Crankcase Breather Hoses

[aliddle]

As previously posted (see A160 dirty engine/oil), I have a problem with my breather hose running from my tappet cover to my sump. The inside of the hose is perished and is dumping crumbs into the oil causing a sludge and a stain. I have now also been told that the hose should be reasonably rigid and in its current soft 'floppy' state would not operate as it would collapse under negative head. This breather hose failure would trap other engine/fuel contaminants in the oil, leading to an accelerated degradation of the oil quality.

What exactly does the breather hose do?
Does it operate under negative head or is there positive crankcase pressure? (It connects to the tappet cover and NOT the inlet manifold).

Thanks....

 

[hmang]

if all it does is go from the head back to the sump, it's more of an oil return than a breather

 

[brandwooddixon]

If it's already persihed then replace it. That would be the cheaper option in the long run.

 

[aliddle]

Actually - I see that it goes from the inlet manifold to the sump. I definately will replace it (you have to drop the engine to get to it!). I am trying to find the cause of my engine knock and the dirty oil. I have just had a look at the inlet manifold side connection and I can blow in OR out - which seems to imply that there is a PCV valve in there and it is all gummed up! If it is built into the inlet manifold does this mean I need to replace the whole thing??? It is probably full of those rubber crumbs....

 

[aliddle]

I have just inspected the breather inlet into the manifold: There is no PCV valve, however the inlet was completely blocked with crumbs of rubber - no air in or out. It seems that the perished rubber breather hose was the initial problem - sludging the engine and blocking the inlet into the manifold: This then prevented crankcase ventilation, which compounded oil contamination by preventing the blow-by gases from being drawn out of the crankcase. I have cleaned the inlet out with carb cleaner and a toothpick and have replaced the perished rubber breather with a copper pipe.

It is quite strange that neither WIS nor my Peter Russek Manual mention this breather at all!

Once again I ask anyone out there to check their engine dipstick to see whether it is stained reddish brown; which will indicate that the breather hose is perished and that the breather inlet into the intake manifold is blocked. 3 out of 3 A160s that I have now checked have this stain on the dipstick. I would like to know how prevelent this problem is and whether it may be a latent defect. I have confirmed that my MB garage does suck the engine oil out of the dipstick guide and discharges it into a mass waste oil container with all other waste oil - this means he has never even inspected my engine oil and did not notice the problem!

Please let me know.....

 

[Aussie Nick]

As I said oil sucking is not ideal. Even so he should have examined the extracted oil. Certainly he should have noticed the rubber bits on the cartridge oil filter when this was allegedly changed..
Hey! When I suck the oil out of my 305 Mercruiser Chevy I have a good look at it and also a feel and a smell to establish the condition of the motor. The old oil can reveal lots. Further if I take these precautions (and I am not even a Mechanic ) how come your guy didn't notice? After all he is the expert. Isn't that what you were paying him for?

 

[aliddle]

Yes, even a casual glance (let alone your vinter's nose!) should have alerted them. I suppose this is where you are probably better off having your regular service performed at the "mom & pop" garage down the road! Can I send you my MVRIA claim to review before I drop it off a 5-dock?

C'mon guys??? Anyone else with stained dipsticks...? "Speak unto the big mike.."

 

[Ellsy Tanners]

They nearly all have stained dipsticks.

this is because the dip stick tubes are abnormally long due to the unusual design of the engine, being at a angle.

Its the same as the oil filler neck which gets mayo build up.

the dip stick is so long that tube never gets hot and is a cold spot on the engine. as the oil warms up it releases its vapours which contains a small amount of steam which drifts up the dipstick tube and condensates on the dipstick itself and over time goes a bit rusty.

thats all it is, and most do it especially the cars that do shorter runs and dont get hot at all.

 

[aliddle]

Thanks for the response Ellsy. I have heard about the MB excuse for the mayonaise in the oil filler cap, but not the dipstick excuse...? It would be interesting to get a formal comment from MB rather than heresay - where did you get the info from?

However, having seen (studied) the inside of 2 stripped MB A160 engines with the same perished hoses and blocked breather I have to disagree on the dipstick stain - this is definately not rust. The same stuff coats the WHOLE of the inside of the engine (sump, oil pump, timing chains, guides, head, tappets... everything is the same colour). I am still getting to grips with photobucket, but will load some photos to show you tonight (aussie time). The dipstick stain is definately the same stuff. I would not be surprised if the filler cap gunge was not related as well.

Now.... Does your car have a stained dipstick? Do you know of people/cars with this problem? I am really keen on following up on the prevalence of this issue.

Thanks....

 

[aliddle]

Here are some photos - take a look at the colour of that head and tappets - that is not rust!

http://s267.photobucket.com/albums/ii316/amliddle/

 

[aliddle]

Ok, I have added photos to the link shown in the posting above. I will add further photos once I have cut stills out of the many videos I have taken.

 

[hotbarnes]

hello aliddle i have been told from another member you may be able to help i have a A170 CDI it is smoking now i have changed the injectors

 

[aliddle]

Hi Hotbarnes,

Woah! A170 CDI - that is diesel; sorry but mine is a petrol car and I have little experience with Diesel. From my (distant) farming days I would hazard a guess that it is a problem with your injectors not atomising the diesel and causing partial combustion - but things have change a lot since those days.

Come one Aussie Nick - aren't you the diesel expert?

Thinking logically, it must be something to do with what you have changed...?

Good Luck. I will keep my ears to the ground and let you know if I hear of anything.