Blow By Project to eliminate Oil on the engine

Has anyone ever tried the following upgrade to a pre 1993 XJ??

1993 XJ CCV Project It sounds like it just about eliminate Blow By

OR should I stick to the more well known Blow By fix???

Well known method

Why not get K&N breathers from Jeg's, Summit etc...and bag all that plastic spaghetti under there.

They make one for a 3/4" PCV, and Mr Gasket Co has 2pks of 3/4" grommets (the valve cover holes are 1") and this would eliminate the need for most of that sorry vacuum mess.

I agree that cleaning the valve cover interior will be a good thing, will do it one of these days since my gasket is leaking too...

Blow-by

What I do is at every other oil change or so, I stick a vaccum hose on the CCV gromet and also remove the thin CCV tube and apply a vaccum. If I feel a strong vaccum, I know it is clear. Since I cleaned the existing tube, replaced any rotten rubber parts, I have had zero blow-by and I have spent about $5.00 on this problem.

I tried using a breather on mine and all it did was ooze oil out the filter and onto my valve cover. I guess it all depends how bad the blowby is.
My fix was to direct the CCV tube into a plastic jar instead of the air filter box. Now the oil collects in the jar! Don't seal the jar up too much, as the pressure still needs to be relieved.
Jeep on!
--Pete

I just did this on my 88 and 92.

For my 88 Xj I bought all the tubes mentioned in the second article you listed. I cleaned out the valve cover and snorkels which needed it badly. Took me a couple of hours. And of course I put in all the new tubes. A bit of a pain keeping them all straight and labeling them and stuff. Also, the tubes were pricier than the article mentioned, at least here in Austin. I spent over 100 for them. I used Indian Head Gasket compound like a few people mentioned here on the site (and let it cure for 24 hours before driving), and so far so good. No blowby, no leaks.

I did my 92 XJ last weekend. A lot simpler that time. And since this was a 92 it involved the pieces from the first article you listed. I didn't know about buying the 2000 tube from the rear of the valve cover. Makes a lot of sense to me, though, if it's bigger. I might buy it the next time I change out that tube, which I'm planning on doing pretty often since that tube doesn't cost too much. I got a bit smarter this time and soaked the whole valve cover and snorkels in a bin full of Simple Green and water overnight. I highly recommend doing this. Cut my scrubbing time in half and actually provided a pretty easy clean up since I just ended up cleaning the whole thing in the bin.

Again, I used Indian Head and let it sit for a 24 hours. No blowby and no leaks so far.

By the way, I couldn't find the snorkel gasket replacements anywhere. I just used a light coating of black RTV on each side of the metal flap inside. Seems to work. And be careful not to overtorque those valve cover bolts. I broke one off.

ThanX for the info. Chad88XJ
I need to replace most hoses, so I am probably going to try the first one with a mixture of parts.
Met a Chrysler mechanic, going to try to get parts @cost
The '91 that I bought last week is in very rough shape under the hood. Probably never been cleaned. I'll post some pic on my web tomorrow.

Make an oil blow by "bong" (water pipe), the oil will be caught there instead of ending up all over the filter. You can further help it by stuffing it with some metal scouring pads (the very coarse metal ribbon type), that will help trap the oil so that when you are going offroad the oil wont be sucked into the air filter box.

XJguy

The oil is not supposed to come out of the air breather hose connected to the large air cleaner/ TB hose. This hose is supposed to bring filtered into the valve cover area, not pump air and oil out (because if it's pumping air and oil out, it means you have unfiltered air getting pumped into the valve cover area & crankcase).

The simple fix is to enlarge the hole in the grommet at the back of the valve cover, where the small hose is ported to the cover.

The factory calls for a 0.10" hole, but oil swells the inside of the grommet and it closes off (along with the fact it collects grunge debris).

With every oil change take a 1/8" drill bit (0.125") and rheem the center hole of the rubber grommet by hand (or with a drill motor for the first time with the nylon insert). This cleans up the "metered" port.

A higher mileage engine may need a larger "metered" port (use a larger drill as a rheem). I have not witnessed any problem with tailpipe emissions from enlarging the port size.

The goal is to open the port (and clean the hose and intake manifold fitting) so that you can feel suction on the large hose that is normally connected to the filtered side of the intake. The suction keeps the oil inside the engine, and out of the filter, along with assuring the air entering the engine is filtered.

