Engine Rebuild Gone Bad

[Zogler-HT]

So this is a disappointing post to make but here goes...A year and a half ago I bought a Yanmar 2210 with a FEL that needed some work. I didn't know it when I bought it but it ended up needing a complete engine rebuild due to low compression and some worn internal parts, included the crankshaft. I got a local diesel mechanic to do it as a side job. Over a year later I got my tractor back and paid too much money. Hindsight is 20/20. At the time I knew nothing about diesel engines. Now I know slightly more and learning everyday.

After about 1 month of use, not even a tank of diesel burned, one evening it blew a puff of white smoke and started clanking really loudly. I limped back to the shed, it was lacking any power, and parked it and contacted the mechanic that rebuilt it. The mechanic won't call me back. I got tired of waiting, it's been over a month, and started troubleshooting.

I cranked it and it seemed to run fine, no weird noises. I thought maybe I got lucky and it was water in the fuel. I used it a couple of hours yesterday and it would lose horsepower on any incline. I also noticed very thin oil spewing from behind the fuel pump shims. I pulled the FIP off and noticed a rod just sitting on the camshaft. This rod moves around freely but I cannot pull it from the hole the FIP fits in. This rod is the diameter of a pencil. After some research I believe this is a push rod. I also noticed, when I pulled the FIP off the tractor, that there was a single washer on one of the studs the FIP fits on. This washer was behind the shims and only on one of the four studs. This helped explain how the oil was spewing from behind one corner of the FIP.

At this point it actually cranks and idles just fine. Not strange noises or smoke. Once you begin using the tracotr the loss of HP on inclines and while cutting grass, and the spewing of the thin oil from behind the shims on the FIP are the main issues I've noticed. The hydraulics seem to work fine.

My guess here is that the washer left behind the FIP shims threw off the timing, though I didn't notice any timing issues before this event occurred, and damaged the push rod disconnecting it completely. Is that probable, or even possible? Would this issue also lead to the diesel fuel mixing in my oil? What are your thoughts ymowners?

 

[winston-HT]

Pull the rocker arm cover and confirm pushrod issue. Yes, the washer under the injection pump will change timing.

Are you confirming you have diesel in your oil? If so, your pump is likely the culprit for that.

 

[Zogler-HT]

I am "mostly" sure I have diesel in the oil. The oil has thinned out dramatically, is spewing out from behind the FIP, and not dropping in level on the oil dip stick. I'm going to drain some oil out and allow it to separate. I thought the FIP was the culprit too, that's why I pulled it off the engine. Once I discovered the rod inside the engine I then changed my thinking. Do I really have two separate engine issues simultaneously? A broken rod and a leaky FIP? The FIP is brand new, but of course so was the push rod. I tend to lean towards the simplest answer being the solution until I prove otherwise. I will further investigate to determine if that is in fact a push rod lose, but is it possible that a broken push rod can lead to fuel mixing with oil? I do not fully understand the valve/piston system yet but will learn it.

I'll do some research on pulling the rocker arm cover and let you know what I find once I pull it. Thanks for the info!

 

[winston-HT]

I am not sure about a broken push rod causing diesel in the oil but if you have an exhaust valve not opening and the injector continuing to push diesel into the cylinder then maybe some could work it's way into the crankcase. Certainly not sure of that but I am sure the first thing I would check is the pushrods. Might look at the underside of the FIP and inspect for signs of diesel. Should not be any.

 

[Zogler-HT]

Well, if a missing push rod most likely won't cause this much fuel in my oil than I think you're right, it's the FIP. When I pulled the pump I did see fuel on the bottom side. I'm my head, which has a definite lack of knowledge in this area, I wasn't sure if the fuel could've gotten there from something else, like this push rod issue.

I assume the "rocker cover" is the same as the "valve cover"?

Also, to help me understand the inner geometry of the engine, are the crankcase compartment and the camshaft compartment closed off from one another or are they open to one another?

If my attachment worked I included a picture of what I am seeing when I look into the FIP cavity. Also, those are the two compartments I'm referring to asking if they are connected.

