Rx7Ay07

Hello everyone,

I know you might be groaning and thinking "yet again another white smoke thread, it's his coolant ring! rebuild!" but I have to make this thread because I am confused as to what is going on with my car. My 1985 GSL has been fine for the 3 years I've owned it and in June this year I was driving and my low oil light came on (which was weird because I had gotten an oil change not that long ago and before 3000 kms) and I did u-turn to go to the gas station for oil before heading home. The car ended up shutting off and I coasted to a stop. It did not overheat and the pressure for oil was good. It's not like the engine ran out of oil and suddenly shot up in temp and the pressure dropped to nothing. I was easily able to start it again and had a friend bring me oil to top up the engine. I was able to limp home with the choke out to keep it from dying at a light/stop and engine sounded rough.

I brought it to the only shop in town that deals with rotaries (but they dont do rebuilds) and they rebuilt the nikki carb for me, put new plugs (the old ones were in bad shape), new spark plug wires and distributor rotor. They did an oil change and that was that. What was strange is they did a compression test before fixing the carb and it had good compression. They did one after the carb was installed and it showed rotor 2 as being lower compression. The older mech there told me there's a chance the apex was stuck? and would perk up once warmed up. I picked up and drove home and the car was limping bad when suddenly just as he said it perked up and it was driving as it used to before and sounded great. The idle is perfect now the carb is better than I've ever had it.

But as I got home the car started spewing intense amounts of white smoke. I got home and let it idle to see if it would continue and it did, took it out to the highway driving it a bit harder ( wishful thinking idk I thought maybe it was like carbon build up) still just smoking bad. It doesn't spew out while under load if I am giving it gas but once you come to a stop it just comes out in pulses.

I'm still able to start it up easily with no problem and it idles great but spews white smoke. Classic signs of a coolant ring being bad right? but here's the thing : the smoke does not smell sweet like coolant. I had another person confirm this so it's not just my nose. While running I took the cap of the radiator and looked for champagne bubbles.....not a bubble in sight.

I rented a pressure tester for the coolant system and hooked it up, pumped up to 15 PSI and it held.....and held....and held.....no pressure loss. While doing this I had my buddy look at the gauge while I was under the car looking for leaks....nothing.

I feel if I had too much premix it would smell like oil and have a blue-tint type smoke not white so I have no idea whats going on.

What should I investigate next? If the coolant system holds pressure then that should mean the coolant ring is still good and coolant is not making it's way into the combustion chamber from there.

I'm digging deep with google trying to find info and the only lead I have right now is that apparently there are 2 O-rings for coolant or something right above the intake manifold? You need to remove the intake manifold to see them? Is it possible for them to crack and seep coolant into the intake manifold ?

What would you guys do with a car that shows symptoms like this? when the pressure test is suggesting that the coolant ring is not worn and letting coolant through ? and I have no champagne bubbles ? and the smoke doesn't smell sweet ?

I fear the worst but I'm wondering if there's something I overlooked that could mean my car is still good.

Thanks for reading.

KansasCityREPU

iTrader: (9)

It sounds like when it happens, it's a good amount of smoke. If your not losing coolant, the only other culprit is the oil control ring(s) starting to go. What do the plugs look like? Have you tested the ignition leading and trailing to ensure spark?

As for the low oil light, you could have a bad sensor. It's in the oil pan.

Rx7Ay07

Hi there, yes it is a good amount of smoke and only on idle or when off power, when driving nothing comes out until you let off the gas. And yes it does not seem like I'm losing any coolant.

The plugs were not ultra fouled or anything like that, however the shop told me spark plug 3 and 4 were "broken". They did not elaborate on what that meant just said "they were broken". They are now changed all 4 have brand new ones and new cables and the distributor has a new rotor in it (I think that is what the part is called).

The low oil light could maybe be a bad sensor but I don't think so, when I had that incident where the car shut off it was already warmed up and I checked dip stick and it was low. I put in 3 bottles worth of oil and by bottle 2 the sensor had stopped. It only ran like that for 10 minutes as I limped home and then the next thing that happened was I had it towed to the garage where they did a full oil change with the right amount. They are knowledgeful and did not use synthetic oil and used the weight I always used 10W30.

