JetStar 3 coolant in oil

DS79

New User
I asked a few weeks ago about the governor thinking it may have been my issue. It wasn't. I pulled a rod and a main cap and found major bearing wear. So I proceeded to order rods and mains for it. Crank was ground in or around 1979 according to the bearings ( crank is .010 rods are .020). Anyways, I was thinking it might have been from a bad cylinder head repair and someone never drained the oil out of the engine. I have had it apart now for a few weeks (finished up my 1st year teaching and those bearings are a SOB to install!) and noticed that I have coolant seeping around the 3rd lifter from the front. I cleaned it off and let it sit and confirmed that's where my coolant is coming from.

Now I need to know how the coolant is getting to that point so I can order some more parts. Do I need a complete top end set or can I just do head gaskets? I would like to get this out of my parking spot soon and I will have a bit more time now that school is out, so if I can order parts once and actually fix this tractor I would be thrilled! Then I can move on to bigger and better things.
Thanks,
DS79
 
That is a non sleeve engine so I would think a crack or bad gasket. Looks like you may have to pull the head too.
 
It. Would be a cracked head or just a gasket. Those engines are harder
to keep head gaskets on, if it has been apart and the blocks and head
are not aligned good and straight the heads will not torque down
evenly. I just replaced a set that were leaking, I took the heads off
bolted the adapter plate to the top with no gasket and had the heads
machined flat. Also Check the blocks with a good straight edge and
make sure they are flat and even, one could be pulled down tighter
than the other or have a thicker gasket under one if someone has had
it apart before. Could be a cracked block but usually it is a head
gasket.
 

This is what I wanted to know. The engine has had newer heads out on it but I don't know who did it or when. It sat a lot over the lady 5 years before I bought it. Guess I'll order a headgasket set and just prepare to pull the heads off once I finish getting the main bearings put in it. Any tips on getting the heads to seal this time?
 
When you pull heads and blocks make sure you change all orings, frost plugs, and water
tubes or you will be pulling apart again.
 
Do I have to pull the blocks? I was thinking those had a separate set of studs and a different gasket? I don't want to do it again but u also don't want to spend more time and money than I need to either.
 
Heads come off as a pair with coolant tube connecting them. Blocks lift as a pair also. If
I was that deep I would pull blocks and put set of rings in if bore is good.
 
I would strongly recommend you get a repair manual for that motor others gave good advice. It is simple enough to work on just a little odd. Oh they had a habit of burning valves too.
 
(quoted from post at 11:54:10 05/14/16) I would strongly recommend you get a repair manual for that motor others gave good advice. It is simple enough to work on just a little odd. Oh they had a habit of burning valves too.
I have no plans to keep the tractor but I want it right before I sell it. It ran great but had a knock. Found washed out bearings and watered down oil causing the noise. So I'm fixing that and the coolant leak then she's going down the road to finance a 1066 Hydro that I found. Like I said it had recent repairs and not many hours since those repairs. Though I'll probably pull compression on it before I tear it apart.
 
It sounds like these guys are giving pretty good advice. But the first thing I would do is pull the valve cover and rocker arm assembly and the pushrod from the leaking hole and see what I could tell anything looking down the pushrod passage with a good light.

At best it sounds like you will need a top end gasket set. Be sure it has 7 water tube 0-rings in it and the rubber donut that goes on the oil tube. (I always replaced the o-ring in the water pump, too.) If you need extra o-rings, I always matched mine up at NAPA.

If you want to do a really bang-up job, replace the freeze plugs too. At least the ones between whatever parts, heads or heads and blocks, you will be doing yourself or the next guy a favor.

After you get the valve cover off, it will become apparent that there is an adapter bolted to both heads that the valve cover seals against. You pull both heads together as there is a water tube sealed with o-rings between them. When you put it back, be certain the tube is in really good shape or replace it. The same thing with the blocks: there is a tube between them too. Also, in most cases there is a 1/4" dia rod in the vertical oil tube between the blocks. It restricts how much oil flows to the rocker arm. Just an FYI if you get into it that far.

I've told you all I can remember. It would sure be good to get an I&T manual on that tractor to consult on all the stuff we left out.
 
I think the topic is covered but - Pull the heads, have them checked for flat and for cracks. New head gaskets and I would coat those gaskets with sealant ( I prefer/recommend aviation form a gasket). My only add to this thread is that today's head gaskets are, in my opinion, junk and need to be treated.
 

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