# Coolant in crankcase



## HS2 (Dec 12, 2015)

I have a JD 2640, 4100 hours on it. It was losing coolant and starting to get hot. I checked the oil and it had emulsified big time. I pulled the oil pan and saw pure green coolant dripping from the main bearings. 

Is the only thing that could cause this a cracked block? Could it be a head gasket or a cracked head? Any other ideas or suggestions?


----------



## Thomas (Nov 1, 2006)

Did you notice white smoke or sorts where the head gasket located or loss of power?

You may want to flush engine to remove antifreeze soon,for antifreeze hard on bearings.


----------



## JDonly (Apr 28, 2012)

Sounds to me like you've got bad cylinder liner o-rings. Your gonna need a complete engine rebuild very soon, like now I would say. Better than a cracked block!


----------



## RC Wells (Dec 26, 2008)

It does sound as if you have a cylinder seal failure, or a head gasket failure. The usual cause is acidic coolant from failure to maintain the pH or change the coolant every three years. A quick check with a voltmeter can identify failing coolant. Put one prong in the coolant not touching anything else, and one on the brass radiator filler or engine block, and any DC voltage reading means you have acidic coolant.

That is a common issue with the John Deere 4.2 through 4.5 liter engines.

The good news is that these are wet lined engines, easily rebuilt by most farmers with a suitable dry place to work, and the rebuild kits are under $1,000, and you essentially end up with a new engine.


----------



## HS2 (Dec 12, 2015)

RC Wells said:


> It does sound as if you have a cylinder seal failure, or a head gasket failure. The usual cause is acidic coolant from failure to maintain the pH or change the coolant every three years.
> 
> The good news is that these are wet lined engines, easily rebuilt by most farmers with a suitable dry place to work, and the rebuild kits are under $1,000, and you essentially end up with a new engine.




Well, I just bought it a few months ago, so I don't know what happened to the coolant prior to me owning it. But what difference does acidic coolant make? After I noticed the coolant going low, I did put some well water in it, which is likely a bit acidic since its sulfur water. I guess I should use distilled water.....? What difference does slightly acidic radiator fluid make? I guess it corrodes something? 

You guys have mentioned "cylinder seals" and "cylinder liner O-rings." Are you talking about the piston rings, or something else? I've never rebuilt ones of these engines, but the book says they have "renewable wet-type cylinder sleeves." I guess these are lined cylinders that can be replaced? This would involve pulling all the cylinders, yes? 

Any advice or help here is much appreciated.


----------



## RC Wells (Dec 26, 2008)

Acidic coolant turns the dissimilar metals in the engine cooling system into a battery. That transfers ions from one metal type to another, which creates dielectric erosion, commonly referred to as corrosion by most folks. That corrosion eats out the sealing surface between the sleeve seals and the block, and allows the cylinder liners to vibrate loose from the sealing material itself and the coolant to flow into the crankcase.

The cylinder sleeves in the engine you have are what are known as wet liners. Those sleeves are what the piston rides in, and are sealed with sleeve seals and the head gasket.

A rebuild kit will contain new cylinder sleeves, new pistons with rings, new top end (head, water pump, valve cover, injection system, etc.) gaskets, new cylinder sleeve seals, new wrist pins and keepers, and new oil pan gasket. In most low hour cases (under 10,000 hours on a John Deere diesel) the bearings will be within tolerances so new crankshaft and rod bearings are generally not included in the kit. Should the coolant be left in the crankcase long enough, then the crankshaft may require machining to remove rust, and then all the crank bearings will need to be replaced with the appropriate undersized bearings. 

The short answer to your question as to pulling the cylinder sleeves and replacing them is yes. The engine is disassembled, the pistons and sleeves removed, the block cleaned, and the new components installed.

The job sounds more daunting that it actually is, but does require a decent set of basic tools, patience, and the repair manual. The most dangerous part of rebuilding one of these diesels is working with the fuel injection when re-installing and priming the system after the engine rebuild is completed. High pressure diesel can blow right through a person's skin and end up in the bloodstream, and that is fatal). It is also critical that all the fuel system components, such as the pump, injectors, and injection lines are kept absolutely clean.

