White smoke post engine rebuild. Help! (1 Viewer)

[ARB777]

Just finished rebuilding my 1fz. A lot of White smoke is coming out of the exhaust while driving around the block for about 5 mins. No smoke was coming out when i first started it and idled it for 1.5 hrs. Is this to be expected or i did not torque the headbolts right? Or my new gasket failed? Any input would be greatly appreciated. Thanks.

 

[half k cruiser]

A couple of questions:
1. How rebuilt is this motor, did you put new rings, bearings, what ?
2. What procedure did you follow for torqueing the HG bolts and what HG did you use ?
3. Did you clean the tops of the pistons with them still in the block ?
4. This smoke is coming from the tailpipe or the manifolds ?

Answer those and we can help you better. If you really tore into this motor then there are a couple of things I can think of.

 

[ARB777]

Thanks half k cruiser
1. Head and block was done in a machine shop with new rings and bearing.
2.followed fsm. Torqued at 29 ft lbs then turned 90deg then turned 90deg again. OEM HG was used.
3. The machine shop tore it apart. I believe they cleaned it separately. Both head and block were shaved.
4. Smoke if coming from the tail pipe.
Additional info:
I did not quite torque it enough the first time. I only did 29 ft lbs plus another 45degrees because it felt like the head bolt are going to break. Water leaked thru the sides the first time i ran the engine. I openned it up again and torqued headbolts accordingly but i did not replace HG anymore. No more leaks this time but a lot of white smoke is coming out of the exhaust. Engine runs smooth though. No coolant loss so far. No overheating. Total time running was 3 hours. Mostly idle.

 

[ARB777]

4. Smoke *is coming from the tail pipe

 

[FrankTorres]

Could be left over coolant.
Did the motor have a bad head gasket before?
If so, it might take a few minutes of actual driving before it burns off.
Oh, you ran the motor for 3 hours, was this driving around or idling?

Hope that's it...

 

[ARB777]

Im really hoping its just left over coolant. Yeah, it was a blown head gasket to begin with. Then i just decided to send the head and block to the machine shop. Thanks.

 

[rockrod]

Maybe pressurize the cooling system and see if it will hold?

 

[dirtrick]

the smoke could be residues from cleaners, degreasers, even oils from your (or your mechanics) hands. during a re-build, hoses are left open and internal parts that never see the outside of the engine are exposed to dust, oils, cleaners, etc.. I would suggest keeping a close eye on temp and oil pressure and keep running it. all that muck might just need to burn out. Mine did this at first, scared the %&$# out of me and then it stopped.

 

[Mighty690]

Thanks half k cruiser
1. Head and block was done in a machine shop with new rings and bearing.
2.followed fsm. Torqued at 29 ft lbs then turned 90deg then turned 90deg again. OEM HG was used.
3. The machine shop tore it apart. I believe they cleaned it separately. Both head and block were shaved.
4. Smoke if coming from the tail pipe.
Additional info:
I did not quite torque it enough the first time. I only did 29 ft lbs plus another 45degrees because it felt like the head bolt are going to break. Water leaked thru the sides the first time i ran the engine. I openned it up again and torqued headbolts accordingly but i did not replace HG anymore. No more leaks this time but a lot of white smoke is coming out of the exhaust. Engine runs smooth though. No coolant loss so far. No overheating. Total time running was 3 hours. Mostly idle.

I did my HG not long ago so I'm familiar. Your note on the Additional Info is where I'm focusing. I too thought I was going to shear a head bold in the torque sequence, but I did it and it's doing great. The fact that it was run improperly torqued and a definite breach occurred indicates to me that you're going to need to open it up one more time and lay down a new OEM HG. A local professional mechanic also cautioned me about this exact scenario. Sorry for what is probably not the input you want to hear.

 

[half k cruiser]

Best case scenario: your rings havn't seated yet, they can take several thousand miles to wear in. I don't think this is the case, I think you messed up when you didn't torque those head bolts down the first time. Basically you have allowed the head to heat cycle while it wasn't properly torqued, theres a chance this could have warped the head. Have a leak down test performed and see if you lose air. Also, you should read up on engine break in procedures. Starting and idling for 3 hours after a rebuild like that is quite a bit different from most of the ways i've read.