Final question, is this stray rod potentially a piece from the governor apparatus? I cannot determine the length of this stray rod but it's a least 4-5 inches long.

Thanks in advance.

 

[winston-HT]

I cannot tell what the rod is but it does look about the size of a pushrod. Here is a partial picture of your pushrod and I do believe it will be longer than 5", probably closer to 10" but do not know that for certain.
Rocker arm or valve cover, can be called either I suppose.

Crankcase, crankshaft, camshaft all share the same space.

If you pull the rocker arm cover your mystery will be over whether or not it is a pushrod or something else.

 

[Zogler-HT]

Looks like this weekend I'll be pulling that rocker cover. If it is a push rod, does that mean I have to break the engine down further, such as removing the gear case, to repair it? Or can a push rod be put back in place with only the rocker cover removed? Just thinking ahead to see what I may be getting into.

 

[winston-HT]

A push rod can be put in with the rocker arm cover removed and rocker arms loosened off. However, "if" there is a missing pushrod we need to find out why it came out.

Your might find this thread interesting. Shows many of the components we are talking about. It is a 3 cylinder but yours is similar, only 2 cylinders. http://ymowners.com/phpbb/viewtopic.php?t=6799&start=30

 

[Zogler-HT]

Checked around for some local shops that could test my FIP for leaks and had no luck finding one. One shop I spoke with said I could test it myself by submersing the FIP in diesel fuel and using an air hose to put compressed air, around 5-10 psi, into the input port and see if there's any bubbles. I tried this and didn't see any air bubbles leaking out anywhere from the FIP.

Is this an acceptable way to test the FIP for leaks?

 

[winston-HT]

Over my pay grade, however, that injection pump puts out around 3000psi so I am not sure a 5psi air test is going to work.

I guess I have harped on it to much but why don't you solve the push rod or whatever rod problem frst and then worry about the injection pump. I am not fully convinced your injection pump is leaking.

 

[Zogler-HT]

Today I finally got to pursue the push rod mystery. I pulled the rocker arm cover off to find a small mess. The rocker arm on the #2 cylinder was positioned about 45 degrees from it's original position. <ATTACHMENT filename="IMG_7085.jpg" index="1"><s>[attachment=1]</s>IMG_7085.jpg<e>[/attachment]</e></ATTACHMENT> Both push rods on this rocker were missing. The nut on top was loose enough to remove by hand. The pin underneath the rocker arm had sheared off. I got one push rod out of the engine with a telescoping magnet. The 2nd rod was pinned between the cam shaft and the wall of the block. I had to remove the oil pan plate and work on that push rod from the bottom side to get it out. Needless to say both push rods were beat up. As far as I can tell there was no damage to the cam shaft or other components. I have some parts to order before I can get it back together.
<ATTACHMENT filename="IMG_7100.jpg" index="0"><s>[attachment=0]</s>IMG_7100.jpg<e>[/attachment]</e></ATTACHMENT>

The rocker arm on cylinder #1 was still intact although close behind. The nut on that one was very easy to loosen.

I still can't answer the question of where the fuel leak is. When I drained the oil it was as thin as water and smelled like diesel. There was a lot of diesel in there! Is there a way the fuel leak could be related to the push rods? If so, how?

I've been thinking this was a fast fuel leak because I've only considered that it must have started this week. But it is possible it's been leaking since I got the tractor back, 2 months ago. I used it for a month, putting about 20 hours on it, and then it sat for the last month because of this push rod issue. I did not cut the fuel supply off so it's possible a slow leak has been occurring this entire time.

Does anyone know what the torque should be for the nut that holds the rockers arms on? I do not want this issue to occur twice and would like to get it set right.

 

[winston-HT]

I mentioned what could "possibly" happen with a missing push rod in an earlier post. Your injection pump is going to continue to pressure fuel whether your valves open or not. Fix the pushrod issue and see what happens.

Not sure about your rocker arm nut torque. "If" they are m12 (.4724') then your torque should be 58 to 72 ft lbs.

