socialistic

iTrader: (2)

I did an Si+MPFI conversion to my '90 DX hatch a few months ago and it's a pretty decent little daily, but I noticed it's going through my royal purple and it smokes. Used a '90 Si hatch for parts, so it's a d16a6 motor.

Now, it doesn't smoke all the time that I can see. It smokes a little when I floor it. If I am going down a hill and off the throttle, then get on the throttle pretty hard = billows out quite a bit of smoke. It's white with a hint of purple, and smells like a 2-cycle motor running. My oil level is the only fluid level going down, I've checked and re-checked the coolant and it's fine, car runs like a champ and doesn't even overheat...I'm in SW MO and even during this heatwave I can let this thing idle all day long without it overheating.

Due to the way it smokes the most, I knew it had to be the valve seals. I came here, everyone seemed to confirm that. I ran several compression tests anyways and they all gave me the same numbers across all four cylinders, 180-ish. Ok, something else that says it must be the valve seals.

Today I replaced the valve seals and the spark plug tube o-rings that are sandwiched between the rocker assembly and the head, since the one for cylinder 2 was letting oil down the tube. As soon as I was done I took the car up the road and back, on the way back down a big hill I let off the gas until the bottom then got back on it. Blew out just as much smoke as before.

What else could it be? Could the piston rings still be bad even though all four cylinders were reading good compression numbers? Is it just a worn out motor? I have no idea how many miles this thing has.

netfreak

My oil consumption went down a *little* after I did my valve seals but still burns a decent amount from what I'm assuming are worn rings. My noticable oil burning at idle and coasting down hills ceased though as those are generally attributed to worn valve seals. My clouds of smoke only come from heavy throttle use now.

socialistic

iTrader: (2)

I don't see any smoke at idle or while cruising. If I'm parked and mash the throttle, or leave a stop a little heavy on the throttle, I'll get a little smoke. If I let the car brake itself down a hill(in 5th gear, usually above 45-50mph) then mash the throttle at the bottom of the hill, I get a big plume of smoke.

The amount of smoke created under these circumstances seems exactly the same as it was before the valve seal and rocker assembly o-ring replacement. I let the car run and warm-up after I was done, and drove it on about a 2-mile round trip...so I don't think it was any leftover oil at that point which means it's still consuming.

Could it be the RP 10w30 I'm running? Should I go to a heavier viscosity, or run conventional? I've heard of people putting Royal Purple in to a high-mile motor that had no previous issues, and then shortly after it starts consuming oil because the RP did it's job too well and broke up carbon/sludge that was basically keeping the worn out motor from consuming oil before. I don't know how legit this theory is, but I guess it could make some sort of sense?

.Manny.

iTrader: (1)

Perform a Leakdown test. It will let you know the condition of the rings.

4drEF

Read through what you did and you get pretty detailed.
It seems to be missing a step where you lube the new stem seals before installing them.
The rubber can stick and tear if installed dry.

Compression test only tells a general reading for the condition of the cylinder, but does not tell what portion may be failing.
Leakdown lets you listen for air hissing so you can determine if the leak is in the head or block.

Does it smoke when you start it up and engine is cold?
Smoke when you pull away from a stop like a drive-thru or a stop light?

Is your PCV in good condition?

10w30 is what the motor was designed for.
If you have leaks, higher viscosity might help band-aid them, but it's not a solution by any means.
If you noticed the problem once you started using RP, then it might be the issue.
No harm in trying a quality conventional oil or a semi-synthetic to prove it out.

socialistic

iTrader: (2)

I used fresh oil-soaked pieces of paper towel to clean the valve stem and where the valve seals go, before installing the new seals. Then I soaked the entire drivetrain with a quart of RP 10w30 before setting the timing and putting the valve cover back on. So everything had a fresh coat of oil and was all moved when I hand-turned the crank, before the car was ever started.

I'll run a leakdown test as soon as I can, the kit is going to run me about $107...I hate dumping money in to a pre-VTEC Si motor like this, but I don't exactly want to swing the cost of a swap right now so I guess I don't have a choice.

I don't notice any smoke when I start it up cold, I can only get it to smoke a little if I hit the gas when parked and a lot during the hill scenario.

