Thread: Series III 2.6L 6-pot massive oil leak from wading plug hole

It could be either engine oil, gearbox oil, or hydrulic fluid from the slave cylinder. First step, confirm which it is. (mainly smell)

If it really is engine oil, there does not seem to be any source other than the rear seal.

But leakage there may have been forced if the crankcase is being pressurised by the crankcase ventilation system being blocked. This engine has closed crankcase ventilation, and misassembly of this can result in it being effectively unventilated, which inevitably means it will build up pressure in the crankcase. If this has happened,it is possible that the seal can remain undamaged.

Wow. This is good. So now you have me thinking about the ccv system. Positive that it is oil and not hydraulic or gear oil.

suggestions on how to inspect the ccv system to determine if there is a blockage? Does the workshop manual diagram the system? Clearly there was pressure build up.

if you have suggestions on how to diagnose then I’m all ears. Either now while the engine is relatively undisturbed from this event or once I pull the engine, I’ll follow your suggestions.

and thank you for your input. Very valuable.

How does the engine manage pressure build up in the crank case via the CCV?

Originally Posted by JDNSW

It could be either engine oil, gearbox oil, or hydraulic fluid from the slave cylinder. First step, confirm which it is. (mainly smell)

If it really is engine oil, there does not seem to be any source other than the rear seal.

But leakage there may have been forced if the crankcase is being pressurised by the crankcase ventilation system being blocked. This engine has closed crankcase ventilation, and misassembly of this can result in it being effectively unventilated, which inevitably means it will build up pressure in the crankcase. If this has happened,it is possible that the seal can remain undamaged.

Originally Posted by matthamilton

How does the engine manage pressure build up in the crank case via the CCV?

It doesn't. Crankcase ventilation is there mostly to prevent pressure build up. All IC engines will experience some blow by. It has to escape from somewhere. If unventilated then seals are the next weakest link.

so on the Land Rover 2.6l 6-pot how does it vent the pressure buildup? Through what vents in the block it is relieved?

Originally Posted by Tins

It doesn't. Crankcase ventilation is there mostly to prevent pressure build up. All IC engines will experience some blow by. It has to escape from somewhere. If unventilated then seals are the next weakest link.

Originally Posted by matthamilton

so on the Land Rover 2.6l 6-pot how does it vent the pressure buildup? Through what vents in the block it is relieved?

People like John JDNSW know more about these engines than I ever will and can answer that specific, but the principle is the same. You may find it's as simple as a blocked or incorrectly installed flame trap (603330 in the pic). I don't know about the 2.6, but some engines have a one way valve. If that is installed the wrong way it's the same as being blocked.

Screenshot 2023-03-08 at 10.10.24 am.png

I just pulled out the workshop manual and was reading about the flame trap. So this is how it's vented back into the carb to re-burn. got it. So here is the entire story: had just pulled the truck out of the garage and backed out and off the edge of my driveway. So the back end was a bit lower than the front. Then the motor stopped. I thought that might be the sign of a stuck float in the Stromberg...at least this is what first came to mind. Took me forever to get restarted and this was unusual since it has been real easy to start. Noticed I had a loose plug in #5 and removed, cleaned all plugs, and finally got started by pulling choke all the way out. It never ran smooth after that. Seemed to be missing and I attributed that to the fouled out plugs. They were dirty and soaked with fuel. I figured I'd run it at a higher idle to help burn off the buildup on the plugs. Started blowing grey/black smoke...again this was new. I still thought that this was just the engine expelling or burning all the excess fuel that had gotten in the cylinders.

Pulled the truck forward to drive it back in the garage. Got out to make sure it was aligned (small garage) and noticed a drip from the bell housing area. Then pulled it in and noticed the oil pressure was dropping quickly. Immediately shut the engine down. Looked underneath the truck and there was a pond of oil about 18 inches across.

The truck had run like a top prior to this episode on Sunday.

Originally Posted by Tins

People like John JDNSW know more about these engines than I ever will and can answer that specific, but the principle is the same. You may find it's as simple as a blocked or incorrectly installed flame trap (603330 in the pic). I don't know about the 2.6, but some engines have a one way valve. If that is installed the wrong way it's the same as being blocked.

Screenshot 2023-03-08 at 10.10.24 am.png

Originally Posted by matthamilton

Pulled the truck forward to drive it back in the garage. Got out to make sure it was aligned (small garage) and noticed a drip from the bell housing area. Then pulled it in and noticed the oil pressure was dropping quickly. Immediately shut the engine down. Looked underneath the truck and there was a pond of oil about 18 inches across.

.

Doesn't sound like CCV to me then. Is there an oil gallery welch ( "frost" to you ) plug in there somewhere?

this truck also had an fuel emission evaporation system on it that ran fumes through a charcoal canister and it was connected via hose to the intake manifold. I plugged that opening on the intake manifold but I can’t fathom that plugging that hole made a difference since the greatest volume of air would be coming through the air filter.

as far as frost plugs, I’m not sure what you mean by the oil galley Welch?

There was some weeping around the crankcase ventilation plumbing coming from the crankcase and venting back into the air intake. It appeared to have leaked around that seal ever so slightly and it makes me wonder if that was from the pressure as well. The block is freshly painted so I can notice fresh leaks.

Originally Posted by Tins

Doesn't sound like CCV to me then. Is there an oil gallery welch ( "frost" to you ) plug in there somewhere?