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I just replaced the head gasket on a 2000 Volvo S80 2.9l that was driven overheated until the engine stopped (stalled or seized, I wasn't there). Engine overheated because a radiator hose slipped off. When it gets up to temperature, I'm still getting white smoke out of the exhaust (though, not nearly much as before the gasket replacement). Other than white smoke coming out of the exhaust, the car seems to run and sound fine.

Took the head to a machine shop to have it milled and checked for cracks. They milled off .020 inches and said they checked for cracks and found none. (I have never used this machine shop before, and don't know anyone who has used them. It is just the only automotive machine shop in the area. They did seem careless by just throwing head up on the counter on the freshly milled surface.)

I checked the block deck by setting a Harbor Freight square on it, and trying to slide a feeler gauge of the specified tolerance under it. Seemed good, but I've never done this kind of stuff before.

I torqued everything to the specifications, of course.

I only visually inspected the cylinder walls with the second piston at TDC. I'm not equipped to pull an engine, so I figured I'm screwed if anything in the bottom end is messed up anyway. Didn't see any cracks. Not sure what else to look for.

The engine is aluminum with sleeved cylinders.

I can only think of these causes of antifreeze burning:

  1. Improper head gasket installation.
    • Possible I guess, but I torqued everything to specifications, and followed a factory service manual.
  2. Cracked head.
    • Had an automotive machine shop check it for cracks. Not really sure how they did that, or if they were thorough.
  3. Warped block deck.
    • I checked for warpage in a very non professional manner. Seemed OK.
  4. Cracked block and sleeve.
    • This is the only way I can think of for antifreeze to enter a cylinder from the block. But, is this very likely to happen? Sleeves are very strong, and the sleeve would have to crack in the same place as a crack in the block adjacent to a water jacket, correct?

Any other possible causes of steam coming out of the exhuast? What causes are the most likely?

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  • How many miles did you put on after the replacement?
    – method
    Oct 23, 2016 at 3:59
  • Maybe 5-10 miles.
    – user43704
    Oct 23, 2016 at 4:34
  • 1
    Maybe there is still some water in the system from the leak? try to take it for a drive and see if it still smokes
    – method
    Oct 23, 2016 at 4:51

1 Answer 1

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My best guess is ... Did you use new head bolts when you put the head back on?

The torque sequence on the head calls for a multi-staged approach of:

  • 1st pass: 15 lb-ft
  • 2nd pass: 44 lb-ft
  • 3rd pass: 130°

The third pass being in degrees indicates a Torque to Yield (T2Y) bolt is being utilized. These bolts are a single use items and require replacement. If you do not replace these bolts with new ones, the old ones will fail at some point. More than likely, the head gasket has failed again and quite possibly the head has become warped again as well.

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  • Yes. I am no pro, but I know most head bolts in the last 20 years or so have been torque to yield. Followed the procedure in VADIS, can't remember if it was 2 or 3 passes, but I remember the final pass was angle tightening (did this by eye though). Car does not overheat, so I don't think it would warp again.
    – user43704
    Oct 23, 2016 at 15:22
  • @user43704 - Question remains: Did you replace with new? And "by eye" is not good enough. This means all of your torque specifications will be different. Torquing the head correctly is probably the single most important thing to accomplish when doing this work. Do it wrong and you end up with ... well, a leaking head gasket. Cannot stress this enough.
    – Pᴀᴜʟsᴛᴇʀ2 ♦
    Oct 23, 2016 at 15:48
  • I chose this answer because it lists another possible cause of failure. But for me, it turned out it was just coolant leftover in the exhaust or something like that. After about 20 miles of driving and a few heat up/cool down cycles, steam stopped coming out of the exhaust.
    – user43704
    Oct 27, 2016 at 2:02
  • @user43704 - You should have just put your own answer and selected it! You do have the ability to ask/answer your own questions. This would not hurt my feelings at all :o) I'm glad it was something simple!
    – Pᴀᴜʟsᴛᴇʀ2 ♦
    Oct 27, 2016 at 9:45

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