Not sure on the PCV, it came with the motor and I had no immediate reason to believe it needed to be replaced. I have a brand new PCV that I bought for either a past b18 or b20, would this work for a d16?

As for the oil, I'm not really sure what to do. I've used Royal Purple as long as I could buy it at the local auto stores, never really gave anything else a chance. What's a good conventional or semi-synthetic oil I could use? I could do an early oil-change, no biggie.

Oh, not sure if this makes a difference, but the breather port of the valve cover is wide open. I usually pull the breather tube and plug the hole on my intakes, and put one of those mini air filters on the valve cover but I keep forgetting to pick one up whenever I'm at autozone.

Also, this Royal Purple is pretty black for not even having 1k miles on it yet. No telling what was run through this motor before I got it, and like I said the mileage on this motor is unknown. Looks like the RP cleaned a lot of crap out of that motor, which may just be my problem I guess.

Eta: Just called a buddy of mine that's in to this **** wayyyy more than I am, and after explaining to him when the car smokes and what I've done to it so far the first thing he asked was "have you checked/replaced the PCV?" I will **** if a 3 dollar part has been causing this the whole time.

socialistic

iTrader: (2)

Just checked the PCV, other than being really dirty it seemed to be working fine but I replaced it anyways. The lower PCV hose looks really gunked up, the upper PCV hose is about half as bad. Could this be a sign of what might be causing this problem for me? Perhaps it's that box the PCV hose runs to under the IM? Any way to clean that crap out?

I let it run for a few minutes. At idle it still doesn't appear to smoke. Once I throttle on it, it smokes a bit, but most of the smoke comes out for a second or two once the RPMs stabilize back at idle, then it stops smoking. Haven't driven it again since replacing the PCV as I'm sure the hill scenario will still result in a cloud of smoke, plus I'm about to head to bed and don't really feel like driving.

Eta: Also, if I remember correctly, spark plugs 2 and 3 were a bit more oily than 1 and 4. The valve cover gasket and spark plug tube gaskets have about 600 miles on them, same as the oil. Today I replaced the valve stem seals, lower spark plug tube o-rings, and pcv. All that's left that I can think of is the piston rings, or something else in the PCV system such as the gunked hoses or the likely gunked PCV box that I know absolutely nothing about.

1990edsedan

I had the same issue a while back, rebuilt head, oil black at 1k..rings were the culprit.

socialistic

iTrader: (2)

All 16 are the same when you get the Fel-Pro seals.

netfreak

You are correct for the Honda OEM ones (I just did mine with them). As per above post, I guess Felpros are all the same.

socialistic

iTrader: (2)

Should I pull the PCV hoses and PCV box on the back of the motor? The upper PCV hose has some build-up in it, the lower hose has a LOT of build-up in it, and I'm sure that box is gunked up pretty bad. How do I remove that box?

Also, should I pull the intake manifold and clean it out? I'm sure the inside of that thing is pretty gunked up from the PCV line and the valve cover breather line.

1990edsedan

That box drains right back into the block, so in theory, there should be little build up. You can remove it, and waste a can of brake cleaner on it and clean it out..

socialistic

iTrader: (2)

The lower PCV hose that runs to that box is built up with a shitload of gunk, the upper hose isn't as bad but does look to have a substantial amount of gunk lining it from the PCV to the intake manifold. Just going by that, one could assume the inside of that box is pretty bad. I'm assuming there was a lot of sludge buildup in this motor, especially since my royal purple only has like 600 miles on it and it's already black.

How hard is it to remove that box? Does it have to be done from under the car? I was thinking about pulling the intake manifold and cleaning it out as well since it has some sludge built up in it, if I do that would it make accessing/removing that box possible from the top? I have the old motor from this DX, that DPFI d15. I guess I could check to see if that motor has the same box and remove it just to see how it's done.

At this point, I'm just taking guesses at why my car still smokes during the hill scenario or when I mash the throttle. I still can't get it to smoke at idle, even after starting it around 6am today resulted in no smoke. Everything about this says valve seals or PCV, but both were replaced. All that's left is the PCV hoses and box, and apparently the catalytic converter which I'm sure is incredibly gunked up from the D15 which had bad valve seals and piston rings and went through a large amount of oil. I suppose I could swap the exhaust over from the Si parts car, while I'm at it.

