Compression coming out of intake
- Thread starter Gls fab
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North Idaho Wolfman
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L3450DT-GST, Woods FEL, B7100 HSD, FEL, 60" SB, 743 Bobcat with V2203, and more
Kubota engines don't bend valves.
Why don't you start with giving more information as to what is going on, and what you are working on.
Why don't you start with giving more information as to what is going on, and what you are working on.
i received an engine for a project. When attempting to turn it over for the first time, it stopped hard. Turns out it got damaged in shipping and a chip of the intake manifold flange broke off, fell down and wedged between the intake valve and head on cylinder #3.
Very low compression on this cylinder after that.
Bent valve was replaced. All was good.
Maybe check the compression on all 3 cylinders before digging in?
North Idaho Wolfman
Moderator
Staff member
Lifetime Member
Equipment
L3450DT-GST, Woods FEL, B7100 HSD, FEL, 60" SB, 743 Bobcat with V2203, and more
Sorry, should have included a disclaimer:i received an engine for a project. When attempting to turn it over for the first time, it stopped hard. Turns out it got damaged in shipping and a chip of the intake manifold flange broke off, fell down and wedged between the intake valve and head on cylinder #3.
Very low compression on this cylinder after that.
Bent valve was replaced. All was good.
Maybe check the compression on all 3 cylinders before digging in?
Kubota valves don't get bent, unless something gets sucked into the intake and is small enough to get past the valve and then get caught between the valve and the head or between the valve and the piston.
In other words was there extenuating / odd / not normal circumstances that could have caused a valve to get bent?
Well as I stated I have compression coming out of the intake it's a Kubota backhoe 4 cylinder diesel two and three have compression coming out of the intake
North Idaho Wolfman
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Staff member
Lifetime Member
Equipment
L3450DT-GST, Woods FEL, B7100 HSD, FEL, 60" SB, 743 Bobcat with V2203, and more
Probably not a bent valve, but you bet you do have a blown head gasket.
Hence the reason 2 cylinders are doing it.
Tear it down.
Inspect the head and the block for flatness.
Inspect the head for cracks, they will be between the valves and pre-chamber if present.
check the height top end height of all the pistons, one or 2 short and you have an issue.
Do you have the WSM (aka service manual) for the engine or Tractor?
You will need it for the torque specs.
I would suggest a OEM head gasket.
There also is an O-ring around the head oil feed pipe, get one of those too as it's not a normal O-ring.
What model of tractor? It helps to know specifically because each engine has its own ticks and tricks.
Not a ton of work yanking then head off tractors. Diesels usually have high compression, which means they are sort of interference engines. Wether it's parts, sticking, whatever it is, the valves generally strike the pistons. If turning by hand no big deal. If it's running, another story. Any engine in this situation on any engine bends valves or damages pistons and rods. Not common with diesels. One the fuel doesn't gum up like gasoline and generally your talking sodium etc filled valves on gasoline engines and solid for diesels. Also ~4000 RPM difference. If in doubt pull the heads and both manifolds. Fill the intake runners with fuel and see if they leak, then flip it over and do the exhaust. If either leaks pull those valves and figure out why. If not sure of yourself take it to a machine shop. One worth it's salt can get valves and seals for any head. They'll tank it to clean, check flatness, for leaks etc. Without saying, while pulling it apart always pay attention to parts and see what caused the issue.
If you do this, get a copy of the WSM, and pay close attention when taking it apart as to the orientation of the head gasket (which side up/which side down) and whether any shims are used. Use only OEM gaskets.