YM1500 OVERHEATING

[wayne c-HT]

MY YM1500 is overheating when using any implement. It has the Hoye water pump on it and I have replaced the head gasket twice. Once when I rebuilt the engine and again to see if that was the overheating issue. There is a waxy substance that comes out of the blow by tube but no water in the crankcase. About the only thing that has not been replaced is the cylinder jackets. I had the head worked @ machine shop when I rebuilt it. Any Ideas ????????????????????

 

[Norm-HT]

Not 1 word about what all you have done to the radiator and flushing the system.

 

[winston-HT]

Could you expound on "waxy substance"? Does that indicate milky colored? How bad is the blow by?

 

[Aaron-HT]

Are you sure it is overheating? What are the symptoms? What is the actual temp reading? A lot of people see water bubbling out of the overflow tank and assume 'overheating'.

 

[robert lipham-HT]

I installed a temp gauge from hoye on my YM1700 , works great , you know exactly the temp.

 

[wayne c-HT]

I had the radiator boiled out and pressure tested when I rebuilt the engine. Everything checked out good.
The blow by looks like grey waxy grease when it comes out. It comes out sporadically in clumps. looks like steam coming out the blow by tube until it eventually spits out the waxy substance.
I installed both temp and oil pressure gauges when I rebuilt it and it is getting above 240 deg F. If I let it idle it will cool back down but takes a while and it jumps back up in temp fast when I resume mowing, tilling etc.............

 

[winston-HT]

Is your blowby amount anything close to this? http://www.youtube.com/watch?v=OLwUS_QGOhU

 

[alan-HT]

Before installing the new HG did you confirm both surfaces were solid and true?

 

[wayne c-HT]

Blow by is at least as bad as the video if not worse. Had the head trued at the machine shop when worked. Using a metal straight edge they both appear to be true and flat.

 

[winston-HT]

<QUOTE author="wayne c"><s>

</s>Blow by is at least as bad as the video if not worse. Had the head trued at the machine shop when worked. Using a metal straight edge they both appear to be true and flat.<e>

/e></QUOTE>

You have a serious problem. That much blowby would indicate worn rings or excess piston ring clearance. Did you check your liner bores when you put new rings in? Something not right in those cylinders and pistons.

Basing this believing there is no coolant in oil or oil in coolant.

 

[wayne c-HT]

Replaced both pistons and rings along with one piston arm and new bearings. Did run a hone in piston walls to slick up. Rings an pistons went in tight. could it be cylinder jackets? No scoring visible. Did have to replace crank shaft also. I've got more money in it than the tractors worth but it is a challenge now to fix it

 

[wayne c-HT]

Did check liner bores per manual and the seemed ok

 

[winston-HT]

I understand the challange. When checking piston and ring clearance one way is to insert a ring and check end gap at different intervels as you slide it down the cylinder. Liners don't wear evenly all the way down.

If the liner seals are bad you would have water in the oil or be bubbling or blowing out the radiator overflow as you have coolant on one side of the liner and compression on top, nothing on the bottom.

 

[Norm-HT]

It appears to be 2 years since you were overhauling the engine. Has it been running OK since then, until recently? That's plenty of time for the radiator fins to load up with chaff and stuff from mowing to cause serious overheating.

 

[wayne c-HT]

Radiator fins are clean you can see through them. It seems to be ok after replacing the head gasket and gradually gets worse. At $70.00 a piece I can't replace the head gasket on a regular basis. Do not have water in the oil or oil in the water. No white or black smoke from the exhaust just the steam and crud out of the blow by tube. Good compression and it runs well , cranks easily and pulls well just runs hot.

 

[winston-HT]

Using the word steam would indicate you think the blowby has water in it. When putting a finger or container under the blowby tube can you collect oil, water or just what?

 

[wayne c-HT]

water and that greasy wax looking substance

 

[alan-HT]

Your oil level is not above the full line, is it?

 

[winston-HT]

Your going to have to take it back down and find out where that water is coming from. Water in the blow by can only come from the cooling system: Bad head gasket, cracked head, cracked block, leaking liners. Machine shop says head is ok so you may have to dig deeper.

Does the coolant level go down with usage?

 

[Norm-HT]

Does the engine turn over fairly easily with a wrench on the crankshaft nut?

