Anything else to do when changing a head gasket?

[Lobanz]

OK. I have both heads back from the machine shop. Had then shop do valves on both. Kubota had some pitting and was quite warped. Stress cracks were on the pre-combustion chambers and they said they didn't leak and that this is not uncommon and wouldn't be a problem. The Yanmar head didn't have any cracks. Great deal at this shop -- they did both heads for $140. :shocked:

I have everything I need for the Yanmar except the radiator. About to start reassembling. New belt, hoses, gaskets, radiator cap. Got some high temp (2400 deg) nickel anti-seize. Of course this does not go on some things, like head bolts, but I do like to put it some as much as I can -- especially on exhaust manifold bolts/nuts. Maybe the Yanmar injectors that are notoriously hard to get out -- they slide in and are held by a bolt on plate; they rust in there where they slide in. Will lean of rust and apply a light coat of anti-seize.

The machine shop mention that I might want to get my injectors tested, but they also said that if I haven't had any trouble with it running rough or having lack of power, then it probably isn't necessary. The injectors are already out. I will call and check the price, but I probably won't get them checked. Haven't had any trouble with them that I know of. What do you guys think about having the injectors tested?

Also, I know that I don't put any gasket sealer goo on the head gasket. What about other gaskets like water pump and/or thermostat housings, etc? In the past, I've used it and not used it and didn't have trouble either way. Will see what the Service Manual says. On both engines, there we are couple of places where there was ONLY gasket sealer goo and no actual gasket (water pumps). I ordered proper gaskets for everything.

 

[Coyote machine]

Injectors are one of the most crucial and most often overlooked parts of many diesel engines. The ply a huge part in making the engine run evenly, and keep it from doing things like overheating.
Pop testing and verifying spray pattern will tell if they are delivering the correct atomized fuel/air mixture. I strongly urge you to get them checked. The loose fuel line distribution caps/nuts could have adversely affected the fuel/air mix or otherwise, but since you now know it was happening you can now prevent it going forward.
Personally, I wouldn't touch the timing until everything is back up and running. Then if you're still having issues and everything else is normal, then address it, possibly. Methodical troubleshooting is the best way to find the cause/effect of an unknown problem.

Injectors are so crucial the major manufacturers/rebuilders reassemble them after exhaustive testing in a clean room to prevent microscopic DUST from adversely effecting their proper operation. Videos of same are on the net; it's quite amazing what lengths they go to to make sure they work correctly. Yours will be deemed OK or not by the pop and spray pattern compliances mentioned above.

As to gaskets/sealers or not. I'd go with what I found on disassembly. Or if there is a question about the waterpump/block interface make sure both surfaces are smooth with no pitting and use grease/Vaseline to assembly the mating surfaces, or a gasket and grease to mate them. Torque to spec and recheck after ten hours.

 

[Lobanz]

Dang. Rocker arm tower stud stripped on the Yanmar. Two of them. Have know idea why. Didn't even get close to torque spec (40 ft-lb). Was not cross threaded. Looks just like THIS GUY's. Hope Hoye has replacements.

Got the head on though, but couldn't proceed past the rocker arm assembly due to the stripped studs. So, we put on the water pump and new fan belt and one of three new hoses with new hose clamps.

My 13 year old daughter wanted to help, so I pretty much just walked her through it. She wanted to learn more about how to use tools. She set the torque wrench, torqued the bolts and everything (we practiced on something else first and I double checked her settings and explained the technique). Worked out well. The two boys (16 and 9) did all the disassembly on the Yanmar and the 9 year old and I did the Kubota. They did a good job labeling everything like I told them.

Anyway, looks like more waiting on parts...

 

[Mace Canute]

Dang. Rocker arm tower stud stripped on the Yanmar. Two of them. Have know idea why. Didn't even get close to torque spec (40 ft-lb). Was not cross threaded. Looks just like THIS GUY's. Hope Hoye has replacements..........

Coincidently I just made two similar rocker hold down bolts for a friend's John Deere A. The threads weren't quite that bad but the thread form was badly deformed. They were a tad larger though, 5/8 inch on the larger diameter and a 1/2 inch on the smaller.

 

[Lobanz]

Coincidently I just made two similar rocker hold down bolts for a friend's John Deere A. The threads weren't quite that bad but the thread form was badly deformed. They were a tad larger though, 5/8 inch on the larger diameter and a 1/2 inch on the smaller.

Hast thou a lathe or other majick?


Here are the part numbers with links to Hoye site in case anyone else has the same problem (tractor is Yanmar 1610D, 3T75U engine):

• STUD: 105225-11350
• ROCKER ARM LOCK NUT M8: 26756-080002

Parts on the way!

But I wonder why they were so weak. They went with the head to the machine shop. Don't know if anything would have happened to them there. Torque spec is 40 ft-lb. Seems a little high. Dunno.

