 rpms the tap does not happen that frequently. It happens pretty fast but I could almost snap my fingers as fast.

If I turn the engine off and check the oil, by the time I crank it back up the noise will be gone. The noise probably won't return for the duration of the work. I did notice once it started tapping when I had driven the tractor up on the brush pile and it was at an angle that made me think it may have been a lubrication problem, but I backed it off the pile and the noise continued. I turned the tractor off counted to 20, restarted and the noise was not there.

So I am wondering is this maybe caused by a hotspot in the engine causing "detonation"?

I am running street deisel, because I have gotten aggrivated with the questions I get when I try to buy offroad deisel. For some reason the clerk always gives me a snoody look and ask me what I am putting the deisel in which really just gripes me.

So I was wondering if anyone else has an idea what this problem could be?

Does it sound like fuel related detonation?

Is it ok to use street deisel or should I be buying offroad deisel?

What should I try?

I want to reitterate this problem has only occured when the engine was ran at a continuous high rpm for a while then the rpm lowered.

I would guess a weak injector.The only difference in your street diesel is tax. You don't pay tax on diesel for farm use.In Iowa they dye farm diesel so they can tell if your trying to cheat the goverment out of your money. Rocky

Well I'm not an expert either, but diesel has a cetane rating. You could try adding power service to boast that cetane rating some and see if that helps. Do most diesels have hydraulic lifters? I don't know but there is a procedure for adjusting the valves. Maybe the valves need adjusting?

 

[LBrown59]

I am running street deisel, because
1*I have gotten aggrivated with the questions I get when I try to buy offroad deisel.
2*For some reason the clerk always gives me a snoody look and ask me what I am putting the deisel in which really just gripes me.
3*Is it ok to use street deisel or should I be buying off road deisel?

1*What sort of questions?
2*why?
3*Both the same so makes no diffference.