1610 head gasket issue

[Box]

I found out some information that I tought I would share. I spoke to a friend of mine who is a diesel mechanic for Cummins. He told me that if the radiator is marginal, either stopped up or maybe not quite large enough for the engine it can suck air through the waterpump seal and introduce air into the system that way. He suggested I have the radiator checked again and also replace or rebuild the water pump. Since the tractor is 25+ years old I was planning to do this anyway in the near future. I have suspected it was not working that effecently from the get go.

Before I change the pump and radiator I plan to do a compressrion test and see if I can determine if any of the cylinders are leaking down. I would think that if one is leaking enough to produce the number of bubbles I am seeing it will show up in a compression test. Once that is done and depending on what I find I will target getting the water pump and radiator taken care of.

I don't see any blockage in the radiator enternally or externally and it seems to flow water well but that does not mean someone has not blocked one of the passages in the past for some reason. I have seen that in old cars before, I cracked one radiator open on a chevy to rod it out and found someone had solder one passage completely up. I guess that was someone idea of how to find a leak. I will not be able to do this for a few months though due to all I have going on with the new house but it will be on the top of my list once we are in the new house. I will post again once I have checked completed these changes.

Box

 

[California]

Have you run a pressure and vacuum test on the cooling system? There is a kit that goes on in place of the radiator cap. Seems to me it would measure this air leakage.

 

[Box]

Have you run a pressure and vacuum test on the cooling system? There is a kit that goes on in place of the radiator cap. Seems to me it would measure this air leakage.

You must be a mind reader. I was just talking to some here at work about borrowing a testing kit from them. I am also going to get a heat gun ...temp gun and see what the readings are on the core.

Thanks

Box

 

[svcguy]

A couple of things worth thinking about:

When bubbles are showing up in the coolant and you can't find the answer, try draining all coolant, flush the block with fresh water a couple of times and fill with fresh water to test. If the bubbles are no longer there, your coolant could have been contaminated. Bubbles or froth (depending) can be caused by traces of rad/block flush, additives, etc.

I have seen people laugh about 'diesel coolant'. Don't. Always use SCA additive to your coolant mix if you are not using a special diesel coolant. SCA is available from heavy equipment dealers, heavy duty service providers or auto parts stores. SCA's create a very hard microscopic film on the coolant side of the wall by converting ferris oxide into Fe305. Otherwise you risk pin hole damage to your cylinder liners or cylinders caused by cavitation. Using nothing but water, this could happen in as little as 500 hours. A damaged cylinder can result in bubbles, but normally you would find coolant in your sump if you have a pressurized rad cap in the system. If a pin hole is small enough though, it can be a one way leak. If you aren't using SCA's, start today.

Ensure you use gasket tack if the type of head gasket calls for it. Don't use it on gaskets that the manufacture asks you specifically not to use it. It can work wonders with marginal conditions.

Unless you suspect something really out of the ordinary, it makes no sense to replace your head bolts. Head bolts are torqued to spec and will not be over tightened. Some bolts need to be replaced each time as they stretch to torque (certain VW diesels are one example) and certainly that makes sense. I am not familiar with Yanmar using 'stretch' bolts.

Before replacing a head, take a machinist straight edge and lay it corner to corner both ways, each half and check with feeler gauges. If you have a warped or dished head, have it resurfaced. If you have nothing to measure it with, hold the head and straight edge up to the light. Tapering space = resurface head.

If in question, always take the head to a machine shop and have them magnaflux it for cracks prior to reinstalling it. It is tough to visually check a head with confidence.

I doubt your pump seal is pulling air. This is a potential problem with larger diesels but I think Yanmar is a bit light for consideration. Not impossible, but not probable.

It may be time to try and silicate the block again. It won't hurt it and certainly might help. Flush, flush, flush before hand if you want success. If you have a leak and it sounds like you do, they tend to get worse over time, not better and silicate often helps small leaks.