I agree with Ed on how it is supposed to work. However, mine has about 225,000 mi on it. Under full throttle there is no vaccume. Crank case blow by escapes through the inlet, the only way to cntroll it is to leave it connected to the air intake. I used a short piece of pvc and two end caps and drilled two holles in the top and connected it inline between the valve cover and intake.

It seems people are finally admitting to this mod

Here's my "oil bong", or can or jug, whatever you want to call it. I originally had the jar just vent the blowby out a hole, but it smells like oil so I ran the second tube back to the airtube. The "oil catcher" works pretty well as long as you keep it emptied, if the jar gets filled up to the tube it goes right into the filter. So I check it every now and then. I usualy discard the oil since it's usually nasty lookin.

Ed, are you sure about that? I have not looked in depth into this, but I was under the belief that the hose is positive crankcase ventilation and thats why its attatched to a vacuum. Oil shouldnt come out, but with many cars (and Jeeps) it does.

XJ " correct me if I am wrong" guy

CCV's and PCV's setups work under pressure and vacumn, back in the 'old days' they had 'road pipes' that dumped the overpressured crankcase splooge directly onto the road and a breather that fit into one of the valve covers for inbound air flow to the crankcase. This road pipe splooge can be seen in old black and white movies where you see these black center sections in each lane of concrete hiways, made it real slipery for motorcycles. Ford I6 and V8's had them right behind the timeing chain cover on the side of the block. Around 68 or so the PCV came into being and they freeze plugged the holes in the block and routed the PCV to the base of the carbs and added a filter in the aircleaner so that on acceleration the over pressured splooge would push thru the carb line and get added to the combustion process and on vacumn or decel would suck air in thru the little filter in the aircleaner housing. The CCV's and PCV's are supposed to route the overpressure fumes of unburned gas and oil thru the combustion process so that it gets burned up. Block either one and you get flow thru the one with the least blockage, in the XJ's case thats the one that goes to the air filter as it's the bigger of the two line.

CCV= dumped into atmospheric pressure
PCV= ventilation by means of vaccum, in the case of modern cars, positive ventilation, or vacuum, helps cause a tighter seal at the piston rings, heads, valves and valve seals. Ive seen auxilliary pumps in race car catalogs to further increase the sealing benefits of a high vacuum under the valve cover; advertside benefits are that you can reduce internal friction by using looser piston rings since the vacuum is helping with any blowby.

How about the CCV systems that are plumbed directly into the collectors on race cars....although I dont think they call it a PCV system it surely is positive ventilation. All those spent fumes racing past that CCV bung must create a tremendous amount of vaccum under the valve covers.

XJguy

PCV = Positive Crankcase Ventilation: one-way ventilation of the crankcase through a check valve, venting vapors only when the crankcase pressure is greater (positive) compared to atmosphere. Later variations vent the PCV to the air filter housing upstream of the filter, at atmosphere pressure, to capture the undesired emissions (and burn them through combustion).

CCV = Constant Crankcase Ventilation: constant crankcase ventilation, at all times with ported manifold vacuum to the crankcase, to always keep the crankcase negative to the atmosphere. A negative crankcase pressure better contains the undesired emissions, and the constant manifold porting of the vapors better assures these emissions are captured (burned through combustion). The filtered CCV make-up air also works better to keep the internal surfaces of the engine clean.

The factory 0.10-inch CCV manifold port works well for a new engine, although may fail to flow enough volume to maintain the negative crankcase pressure in a worn engine. The solution is to provide a greater volume of ported vacuum from the intake manifold to the valve cover (a larger metered port), and make sure it is clear of obstructions.

When I purchased the Wife's 89 XJ the CCV tubes were clear (a receipt was in the stack reflecting the retrofit tube kit) but the fitting on the intake manifold was plugged shut. Cleaning the manifold fitting and opening up the nylon port fitting (to 0.1875") stemmed the oil purge flow. The larger tube going to the intake hose will stick to your finger from the suction (the easy test). The XJ still has 155,000 hard miles so the oil leaks also needed attention, and the valve cover oil fill cap area needs cleaned every few thousand miles, but there is little oil in the filter.