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-   -   Help with smoke at start up (https://www.rx7club.com/new-member-rx-7-technical-256/help-smoke-start-up-1126299/)

stukinthe90s 05-14-18 11:20 PM

Help with smoke at start up
 
Newbie here attempting to work on his car because I want to learn. I have spent a few hours researching here and messing with the car so far. Here is where I'm at. On cold start up car smokes heavily for 4-5 minutes then goes away. Does not smoke much after that or on warm start up. Smoke does not smell sweet. Looks pretty white to me but may have a hint of blue. I did not see any oil in the intake as I read to check that. From what I have read it seems like it may be the oil control rings. Should I check anything else before I attempt to pull the motor?
Back ground. I just bought the car from a guy that was a complete liar. I knew that going into it. He said the motor has 800 miles on a rebuild but I don't buy it as its smoking, leaking, and he had 0 paperwork to back that up. Car has 105K on it. So my big question what is the list of items I should check? I'm hoping to not have to pull the motor as that's a bit above my capabilities at this time. Thanks for the hand holding.
https://cimg9.ibsrv.net/gimg/www.rx7...89e3577db0.jpg

lduley 05-15-18 06:47 AM

I hate to say it, but that much smoke of that color is a coolant seal failure, gonna guess your losing antifreeze?

Sgtblue 05-15-18 07:30 AM

Agreed.
Have the cooling system pressure tested. But almost certain that engine is coming out.

stukinthe90s 05-15-18 03:01 PM

Ugh that sucks. Its odd that the car did not smoke like that when I bought it. It seemed to have started overnight after I got it home. I will look into what it takes to get the cooling system pressured checked. Thanks for the help guys!

Sgtblue 05-15-18 03:09 PM

Check the coolant for signs a ‘stop-leak’ additive was used. Doesn’t hurt anything itself, but if present it would suggest the seal has been failed for a while. That can lead to rust and pitting of the seal grooves and make the inevitable more expensive. It could have just been sudden and catastrophic, but that’s a lot of steam.

stukinthe90s 05-15-18 03:25 PM

https://cimg9.ibsrv.net/gimg/www.rx7...608cbc0bed.jpg
I did notice a bit of rust in the coolant.

Sgtblue 05-16-18 04:02 AM

Hard to tell for sure, but that's probably discoloration from that stop-leak stuff.

Raymond Cascella 05-16-18 01:35 PM

Don't condemn the moter so fast my rx7 did the same thing yrs ago seams the tpi was too rich. If I took it for a good highway run it would stop for a while. Your coolant looks fine, keep an eye on it, If you have a leak you will notice that it will have a loss of coolant. The rotary is a tough mother mine runs like new with over one hundred thousand miles on it. Take it on a good high speed run if it doesn't overheat its probably not a coolant seal. Too rich of a mixture can make a rotary smoke at cold start up

Sgtblue 05-16-18 04:38 PM

*I'm not sure what a "tpi" is, but that looks like steam (white smoke) in the picture, not black smoke...which is what you get from running rich.
*The coolant looks contaminated to me. Either old and a little rusty, or from something else. But clean ethylene glycol coolant is a bright almost florescent green, not swamp water.

Originally Posted by stukinthe90s (Post 12274710)
....So my big question what is the list of items I should check? I'm hoping to not have to pull the motor as that's a bit above my capabilities at this time.....

Post #3 here---> https://www.rx7club.com/new-member-r...r-seal-941463/

Bronxrican 05-16-18 09:05 PM

+1 what Sgt Blue said. When I bought my FD, it had the same issues you describe, white smoke on start up. Then, after it warmed up, all clear until it cooled off and the coolant pooled inside the engine and would smoke upon start up again. When we opened up the engine, my coolant seals were damaged along with the rear iron. I'll post up a pic of how my car "smoked" on start up...prepare for a possible rebuild.

Bronxrican 05-16-18 09:34 PM

https://cimg8.ibsrv.net/gimg/www.rx7...002be44f6d.jpg

Before the build
Here is a pic of what mine looked like upon start up (before my rebuild)...all white smoke.

Raymond Cascella 05-20-18 05:40 PM

Sorry I ment tps not tpi also, as an after thought I would ck to see if the omp is not stuck in wide open position,always ck for simple fix first, before major rebuild.

