1550 Diesel Intake valve seals??

[rocko]

Question is are they supposed to be there. Reason I'm asking is because it apears to me I've got oil seaping out between my intake manifold and head. I'm thinking it may be coming from top down around valve stems and showing up where it is. I'm figuring I should also change intake seals cause if oils getting out airs probabley getting in. But need to figure out whats happenning there first. Any opions or input appreciated. Rocko.
 

[J. Schwiebert]

O. K. The 1550 diesel will have rotators on the intake valves. Here is what you do. Take the intake manifold off and have someone turn the engine over with a socket and a bar slowly. While the engine is being turned over look at the valve stems when each valve is open. See how oily they are. We put P/C valve seals on many Oliver engines and it was a field fix for the older engines after they became standard. Also there are 2 1550 diesel heads (different valve sizes) How about a tractor and engine serial number in case you have more questions. You can also change valve seals without removing the head. Your questions? Oh: when you take the valve cover off look for sticking exhaust valves as well. J.
 

[rocko]

Hello J. I have just yesterday taken off valve cover and checked valve lash settings do to excesive smoking and running rough. I'm suspious of bad injectors or pump but trying to eliminate other possible causes first. All were moving and lash was pretty good, did ajust a couple. I'll do as you suggested with intake and check valve stems tommorow. When I was putting valve cover back on notice that side was quite oily/dirty. Thought it could be Energy Cells leaking. Cleaned area and ran it today for 1/2 hour feeding. After that noticed seepage from intake. Tractor Serial # 355=42007 #'s off engine behind starter 185320 and 160913A. Tell me more about these P/C valve seals and procedure for installing them please. Also Would like to test pump preasure, could use advice on that. Rocko.
 

[B A Star]

 

[rocko]

Thanks for the reply B A Star. I read through that Service Bulletin. I'f I read it right it's pertainimg to 1600 and 1800 gas models, would that apply to my 1550 Deisel also? Also think it was dated 2-21-64 and if I'm reading my serial # right # 205 669-502 my tractor wasn't built till 68. Thanks for your help. Rocko
 

[rocko]

Sorry J, # I gave in 1st reply was model # 355-42007 serial # is 205 669-502 making it a 68 if I'm reading it correctly from lists available to the left. Thanks for your help. Rocko.
 

[oliver90owner]

Rocko,

Diesels are different from the gas engines in that the intake side is free air so dilution with more 'free air' makes not a jot of difference, as it might, to the mixture of a gas engine with (carburettor).

The diesel should be running with a minimum vacuum at the intake side (not like a gas when the carb throttle valve is closed completely), limited to the state of the air cleaner, so oil is not sucked down the guides, but it can be blown down with crankcase pressure (another possibility?).

If the valves or guides are worn so much that excessive leakage is occurring, then likely it is getting close to the time for a cylinder head overhaul at the minimum. Not as bad on these slower revving engines as on the higher revving modern auto diesels (but they can go a long time without attention these days). Loose valve guide clearance will eventually lead to worn seats/valves. Then things, as in problems, get compounded.

But some engines are more prone to this and lots are fitted with seals anyway
 

[rocko]

OK so I did what J suggested. Removed intake as well as valve cover. Appears what problem is is that stud bolts that screw into block is where oil is coming out. Threaded holes go through to oil side of head and bolts are not sealed. Poured oil down one intake valve stem and it filled and started coming out threaded hole.(I had removed all studs at this point.) Obviously no seal at top of valve stem. I wondered if oil was entering cylinder when valve openned, so I turned engine over by hand didn't see oil level inhole change but I was on oppisite side of engine to turn over engine. Pulled fuel shut off and turned engine over with starter. Again didn't seem to change level in hole or oil pouring through rocker arm system for that matter. Every thing moving and looks well lubed but no noticable amount accumulating in 30 sec. or so. So I assuming that if there are seals at the bottem stopping oil from entering cylinders but below thread holes in head although my test was not overly scientific and I could well be wrong. Casting number on head inself is 180402K if thats of any use. Figure to seal studs with some kind of gasket sealer and put her back together as I will need it to feed again tommorow. Would still appreiciate any further input from you more knowledgable folks out there. Thanks again Rocko.
 

[rocko]

Thanks for your input oliver90. Engine was rebuilt about 800 hrs ago. I did most myself but had head into shop for redo of valves. Thats why I was a little concerned when I notice oil seeping out intake. Don't recall if I ever removed studs from head on intake side(see my last post) But I know I would never have expected that they would go through to oil chamber of head. Thanks again for your input. Rocko.
 

[J. Schwiebert]

What stud bolts? You took the valve cover off and there are 6 studs that hold the rocker arm shaft on. Is that what you are talking about? How oily were the valve stems when you looked at them through the intake ports. Are you thinking about working on the miss right now?
 

[rocko]

Hello J. I took the intake manifold off as you suggested. I also took the valve cover off. The six stud bolts I refered to are the intake manifold to HEAD (I mistakenly typed block other post) mounting studs. The threaded holes these thread into go straight into oil chamber of head and were loose and leaking. Valve stems are not visible from intake ports. Yes I am still chasing that miss and excesive smoking issue. I have previously taken the exhaust manifold off and watched which cylinders are smoking and it seems to move around and change as engine warms up. Thanks Rocko.