Still smoking after head change
#1
Still smoking after head change
I have a 4.0 OHV with 105000 miles that started pouring white smoke/steam out the tailpipe on startup in the morning and after sitting for a while duting the day. It would clear up after a few minutes of driving. Sometimes in the morning it would bog down and run rough until it cleared itself out.
I pulled the plugs and cranked it and coolant shot out the #4 cylinder, so i decided to replace the head gaskets.
Once I got it apart I found cracks between the valves on the heads at the #4 and #3 cylinder positions. They both looked like they were steam cleaned in those two areas.
So I ordered new heads and replaced them and the gaskets, put everything together, prayed, and started it up. It blew a crapload of white smoke for about 5 min(which i kind of expected for the first start) and then settled down.
The problem is that it is still blowing white smoke at start up, it is less than there was before but it still there and more than there should be for the temp outside. goes away after driving for a while.
I took the plugs out and cranked it after letting it sit overnight and no spray of coolant like before, so that is good.
Anyone have any ideas? Should I take everything off again and re-torque? How do you even check to re-torque with those bolts that you turn an extra 90 degrees? Can't just turn them another 90 can you?
I just want it to stop before my engine stops,
-Scott
I pulled the plugs and cranked it and coolant shot out the #4 cylinder, so i decided to replace the head gaskets.
Once I got it apart I found cracks between the valves on the heads at the #4 and #3 cylinder positions. They both looked like they were steam cleaned in those two areas.
So I ordered new heads and replaced them and the gaskets, put everything together, prayed, and started it up. It blew a crapload of white smoke for about 5 min(which i kind of expected for the first start) and then settled down.
The problem is that it is still blowing white smoke at start up, it is less than there was before but it still there and more than there should be for the temp outside. goes away after driving for a while.
I took the plugs out and cranked it after letting it sit overnight and no spray of coolant like before, so that is good.
Anyone have any ideas? Should I take everything off again and re-torque? How do you even check to re-torque with those bolts that you turn an extra 90 degrees? Can't just turn them another 90 can you?
I just want it to stop before my engine stops,
-Scott
Last edited by ssancinito; 06-13-2011 at 09:13 PM.
#3
I hope you torqued the torque-to-yield headbolts correctly. You need a torque angle gauge, or a torque wrench that offers angle measurements to do that right.
You have driven it quite a bit, right? Sometimes it takes a little while to burn out all the coolant in the exhaust. I hope you replaced your O2 sensors too, as coolant ruins them like nothing else.
You have driven it quite a bit, right? Sometimes it takes a little while to burn out all the coolant in the exhaust. I hope you replaced your O2 sensors too, as coolant ruins them like nothing else.
#4
I torqued the bolts in 3 stages with a torque wrench
25 ft lbs
55 ft lbs
then another 90 degrees
I may have wussed out and only turned them 80 degrees. was worried about the heads snapping off. Never used torque to yield bolts before, wasnt very trusting.
Think I should tear it back down and turn that last 10 deg?
And i did not change my o2 sensors. Any way to check them or should i just change them regardless?
25 ft lbs
55 ft lbs
then another 90 degrees
I may have wussed out and only turned them 80 degrees. was worried about the heads snapping off. Never used torque to yield bolts before, wasnt very trusting.
Think I should tear it back down and turn that last 10 deg?
And i did not change my o2 sensors. Any way to check them or should i just change them regardless?
#7
The angle specification is likely for 85-95 degrees, so if you're short by 5 degrees I really doubt that's an issue. As long as you torqued the bolts correctly as you said you did, AND the sealing surfaces are true and clean, you should be good.
You can use a scan tool to read the output signal the O2's are sending if you're curious, but they are definitely bad if coolant got into the exhaust. Coolant kills O2s fast.
You can use a scan tool to read the output signal the O2's are sending if you're curious, but they are definitely bad if coolant got into the exhaust. Coolant kills O2s fast.
#9
im going to put my money on a warped block. i would say that if you are 100% positive you did everything to install the head gasket properly the block is more than likely warped right where the heads where cracked and the new head gaskets are blown out again due to cylinder compression leaking out at those spots. if you have drivin the vehicle like this for at least a few days then i would pull the heads again and use a true straight edge on the new heads and block
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