Help...White Smoke after HG Change

[retorq]

The heads can crack from combution chamber temp but only micro cracks near the valve seat. Never seen a vortec head crack to leak coolant. And calve adjustment is simple.

If he ran it low enough that there was NO water in the coolant passage around the exhaust on the center two cylinders (4+6) where the exhaust valves are right next to each other and the engine was running under load, the jacket there will crack, it's not that thick.

Ok, thanks sunlit. Im going out there now to check and test everything again then go from there. Talked with a buddy last night who has a known good set of heads I can get if needed. But they are off an 89 model 350, and from what he says they are double humps. Thanks again.

Those will run like shit on a Vortec not to mention your intake won't bolt up.

Also every one of those head bolts goes into a water jacket, did you seal them all??

 

[DevilDog]

If he ran it low enough that there was NO water in the coolant passage around the exhaust on the center two cylinders (4+6) where the exhaust valves are right next to each other and the engine was running under load, the jacket there will crack, it's not that thick.



Those will run like shit on a Vortec not to mention your intake won't bolt up.

Also every one of those head bolts goes into a water jacket, did you seal them all??

Man just full of great news this morning arent we wasnt to sure if I could use those heads or not just a thought. And sure did, cleaned each bolt and put plenty of sealant to each one. Just a wandering thought...should I go back to retorque them again or is twice checked good enough in your opinions?

Just returned from test drive...so a little smoke when first started out then none while driving. Stopped by the local jet wash to clean engine compartment good, about 10 mins, when driving out had smoke for about 2 miles then none. Did notice that shes running rough though, understandable, shes cooling off right now then another check of everything. Still no coolant loss / contamination. Temp ran between 150 - 210 ish the whole time. But judging from the sounds of it there is still some air going through the system, when started out for drive, with heater on low, could hear the coolant flushing through the heater core. Also total drive time was about 30 mins including the stop at the jet wash.

 

[retorq]

Sorry.

Park it on an incline, open the cap and let it run up to temp ... that's how I do mine and almost never have an issue.

 

[DevilDog]

Got it, didnt even think to do that one...whys it always the simple stuff we forget to do Headed back out there now to check everything again, been sitting cooling off about an hour now so we shall see. Thanks

 

[DevilDog]

ok, latest update...after doing incline and topping everything off, about 30 mins runtime, let it cool down again and checked prior to driving, everything was full. When pulling out, a small amount of air was heard still going through the system, nowhere like before. Have good heat on both heater and defrost, no problem there. Anyway, had smoke for about the first 5 minutes of drive time, then all was clear no more smoke even when throttle was run wide open. Still running rough but again understandable. After driving for about 30 mins without issues took her home. After sitting for about an hour, went back out to check on everything and levels were all good to go without any contamination. However when I started it back up for another drive, she smoked again, same thing, smoked for about 5 minutes and no more. My thought is that maybe the head has cracked somewhere in the inside out of view, and that when cooled off the crack is opening enough to allow some coolant to get in the cylinder, but when warmed up its closing on itself and almost sealing to the point it isnt leaking enough to cause the smoke issue. Also I did notice when I went for the drive that while out there, I did hear a rather loud "burp" go through the overflow tank, while stopped at a light, and just attributed it to air in the system bleeding through, that was the only time it has happened. Have not noticed any "ehaust" like odor in the coolant or overflow tank.

---------- Post added at 04:14 PM ---------- Previous post was at 04:02 PM ----------

forgot to mention that while driving and also at idle in the driveway temp maintained between 175 and 210. Never went higher than 210, even after a couple good miles of wide open throttle and about 80 mph, sure nice to live in the country lol

Also if someone has nothing better to do...check this link out and tell me what you think??? preparing for the worst case scenario. Thanks to all.

http://www.shop.headsonly.com/GM-35...T-CYLINDER-HEAD-1996-1999-CHEVY-350-96-99.htm

 

[SunlitComet]

entirely brand new each: http://www.jegs.com/i/Chevrolet+Performance/809/12558060/10002/-1

clean and tap your holes and use new felpro head bolts. one set for each head: http://www.amazon.com/Fel-Pro-ES72856-Misc-Set/dp/B000C2AHWC/

and gasket set : http://www.amazon.com/Fel-Pro-HST7733PT16-Gasket-Head-Set/dp/B001C98GAO/

and intake bolts one set only: http://www.amazon.com/Fel-Pro-ES72224-Engine-Intake-Manifold/dp/B0039SOMUE/

if the cylinder block is good and the jog done right. this will last the life of your block at least.

---------- Post added at 02:59 PM ---------- Previous post was at 02:58 PM ----------

sunlit approved repair parts.

 

[DevilDog]

Sunlit you have perfect timing !!! Update from the last test drive...all went well, started fine with very little smoke, about 2 mins worth, went for about a 20 minute ride with no problems, except the previous reported rough running, temp never strayed from 1 mark below 210, upon return home opened hood just to check, and "BURP" right up the overflow, when I popped the cap was hit with fuel odor immediately, shut it down and started pulling plugs, all were good except #4...fouled. No doubt in my mind that between the fouled plug and the burp of fumes in the cooling system that its a cracked head somewhere around #4. Ill be doing the new head thing tomorrow as I have nothing better to do with my time lol, and will let you know how it goes from there. Many thanks to Sunlit and Retorq who told my thick skull earlier on that this was probably the case.

 

[SunlitComet]

Have you old ones tested first you may just have damaged a head gasket during install perhaps.

---------- Post added at 04:20 PM ---------- Previous post was at 04:17 PM ----------

If cyl 4 i know it is not the intake gasket that is damaged as the water path only passes in front of two front cylinders on the vortecs 350.

 

[DevilDog]

Will do for sure. Im headed to town tomorrow, we have a shop there that does heads and machining so Ill get them to check em out. Called them a little while ago as we a small town folks and everyone knows everyone, hes pretty certain hes got a set there thats already done that I can get if needed. I shall let you know for sure tomorrow. Thanks again.

 

[retorq]

If cyl 4 i know it is not the intake gasket that is damaged as the water path only passes in front of two front cylinders on the vortecs 350.

No it doesn't.