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How much white smoke is normal after a rebuild? (10AE)
Wife had her engine rebuilt a few months ago and just finally broke the engine in @ 500 miles. Did an oil change, the car sat for a few days, and this is the first start-up since oil change.
The engine builder keeps telling me it's anything but the engine, but I'm starting to get the feeling he's gaslighting me.
What do y'all think? This is during the cold start. 5/10 minutes into it, just as much smoke was coming out. It's 30° outside. The car has no cat.
For a 30*F morning that white smoke might just be normal condensation in the exhaust system boiling off, and that can occur regardless of whether the engine is brand new, recent rebuild or has over 100K miles on it. To rule out other potential problems, such as coolant seal or oil burning issues, we need some more info:
1. What did that smoke smell like? If it had a sweet smelling odor, it would indicate some antifreeze being burned. Though without a catalytic converter, the smell test here might not be very conclusive - just the normal rich running fuel stench of a cat-less rotary may overpower your nose's ability to pick up the more subtle sweet stench of burning antifreeze. If the smell had a more pungent stench than fuel, it could be oil burning, but the smoke from oil burning tends to be a bit bluer in color than the white smoke you pictured. Though oil burning is possible if you overfilled the oil when you did the oil change - check the level on the dipstick to rule that out, it should not be higher than the FULL line.
2. What does the coolant level look like in both the overflow tank and under the radiator pressure cap when the car is cold? The tank level should be sitting at the fill line, and the level under the radiator cap should be right about to the top. Did the engine ever overheat during its break-in period?
BTW, do you mind sharing what shop did the rebuild? I'm curious since I see you're in DE, which could be pretty close to me in Elkton, MD.
Last edited by Pete_89T2; 11-13-23 at 08:28 AM.
Reason: added info
I'll check the coolant levels later today when I get the chance.
For the smell, it just smelled like normal catless exhaust. No sweet smell as far as I could tell.
For the rebuild, all seals were replaced, and a street port was supposedly done. Done @ Advanced Rotary in NJ.
And to be clear, the amount of smoke has been consistent during the break-in process; I just finally decided to ask the question. The car does start up very roughly if it sits for more than 3 days; we usually give it 5-10% gas when starting up, and we blip the throttle every once in a while before it decided to "sound" normal. It feels like it's gurgling at first, or coughing, before the exhaust finally opens up during start-up.
Also, it does still smoke, albeit at a much lower volume, after the car has been driven while fully warmed up, at idle. This happened during 60s & 70s degree outside temp as well.
You can perform a block test with the block test fluid to check for exhaust gasses in the coolant.
You could also pressurize the coolant system and monitor for pressure loss.
When my friends and I build a rotary engine, we all share and use a coolant system pressure test kit from pineapple racing which mounts on the front iron water pump studs to ensure the coolant seals are properly installed and working. You can check to see if the builder does this as part of his verification process before delivery.
You can perform a block test with the block test fluid to check for exhaust gasses in the coolant.
You could also pressurize the coolant system and monitor for pressure loss.
When my friends and I build a rotary engine, we all share and use a coolant system pressure test kit from pineapple racing which mounts on the front iron water pump studs to ensure the coolant seals are properly installed and working. You can check to see if the builder does this as part of his verification process before delivery.
I'll refrain from reaching out to the builder until I have any more reason to doubt him. I don't want it to feel like I'm complaining until I have a reason to do so. Last time he had the car, it took him 5 months to finish the build, so I don't want to take it unless I absolutely have to.
I'll refrain from reaching out to the builder until I have any more reason to doubt him. I don't want it to feel like I'm complaining until I have a reason to do so. Last time he had the car, it took him 5 months to finish the build, so I don't want to take it unless I absolutely have to.
^That will work to test for failed coolant seals in the engine, it detects the presence of combustion gases in the coolant. Alternatively, you can go to a local Advance auto parts store and use their tool loaner program to use a cooling system pressure test kit, like this one: https://shop.advanceautoparts.com/we...0051&langId=-1 Other auto parts retailers have similar loaner tool programs - you give them a deposit for the tool, and when you return the tool intact, you get a full refund of the deposit.
Basically you use this tool to pressurize the cooling system, and see if the pressure drops over time. If it holds, all is good, if it drops over time, and you're not seeing any evidence of an external leak (e.g., leaky hoses, leaky radiator or connection points, etc.), it means the internal engine coolant seal is leaking.
^That will work to test for failed coolant seals in the engine, it detects the presence of combustion gases in the coolant. Alternatively, you can go to a local Advance auto parts store and use their tool loaner program to use a cooling system pressure test kit, like this one: https://shop.advanceautoparts.com/we...0051&langId=-1 Other auto parts retailers have similar loaner tool programs - you give them a deposit for the tool, and when you return the tool intact, you get a full refund of the deposit.
Basically you use this tool to pressurize the cooling system, and see if the pressure drops over time. If it holds, all is good, if it drops over time, and you're not seeing any evidence of an external leak (e.g., leaky hoses, leaky radiator or connection points, etc.), it means the internal engine coolant seal is leaking.
I see, thank you. I'll see if I can find videos on how to use it and I might go that route. Otherwise, the liquid kit seems easy enough, just pricier.
I see, thank you. I'll see if I can find videos on how to use it and I might go that route. Otherwise, the liquid kit seems easy enough, just pricier.
The pressure tester is pretty easy to use - I pick one up to test mine anytime I do a build/install an engine, or do mundane cooling system maintenance such as replacing hoses. Better to check for leaks up front rather than finding them on the road where you might overheat & kill your engine. The test procedure with these testers are pretty simple, and they usually come with laminated instruction cards:
1. Make sure the engine is cold before testing.
2. Find the appropriate adapter cap in the kit that fits to your radiator, and attach it to the radiator. The pump part then connects to the adapter piece with a quick-connect coupler.
