catch can

Very much agree with the valve seat cushioning and upper ring lubrication due to the oil mist from the PCV system on a non EGR diesel.

I have seen 'dozer and excavator engines with 10-15000 hours logged with absolutely minimum bore and valve seat wear.

A MAN air cooled diesel operating an oil well pump in W. Qld. I saw had 44000 hrs. running on de waxed oil from the well with no other servicing than oil changes and injectors.
mike

Bit OT, Slow & Mike, but will be interesting to see if any of these "new" diesels will rack(pun?) up the hours that the old style engines did.

We had a Hatz 3 cyl 25kva genset, bought new, that clocked up just over 40K hours before we pensioned it off and bought a bigger Hino unit. Other than normal servicing, only needed 1 or 2 minor repairs.

On these V8 Landcruisers, we had a young bloke that did some contracting, did a lot of kms/week, and drove the ute like he hated it. While he did have some other "issues" like brakes, tyres and side-swiping the odd Gidgea tree, the engine clocked up over a million kms, with normal servicing. So maybe these newbies might last............

Bob

If this oil mist is actually helping to lube the valves then would that mean the intake valves are getting lubed and the exhaust valves are missing out.

In the past vehicles expelled the oil vapour directly into the atmosphere which is not a good thing. So these days due to stricter air pollution regulations it is returned to the engine so it can accumulate in intercoolers line the walls of the intake hoses with a film of oil, enter the intake manifold so it can be burned off and the extra toxins are still emitted into the atmosphere via the exhaust which is still not a good thing. This over time can result in decreasing the engines fuel economy and power which in very counteractive.


So installing a catch can should be beneficial for the engine as the mist is collected as a solid and not burned off into the air we breath as gas and can be disposed of in a safer manner. Or it can be filtered and returned to the sump via a hose off the catch can.

Hey Bob, hello and I'm not believe I am thinking slower as the years roll on.

I don't know how long the newer light vehicle engines will go for but as you say some are getting high in the kilometers so I guess time will tell.

Heavy engines appear to be coping very well and the later ones are not showing many problems at all now the yanks have ironed out the egr temperature problems.

The Europeans have been getting right for a long time now in the heavy truck section.

Have to wait a couple of years yet, but I will be very interested when they get Nikola trucks up and running to see what their results are on long haul.

A person that specialises in servicing Prado's says don't use a catch can on them as he has always found that motors that have catch cans fitted have lower compression ratios on high mileage motors.

Don't shoot the messenger just repeating what he says he has found.

Pers I will be getting the EGR function turned off in my Prado when I can get round to it and leaving the plumbing as standard.

That's an odd claim from a specialist I always thought as any motor ages it will loose compression there must be more to this statement.

He's just stating he has found with similar mileage motors those without catch cans fitted have high compression figures than those with catch cans fitted and doesn't recommend fitting them. This would seem to imply the though oil mist in the PVC gas is beneficial to engine life though probably not by design.

My local mechanic has a rural very busy workshop states to me that dismantling and decoking blocked intake manifolds is fast becoming a major part of his work.
Like employing a mechanic just to do this work.

I on the other hand, have a recently acquired PX that has had THICK deposits of gunk around the throttle body area. It was so hard and baked that I had to remove the intake body and physically wash it clean.
I intend on a catch can, also a treatment with a can of liquimoly decarboniser.

Just in case you're looking for something to do on a lazy week-end, Paul E6, your engine could probably benefit from decoking the inlet manifold and inlet ports on the head as well :-)

Les, the px1 doesn't require a hole in the banking plate. Mine has been in for 5 years now.

Some say the px2 with no def requires a hole and others say they have a full blanking plate with no fault codes.

Umm, if I take my vehicle as an example, I had a genuine Provent fitted for about 30000Km, during that time I collected around 100ml of waste from the provent.

In the same time the engine burnt around 3600Ltrs of diesel oil, I would imagine the extra soot created by burning 100ml of engine oil would be pretty insignificant to that created by burning 3600Ltrs of diesel?

Negligible in that regard, it's if your vehicle also has an EGR system, then your manifold deterioration would make for bad running (& worsening econ, more wear) after time.

Blow by will get worse as engine components age / wear too.

Yep agree the EGR is the main issue.

The amount of oil I collected with my catch can is very similar to what others with Prados have collected so there is nothing exceptional with my motor.

If you look at your figures of 840ml of oil, firstly as many have commented on different forums, most of the waste from the provent for instance appears to be a water with some oil mixed in and this is what I also found and is consistent with what i have read, ie oil does not evaporate at normal engine temperatures, the pcv flow is mainly made up of by pass from the piston rings and mainly consists of exhaust gases and water vapor and diesel, it will however carry some highly atomised oil particles from the motor. So one question would be how much of the 840ml of waste you collected is water and how much oil?

Also what would be the percentage of the 840ml you collected compared to the total volume of air and water vapor from the atmosphere that has passed through the turbo in the same period?

Personally I have never heard of anyone having to replace a turbo charger in a small diesel engine as a result of damage proven to have been caused from PVC flow. I have heard though of many who have had to replace turbos due to seal failures causing oil leaks, and turbine van failures attributed to injector failures and glow plug failures in both newish and old motors.

Regarding carbon build as a result of the oil mist fom the PVC increasing the compression ratio, from a practical point if we have two motors that have done 200000Km, the one without the catch can fitted has similar compression figures to a new engine and the one without has 20 PSI lower I know which engine I would prefer to own.

The muck is a different issue, yes I agree the carbon from the EGR is not a good thing hence I will have the EGR turned off down the track. The oil mist I'm not convinced does any damage and at least one that services engines daily indicates he has found it is beneficial so will leave that as is.

My neighbor recently fitted a catch can to his motor, we had similar discussions and the generally consensus with the motoring fraternity of his car make was to fit a catch can but also have some type of upper cylinder lubrication!

Another interesting observation, one of my mates had the injectors of his 120 changed about 6 months ago at around 120000Km, he has no catch can fitted. He instructed the service company to clean the inlet manifold, EGR valve etc when they had it pulled down to remove the expected gunk. When they pulled the motor down they found it to only have a light coating of oil and carbon and there was no need to clean it. This was quite a surprise when you see what others have found, his usage of the car is similar to mine, the car is basically used for touring, pulling a small camper van around the 1700Kg, personally I would have thought with all the towing the motor would be well gunked up but this proved not to be the case. not the case.

Or buy a $10 stainless steel blanking plate and youwill never have a problem with a px ranger engine.

PAJ hit the follow up button as this will lead to a direct reply.

I disagree, Remove soot or remove oil mist and the same result will occur. My inlet is as clean as and I have no sensor problems what so ever.

Then again my bucket of poo hasn't had any problems and it has worked hard all its life. Maybe from your workshop experience you could record the 4wd vehicle that has the biggest manifold blocking problem.

$10 for soot and $250 bucks for oil.