Mk3 Cavalier Owners Club | Vauxhall Cavalier Dot Com

hi guys, just cleaned my breather pipes on my c18nz engine and the bottom pipe by the dipstick was totally blocked off,took me a good half an hour to unblock it,full of hard tough crud.my question is what effect does this have on the engine being blocked up,does it cause any lasting damage and would it account for the coolant tempreture being so high when i stop moving or does it not affect the engine tempreture.

Not sure what affect it has on the engine but they will have plenty of crap i them, and if they have never been cleaned from new then its not un-common for them to be blocked up.

The breather hoses on the engines are there to simply re-route some of the exhaust gases back into the intake stream, to cut emissions. Being blocked up wont do any harm, but it wont run as clean, and it will cause the engine to run a bit weaker than normal. If one's blocked, chances are the others are too. Its worth the effort to unblock them, but i don't think its got anything to do with temp. If you already haven't, check the others, both of them running from the cam cover.
Hope this helps.
Andrei.

i followed your how2 guide so top marks to you, are there any other pipes that need to be checked apart from the two your guide mentioned,not very good with cars and stuff but i am learning slowly thanks to lots of help from this great site.i found it very awkward to clean out the inside of the metal pipe that runs next the dipstick, in the end all i could do was push a small rag through using a piece of stiff electrical cable, could not get all of the crap out but about 95% of it.

Nope, there are no other breather hoses. Just the 2 from the cam cover, and the short stubby one that runs to the metal pipe which you just mentioned. If you undo the two 13mm bolts at the bottom of the oil dipstick, you can take out the whole pipe and clear it that way. Much easier. I find that a good dollop of washing up liquid and a long thin soft bristle brush does the trick if you havent got access to a carb cleaner. Its a lot easier than you think once you get it done. The other quite tricky bit is...
The long thin breather hose that runs from the cam cover(square bit) to the back of the intake manifold branch, where it plugs onto the small metal tube at that end, it is more than likely blocked inside that metal tube. Just find any thin long metal object (a good size nail does the trick nicely) and keep jamming and twisting it in there with a pair of grips or pliers until it moves through freely. The breather hose will probably put up a good fight when coming off, so careful not to split it. I'd get some pics up but i cant at the mo unfortunately. You'll see what i mean when you get there. Also the very same but back at the cam cover end Hope that makes sense. Once its all done, stick some injector and fuel system additives in, (I use STP) give her a nice good run and you should find it makes a noticeable difference in fuel economy and smoother idling. Certainly did in my case.
Anything else, just ask.
Andrei

Mine started leaking oil from the dipstick tube gasket when my breather system blocked up so it is worth doing.

Very worth doing it, new gasket is 79p from Vauxhall, the rubber tube is about £3.

blocked breather(s) obviously causes a build up of pressure in the system as there is nowhere for the gas to recirculate. common faults as a result of this can be cam cover gasket leak, or worse still crank seal leak. worth doing breathers every 18 months/service interval depending on mileage. it doesnt take long once its done, it's just that initial unblocking where you find 15 years worth of crud! haha!

What engine is that pic of?

Somewhere on the inlet of a v6 I beleive.

Oh right cool. I was gonna say, if that was the same block as mine, i would have been out there within seconds finding that clog.

hahah nah it's the larger breather outlet on the crank case for the v6 hehe, using it as an example of the kind of build up 15 years worth of 'non breather cleaning' can result in. and to think the previous owner was a bit mystified when it came to the cam cover leak...

But on a serious note, i know what you mean by the prehistoric crud. Every breather tube was blocked before i cleaned it last, not just the hoses, but the metal tubes where they plug onto. I was surprised how hard it was to unblock. Makes me wonder, also, why i've had to replace 2 cam cover gaskets last year. I know now. Trial and error, really. But well worth the effort.

aye thats it, its a bit of a bugger to do the first time round, but if you include what is then only a 10 minute job into your regular service schedule then it shouldnt ever be a problem again, and besides, you'll notice the car perform a lot better.

Can definitely agree with that 100%