Good luck.

 

[Box]

Man I was almost done with this post, clicked the spell check icon and the whole thing went into cyber space I hate it when that happens.

SVCGUY....Thanks for your input, I need all the insight I can get on this.

I know all about SCA's. A little history on myself I have been selling larger diesel engines for about 14 years now. I use Fleetguard's DCA products in my FORD F250 and I have a gallon bottle of the Fleetguard Complete 50/50 pre mix that I plan to use in the tractor once I get a handle in this issue. You are right that cavitation can eat up an engine and especially the liners in no time really. Seeing is believing and I have been witness to more than one engine liner that was damaged by someone not using SCA additives in their engine. So I am on the same page as you when it comes to using the correct antifreeze in a diesel engine.

Now having said all that, I am not a mechanic and although I know quite a bit about the larger diesel engines with liners I do not make my living working on them. I just help folks buy one to fit thier needs, mostly Oil Field OEMs that are building oil well servicing equipment. This little Yanmar engine appears to be a very simple design to me, but I have learned that there are some unique things about these engines as I guess we all have. I guess you could say I am a bit of shade tree mechanic as I have always done the service on my cars and trucks when I could and I ride a Harley which means I am always fixing something on the bike. They are alot better now than the once where but they still have some issues. So I'm not scared to try to work anything if I know I can get the tools and parts I will need.

I am not sure if you read all of my posts in this tread, but I had head off on the 4th of July and did check it with a straight edge and could not see any warping so I put it back together. I did not however check it with a light behind it which might have been a mistake becuase it ran like crap when I fired it back up and when I tore it down I found that the #2 cylinder was leaking combustion around the head gasket and one of the water jacket holes. I took the head to a machine shop in Houston to have it checked for cracks and warping. They found that the head was warped and they did not find any cracks. The where not able to pressure test the head which has me a little concerned, but they did surface the head and grind the valves to match so I am fairly certain the head gasket is now sealing. The engine certainly runs much better than it was before I started working on it, now if I could only find the source of the air bubbles then I think I could get it "fixed" and back to an almost like new condition.

I assume by silicate you mean a block sealer like K&W. I used K&W early on, but at that time I think the head gasket (original) was leaking so I am not sure it was able to have any effect on the engine. I think I will take your adivce and give it another go, as you said it can't hurt anything to try and sometimes it does help.

I will be out of town this weekend, but the first free weekend I get I am going to do the following:

1. Pressure test the radiator.
2. Check the compression on each cylinder
3. If I don't find anything out of the spec in test 1 or 2 I am going to flush the radaitor 3 to 4 times with a good flush and then several more time with plain water.
4. I will then check the radiator core with a temp gun to see if there are any cold spots on the core.
5. If no cold spots are found I will try sealing the block again.
6. After the block sealing procedure is complete I will check the radiator core again to see if here are any cold spots, just in case the sealing causes any blockage in the core.

Then I guess I will hold my breath and see if I have made any progress. If I have not I guess I need to pick a time when I can have the tractor down long enough to test pressure test the block. That is only place I can think of the compression coming from if there is no leaking at the radiator or cylinder. As you said it would have to be a pin hole that is only letting compressed combustion air out and not water in.

Thanks again for you ideas and input

Box

 

[svcguy]

Hi Box,

I have to apologize as I was speed reading through everything and didn't catch the whole story.

Yes, sodium silicate is a simple block sealer like K&W and is actually quite effective on small leaks. Many people are hesitant to use it, but it actually works quite effectively, especially with something like a pinhole where the pressure of the cooling system can block it off and the SCA can build a film over it.

Sounds like you have it pretty well in hand and once those bubbles are stopped, you probably won't see them again.

 

[Box]

I was by my new place yesterday for the first time since I ran the tractor for 4 hours or so hours on Sunday.