Natey 05-20-18 08:06 PM

Looks like you need a rebuild. It is a little strange that we aren't seeing any milkshake crap in the radiator neck though.

Sgtblue 05-21-18 03:41 AM


Originally Posted by Raymond Cascella (Post 12276079)
Sorry I ment tps not tpi also, as an after thought I would ck to see if the omp is not stuck in wide open position,always ck for simple fix first, before major rebuild.

A stuck OMP while probably possible, is very unlikely. And on the stock ECU, there are not one but THREE possible codes that are generated if anything is wrong. And each will cause a Check Engine Light. And again, that "smoke" appears to be white (steam), not blue, which is what burning oil smoke is.

stukinthe90s 05-24-18 01:16 AM

Reporting back. I pressurized the cooling system to 10 psi an there was no drop in pressure after 10 minuets. I pressured it up to 15 and heard bubbling in the overflow tank and pressure dropped to 14 right way. After sitting for an hour it’s down to about 13.5.

stukinthe90s 05-24-18 01:27 AM

Rereading the thread I should note the check engine light is on. Seller stated it was from the cat being removed and this could be true but I guess it could be on for more than that as well.

Sgtblue 05-25-18 03:47 AM

Off-hand I can't think of any code that would explain the exhaust. But you can pull your own codes. There can be more than one.
---> Check Engine Light Codes

FührerTüner 05-25-18 05:29 AM

The asswipe you bought it from probably warmed up the car before you came to look at it.

You should drain the coolant completely, run it for a minute or so, squirt some oil into the park plug holes, and turn the engine over by hand a few times. This will prevent rust and save what may be a rebuild-able core, until youre ready for a rebuild. Sorry man.

stukinthe90s 05-31-18 12:11 AM

Wondering if anyone has a bit more input on the pressure check I did on the cooling system. I’m hoping to have some time in the next two days to check the cause of the check engine light per sgtblue’s post. Thanks again for all the hand holding guys.

FührerTüner 05-31-18 03:13 AM


Originally Posted by stukinthe90s (Post 12276916)
Reporting back. I pressurized the cooling system to 10 psi an there was no drop in pressure after 10 minuets. I pressured it up to 15 and heard bubbling in the overflow tank and pressure dropped to 14 right way. After sitting for an hour it’s down to about 13.5.


Originally Posted by stukinthe90s (Post 12278420)
Wondering if anyone has a bit more input on the pressure check I did on the cooling system. I’m hoping to have some time in the next two days to check the cause of the check engine light per sgtblue’s post. Thanks again for all the hand holding guys.

Coolant pressure test failed. All signs point to coolant seal failure. Face the facts my man.

https://cimg6.ibsrv.net/gimg/www.rx7...7729d8744d.png

stukinthe90s 05-31-18 02:08 PM



I don’t mind facing the facts but as a newbie I was not sure if that was a failed test or not. As mentioned it held 10psi fine and only dropped a bit at 15 psi. One more question if you don’t mind. I was putting the pressure tester on the upper yellow cap not the lower one. In reading a few other threads it seems this may be incorrect? The lower one seems to be leaking a bit out of the neck now.

stukinthe90s 05-31-18 02:09 PM


Sgtblue 05-31-18 04:05 PM

The tester should be put on the AST (lower silver cap), not the filler neck (yellow) cap. The AST cap will/should have a spring which opens at about 12 or 13 psi. You want that out of the equation when pressurizing the system. I'd take it up to about 20 psi and see if it holds.

A couple of additional tests you can perform.....
Rotary Resurrection home of the budget rebuild.

stukinthe90s 06-02-18 06:21 PM

Just wanted to thank everyone for the help and input. I pulled the EGI fuse and it blew bubbles out the filler cap so I think like most were saying the seals are done. I will look into who to have rebuild the motor and pull it and ship it out. Thanks again.

FührerTüner 06-03-18 12:25 AM

Do this.


You should drain the coolant completely, run it for a minute or so, squirt some oil into the park plug holes, and turn the engine over by hand a few times. This will prevent rust and save what may be a rebuild-able core, until youre ready for a rebuild.


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