 

[wayne c-HT]

Engine oil is 3/4 up on the dip stick. That is 4 quarts of oil as specified.
It is moisture coming out the blow by and occasionally the grease comes out. It gets worse the hotter it gets.
It turns over easily with compression release on and more difficult with it off.
Took off the valve cover and did see some moisture in it on the top but the oil looks like it has nothing in it. Black no milky.
If it were the block wouldn't the oil be full of water and milky looking when drained?
If it was the gasket what should I see when the head comes off? This will be the third time off and I have not seen anything to indicate a leak either time. It has 751 hours on it now and had 571 when rebuilt. I put the Water pump on 10/13/11 and thought I had the overheat issue fixed for good. It worked for awhile and eventually heating issue again. Replaced head gasket just to see if there might be an issue there but it worked for awhile and gradually got worse to where I am today. Any wrong way to put the head gasket on?? Manual says to put strpe side up but the gasket I received had no stripes so I put it on how the old one came off?
It runs great and cranks easily. If it were not for this issue it would be great. I can pull it back apart but not sure what I am looking for.

 

[winston-HT]

<QUOTE author="wayne c"><s>

</s>Engine oil is 3/4 up on the dip stick. That is 4 quarts of oil as specified.
It is moisture coming out the blow by and occasionally the grease comes out. It gets worse the hotter it gets.
It turns over easily with compression release on and more difficult with it off.
Took off the valve cover and did see some moisture in it on the top but the oil looks like it has nothing in it. Black no milky.
If it were the block wouldn't the oil be full of water and milky looking when drained?
If it was the gasket what should I see when the head comes off? This will be the third time off and I have not seen anything to indicate a leak either time. It has 751 hours on it now and had 571 when rebuilt. I put the Water pump on 10/13/11 and thought I had the overheat issue fixed for good. It worked for awhile and eventually heating issue again. Replaced head gasket just to see if there might be an issue there but it worked for awhile and gradually got worse to where I am today. Any wrong way to put the head gasket on?? Manual says to put strpe side up but the gasket I received had no stripes so I put it on how the old one came off?
It runs great and cranks easily. If it were not for this issue it would be great. I can pull it back apart but not sure what I am looking for.<e>

/e></QUOTE>

Head gasket. <LINK_TEXT text="http://www.hoyetra...port/knowledgebase.php?article=74</LINK_TEXT>

Does the coolant level go down with usage?

You would be looking to find how water is getting in the crankcase.

 

[Norm-HT]

"Engine oil is 3/4 up on the dip stick."
What does that mean? Is it AT the full mark? Does your tractor stay outdoors? This water may have nothing to do with overheating. I would back-flush the system, and see if it will take full force of water hose.

 

[wayne c-HT]

the oil is covering the hash marks on the dip stick except the upper 25%. There is no full or low mark on the dip stick.
If the block was cracked wouldn't there be water in the crank case? When I drain the oil I do not see evidence of that.
The coolant does get low over time but it boils out of the reservoir bottle when hot which it then sucks it all out of the bottle back in the radiator as it cools.
Not sure how you back flush with the water hose. How do you get a tight seal. If I do this should I see water coming up through the head if I take the valve cover off? Tractor does stay outdoors.

 

[Norm-HT]

<QUOTE author="wayne c"><s>

</s>the oil is covering the hash marks on the dip stick except the upper 25%. There is no full or low mark on the dip stick.
If the block was cracked wouldn't there be water in the crank case? When I drain the oil I do not see evidence of that.
The coolant does get low over time but it boils out of the reservoir bottle when hot which it then sucks it all out of the bottle back in the radiator as it cools.
Not sure how you back flush with the water hose. How do you get a tight seal. If I do this should I see water coming up through the head if I take the valve cover off? Tractor does stay outdoors.<e>

/e></QUOTE>

The top and bottom of the hash marks ARE the full and low marks. Unhook the upper rad hose at the rad, stick a garden hose in as far as it will go and stuff with rags. Cover batt. and electricals with plastic, turn on water, it will run out open rad port. Should take full force of water. If tractor is stored outdoors you can expect water in oil and transmission.

 

[wayne c-HT]

Drained the radiator and the oil and saw no contamination either way. Back flushed system and it is running cooler. Did not see anything come out of the system but for whatever reason it is running 45-50 degrees cooler now. Still have the blow by but it runs cooler for now. When the weather lets up I'll work it with the bush hog and see if it holds up.