I checked the over flow bottle to see if the system had returned the coolant which was pushed into the overflow bottle on Sunday back into the radiator. It had not, so this tells me there is a leak somewhere in the cooling system. On Sunday the level in the over flow bottle raised from the low fill mark to just above the high fill mark and it was still there yesterday. If the system was maintaining pressure it should have sucked the coolant which was pushed out during operation back into the radiator when the engine cooled correct? Thats how every other cooling system I know of works, but this is the only one I have ever been involved with that was built to work with out a T-stat to I was just wondering if I am missing anything.

The radiator cap is new and there was some pressure released when I removed the cap on the cold engine. Not much but there was a short hiss of pressure release when I loosend the cap.

It will be interesting to see if the cooling system hold pressure when I get my hands on the radiator pressure testing kit.

Box

 

[SATOHBULL]

Are you sure the hiss when removing the cap was pressure, not vacuum?

The reason I ask is that when the engine cools, the water shrinks, creates a vacuum and 'sucks' the water back from overflow res.

Since yours did not do that, but there was a 'hiss' from the cap, it may be that the cap is bad and the wrong one. The vacuum should be routed from the radiator to the overflow.

In any case, it seems to me that the pressure differential , either pressure or vacuum would indicate a tight, leak free system.

I just had an experience on a car that may be similar to yours. Ford v6 in a 96 Taurus with only 35000 miles. Heating when driving at highway speed. looking into the fill neck when running there were lots of bubbles, but only after running a while.

What it turned out to be was the water pump! all the fins were corroded off the impeller. So the water wasn't moving much at all. The water in the head would vaporize from local heating creating the bubbles.

So, check your coolant flow.

 

[Box]

Are you sure the hiss when removing the cap was pressure, not vacuum?

The reason I ask is that when the engine cools, the water shrinks, creates a vacuum and 'sucks' the water back from overflow res.

Since yours did not do that, but there was a 'hiss' from the cap, it may be that the cap is bad and the wrong one. The vacuum should be routed from the radiator to the overflow.

In any case, it seems to me that the pressure differential , either pressure or vacuum would indicate a tight, leak free system.

I just had an experience on a car that may be similar to yours. Ford v6 in a 96 Taurus with only 35000 miles. Heating when driving at highway speed. looking into the fill neck when running there were lots of bubbles, but only after running a while.

What it turned out to be was the water pump! all the fins were corroded off the impeller. So the water wasn't moving much at all. The water in the head would vaporize from local heating creating the bubbles.

So, check your coolant flow.

Thanks SATOHBULL, I let eveyone know what I find out ofter testing the radiator.

 

[Box]

Man I was almost done with this post, clicked the spell check icon and the whole thing went into cyber space I hate it when that happens.

SVCGUY....Thanks for your input, I need all the insight I can get on this.

I know all about SCA's. A little history on myself I have been selling larger diesel engines for about 14 years now. I use Fleetguard's DCA products in my FORD F250 and I have a gallon bottle of the Fleetguard Complete 50/50 pre mix that I plan to use in the tractor once I get a handle in this issue. You are right that cavitation can eat up an engine and especially the liners in no time really. Seeing is believing and I have been witness to more than one engine liner that was damaged by someone not using SCA additives in their engine. So I am on the same page as you when it comes to using the correct antifreeze in a diesel engine.

Now having said all that, I am not a mechanic and although I know quite a bit about the larger diesel engines with liners I do not make my living working on them. I just help folks buy one to fit thier needs, mostly Oil Field OEMs that are building oil well servicing equipment. This little Yanmar engine appears to be a very simple design to me, but I have learned that there are some unique things about these engines as I guess we all have. I guess you could say I am a bit of shade tree mechanic as I have always done the service on my cars and trucks when I could and I ride a Harley which means I am always fixing something on the bike. They are alot better now than the once where but they still have some issues. So I'm not scared to try to work anything if I know I can get the tools and parts I will need.