Are the oil control rings inside the engine? I guess I'm still looking at having to rebuild ?

KansasCityREPU

iTrader: (9)

The oil control rings sit on the flat part of the rotor and "ride" on the iron face of the "irons". They are what give the pattern on the iron face.

The next test would be to measure the oil line of the dipstick, drive the car, and monitor the oil after each trip. Looking for the oil consumption to go down rapidly. It's not uncommon to lose one quart between changes because of oil injection and general usage on a tired engine.

I've seen oil control rings so bad that oil dripped out the tailpipe. Replacing the oil control rings is a complete rebuild. On a 12A, keep your fingers crossed the housings are still within spec. Missing chrome is a killer.

Rx7Ay07

Hmmmm I see, thank you for that. Before I got to your reply I was looking up the oil control rings and yeah that could also be a cause for smoke. I was under the impression that only coolant or potentially water could make thick white smoke but considering the smoke doesn't smell sweet and the coolant is not draining....

So if the an or both oil control rings are bad it could cause thick white smoke instead of oily blue or black smoke ? I was hoping that maybe something they used in the carb-rebuild was being consumed or maybe I had put too much premix in the gas tank and the fresh carb is causing it to smoke but it would be blue and oily if that was the case.

I guess the engine is toast and will need a rebuild which I sadly can't afford nor do myself. That is a shame

KansasCityREPU

iTrader: (9)

Do you still have the OMP or are you only premixing? If you still have the OMP, stop premixing for now and run some fresh gas without premix. If premix is the cause, this should rule it out. Premix would also be a blueish cloud in the exhaust because it IS oil. I think a lot of times exhaust smoke cannot be determined by color. The smell is more of a giveaway. As far as the carb rebuilt causing it, no. Unless you have a really rich mixture then you'd smell a lot of gas in the exhaust and your eye would burn.

Testing is your only coarse right now. Monitor the coolant and oil levels.

RX7_Renesis

iTrader: (1)

You mentioned in your original "Introduce Yourself" post that the "add coolant" light was on and you had a very slow leak in one of the coolant hoses from the radiator.

If those issues have been addressed and you are still getting the "add coolant" light (but no visible leaks on the ground) .. then it must be getting into your engine and out your exhaust somehow.

If you're not loosing coolant then check and double check your oil consumption. Maybe the carb rebuild messed up the linkage for the oil injection (stuck open or adjusted too tight) and you are feeding too much oil into your engine during idle.

At idle you should have between 0 ~ 0.04-inch of freeplay in the rod.

If you need procedures on checking the oil metering pump volume, that should be easily available. If not .. then just ask and I'm sure someone can post the procedure for you.

Rx7Ay07

Thanks for the replies guys really appreciate the help.

Yes when I got the car it had that issue with the check lights but it was intermittent. In an attempt to fix my gas gauge not working on the gauges I had removed it and had it resoldered by a shop. Since then the warning lights don't spaz out anymore.

The coolant leak was from the radiator hose where it meets the radiator and was very minor. I don't think coolant can leak from there and make its way into the engine so that shouldn't have had anything to do with it.

The coolant level doesn't fluctuate, last I checked it was exactly at middle in the reservoir as it has been for a while.

You're mentioning a linkage for oil injection....is this part of the OMP? It was deleted before I bought the car. If not please give me more info about this so I can investigate it on the carb or wherever this linkage is but it sounds like you meant the OMP which I don't have.

I'm afraid I think the worst has happened for my engine because I won't even be able to check oil consumption.....there's no way I can drive this car with the amount of white smoke it puts out. The police will be on my *** in no time leaving a cloud like that wherever I go. So unless I go for a drive with my wallet ready for whatever ticket they will give me I don't know how I can test this car.

The other thing I find weird is before the carb rebuild even in summer starting this car cold required having choke pulled out and slowly let off as it warmed up. In colder nights or days I'd have to let the engine reach operating temp to avoid any sputtering out. After the rebuild the car only needs the choke for ignition and I can then push it all the way in right away and it idles completely fine but much higher than before. I used to idle under 1k at like 850-900 and now it seems to be 1200 rpm.

