socialistic

iTrader: (2)

I'm running a '90 DX that I did an MPFI conversion on and swapped pretty much everything I could from my Si that needed too much body/wiring work to dick around with. Swapped over the motor, trans, ecu, knuckles, axles, master cylinder, front brakes, resistor box, and so on. The car starts/runs/drives beautifully, no CELs, but I have no idea of the history or mileage on that Si drivetrain. It did have some sludge in it, but nothing too terrible. I have been running RP 10w30 through it since the swap.

Anyways, since the swap it has been burning oil. Most of the oil smoke is blown out at the bottom of a hill after letting the engine brake downhill, once I hit that throttle it blows out a cloud. It smokes a little at idle when cold and when I first start driving. Every so often it will randomly blow out constant smoke if I'm driving a little harder than normal, as reported by a buddy that was following in his car.

I replaced the valve cover gasket, upper spark plug tube gaskets, lower spark plug tube o-rings(under the rocker assembly), and the valve stem seals. All gaskets/seals/o-rings were FelPro. No change in smoke output after all this stuff was replaced, and compression is still reading 185+ across all four cylinders making me think it's the oil seal rings. At this point it seems pointless to do any further compression tests or leak-down tests, since the compression rings are good and will continue to give me good results on those tests.

So...is it the oil seal rings, or the valve seals? The symptoms scream valve seals but I replaced them. The reason I still question those seals is because I see kits that contain two different size seals for IN and EX, whereas the FelPro kit were all the same size...and I was sure to examine the hell out of them to be sure of that before installing. If it's the rings and not the seals, is there a way to tell if they're stuck or actually bad? I don't want to jump in to a rebuild if they're just stuck, and I don't want to soak the internals with that B-chemical stuff overnight if the rings are bad. Kind of in a catch-22 with this car, especially because it's just a daily project that I plan to sell/trade which means I don't want to dump a crapload of money in to it.

Also, is it at all possible that the HG is bad and causing this? I wouldn't think so, but felt it was worth asking.

Projekt_ED3

I had the same problem with one f my JDM b18b motors. It ended up being the valve stem seals but since you already replaced them im a little confused why your still having the same oil consumption problem. Maybe seals are too small but im not really sure why the seals would be different sizes.

socialistic

iTrader: (2)

I read in numerous places that all the various brands of seals came in two different sizes, even felpro came in two different sizes up until X years ago. Now the felpro sets are apparently 1-size for IN and EX. Because of this confusion, I'm not sure if this is still my problem.

If the valve seals aren't the problem, and the cylinders are holding better than average compression, then it HAS to be the oil seal rings...but are they stuck, or bad? My options at this point are somewhere between "Expensive" and "Pain in the ***" so I'd like to figure out what's up before I make a decision. I have a '90 DX motor here that smoked and bogged under throttle, and a local guy has a "clean/complete" z6 block for sale...can't find any other blocks or complete motors for sale within a reasonable price range. They tend to sell for $600+ on craigslist which is hilarious.

Projekt_ED3

If it was the piston rings then it would always burn oil at idle and any rpm level whether it is being driven hard or being babied it would always smoke. That fact that it spits out clouds of smoke when you get on it or after letting it engine brake tells me that it is loading up on oil in the head and then leaking into the combustion chamber when the valves are fully opened up. A leak down test would help narrow it down to where it is actually leaking though.

socialistic

iTrader: (2)

Yeah, it definitely doesn't appear to smoke ALL the time. It always does it after engine-braking downhill when I throttle it at the bottom, sometimes on cold idle/cold driving, and even more rarely under normal driving conditions.

Just seems rather random and head-related, but I replaced all those seals...think it could be the head gasket? I haven't done a leak-down test because I don't have a tester, I should probably get to that.

It's also worth noting that going by the dipstick, oil consumption doesn't appear to be that bad. I'm wondering if I could just get away with an oil change with some heavier-weight stuff. I tried that Lucas oil stabilizer and that didn't really do much.

OneBadTurboCRV

If you think t is the OIL CONTROL RINGS (not the oil seal or whatever you called it) then use the old school trick. Spray WD-40 (SPECIFICLY) down the cylinders (through the spark plug holes - repeat this every hour 3-4 times let it st over night. If that done free them up/fix the problem then either they are jammed in there or that isn't the problem.

With the FelPro kit they should have been 2 different colors on the springs - black and silver.

raffaelli

Disconnect and plug the PCV and try to reproduce the smoking. You may be getting oil in the the intake manifold. One of my A6's has that issue, don't know why as the leak down is 5% max. But I routed the PCV to a catch can, no problems anymore.

Cameron R

I had the exact same problem. I rebuilt the motor, but only honed the cylinders and re ringed it. The motor took 5000kms to seal back up, but she'll still pull some oil on long deceleration events. Do yourself a favour and overbore the engine and fit new pistons!

socialistic

iTrader: (2)

A buddy of mine threw an idea out there...valve guides. If it's those, I'm guessing the leakdown test will result in a hiss from the cylinder head? It's gonna suck trying to figure out of the hissing is from the guides or my brand new valve stem seals.

Yeah, oil control rings is what I meant but for some reason I keep calling them oil seal rings. I haven't tried the wd-40 trick, do the pistons need to be at TDC? I'm assuming I have to do an oil change after letting it sit.

The felpro valve stem seals were all identical. No colors or markings to distinguish one from the other. I literally laid them all out on my toolbox's work surface and looked at each one closely, making sure they were all the same before installing. After searching around I found a thread on HT where someone said felpro valve seals have a new type of springs on them and are all the same for IN and EX now because of those springs.