I am speculating, but I would expect the typical cost for an appropriate diesel shop to rebuild one of these engines in what is known as an "in frame" rebuild (lowest cost) would be around $3,200 with the labor involved. Some independent shops may be considerably lower. Of course, a clean tractor will cost substantially less to rebuild than a grimy mess. 

Hope this helps.


----------



## HS2 (Dec 12, 2015)

This is very helpful, thank you very much. 

I was running mostly pure coolant with a little water in it. I took off the oil pan and saw green dripping from the crank, then got so frustrated I just buttoned it back up and left it as it was. Do you think if I let it sit a month or two it will harm anything, or do I need to jump on this project ASAP?

Other than visibly looking for cracks, is there any easy way to positively verify the block is not cracked?

I have a shop manual but I also see there is a technical manual that costs around $100. Would I need that one if I do this myself?

Any recommendations on which brand of rebuild kit to get?

Thanks again for all your help....this is invaluable to me.


----------



## RC Wells (Dec 26, 2008)

I see no need for the technical manual if you have the shop manual. There is no effective way to check for a cracked block with wet lined cylinders outside of visual inspection once it is torn down.

A cracked head can be checked once it is removed, but that is an unlikely source unless the tractor was run with low coolant and then coolant added when it was hot.

I would shop around for the rebuild kit. I do not believe that John Deere is still providing the major internal engine component parts, but there are plenty of aftermarket sources. Most of the aftermarket folks carry TISCO kits, do some price shopping. If you have a tractor salvage yard in your area, it is likely they carry TISCO kits too.

If you are going to do the work yourself, I would start the tear down before I purchased the rebuild kit, so you know exactly what components you will need. You may want to pick up some Plastigauge and check bearing clearances once the oil pan is off so you can do a visual inspection. Plastigauge works very well for folks that do not have micrometers and standards to keep them properly adjusted, and it costs pennies to use.

The most important thing for the do-it-yourself mechanic is to obtain some large cardboard sheets and carefully place and label all the small parts and bolts removed. Things like main and rod bearing caps are specific to the exact location from which they were removed, as are the bolts that go with them. Same for the head bolts and valve train components.

Even with a full shop at my disposal I still use sawhorses and 4X8 sheets of flakeboard as temporary benches for storing and arranging components, and for placing the cardboard with labels. The camera in a cell phone can be your friend when working on a project like this too.

As you get into this, feel free to ask additional questions.

Have a Merry Christmas!

Randy


----------



## HS2 (Dec 12, 2015)

Thanks for the advice. I'm thinking this job through. It does not sound too difficult, but where the tractor is, I don't have a good shop, just a shed that is open on one side. Not an ideal place, but I could accomplish it. 

I'm assuming that if the sleeve O-rings are bad, then just changing the head gasket will not fix it.....correct? And it would seem that by the time I pulled the head, I'm halfway through with an entire rebuild. Am I correct? 

Also the JD book talks about "loosening using a sleeve puller, then removing by hand." Not sure what a sleeve puller is.....could I get the sleeves out without a special tool?


----------



## RC Wells (Dec 26, 2008)

You will know more about the source of the problem once the head is removed and inspected, but the usual leak is at the bottom of the cylinder liner where it abuts the cast iron block below the water jacket. I have never seen a head gasket solve the problem with a leak as significant as you describe.

A compression leak can usually be solved with a new head gasket after the head is checked to be sure the sealing surface is true and there are no cracks.

The puller is a simple device that can be rented from most tool rental places, or purchased from ebay for not a lot. All they are is a tool with a disc at the bottom that abuts the cylinder liner, a long threaded shaft like a wheel puller, and a set of extended arms that allows the liner to slip up and out the top of the block. I would recommend taking a look at what is on ebay, and then considering building your own if you have the materials handy. Once you start trying to remove the liner, it does not hurt to use a lot of penetrating oil and a lot of patience. Do not rush, take your time.

I have a big C02 fire extinguisher that I put the cone down the cylinder and get it real cold before I start pulling, I also use a small ball pein hammer and tap the inside of the liner at the bottom to break any rust and sediment loose. Once you get it to work around in the block on top, then oil the stink out of it all around the top rim of the liner, let the penetrating oil drool down and do it several times. Sometimes it helps to oil it good a few times, then let it set for a day or two to allow the oil to break loose any rust and sediment at the base of the liner where it seals to the water jacket (block).