This really sucks because the engine sounds better than ever and it drives fine but it seems like the engine requires rebuild anyways and that means the death of my RX7 because I'm too poor

KansasCityREPU

iTrader: (9)

If your putting out that much smoke, then just start it in the driveway and monitor coolant and oil. With this much smoke, I find it hard not to be able to identify the issue.

So, the OMP was remove which means that in itself is not the issue. How much premix are you mixing into the gas?

Rx7Ay07

When I looked it up there was much debate between half an oz per gallon or one oz per gallon. I did half oz per gallon so for a full tank I was putting in 7.5 oz of castrol 2 stroke oil. I don't remember the exact details of the bottle but I remember making sure it "meets or exceeds ISO EGD, ISO EGC, JASO FC, or JASO FD"

I can try and start it again in my parking lot and take a video of me monitoring the coolant reservoir and dipstick but I will have to be very careful when I chose to do this. I live in a condo/apartment thing and there's a parking lot out back with about 6 spots and there are other buildings near, the smoke will get people's attention. I will try and see if I can get that captured on video sooner than later....

KansasCityREPU

iTrader: (9)

If it's putting out that much smoke on startup, it's not oil. Your OMP amount should be 1oz per gallon with no OMP connected but would not be the issue of the smoke.

This would be an extreme test and I've never done it, but you could remove the radiator hoses and drain the block of coolant by removing the small bolt at the bottom of the center iron. This will drain the "block". Start the car. You will get some smoke but it should subside. Monitor the temp gauge and do not let it get about 1/2. You should get a couple of minutes of run time. The smoke should subside if it's a coolant leak into the rotor area.

Just like a blown apex seal, coolant seal failure can happen at anytime and sometimes without warning.

RX7_Renesis

iTrader: (1)

If the OMP was deleted, then disregard checking for free play on the linkage or rod.

If you need to go for a short test drive, Alymer is out in the middle of nowhere. Just head out early on a Sunday morning. Make sure you avoid the Tim Horton's on John Street or Talbot Street so you don't draw any attention from the OPP. Maybe try Regional Road #40.

Have you checked the coolant level in your rad .. or just the reservoir?

Are you running with the proper mix of coolant in your engine or are you running with distilled water? Coolant should give off a sweet smell out the exhaust .. however if you're running straight water then there shouldn't be any smell to it.

This is a great suggestion. Not sure how easily you can work on your car in your condo's parking lot. You could also try draining your engine oil to see if you have any signs of the dreaded milkshake.

Rx7Ay07

Hi to both,

"This would be an extreme test and I've never done it, but you could remove the radiator hoses and drain the block of coolant by removing the small bolt at the bottom of the center iron. This will drain the "block". Start the car. You will get some smoke but it should subside. Monitor the temp gauge and do not let it get about 1/2. You should get a couple of minutes of run time. The smoke should subside if it's a coolant leak into the rotor area." I might consider doing this because yeah it would help determine if coolant is making it's way in. Any idea of what would it mean if the smoke did not subside?

"If you need to go for a short test drive, Alymer is out in the middle of nowhere." I think you might be thinking of Aylmer Ontario but I'm in Aylmer QC so it's a small town close to a highway but getting to the highway will attract attention. Funny story about that, when I got back from picking up the car at the last mechanic shop I decided to continue on said highway to see if maybe I could ring out the smoke and just as I turned around to go home when I realized it was not going away there was a Tesla doing a U-turn and I saw the driver looking at my car like 0__0 when a huge puff of smoke came out hahah

I am running with 100% coolant no water mixed in. As for checking the radiator level, before I did the pressure test I ran the car and looked for champagne bubbles of which there were none whatsoever. The coolant was topped up right to the cap it was full. When I did a pressure test two weekends later and opened the cap the coolant was at the exact same spot, fully topped up. Is it possible to have too much coolant ? I've read things about "over-pressured" coolant but idk anything about that.

Rx7Ay07

Another thing I'd like to try is drain the gas tank and put in fresh gas with fresh 2T oil. I bought a siphon to remove the gas only to realize I am a dumb *** and don't have enough jerry-cans to empty said gas tank....if I manage to buy a large enough jerry-can I think I will give that a shot too.

midnight mechanic

100% coolant? it needs to be mixed with water, 100% coolant will freeze 9 F

KansasCityREPU

iTrader: (9)

Your tank has a drain plug.