 

[brain55]

If they are 8mm studs, then the torque spec should only be 20 ft lbs.

Brian

 

[Lobanz]

If they are 8mm studs, then the torque spec should only be 20 ft lbs.

Service Manual said 40 ft-lbs, and parts supplier (Hoye) confirmed (probably looking at same service manual). I suppose service manuals can be wrong too. There is another Yanmar service manual that covers several engines, will cross check with that one.

 

[Lobanz]

Injectors are one of the most crucial and most often overlooked parts of many diesel engines. The ply a huge part in making the engine run evenly, and keep it from doing things like overheating.

Well, you definitely were right here. The Yanmars were all fine. But the 2 of the Kubota's injectors were stuck open and 1 was stuck closed. The guy say that it would probably have ran but that it should have been making a lots of smoke. Wasn't making lots of smoke and didn't seem to run bad at all -- just overheating. The diesel mechanic DID say that the delivery valve holders being loose WOULD ****** the timing. He also said that he would have expected them to leak horribly. They didn't leak to my knowledge.

$65 each to rebuild -- replace all the guts so will be like new. $84 ea + shipping for new ones.

So, there is enough evil happening here to explain the overheating. Hopefully, the cylinders were not washed down to the extent that the rings are eroded. Hopefully THAT's not the real cause of overheating. We'll see.

I video'd the injectors on the test machine and stuck the clips together:

 

[Coyote machine]

Well, you definitely were right here. The Yanmars were all fine. But the 2 of the Kubota's injectors were stuck open and 1 was stuck closed. The guy say that it would probably have ran but that it should have been making a lots of smoke. Wasn't making lots of smoke and didn't seem to run bad at all -- just overheating. The diesel mechanic DID say that the delivery valve holders being loose WOULD ****** the timing. He also said that he would have expected them to leak horribly. They didn't leak to my knowledge.

$65 each to rebuild -- replace all the guts so will be like new. $84 ea + shipping for new ones.

So, there is enough evil happening here to explain the overheating. Hopefully, the cylinders were not washed down to the extent that the rings are eroded. Hopefully THAT's not the real cause of overheating. We'll see.

I video'd the injectors on the test machine and stuck the clips together:

You're welcome! That's some of the best money you could spend. Not possible for the tractor to run right with the injectors behaving like that. And the delivery valve holders on top of the injectors, not a good situation. The 2 pissing injectors would have delivered the wrong amount of fuel, and the dead one would cause a lean cylinder. Did you note which cylinder each one was in? So you had a retarded, lean on one, over fueled on two condition.
You're lucky it ran at all. I'd suggest you get the best fully synthetic oil and run it exclusively from now on. Wide open injectors could have caused premature cylinder wall and lower end bearing wear, in addition to overheating from the dead one. By running synthetic oil you have a chance of preventing further damage of those and all crucial engine parts.:thumbsup:

 

[Lobanz]

[...] I'd suggest you get the best fully synthetic oil and run it exclusively from now on. Wide open injectors could have caused premature cylinder wall and lower end bearing wear, in addition to overheating from the dead one. By running synthetic oil you have a chance of preventing further damage of those and all crucial engine parts.:thumbsup:

Hmmmm.... Well, should I be running synthetic in all the engines? You mean like Mobil-1? Been running Rotella-T Triple Protection (15w40 I think). I buy it in 5 gal buckets.

Wish I had a compression tester. After a valve job and a new head gasket, that should tell me about the rings. Might be a good $30 to spend.

 

[Coyote machine]

It would make it easier to run synthetic in all, less storage, remembering what goes in what/when, etc.
You don't want to know about the rings. Are you gonna pull her apart to replace rings now; I doubt it. Put her back together and drive; you've done a great job working to fix this motor, as you said, it was running the way it was and other than overheating..... So now it should run much much better.
The Rotella T is good oil. Your climate will take the 15-40, up north we need 5W-40 for the cold.

 

[Mace Canute]

Hast thou a lathe or other majick?


Here are the part numbers with links to Hoye site in case anyone else has the same problem (tractor is Yanmar 1610D, 3T75U engine):

• STUD: 105225-11350
• ROCKER ARM LOCK NUT M8: 26756-080002

Parts on the way!

But I wonder why they were so weak. They went with the head to the machine shop. Don't know if anything would have happened to them there. Torque spec is 40 ft-lb. Seems a little high. Dunno.

Yes, an old South Bend 9 inch model A.

40 ft-lb - that's obviously too much...the stripped threads say so. A quick Google check of general torque specs seems to give 20 to 25 ft-lb for a class 10.9 8mm fastener.

 

[Lobanz]

The radiator shop said that the Yanmar radiator was pretty clogged up, but it didn't leak. They let it stay in the tank over the weekend. I'm chalking up the Yanmar overheating only when under heavy load for extended periods to a dirty radiator. Should have it back together in a few days. Perhaps I can get the Kubota running again this weekend.