For penetrating oil just mix a quart of any inexpensive automatic transmission fluid with a quart of acetone, and you will have the best penetrating oil available. If you can find a small bottle of Wintergreen oil, toss that in the penetrating oil mix and it will give you an active molecule that worms its way into the rust and corrosion.

Be real careful with the Wintergreen oil, as it will carry dirt and such right into your skin too.

I always wear nitirile gloves (Harbor Freight ElCheapo version) when working with dirty engine parts.


----------



## HS2 (Dec 12, 2015)

I'm convinced it's the cylinder sleeve leaking. I had drained the oil and left it for 5 or 6 days, then opened the drain plug and out came more than a quart of green coolant from the oil pan. So with a leak like that I'm guessing it has to be the sleeve seals. 

I've looked at the rebuild kits and have been thinking through the rebuild job. I've not rebuilt one of these before, but I'm fairly mechanical and not intimidated by the idea. I'm also not one for doing a job like this half-way........it seems to me that if I'm going to pull everything apart, I might as well go ahead and change the main bearings. Wouldn't that seem logical to you? It just seems to me that if I'm going to have to spend the hours and $800 to $900 on a rebuild kit, I might as well spend another $300 and get the main bearings and whatever else is in the full kit. What are your thoughts?

I found a local place that will rent a good sleeve puller, which sounds better than making one or buying one. Are there any other specialty tools I'll need? Obviously I'll need a torque wrench, but any other tools that aren't in a common man's tool box?


----------



## JDonly (Apr 28, 2012)

I agree with replacing the bearings if you're that far into it. You'll also need a ring compressor you'll likely be able to get at the same local place. The important things in my opinion are to make sure all the o ring grooves are cleaned and scraped out good so the new ones fit in right. It can be tricky installing the new o rings and liners, make sure they're in the groove. Also check liner height so the new head gasket seals properly. Doing an in frame you won't be messing with the cam and you might not even need a valve job. Just have a shop check it out and make sure it's not warped. The rest is fairly simple. And you don't need to remove the injector pump unless you've been having issues with that. If you've never rebuilt an engine before, good luck!


----------



## RC Wells (Dec 26, 2008)

A bit late getting back to this, but I would hold off buying bearings until you have disassembled and inspected the crankshaft. Depending on how much coolant and water were in the crankcase and for how long, you may need to consider having the crank journals turned, and that would require purchase of undersized bearings. No sense buying something you may have to send back.

I generally fully disassemble and inspect everything before I buy an engine kit. Saves a lot of fooling around trying to get the correct parts later on.

Just my thoughts.


----------



## HS2 (Dec 12, 2015)

I'm still thinking through this engine rebuild while I'm waiting for warmer weather. A couple of questions. 

If I'm going to go ahead and do an entire rebuild, it would seem like a good idea to pull the crank and change the seals. Would you agree? Anything tricky with this job? 

The book says there are valve inserts pressed into the head. In an old engine, would it make sense to replace these? I assume a machine shop would be able to tell me if this needed doing?

Would there be anything else that would make sense to go ahead and replace on an old engine? Anything in the valves? Cam? I just figure if I'm going to do all this work, I might as well spend a few more bucks and replace anything that might be worn out.


----------



## RC Wells (Dec 26, 2008)

With the low hours on the tractor, I would not worry about the head outside of having it checked for any cracks and straightness unless you see obvious damage or wear. The camshaft is something I would not touch, nor even remove the lifters unless you see obvious damage or wear.

The crankshaft needs to be carefully inspected too. Unless you have damage from the coolant, or it is excessively worn, I would not remove it. Leaking seals will be noted, and if they are bad they can be replaced. The use of Plastigauge to check bearing clearances is a good idea before you order the engine kit. But, unless there is evidence of damage or excessive wear that may not be necessary.

The water pump should be checked while you have the engine apart. This is something that normally would be replaced only when it begins to leak or is dragging a water pump bearing.

The hours are so low on the engine, I really do not expect you will need much other than the kit for the cylinders. But, inspection will tell you once you open it up and start the process. If you had 14,000 hours, then I would say to pull everything, have the crankshaft turned and trued, and replace all bearings.


----------