1990edsedan

You can remove it from the bottom, but if you are going to remove the intake, then you can easily get at it from top as well. It's bolted on. Yes the D15 has the same box.

Let me get some info, how many miles was on this engine?

Was it always on a synthetic diet?

It is NOT your valve seals. If you see smoke when you let off the throttle, then yes. If this happens under load it is rings. Sorry to say. Now it could be that one or two oil control rings could be bad - hence when you do a compression test, the results look like you have healthy compression, as not all of the rings are shot. You could get away with a re-ring, but you are looking at pulling the head, new headgasket, and bolts..re-timing..well you get the picture..

socialistic

iTrader: (2)

I pulled the PCV box from the other motor and cleaned it out, had a lot of sludge in it but the lower PCV hose on that motor wasn't as dirty as the one on mine. Still deciding on if I want to pull mine, and the IM. It's just too damn hot out there lately. Right now I'm waiting for the motor to cool off so I can adjust the valve lash, I can only imagine how off it is right now.

I have no idea on the d16a6 mileage. It came in a '90 Si hatch I got with another car in trade. The Si I believe had around 200k on the clock, and the guy said the motor was replaced at some point. I have no idea what kind of oil they ran through it, but if I had to guess they were using the cheapest conventional oil they could get.

I did an oil change with Royal Purple 10w30 and now it smokes during the hill scenario and when I floor it(mostly on the RPM drop after I let off the throttle). I have at least 500 miles on this motor since swapping it in to my MPFI-converted '90 DX hatch, if my math is correct it's more like 600-650. The Royal Purple is already pretty black, completely lost its purple tint. There was a decent amount of sludge buildup in the IM but not much, the upper PCV hose had a decent lining of sludge, the lower PCV hose was damn near clogged with sludge, the old PCV was stuck in the open position due to sludge. The valvetrain has that nice bronze film all over it, and the under-side of the valve cover has that baked-on oil in some places.

Several compression tests resulted in 180 across all four cylinders without having to drip oil in to the spark plug holes, haven't run a leakdown test yet since I don't have the kit. Upon pulling the plugs, I'm pretty sure plugs 2 and 3 were oily but they also happened to have either bad spark plug tube seals or bad spark plug tube o-rings, both of which have been replaced recently.

Other than it smoking during those specific scenarios, there's nothing else seriously wrong with this car except the ECU not relaying the signal from the ELD to the alternator when more volts are needed(yes, I tested this, its not the ELD or the alt, definitely need a new ECU) and that pressure valve in the fuel pump not holding pressure when the car is off which extends the start-up time a little bit. Both of those problems can be ignored for now, since they don't hinder the cars ability to start/run/drive. I think it might be running a little rich, and I haven't checked fuel mileage yet.

sanimalp

Unfortunately I think it is your rings. Usually smoke is a result of oil being burned in the combustion chamber. I think you have done your due diligence in terms of replacing the valve stem seals. Autozone may rent a leakdown tester so you don't have to buy one, but I really think the rings are probably bad. How many miles does the engine have on it?

It is rather expensive to have all the machining done to get it back to where it should be. You could check out hmotors for a sohc zc for like $400 or so + ~$150 shipping. That would likely come in around the same price or a little less than having that engine re-ringed, and you end up with a spare builder engine, plus the ZC is higher HP anyway..

socialistic

iTrader: (2)

Yeah, at this point I'd have to agree that it's the rings, or like another post above said the oil rings since I do still have good compression numbers. Autozone does rent that tool, but if I'm correct I have to pay full price to rent it...if I had the $110 I'd just buy it since my toolbox should have one.

I have no idea of the mileage. Like I said, the Si had 200k-ish on it and the previous owner claimed the motor was swapped at some point with another "lower mile" d16a6. The motor didn't appear to be in bad shape, but they were clearly running cheap conventional through it and likely skipped a few oil changes and just topped it off when it needed oil. It starts, runs and drives great. I did the valve lash yesterday and most of the IN and EX valves were too tight according to the smallest blade size(.007 for IN and .009 for EX), now all the valves are set to those numbers. I always adjust to the tightest allowed number.