 

[ARB777]

I did my HG not long ago so I'm familiar. Your note on the Additional Info is where I'm focusing. I too thought I was going to shear a head bold in the torque sequence, but I did it and it's doing great. The fact that it was run improperly torqued and a definite breach occurred indicates to me that you're going to need to open it up one more time and lay down a new OEM HG. A local professional mechanic also cautioned me about this exact scenario. Sorry for what is probably not the input you want to hear.

Truth hurts. Its best to hear it from someone rather than telling yourself. Thanks a lot for the input. I will open it one more time. Hopefully it did not warp head like what half k is saying. Ill probably have more question along the way. Thanks again.

 

[ARB777]

Best case scenario: your rings havn't seated yet, they can take several thousand miles to wear in. I don't think this is the case, I think you messed up when you didn't torque those head bolts down the first time. Basically you have allowed the head to heat cycle while it wasn't properly torqued, theres a chance this could have warped the head. Have a leak down test performed and see if you lose air. Also, you should read up on engine break in procedures. Starting and idling for 3 hours after a rebuild like that is quite a bit different from most of the ways i've read.

You are probably right. I am hoping for the best case scenario. I only ran it a couple of minutes (approximately 15 minutes) the first time though. Just wondering how long it would take before it actually cause damage. How do u suggest I break it in next time? When I open it up again and replace the HG. Thanks for your input.

 

[BOOSTED80]

You are probably right. I am hoping for the best case scenario. I only ran it a couple of minutes (approximately 15 minutes) the first time though. Just wondering how long it would take before it actually cause damage. How do u suggest I break it in next time? When I open it up again and replace the HG. Thanks for your input.

Minimize idling , vary the load on the engine(ie: hills, mountains) keep the rpm in the mid range area for the most part but occasional higher rpm bursts won't hurt.
You need to seat the rings properly & you won't do it with idling .
Also use a good mineral break in oil & drop it after 1000km..same goes for the filter.

 

[ARB777]

Minimize idling , vary the load on the engine(ie: hills, mountains) keep the rpm in the mid range area for the most part but occasional higher rpm bursts won't hurt.
You need to seat the rings properly & you won't do it with idling .
Also use a good mineral break in oil & drop it after 1000km..same goes for the filter.

using 10w30 conventional oil from mobil1. What varying speed would you recommend?

 

[half k cruiser]

Here's how I broke mine in : ran for five 10 or 15 minutes at idle, changed oil and filter. Drove it for about 500 miles, changed oil and filter. Its at 4000 or so miles since the rebuild, time for another oil changed. When you do the 500 mile drive you don't baby it you just drive it normal. Getting on the highway I would get the rpms up pretty good on the acceleration ramp. Anyhow, get the leakdown test done and see whats going on. Also, did you look in the coolant overflow with the truck running, rev it up a bit and see if it blows bubbles ?

 

[Mighty690]

It's not the rings seating, IMO. Clarify for yourself if you're seeing steam or smoke. It you're burning oil it'll have a definite smell, and if it's coolant that too will have a definite smell.

 

[Howard705]

Best case is antifreeze in the whole exhaust system in all the low spots-idling may not be enough to evaporate it downstream-driving under a load will be. If gasket blew bad this happens every time-seen it dozens of times-takes a long time to get rid of it.

 

[SmokingRocks]

I would do a leak down test ASAP. If it passes then what howard said is probably the case.

 

[ARB777]

Found oil in my radiator. Opening it up for the third time to replace HG. Going with ARP studs this time. Has anyone tried going this route?

 

[Mighty690]

I considered ARP studs. While they're likely superior in boosted applications (meaning I doubt you'd see loads that would cause them to be beneficial), they're going to be more work to trim (one apparently) and install due to the location of the engine relative to the firewall. I'd suggest you contact C'Dan or Beno and get some new OEM bolts. I didn't purchase new bolts and I would have liked that peace of mind as I retorqued that second 90 degrees!