fbarnhill

Ok, I am puzzled.
I rebuilt my 86.5 about 5k miles ago and have been a little dissappointed in the fact that when you nail it, in addition to tire smoke, you get some oil (lot) smoke out the back. My last fillup, I checked the oil and put 5 quarts of oil in it. I was determined that it was the valve seals but Ray M. at Ram Automotive assured me that it might be something else. So, I re-read the 85-86 intake r&r writeup and realized that I didn't double the washers on the cam cover bolts, nor did I use Honda Bond. Now, I can see a couple of leaks there and figure probably the same on the filler tube. So, I got together the parts and started to remove the top end today. Well the left side intake tank was the first thing to be removed after the air box and hoses. Guess what? It had at least 1/4" of oil just sitting in the bottom of it, way out there to the side. You could have picked me up from the floor. My question is, what could cause this? I remember the pcv valve surprised me when I found it and there is a slight possibility that I put it in backwards... I can admit my mistakes. However, I think I blew through it and got it right, So, guys, what could cause this thing to accumulate this much oil in the intake? I have the solution in a nice catch can and will do this in the repair. However, could this be an indication of something worse? Blowby or something like that?

Please don't hold back, I can take it. However, I must say that even with the influx of oil, the damn thing runs like a scalded dog. I can't wait to see what she will run like with no oil mixed in...

Alan

Indeed sounds like the PCV system (such as it is).

Maybe you have a lot of blowby pushing excess oil into the intake.

Alan

PorKen

EDIT - 5 quarts is excessive.



Some oil is normal if you run at higher rpms with the stock crankcase venting.

S3 plenums have those nice oil collection 'sumps'. (S4->up burn the oil, directly. )
You'll also find a nice puddle in the MAF->TB housing.


I found it helped somewhat to run at the halfway mark or lower on the dipstick. Never full or over.

If you eliminate the crankcase venting to the intake, no more oil.

Kiln_Red

I'm with Alan on the blowby. Adding 5 quarts of oil isn't normal. Reinserting the PCV the wrong way wouldn't cause that kind of loss between change intervals. During the rebuild, what work was done to the heads? Pistons? Bores?

GregBBRD

Did you put the baffle back in, under the oil filler? That piece has been NLA for years. You have to salvage the original one and put sealant on it, to re-use it.

A really high quality, well engineered oil separator, in the block below the oil filler neck, really helps these engines. I've got a new design that reduces the velocity and helps the oil "fall" out of suspension.

Alan

Greg - can you say more on the new baffle? In dev't or available? Is this sized like the 928 Intl one (or bigger) and presumably has an enclosed design with acute angle internal baffles & a drainback mechanism?

I would be very interested in a good solution here.

Already had some ideas for a lateral vertical baffle design - but I don't really have the ability to build it.

Alan

fbarnhill

Thanks for the responses guys. Yes I did put the baffle back in. Also, I have noticed that everything seems to work better when the oil level is lower. That is one reason that it was 5 quarts low. I just didn't fill it up on the previous refil. I am putting in a catch can and removing every possibility that oil can get into the intake system. The car just runs too good for it to be anything else. I mean she purrs like a kitten and then growls like a tiger when pressed. So, I would like to keep her that way. However, it kindf of sucks to spend all that $$$ only to have this issue. I was just wondering which of all those lines under the intake that could be sending all this oil to the plennium.

Shane

Frank start with this thread:

https://rennlist.com/forums/928-foru...-question.html

There are other solutions out there, like I know Greg Brown sells an oil control kit that is outstanding, but I had already bought the sharkvent.

fbarnhill

Thanks Shane, I have already started dissassembly. This time I will definatelly get the pipes powder coated. I painted them twice using both etching primer and the red zinc-ozide on top of that, then paint, clear coat. I will never waste that much time and go that route again. I saved maybe 150.00 but came out with a new engine that looked like it had 75k miles on it. So, I am going with bright white tanks, and a lite blue titianium on the tubes. I am also adding the oil control tank. I can't wait to get her back on the road. However, with this disease I have to fight daily, just this little job could take 3 weeks. However, it gives me something to look forward to. I sure wish I could make the DE event this month but we are going to visit the grand kids that weekend. So, maybe the next one.

Thanks Shane for the link. I will read it through tonight and put my solution together. Now, how about the system that pulls the fumes from the carbon canister? Can that be done away with as well or should I leave it alone? It is just a bunch more vac lines that I would love see go away for a nice clean look.

davek9

I run both 85 & 86.5 @ the full mark and would never let one go below 1 qt.
A spirited run w/ the MI crew to STIM and back, never needed to add any oil, although I did take 4 qts W/ me.

Whenever I've removed the intake plenum box's I'll usually find at least a thimbles worth in each.
The check valve will only go in to the oil filler vent tube one way as it's larger on one end (top).

What's is you're compression readings, if low do a leak down and lets see what's going on.

Dave

neilh

Hi, Frank.
Let me know if you need a hand over there... good luck with the intake work, sounds like you have a good plan.
Neil

fbarnhill

Thanks Neil, We are heading to MS to see the kids on the 27th. I think I will just take the tubes off and take them and the wheels and drop them off at the powder coaters and pick them up when I return. Looks like I won't be driving the shark for a while. I was actually happy to find the oil in the plennium. Now at least I can fix the symptom and find the cause a little later. Maybe one day next month you can come over and we can do a leak down test?

Cheers,

GregBBRD

If the stock baffle is in, you've got a problem. Should not use that kind of oil. The fact that it is pumping it into the intake either tells you it is building too much crankcase pressure or not properly getting rid of that crankcase pressure. Impossible to tell, from here.

GregBBRD

Like this:

fbarnhill

Greg, I have one verry similiar to that one but wasn't sure how to use it. I got it in a box of 86 parts I bought on ebay for 100.00 a while ago. Would I use that as well as the other baffel? I intend to add it this time as I am doing the intake.