 

[Lobanz]

OK. Finally got Yanmar back together and it won't start.

Got new rocker arm tower studs and nuts. Put on rocker arm. Set the valve clearance to .008 per Service Manual, but used THIS procedure because it was very hard to see any indication of TDC on flywheel. Changed fuel filter. Bled fuel lines starting at fuel bowl, then injection pump, then injectors. Fuel came out around the injectors. Had decompression lever pushed in while bleeding to save battery. At first I thought it was going to start -- seemed like a cylinder would fire sporadically, but then it just stopped trying.

Here's what it's doing:

I figure it's got to be either fuel or compression. I'm guessing the thin white exhaust is atomized fuel from the injectors, so it's probably compression. Perhaps I didn't get close enough to TDC when I set the valve clearance. Will have another look at the flywheel tomorrow. Might try jump starting also. Maybe battery is a little weak.

Any other ideas?

 

[Coyote machine]

Definitely verify, as best as possible, TDC mark(s), and any other reference marks you can locate.
What is the condition of the glow plugs, assuming it has them? The injection pump timing is critical too. If you leave the pump loose enough to move ever so slightly in one direction or the other this too could help to get her started.
10-15 seconds max on cranking so to not cook the starter windings. Take breaks, charge up battery, then try again.

 

[Lobanz]

Definitely verify, as best as possible, TDC mark(s), and any other reference marks you can locate.
What is the condition of the glow plugs, assuming it has them? The injection pump timing is critical too. If you leave the pump loose enough to move ever so slightly in one direction or the other this too could help to get her started.
10-15 seconds max on cranking so to not cook the starter windings. Take breaks, charge up battery, then try again.

No glow plugs. Has a thermostart element in the intake manifold.

Haven't messed with the injector pump. Could head machining throw off the timing?

I've got a couple of big Odyssee 100 amp hour AGM batteries I can use too. They should be able to crank an ocean liner.

I'll get my coffee and head out there in a bit. Checking TDC marks first.

 

[Coyote machine]

Head shave could marginally affect overall compression, but TDC is still the same, it is a function of piston position of #1 cylinder.
Cleaning injectors could have tweaked the amount of fuel delivered, so pump timing MAY need adjustment too.
If you can make a very exact mark of where the pump is set now then you could have a second person move it ever so slightly in either direction, to see if she comes alive while cranking. VERY SLOWLY! Incremental adjustments....:thumbsup:
Easy on the batteries, you want to start it, not smoke it!

 

[Lobanz]

:cool2: OH YEAH !!! :cool2:

'Sworkin! Think it was valve clearance. There was a flywheel inspection hole, but no marks. I guess the hole is there so that you can confirm that the flywheel is indeed there and it does actually spin.

So, we found TDC by removing the injectors and poking a small wire down through the tiny hole in the pre-combustion chamber. Turns out I could actually see the cylinder when it was TDC through the tiny hole. So when it was coming up, we looked at the position of a fan blade. We traced the fan blade until the cylinder just started to go down and backed it up until the fan blade was in the middle of our two marks. I think we got TDC very accurately. And I did confirm that the valves were too tight at this point. We did the same on all cylinders.

Also, we put some fuel in the thermostart reservoir and I think that helped is start too. The thermostart is like a single glow plug in the intake manifold that gets a dribble of fuel on it. Makes a lot of smoke and eventually some flame. But it seems like it helped. This also accounted for some of the white smoke we were seeing.

Now it starts up VERY quick. You can hardly operate the ignition switch fast enough to make it not start. Very nice. Started pretty well before though. Drove it around on full throttle. Seems to work very well.

It's full of mostly distilled water at the moment, but I think I'm going to put some load on it and let it mix the water up a bit to get old antifreeze. Then I will drain and fill with 50/50 Rotella ELC coolant. The oil and filter was changed right before I started all this, but I will probably drain and fill it too in case any nastiness got in there when I was cleaning the head and such. I also want to drain and fill the transmission/hydraulic oil and clean the filter screen. Hasn't been that long, but I've noticed a bit of squealing then I first turn it on.

New hoses, belts, gaskets, filters and fluids. Should be in real good shape.

 

[Coyote machine]

Excellent!
Nice work. Definitely use coolant to protect the entire cooling system passages and water pump/radiator.
Now let's see the other machine running!

 

[Lobanz]

Replaced engine oil and transmission/hydraulic fluid in Yanmar. Cleaned transmission suction filter screen.

Flushing coolant system with distilled water. Ran her with some load (box blading) for 30-35 min. Afterward, I drained the water and it was kinda murky brown. Filled again with distilled water, rand for a few minutes. Still murky, though less so. I would like to see clear water before I put expensive coolant in there.

I've heard of people hooking up a garden hose to lower radiator hose and unhooking upper radiator hose and power flushing (starting with a cold engine of course). Any ideas on that?