Heads Replaced-Need Advice
Thread Starter
Racer
Joined: Jun 2019
Posts: 390
Likes: 126
From: Franklin, TN
Heads Replaced-Need Advice
Quick back story. I bought a 93 convertible that had an overheated engine due to ruptured hose and got antifreeze in the oil pan.
I removed the heads, had them milled and finished the install today. The good news is that when everything was connected, the engine started right up. It idles very smoothly and revs with no hiccups, hesitation, etc. The engine runs quiet with no knocks or rattles. The bad news is there is a lot of white smoke exhaust. I know what that is supposed to mean (head gasket) but I am hoping for another cause. I can't believe that the engine is running that smooth, with no misfires, and has a bad head gasket.
My questions are: 1) Is there another possible cause of the white smoke that I should investigate (pollution control)?, 2) Is there any way to salvage the installation, re-torqueing head bolts, using mystery oil (: ,anything at all?, 3) Will a compression test tell me if my new gasket is bad?, 4) Not a question, but I suppose it could be a engine block issue, warp or crack.
I would appreciate your input. I am just looking for a lifeline but I am sure I will have to go back in to the engine.
I removed the heads, had them milled and finished the install today. The good news is that when everything was connected, the engine started right up. It idles very smoothly and revs with no hiccups, hesitation, etc. The engine runs quiet with no knocks or rattles. The bad news is there is a lot of white smoke exhaust. I know what that is supposed to mean (head gasket) but I am hoping for another cause. I can't believe that the engine is running that smooth, with no misfires, and has a bad head gasket.
My questions are: 1) Is there another possible cause of the white smoke that I should investigate (pollution control)?, 2) Is there any way to salvage the installation, re-torqueing head bolts, using mystery oil (: ,anything at all?, 3) Will a compression test tell me if my new gasket is bad?, 4) Not a question, but I suppose it could be a engine block issue, warp or crack.
I would appreciate your input. I am just looking for a lifeline but I am sure I will have to go back in to the engine.
Drifting
Joined: Jan 2005
Posts: 1,354
Likes: 324
From: San Antonio Tx
I assume you checked the heads and block for cracks. It's very likely you have some antifreeze in the exhaust pipes. I have had that happen with a blown head gasket. I had to drive quite few miles and get the exhaust hot enough to clean it all out.
Thread Starter
Racer
Joined: Jun 2019
Posts: 390
Likes: 126
From: Franklin, TN
Thanks RWDsmoke. I did examine the heads and block for any obvious cracks and I assume the local shop checked the heads. I did not see any obvious damage. Your experience is a real possibility for me also. I failed to remove the knock sensors before removing the heads and antifreeze was everywhere. The engine runs smoother than my coupe that has half the miles on it, so I will run it some more to see if it eliminates. Also, just discovered the chemical test that will check coolant out of the radiator for fuel. May run that just to be sure.
Drifting
Joined: Nov 2018
Posts: 1,752
Likes: 645
From: USA
Get a cooling system pressure checking tool, put it on in place of your radiator cap and pressurize to 15 lbs give or take, pull all of the spark plugs. Now observe what happens! Does it hold pressure? Is coolant running out of one of the spark plug holes? If you have access to a bore scope (camera) look into each plug hole, anything? Also, right away, does your new oil look like chocolate milk? I hope it is just trapped antifreeze in the exhaust from before, hope it's not a cracked cylinder (bore) or a crack from a coolant hole or head bolt hole running to the edge of the fire-ring of the head gasket! Good luck 👍
Last edited by '78CorvetteS.A.; Jan 12, 2021 at 06:19 AM.
Thread Starter
Racer
Joined: Jun 2019
Posts: 390
Likes: 126
From: Franklin, TN
Thanks 78'CorvettesS.A. I did check the oil after running the engine for quite a while and it looked normal. Are you saying that the antifreeze will turn the oil milky very quickly? I am going to rent a block test kit today at the auto parts store. I will check to see if they have the other tools you mentioned. I will do almost anything to keep from having to remove the heads again!
Le Mans Master
Joined: Aug 2015
Posts: 6,090
Likes: 1,972
From: St. Charles MO
I think this is good advice: drive it for a significant period of time if you can and see if it stops tapering off. A few years ago I had to replace a turbo on a stock VW I owned. The original had let go and flooded the intake tract with oil. Even though I drained the intercooler of (a fair amount of) oil, it took 30 minutes of driving after I buttoned it up to stop smoking. Like you, I was convinced something had gone wrong with the repair, but someone gave me sage advice to wait it out and see what happened.
Thread Starter
Racer
Joined: Jun 2019
Posts: 390
Likes: 126
From: Franklin, TN
THE SMOKE HAS CLEARED!!!! Thanks to all you guys, especially RWDsmoke, for your advice and counsel. I took the car out of the garage and let it idle for a good long while, revved it to 2000 rpm for a good long while, then took it for a long 20+mile drive. At the beginning, I was embarrassed by the smoke cloud, by the end of the drive there was no smoke emitting from the exhaust. The car ran really well, no misfires, etc and the operating temp was below 200. I am declaring a victory!
Thanks again to all. This is a great site for helpful info.
Thanks again to all. This is a great site for helpful info.
