Filler tube with breather

[Johnno1969]

My 2.25D has always seemed to have quite high crankcase pressure at higher revs and suffered from oil blowing out through the breather on the rocker cover and a number of other places.

The oil filler tube has what basically looks like a radiator cap on it; when it's turned down it seals. If I could convert to the (I think earlier) type of filler tube with a breather in the cap, it might help keep the crankcase pressure down.

So...two questions: Is there likely to be any problem in converting to the breather cap and, if not, has anybody got a filler tube and breather cap which they might be able to spare?


Cheers,

John

P.S. By the way, I am also converting to a 200Tdi aircleaner and will be modifying the breather on the rocker cover to take a much-larger breather tube to run to the aircleaner.

[Johnno1969]

Well, in the complete absence of a cacophony of "No, don't do it!!" replies, I guess I will convert the engine to the breather-type filler tube....

[incisor]

be interesting...

[Johnno1969]

be interesting...

Yep, well... it'll be interesting to see if the 2.25 spits out less oil as a result...

[schuy1]

The "radiator" type oil filler cap is part of the later PCV system Land Rover fitted towards the end of the '70s. It worked in conjunction with a sealed rocker cover breather that was vented into the air intake b4 the carby . I dont recall seeing diesels being fitted with it, only petrols but then the oil burners of that vintage have always been thin on the ground!
Cheers Scott

[Johnno1969]

The "radiator" type oil filler cap is part of the later PCV system Land Rover fitted towards the end of the '70s. It worked in conjunction with a sealed rocker cover breather that was vented into the air intake b4 the carby . I dont recall seeing diesels being fitted with it, only petrols but then the oil burners of that vintage have always been thin on the ground!
Cheers Scott

Thanks Scott,

That makes sense, as the engine dates, I am pretty sure, from 1978 and I put it in my IIA some time back. It has the sealed rocker cover breather with the tiny wee connection that vents to the air intake. I am keen to convert to the earlier type of filler tube cap and modify the rocker cover breather as it does seem to build up a lot of pressure.

Cheers,

John

[schuy1]

yes retro fitting is perfectly doable :) With the sort of pressure that is overcoming intake suction, particularly on a diesel you may have more issues there though. Implementation will tell though. :D

Cheers Scott

[incisor]

Yep, well... it'll be interesting to see if the 2.25 spits out less oil as a result...

be careful what you wish for.....

but it should be positive imho

[wrinklearthur]

I would be careful of introducing a situation where the engine could run away, make sure that the oil is returned to the sump and only the sump gas is fed into the air intake.

[schuy1]

I would be careful of introducing a situation where the engine could run away, make sure that the oil is returned to the sump and only the sump gas is fed into the air intake.


Maybe that is why I have never seen that setup on a S3 L/R Diesel?
I dont have a diesel manual for a S3 only 2A's but that would be a problem if it did :/. I think john is going to fit the gauze rocker cover breather in conjunction with the gauze filler breather as per an early setup and not vent into the motor at all?

Cheers Scott

[d@rk51d3]

I reckon I have the S3 diesel manual at home. I'll check it out tonight, if I remember.:o

[Johnno1969]

I would be careful of introducing a situation where the engine could run away, make sure that the oil is returned to the sump and only the sump gas is fed into the air intake.

Hey Arthur,

I've been planning to route the rocker breather line to the air filter housing as per a Tdi (possibly modifying the housing so that the crankcase gases are drawn to the "dirty" side of the element so that any excess oil either adheres to the paper element or runs out through the drain valve...). I guess I could re-route that line to the sump to completely avoid the danger of running-away, which is a good point (on that score, I am considering a cutoff valve for the air intake, whatever setup I adopt). It's never sent large volumes through the breather - just enough to make a mess in the engine bay on a long drive occasionally.

Thanks,

John

[Johnno1969]

Maybe that is why I have never seen that setup on a S3 L/R Diesel?
I dont have a diesel manual for a S3 only 2A's but that would be a problem if it did :/. I think john is going to fit the gauze rocker cover breather in conjunction with the gauze filler breather as per an early setup and not vent into the motor at all?

Cheers Scott

Hey Scott,

I have been thinking of setting it up the way the rocker breather is routed on a Tdi (to the intake at the air cleaner), with the possible risk of running-away that Arthur mentions. It is a good point, and one which I need to address. It has had a similar setup up to now and not run away ever (though that is no reason for me not to be cautious now). I'm thinking of modifying the cleaner housing to fail-safe it. Watch this space...

Thanks,

John

[d@rk51d3]

Can't find any real mention of the PCV system, even in the troubleshooting guides. However all diagrams show the radiator style cap on the filler, and a breathing cap on the rocker cover that goes......... down to the intake chamber, i believe.


If you're getting that much crankcase pressure, I'd say there are other issues at play, as schuy1 said earlier.

Could be rings on the way out,.....BUT...a blockage in the oil return hose off the rocker cover, or even a worn seal on the breather cap can do it too.

Start with the easy stuff (seals and hoses). :cool:

[Johnno1969]

Can't find any real mention of the PCV system, even in the troubleshooting guides. However all diagrams show the radiator style cap on the filler, and a breathing cap on the rocker cover that goes......... down to the intake chamber, i believe.


If you're getting that much crankcase pressure, I'd say there are other issues at play, as schuy1 said earlier.

Could be rings on the way out,.....BUT...a blockage in the oil return hose off the rocker cover, or even a worn seal on the breather cap can do it too.

Start with the easy stuff (seals and hoses). :cool:

Thanks for looking into that. Yep, I believe that the system has always had the breather tube from the rocker cover to the air intake. Possibly risky, as we've all noted. That's what the engine has had since I got it in 2000. Truth to tell, the crankcase pressure has not been that big an issue - just some oil spread about sometimes after a prolonged run at greater revs. The engine is in lovely nick - compression is terrific and it performs well, uses very little oil and blows a clean exhaust, so no problems there of which I'm aware. I just would like to "ease" things for those times when it does run a little harder. Really, I am open to a number of options. Whatever I end up doing, it will be safer from running-away than it has been in the last twelve years.

Thanks,

John

[d@rk51d3]

Good-O. Sounds like it might just be the cap seal then.

[schuy1]

Ahh very good :) That does not sound too bad now that you have elaborated on it :D HeHeHe for some reason one tends to think the worst about motor symptoms :D
cheers Scott

[Johnno1969]

Good-O. Sounds like it might just be the cap seal then.

This was a problem, but I sealed it pretty well a while ago. All the same, I will be looking at the whole things again soon.

Thanks,

John

[Johnno1969]

Ahh very good :) That does not sound too bad now that you have elaborated on it :D HeHeHe for some reason one tends to think the worst about motor symptoms :D
cheers Scott

Thanks Scott. Yeah, that's pretty much it. I have never had any problems with the engine (knock wood) and it has always run really well. Just the persistent niggle that suggests it's not getting rid of its crankcase pressure as easily as it should.

I must remember to revisit this thread once I get the vehicle running again.

Cheers,

John