All HM has available is an obd-1 D15B VTEC for $675+shipping, and an obd-2 ZC non-VTEC for $599+shipping. I'd be better off spending the extra $75 and getting the slightly higher HP vtec motor, and not have to downgrade from obd-2. If I remember correctly, shipping was $130-150...can't seem to find it on their site anymore. Either way, that's out of my budget for quite a while due to school and such.

I do have that d15b? DPFI motor that originally came out of this DX. Is that block worth saving? I could throw in new bearings and rings, find a VTEC head to rebuild and throw on it, and have a 'rebuilt' VTEC motor that didn't cost a fortune and should be fairly reliable/decent DD motor with bolt-ons. This would also give me a chance to familiarize myself with block rebuilding, and D-series internals in general since I've always been a DOHC guy. I'd just be looking at the cost of getting it tanked and checked, new rings, new bearings, top-end gasket set, and the cylinder head. Everything else I would need(parts/sensors/etc) I could rob from my d16a6. The goal here isn't to make power, I'm just going for a reliable DD until I get in to another Integra to build, or get everything I need for a B swap.

1990edsedan

That is what i would do. Switch back to regular dino oil for now and run it, no reason to **** away money on synthetic at thus point. Bring the block inand get it hot tanked and checked for cracks. Then have it bored to next oversize and get the corresponding rings. Refresh your bearings and bushings on the rods. Going this route will be cheaper and much more fun.

socialistic

iTrader: (2)

If I do all that, it's going to be on the d15b2 block. I'll just run this d16a6 with bad oil rings until the d15b2 block + whatever head is done. What VTEC head will fit a d15b2 block? Is that block even worth rebuilding, or do I *have* to use a d16 block?

sanimalp

Nah, you can use the d15 block with a vtec head. The z6 or the y8 head will both fit. it is the same as swapping the d16 otherwise. The nice thing about the d16a6 though is the rods are a bit beefier.. the d15 rods are like toothpicks, so even though the stroke is shorter, it isn't quite as happy revving as the a6.

The A6 block is the most desireable to use with a vtec head due to the longer stroke and beefier rods, so don't give up on the block just yet.

The thing about the mini-me swap(sohc vtec head swap) though, is that you will end up spending about the same money doing it as buying an engine from hmotors.. figure the cost of the head, head gasket, intake and exhaust mani gasket, new timing belt to work with the swap, obd1 distributor, sohc vtec obd1 computer, wiring conversion harness, and any work needed on the vtec head, and you are just about to the same numbers as just buying an engine from hmotors.

I know all this because i was in the same boat when i was in school. I acquired a sohc vtec head very cheap and made spreadsheet of the cost to do it right, in my mind, into the A6 SI i had, and the price came out to about the same as just buying a complete sohc zc that was plug and play. unfortunately, the options you have listed from hmotors are not as useful because some of the same issues are present going OBD1 for the sohc zc. The tricky part is that you could run that obd1 sohc zc as obd0, but vtec engagement and wiring would cost money still.

Its a tough call man, IDK.. given the budget, i think i would drive the A6 and save for an A6 rebuild, as that may come out the cheapest in the end, as long as you get it built by someone who knows hondas. hell, you could send it out to a honda speed shop for like $1k and you would have a badass d on your hands..

socialistic

iTrader: (2)

I'll probably just run the a6 and top off with cheap conventional when it needs it, until I could swing the $850shipped for that obd-1 d15 vtec that HM has. It's about 10hp more than the obd-2 zc they have in stock, and it's only $75 more then that zc motor.

Driving on the a6 while saving to rebuild it is out of the question, as that would result in vehicle downtime at some point. I'd have to either rebuild a second motor, or import a second motor. Just a swap I can do in a few hours, so that's no problem. Having only one car really limits what I'm able to do with that one car.

Edit: A bit off-topic, but it's about the valve lash adjustment I did the other day. I did it by the Chilton's manual(cold motor, turn crank 180 degrees(cam turns 90), in the order 1 3 4 2. Seems like I'm getting a louder/more distinct ticking from the top-end now. I adjusted all the valves to their lowest allowed spec(.007/.009). Should I re-do it, but this time pull the plugs and use a marked dowel-rod so I can be 100% sure the piston is at tdc? The only thing I can think of that happened here is doing the crank turn method wasn't precise enough, and I probably adjusted some valves a little before or after TDC...