 

[Zogler-HT]

Last night I finally found time to be putting this engine back together. I still have some putting together to do but wanted to discuss something I noticed. For setting valve clearances, I followed the how-to article on the Hoye website, https://www.hoyetractor.com/valve-set.htm. Keeping in mind I've never set valve clearances before, I noticed that I had to loosen my valves from their previous setting. For two of the valve I had to loosen the set screw over two complete turns. None of my valves were "loose" at the top of the "stopped" position mentioned in that article. Basically the valve spring was compressed at all time throughout the cycle of motion. I assume this means that none of my valves were opening or closing fully. Is that correct? I feel that this is weird but maybe it's normal? What does improperly set valves do to the system?

 

[winston-HT]

Probably what bent the push rod when the overtightened valve hit the piston. Valves must be allowed to close completely, that is why you have the clearance between the rocker arm and valve.

 

[Zogler-HT]

I got the engine put back together this afternoon and she cranked right up. It sounded good and drove good. One of the times I was cranking the engine I thought I saw a puff of smoke shoot from the side of the engine, opposite side to the muffler. After further investigation I found this:
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<ATTACHMENT filename="IMG_7142.jpg" index="0"><s>[attachment=0]</s>IMG_7142.jpg<e>[/attachment]</e></ATTACHMENT>
I circled the area. Liquid, a I assume radiator fluid, was bubbling from this area. Is this a blown head gasket? Is it something that needs immediate attention(meaning don't use it until it gets repaired)?

The problems seem never ending but hopefully I can eventually get to the end of these problems and get a working tractor. As always, thanks in advance for the great advice!

 

[winston-HT]

Although I don't think I have ever seen that before it would appear your head has holes in it. The way it is pitted would lead you to believe it sat on the ground for a long period of time. New heads are expensive but you may be facing that. I suppose no harm could come from trying a little liquid metal of some kind. However, your mention of smoke coming out still needs to be confirmed as to where it came from.

https://www.hoyetractor.com/PROD/CH-2000L.htm

https://www.hoyetractor.com/PROD/CH-2000.htm

 

[Zogler-HT]

I'm not sure about the history of the tractor, in terms of the head sitting on the ground. I guess it's possible. During the rebuild a few months ago all surfaces were milled and of course new gaskets were used. I decided to try loosening the head bolts, I have 6 total on my engine, and torquing them in stages following information from this post, http://ymowners.com/phpbb/viewtopic.php?t=6799&amp;start=30. Thank you to agirlandhertractor for the great post! I also torqued them again after a heat up/cool down cycle.

I was comparing the torque settings stated in that post versus what I have in my manual. While my manual doesn't specific address the head bolts with a torque amount, it does list the following table. Sorry it's upside down. It's not cooperating.
<ATTACHMENT filename="IMG_7145.jpg" index="0"><s>[attachment=0]</s>IMG_7145.jpg<e>[/attachment]</e></ATTACHMENT>
From past research I was thinking I needed to torque the head bolts up to about 78 ft lbs. My bolts aren't marked but I assume they a "hard steel" quality. My head bolts are 22mm. According to the chart I should torque them between 87-108 ft lbs.

My question is, does this sound correct? I do not want to damage anything for sure. Is it okay to torque mine a little more according to the chart?

 

[winston-HT]

final torque 130ft lbs + or - 3.6ft lbs. start in the middle and work to each end. 40, 65, 90, 130.

 

[Zogler-HT]

Over the past couple of days I've torqued the head bolts as suggested. I've gone through a couple of heat/cooling cycles and retorqued afterwards. The head gasket leaks seemed to have gone away. I was fighting leaks around the valve cover each time I would reinstall it and then this final time I figured something out. I was tightening the valve cover bolts too much. I think it was warping the cover and creating leaks. The last time I tried just getting the bolts snug and there's no leaks. Took the tractor out and used the brushed cutter for about a half hour on knee to waste high grass/brush. It performed great. It's running better now than it did after the engine rebuild. Getting those valve clearances set correctly makes a big difference on horsepower. Hopefully all this stays good and I can get some work out of it. Thank you Winston for all your help on this project! This forum is a life saver, and money saver for those of us who like to try it our self and just need a little guidance.