Rebuilt D7H engine oil level problem

wayne.d7 · Jun 21, 2021

Hi guys I’ve rebuilt the engine in one of my D7H serial no 5WB 4127 3306 10Z 219119
New crank,pistons,liners,valves guides bearings the whole deal it’s back at work and running great
The engine oil level is a worry
When I check the oil level at the end of the day,with engine at idle it is down 4 or 5 litres,when I check in the morning before starting,it is back at the full mark
When I start the engine from cold,and let it idle for a few minutes,and check again,there is only half an inch of oil on the stick,this is a real worry, I did the same procedure on one of the other 7s and it only drops 1/2 inch from the full mark
I’ve checked the top of the engine for excess oil that was ok I’ve dropped the oil pan and poured oil into the filler pipe to make sure it’s not flooding the front gear housing,the crankcase breather is clear,the turbo drain is clear Any ideas guys,any help sorting this out will be really appreciated Regards Wayne

.RC. · Jun 21, 2021

Doesn't the dipstick on one side say check with warm oil and engine running?

And on the other side of the dipstick there is a "safe starting level" mark?

wayne.d7 · Jun 21, 2021

Hi RC yeh that’s correct and I’m aware as to how these are applied
I’ve owned every model D7 over the last 42 years had plenty to do on the 3306 but this has got me scratching my head thanks for your reply

Cmark · Jun 21, 2021

I can't say I've come across this problem before but have you thought about your scavenge pump?

wayne.d7 · Jun 21, 2021

Hi Cmark the pump was regearded and new pressure relief valve
I’ve thought maybe large internal oil leak but has 80 psi at high idle and 20 at idle

Cmark · Jun 21, 2021

Yes but the scavenge section is completely separate from the lube section. I don't think there is any way to test it with the engine running. AFAIK you can only check the gears are good, and that the pickup tube and seal isn't damaged.

wayne.d7 · Jun 21, 2021

I will check the pump and pickup tube again there’s a lot of oil hanging up somewhere in the engine at cold start could be as much as 8 litres

Bluox · Jun 21, 2021

Cmark said:
Yes but the scavenge section is completely separate from the lube section. I don't think there is any way to test it with the engine running. AFAIK you can only check the gears are good, and that the pickup tube and seal isn't damaged.

Wouldn't the oil run down the plate to the sump if the engine was level?
Maybe park the tractor with the rear end uphill?
Bob

Cmark · Jun 22, 2021

Bluox said:
Wouldn't the oil run down the plate to the sump if the engine was level?
Maybe park the tractor with the rear end uphill?
Bob

Yes, I would imagine so as well. It's just my best guess so far given the situation.

Bluox · Jun 22, 2021

Cmark said:
Yes, I would imagine so as well. It's just my best guess so far given the situation.

I hope he lets us know what he finds bet it's something silly.
Bob

Nige · Jun 22, 2021

Is there an orifice designed to limit the oil flow to the valve gear on that engine.? From the sounds of it the oil is taking too long to drain back to the oil pan. Provided the tractor is level it ought not to be necessary to scavenge oil from the back of the pan to the front, gravity should do that.

chidog · Jun 22, 2021

Did it do that before you worked on it? Was it an inframe overhaul? I don't know those tractors well, but I have had similar with some older stuff. Bad rear seal transfers oil into the torque converter and over fills the transmission etc. and then it could possibly drain back when setting shut off.

nicky 68a · Jun 22, 2021

Very interesting post.
I had a similar problem with a D342 in a D8.Like the OP,I was well aware how to check oil,but the oil seemed to disappear during the shift to the point I’d switch it off at brew time to let it settle half an hour,then check it.
It would give you a heart attack checking it after a couple of hours with the engine ticking over.I knew the oil was in there after spending a few weeks being sure it wasn’t slowley transferring,but I often ended up overfilling it.
As for checking it after a cold start 10 minuits into the shift,it would naturally show a low level.
To be honest,I never got to the bottom of that engine and I never liked it.
Some years later after around 3500 clock hours,I replaced the entire engine as the oil pressure would drop after a few hours.
I should say,that many years ago during a bit of a tart up,my chap found the oil gallery had fretted at the elbow where it fired oil into the filter.It was a good find by him as my eyes never saw it.
Perhaps it went again?.
Anyway,I feel your pain sir,and keep us updated please.
Good luck

Cmark · Jun 22, 2021

Here's a shot in the dark. The dipstick tube should have a small tube attached that allows it to breathe. Is everything in order there? No plastic caps been left in place from the repair?

Vetech63 · Jun 22, 2021

What is the odds that the head gasket was wrong or installed backwards and the drain port for the valve drain is blocked off? I've actually seen this happen on another engine. I don't remember how that engine is set up and whether the drain is through the pushrod casting holes.

oarwhat · Jun 22, 2021

Maybe have a look in the valve cover to see if the oil is pooling there.

wayne.d7 · Jun 26, 2021

Hi guys thanks for your reply’s Nicky especially reassuring to know I’m no alone on this trek I’ve removed the oil pan and all looks ok it’s fair got me scratching my head this one
I’ve started another of the D7s and checked when cold and it’s hiding about 5 litres when cold so that’s 3 I’ve checked that all show different oil levels
Yeh Nicky add oil which overfills it,it burns the overfill off in a shift,use the cold level and uses very little maybe 2or3 litres after 40 hrs
We fuel up and check oil levels at end of day this tractor has always been an engine oil user. This low level on start up makes me real nervous I’ve followed up on everyone else’s suggestions thanks guys.Mark your shot of the dipstick and tube there’s no stick showing out of bottom of tube that is what I found when I removed mine On the earlier PC 3306 there’s at least 2 inches of the stick out the bottom of the tube I’m thinking maybe turbulence in the pan when cold not allowing an accurate read ? Thanks guys great site this,you guys do it proud

nicky 68a · Jun 26, 2021

Funnily enough,I’m in the process of ordering a new dipstick tube for a D9 from Cat.
It’s actually worn holes in it and I’ve patched it up a couple of times with bits of tubing,old hose and clips.It still leaks abit of oil,but after reading this thread the other night,I’ve decided to stop faffing about and just buy one

Nige · Jun 26, 2021

Have you tried removing the valve cover(s) and run the engine to check if oil is accumulating in the top end.?

wayne.d7 · Jun 26, 2021

Yeh Nicky I recall my PC engines showing some wear on the stick where it exits the tube my thinking now is cut 2 inches off the end of the tube at least I then can be sure of a better contact with the oil and hopefully a more accurate reading
Yeh Nige I did exactly that early on,the oil capacity on top of the head is minor it flows over the side down to holes in the casting between the cam followers and into the pan
When I lie under the engine with my spot light shining up into it I’m thinking there’s no way that amount of oil can hang up in there,if I spill some on the workshop floor it runs faster than I can What do you think of my above suggestion worth a try? I have 2 more D7s that I can do a cold start comparison on when I get to them

Rebuilt D7H engine oil level problem

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