3. Pump up the pressure with the hand pump; it will have a gauge to read the pressure - you'll want to pump it up to about 16 to 18psi or so, no need to push it any higher. When its pressurized, make note of the time & your pressure reading.
4. Take a look at the pressure gauge after a few minutes - it should be at the same pressure you pumped it up to. If that's the case, go grab a beer and come back about a half hour later. If it's still holding pressure, you're done - there's no coolant leaks. Otherwise, start looking for places coolant might pissing out from externally (hoses, etc.).
The pressure tester is pretty easy to use - I pick one up to test mine anytime I do a build/install an engine, or do mundane cooling system maintenance such as replacing hoses. Better to check for leaks up front rather than finding them on the road where you might overheat & kill your engine. The test procedure with these testers are pretty simple, and they usually come with laminated instruction cards:
1. Make sure the engine is cold before testing.
2. Find the appropriate adapter cap in the kit that fits to your radiator, and attach it to the radiator. The pump part then connects to the adapter piece with a quick-connect coupler.
3. Pump up the pressure with the hand pump; it will have a gauge to read the pressure - you'll want to pump it up to about 16 to 18psi or so, no need to push it any higher. When its pressurized, make note of the time & your pressure reading.
4. Take a look at the pressure gauge after a few minutes - it should be at the same pressure you pumped it up to. If that's the case, go grab a beer and come back about a half hour later. If it's still holding pressure, you're done - there's no coolant leaks. Otherwise, start looking for places coolant might pissing out from externally (hoses, etc.).
Thank you, it does sound simple.
I just went to my 2 local Auto zones and neither one had it. The next store up north has it, but it's a 40 minute drive from me. I'll probably wait until this weekend.
Meanwhile, I did drive the car back home and it gave me the "Add Coolant" buzzer when turning right for more than 3 seconds. I just checked the overflow tank and I don't see any liquid in there. I'll let it cool down and check everything later. I swear it was past the minimum line two weeks ago before we changed the oil.
I'm currently leaving it pressurized for another 30 minutes to see if another drip shows up anywhere else.
The previous owner installed an aftermarket water temp sensor that barely works, and the hose that was cut to fit is all janky. I'll try to adjust it this weekend but if it all fails I'll buy a new radiator hose and disconnect the sensor altogether. This definitely explains why I thought I had lost coolant even I had just checked it, but obviously doesn't explain the smoke.
The blocktest fluid comes in tomorrow. I'll see if I can put it to use as soon as I get home.
Used the Block Tester today, took a few tries til I wasn't sucking up coolant but we eventually got it right. The fluid remained blue the entire time, so I'm assuming the seals look good.
Do you guys have any other suggestions? Would a bad turbo seal cause smoke like that too? Or do you think maybe I should give up trying to look for something wrong when everything seems fine?
I can't seem to be able to edit my last post to add an update, so here we go:
We started her up today to take her out and see how she feels after we adjusted the upper coolant hose and reduced the leak from it and... We saw no smoke coming out of the tailpipe. Like, there was maybe 1% of the smoke on the pictures above. Not just that, she also started up much more smoothly this time.
I'm not sure if it was the coolant leak or maybe there was air trapped in the system that came out while we did the Block Test, but it seemed to do something... We're gonna keep an eye on it and let her sit for a few days like she usually does and then report back. If the smoke is gone after that, we did something right.
well, the smoke is not normal so, no, you should not be giving up.
yes, a bad turbo seal can cause smoking. i've never had to deal with one, myself, so this is conjecture on my part, but i imagine it should smell like burning oil though.
it can't hurt to pull the downpipe and check for signs though.
Originally Posted by carsebuco
For the smell, it just smelled like normal catless exhaust. No sweet smell as far as I could tell.
For the rebuild, all seals were replaced, and a street port was supposedly done. Done @ Advanced Rotary in NJ.
is the engine being run wth the stock ECU, injectors, etc.?
We let the car sit for a few days, and no abnormal amount of smoke came out. Before, pretty much every cold start-up would cause immense amounts of smoke, but that is no longer the case. I am unsure if it was a bubble in the coolant system or if me fixing the coolant leak helped, but now we see a normal amount of smoke come out during start-up.
I still purchased a upper coolant hose that we might use to replace the current one with the shitty aftermarket thermostat, but we no longer saw the coolant go from FULL to EMPTY during a drive. That's a good sign too. I think, until things chance, we'll keep driving the car as is and stop worrying about it. If smoke comes back we'll deal with it. Naturally, the car has other things that need fixed, but this seemed that it needed to be dealt with first, and it seems that we have accomplished that. Thank you all for your help.
Now onto front diff bushings, coilovers, and to replace steering rack boot...
Originally Posted by diabolical1
well, the smoke is not normal so, no, you should not be giving up. yes, a bad turbo seal can cause smoking. i've never had to deal with one, myself, so this is conjecture on my part, but i imagine it should smell like burning oil though. it can't hurt to pull the downpipe and check for signs though. is the engine being run wth the stock ECU, injectors, etc.? pull the plugs and see if they tell you anything.
When speaking to the builder, he said he saw no signs of a failing turbo, but that the turbo could have been the culprit. The car has stock ecu, injectors, and pretty much everything else aside from downpipe, street port and intercooler. He did say he found a failing injector and that he swapped with a used one he had sitting around.
11-13-23, 06:25 AM