If you don't have coolant in the rad, it's kind of hard to do the sniff test for a sweet smell.

RX7_Renesis

iTrader: (1)

Any chance the shop that rebuilt your nikki carb and serviced your engine added Seafoam or some other type of engine cleaner / fuel treatment to your gas tank?

Rx7Ay07

They didn't mention doing anything of that. They are knowledgeable about RX7's though and I told them I premix in the gas tank and that there is no OMP (which they probably noticed when working on removing/installing the carb). However they don't diagnose/work on engines other than doing the compression test or oil change.

Maxwedge

iTrader: (1)

Wait, what? They are knowledgable about rotaries but the only services they'll do are comp test and oil change?

I think you mis-wrote that, but Im on your side. They prolly would have mentioned it if they ran seafoam through it ("Hey we did a fuel system clean-out for you") but it was a valid question. Seafoam helps clear out the lines but smokes like a bitch.

Rx7Ay07

Yes I'm quite sure they would have mentioned if they ran sea-foam because we spoke on the phone and the owner understood my level of understanding etc and we were troubleshooting together before he offered the carb rebuild. I didn't mis-write it, it's kind of a special situation. Where I live if you call any local garage and ask for help with a rotary car they will tell you they can't help and can only work on everything BUT the engine. This shop is Japanese owned and the father who has now retired used to work on rotary cars. I chose them because they have a blog and once helped a guy with an FC determine a weird issue he had and it turned out they were able to determine he had fake NGK spark plugs. Because of that blog post I thought of them and went to them but the son told me the father had since retired and so they no longer work on rotary cars. Despite that, because of his father's past knowledge and having worked in the shop when his dad ran it he was willing to take my RX7 in and work on it. But yeah they can't do rebuilds or anything like that, I'm lucky they were able to work on the carb. I had called a special shop that deals with hot rods and carbs but they told me they don't work on anything but American cars....

Someone above mentioned that it's strange I have 100% coolant. I thought about it and realized I never filled the radiator, since owning it that has only received attention once when I brought it in for fluid changes. They probably poperly mixed it for the radiator. I meant that I have only put 100% coolant in the coolant reservoir to make sure it was between full and empty.

RX7_Renesis

iTrader: (1)

Engine Coolant, Engine Oil, or Funky Gasoline ..

Let us know when you figure it out.

Rx7Ay07

I will definitely post here when I get the chance to take a video of it idling while I check those fluids. God I hope it's just funky gasoline but I doubt it that would be too easy :P Thanks everyone.

Rx7Ay07

Okay so this is a totally crap video that doesn't really show off any useful stuff but at least you guys will be able to see the amount of white smoke I'm dealing with.

I fully admit this recording is ****, it also cut off when I put the phone in my pocket so I could wipe the dip stick and re-insert it. I wasn't able to keep the car on for too long before it shut off on it's own which is unusual. I want to get a big jerry can Sunday and try and empty the gas tank and refill.....once it has fresh gas we will see what happens. If it isn't fuel then whatever it is I consider the engine to be dead and will need to figure something out. Really hoping it's bad gas or something like that but I don't have my hopes up.

*the gas meter doesn't work in my car so it always says empty so don't think yo! you're out of gas!*

Here is the video so you can see the smoke : https://streamable.com/30ga46

RX7_Renesis

iTrader: (1)

I know you said you pressure tested the cooling system .. however that certainly looks like water/coolant coming out of the exhaust.

I noticed your "Low Coolant" light was ON.

Seafoam or gas treatment usually produces way more white smoke (vapour).

Toruki

I agree ^^^^

When you walked through the smoke/mist did it smell burnt or sweet? I know folks have asked this, but maybe you noticed on this occasion?

Also, are you just checking the coolant reservoir? It can be a hint but doesn't tell you your actual coolant level. Once you turn off the car, put a multiply folded rag over the rad cap and open it SLOWLY to relieve pressure and steam. Make sure you have protective gloves. Or you can wait for the whole thing to cool. Remove the rad cap and look at the level there. Again, some might have suggested, but I didn't want to go back through the whole thread :P