The upper and lower PCV hoses had a lot of buildup, especially the lower. The old PCV was a little gunked up but still worked, I replaced it anyway. I don't think the new PCV has been sucking up any oil.

I'm hoping to avoid a block replacement or rebuild, but it's looking like those piston rings are whooped. If that's the case, I'll probably just sit on this issue until I can find a reasonably priced complete motor. Can't justify dumping even more money in to this low-hp/non-vtec a6 motor.

socialistic

iTrader: (2)

Just pulled my plugs, pretty much all four have oily threads. The center post and ground strap are a gray color.

Oil on the threads = spark plug tube oil leak? Or can those spark plug threads still get oil on them from bad oil control rings? I'm wondering if one of the spark plug tube gaskets or spark plug tube o-rings got messed up during install, and that's what is causing the problem.

OneBadTurboCRV

Spark plug tube seals sounds like your problem since the factor of oil not being all over the ground strap, electrode, and insulator. You can do all four pistons at the same time it doesn't matter - if you want to put all the pistons half way up in the bores.

socialistic

iTrader: (2)

I looked down the tubes with the help of a bright flashlight and noticed some oil pooled up on those ridges. I'm hoping the problem is those gaskets, and not the rocker assembly o-rings or the oil control rings.

If I do a leakdown test with the valve cover left on, in theory I should hear a hiss from one or more of the tubes if those gaskets or o-rings are the problem...right?

OneBadTurboCRV

Think about it - if you could it would be a very bad thing...

10psiLsEf2

PISTON RINGS.
The only way your electrode would be wet is the tube seals are leaking and when you remove the plug the oil drips down into the combustion chamber OR your rings are shot.

IMO its your rings

socialistic

iTrader: (2)

If it was the piston rings it would be burning oil/smoking constantly, not only during certain driving scenarios. It's either the valve stem seals, spark plug tube gaskets, spark plug tube 0-rings.

I just had two friends offer up one other solid idea that never occurred to me before, and honestly seems like this could be the issue...worn valve guides. What do you guys think?

If it's the valve guides, I don't really want to do a head rebuild. I have a '90 DX head(d15b?) here that I could take a risk with, or just sit on this oil consumption issue until I find a VTEC head. The latter option would be quicker, and probably cheaper if I don't have to rebuild it.

DCRB

for oil to be leaking into your combustion chamber from you spark plug tubes your spark plugs would have to be stripped out. i'm going with worn valve guides. you've replaced every other wear item. my sisters accord has oil filled to the brim on her spark plug wires and burns 0 oil (she wont let me touch her car mechanically :'(). the a6 head is the same as the b1/2/7. what makes it different is the cam.

with any head you get you should have the valve seats checked and if needed re ground at minimum unless it's a rebuilt head for best use.

socialistic

iTrader: (2)

Yeah, I'm definitely leaning towards the valve guides on this one. It's the only thing other than valve stem seals that would explain my exact problem. I'll still do a leak-down test just to be sure.

There was a little oil on the ledge of one or two spark plug tubes(plugs removed at the time), but that could have been left over from the old o-rings/gaskets. The thing that stuck out here was the oil-soaked threads of the spark plugs, but I guess that could have happened as I was removing them.

Right now I'm shopping around for a complete z6 or y8 top end or entire motor if the price is right. Once I get those leak-down results and can confirm it's the head, I figure I could use this as an opportunity to go with a mini-me setup and squeeze a little more HP out of this motor.

OneBadTurboCRV

You can check for worn valve guides by doing a vacuum test. You can't test for worn valve guides with a leak-down tester... they are sealed off when you do any combustion area tests - think about it.

slowhonda91ef

mine does the exact same thing. after 2 different heads im thinkin rings

socialistic

iTrader: (2)

Good point. Forgot about the whole TDC thing.

Don't have the know-how nor the tools to do this vacuum test you speak of, so at this point I just need to pick which half of the motor to replace and hope that fixes the issue. Crap.

10psiLsEf2

spend your money on a head job and we will see you post again that your still smoking!

socialistic

iTrader: (2)

It's either the valve guides or the oil control rings. A leak-down test won't point at valve guides because the valves would be closed, and it won't point at oil control rings because the compression rings are holding at 185+ on all four cylinders.

I have to pull the trigger on replacing the block or the head. Chances are that it's the head, so I guess I'll just go with that and use this as a chance to go mini-me. Worst case scenario I have to replace the block afterwards.

10psiLsEf2

didnt mean to be a (dic&) but just saying.

OneBadTurboCRV

Search... there are even videos on the YouTube how to do this...

Steady needle, at 15-22: Engine in good condition. (An engine with long duration camshaft will have a lower vacuum and a less steady needle, maybe 10-15 with 1-2 “jerks”. That’s still an engine in good condition)
Steady needle, lower than normal: Ignition timing too late or vacuum leakage
Steady needle like in "normal", but occasionally fluctuates at idle: Ignition miss or sticking valve
Steady needle like in "normal", but drops regularly: Valves need adjustment or burnt valve
Floating needle, maybe in the area 10-20: Carb out of adjustment or vacuum leakage
Shaking needle, becomes worse as rpm increases: Ignition miss, blown head gasket
Shaking needle, becomes steady as rpm increases: Worn valve guides

socialistic

iTrader: (2)

Watched that vid already, but I don't know where to get this vacuum tester. The only auto parts store around here is Autozone and they don't appear to have a guage like that, just stuff like Autometer vacuum/boost gauges.

Eta: Found it on the autozone website, it's called a vacuum pressure tester. I'll ****** that up and go from there.