Diesel Blow-by Question

[loopman]

Hello,

I have a Iseki TE4270 tractor (E3AE1 engine) which had been running great, has about 1200 hours on it and then very suddenly I am seeing quite a lot of blowby. oil splashing out filler cap on top of tappet cover after about 5 minutes of running. New correct grade oil and new filter - same issue.

Everything I have read in these forums indicate broken or stuck piston rings, however...

It starts easily
Runs without smoking
And when I do a compression test on the cylinders I get 410, 420 and 440psi. (Workshop manual says overhaul not required until less than 370psi)

So how am I getting so much blowby if I have good compression?? If it were rings, or head gasket etc. I should see at least one cylinder with low readings shouldn't I?

Thank you.

 

[Egon]

Valve seals??

 

[Texasmark]

Valve seals??

I doubt at 1200 hrs. I think you need some "snake oil" in your oil and fuel to clean out some crud for starters and while you are at it, check your inlet air filter and maybe something like a birds next in your filter area......didn't over fill your oil did you?

I have a 3800 hour, 1963 Ford 2000D that has blowby that corrects mostly after the engine warms up. I use snake oils. It starts in the winter in a couple of seconds with no starting aide after having sat for a month or so without running. Didn't do a compression test but don't need to as I know that compression is what makes the heat that ignites the fuel mist (your numbers are good). For me, I suspect worn valve guides as the culprit, not in your case.

 

[Zebrafive]

My JD 2030 with 4400 hours has blow by. The vent tube will make a dust storm in the dirt on the ground below it. But no oil, only forceful air comes out. It only goes away if the tractor is worked hard. I suspect worn rings.

 

[Texasmark]

My JD 2030 with 4400 hours has blow by. The vent tube will make a dust storm in the dirt on the ground below it. But no oil, only forceful air comes out. It only goes away if the tractor is worked hard. I suspect worn rings.

On yours yes, on his, no unless it has seen some really hard times.

The compression blows by the rings and pressurizes the crankcase....attempts to but the vent prevents it. Your tractor hard to start, especially in the winter....I guess it's a diesel. I'm going to guess that your oil rings and or their springs are ok. Your problem may be inhaling dust which gets the top ring especially to the point where, like on a Ford 3000 I bought, it ate up the top ring and wallowed out the groove in the piston such that I had to replace all 3.....but mine was at 5600 hrs and hard to start, purchased that way. Reasoning on mine was that the PO removed the rubber hose between the oil bath air cleaner and the intake manifold. When I did the inframe, the bottoms were in spec. telling me that the guy at least changed his oil and didn't do any lugging.

 

[Roadworthy]

How is your engine oil level? With some tractors when the shaft seal leaks on the hydraulic pump it dumps hydraulic fluid into the oil. You then have too much fluid in the crankcase.

 

[Jerry/MT]

Hello,

I have a Iseki TE4270 tractor (E3AE1 engine) which had been running great, has about 1200 hours on it and then very suddenly I am seeing quite a lot of blowby. oil splashing out filler cap on top of tappet cover after about 5 minutes of running. New correct grade oil and new filter - same issue.

Everything I have read in these forums indicate broken or stuck piston rings, however...

It starts easily
Runs without smoking
And when I do a compression test on the cylinders I get 410, 420 and 440psi. (Workshop manual says overhaul not required until less than 370psi)

So how am I getting so much blowby if I have good compression?? If it were rings, or head gasket etc. I should see at least one cylinder with low readings shouldn't I?

Thank you.

You have good compression so I don't see how it could be rings. Make sure your crankcase vent tube isn't clogged. If it is, the normal blowby will pressurize the crankcase and when you take the fill cap off it will vent out of there. If it continues this way you have some seals ( like the rear main) leaking.

 

[Jim Nelson]

What Roadworthy said would be my first guess,I had a B7200 Kubota that this happened to and ended up having to replace the whole pump because just replacing the seal didn't work. It's been so long ago that I don't remember the cost but I don't think it was too much.

With this coming on suddenly this makes more sense to me than rings or valve guides unless it some how broke a ring.