I am not sure if you read all of my posts in this tread, but I had head off on the 4th of July and did check it with a straight edge and could not see any warping so I put it back together. I did not however check it with a light behind it which might have been a mistake becuase it ran like crap when I fired it back up and when I tore it down I found that the #2 cylinder was leaking combustion around the head gasket and one of the water jacket holes. I took the head to a machine shop in Houston to have it checked for cracks and warping. They found that the head was warped and they did not find any cracks. The where not able to pressure test the head which has me a little concerned, but they did surface the head and grind the valves to match so I am fairly certain the head gasket is now sealing. The engine certainly runs much better than it was before I started working on it, now if I could only find the source of the air bubbles then I think I could get it "fixed" and back to an almost like new condition.

I assume by silicate you mean a block sealer like K&W. I used K&W early on, but at that time I think the head gasket (original) was leaking so I am not sure it was able to have any effect on the engine. I think I will take your adivce and give it another go, as you said it can't hurt anything to try and sometimes it does help.

I will be out of town this weekend, but the first free weekend I get I am going to do the following:

1. Pressure test the radiator.
2. Check the compression on each cylinder
3. If I don't find anything out of the spec in test 1 or 2 I am going to flush the radaitor 3 to 4 times with a good flush and then several more time with plain water.
4. I will then check the radiator core with a temp gun to see if there are any cold spots on the core.
5. If no cold spots are found I will try sealing the block again.
6. After the block sealing procedure is complete I will check the radiator core again to see if here are any cold spots, just in case the sealing causes any blockage in the core.

Then I guess I will hold my breath and see if I have made any progress. If I have not I guess I need to pick a time when I can have the tractor down long enough to test pressure test the block. That is only place I can think of the compression coming from if there is no leaking at the radiator or cylinder. As you said it would have to be a pin hole that is only letting compressed combustion air out and not water in.

Thanks again for you ideas and input

Box

Hello Everyone,

I borrowed a pressure testing kit from a buddy this weekend and tested the radiator. It seems to hold about 15 lbs, or at least it held that amount of pressure for the 15 minutes or so that I had the tester hooked up. So I guess I will say that the radiator has passed the pressure test at this time. I didn't start the unit with the testor installed, should I have? Didn't think about that at the time. Hind sight being 20/20 and all. I still have the testing kit so I can go back and recheck if I need to.

I am going to stop by Northern Tool or HF tonight and purchase a infered (SP?)thermometer to see if there any cold spots on the radiator. I would have done that this weekend, but it was sort of a fluk that I ran into my buddy so I decided to take advantage of having his tool close at hand.

I ordered some of the chamber gaskets (crush washers) for the injector ports today so I can pressure test each cylinder some day soon. I also ordered a new water pump off e-bay. I figure a new one can't hurt anything and the price was very resonable.

I have about 7 hours on the engine at this time, so I am getting near to time to recheck the torque on the head and also reset the valve clearnce. When I have the tractor down for those items I will replace the water pump and also check the cooling system

I will post again after I get the compression testing done. I am thinking I either have an issue with the radiator it's self being plugged or blocked in someway, the water pump (maybe the seal is sucking air but seals when pressure is applied with the testing pump), or maybe there is a pin hole in block, but if there is a pin hole it is some acting a one way valve as I just changed the oil and there was no coolant in it at all.

I will post again after I get the next test completed.

PS...I received the replacement banjo bolt for the one that I broke and had to make a homemade replacement for. The new bolt was the same size but had a 14mm head while old ones had 13mm bolts. Not sure why they change this but this is second time I ran across something like this on this engine. I had to order new nuts for the studs that hold the rocker assembly down and the new ones where 14mm while the old ones where 17mm. The manual said to torgue these to 40lbs, but I didn't think the 14mm would handle that so I snugged them down and left if at that. I will check the break away toruqe on them when I disassemble to check the head tourge and see what I have. It is all working so it must be close.

Box