head gasket issues

Post by **justang1997** » Sun Dec 02, 2012 4:58 pm

So I just put a new head gasket on my car. Its a 1997 chevy cavalier that we bought just to drive to work and stack miles on. It was getting great milage and running very well and then the timing chain broke. I had a shop replace the timing chain. It had a bent valve in cylinder 3 so I took the head off and took it to a machine shop. They replaced the valve and cleaned the head. I put it all back on the car last night with new gaskets all around and new head bolts properly torqued.

Started the car and got white smoke and coolant on the oil dipstick. Now here is my question.
The one thing I neglected to do was chase the head bolt threads in the block with a thread cleaner. Could this have caused my head to not be torqued down correctly to the point coolant leaked across the gasket and into they cylinders?

Im taking the head off all over again and chasing the threads and using a new gasket. Hopefully it seals up this go around.

Post by **etownguy** » Sun Dec 02, 2012 5:04 pm

Could but very unlikely. Either something left on the block holding a gap in the gasket. Head gasket put on backwards ( sometimes it is easy).

Post by **justang1997** » Sun Dec 02, 2012 5:17 pm

gasket was labeled with up side so probably not an upside down gasket. I cleaned the engine surface pretty darn good. I oiled the cylinder walls really well too. Maybe some oil got on the surface of the block where the gasket went and I didn't see it?

Post by **Ian** » Sun Dec 02, 2012 5:45 pm

Is there a possibility that the car may have been over heated to where it may have warped the block or head(before the timing chain or after)

Did you check the block surface when you had the head off?

Also what did you clean it with?

Post by **Ulwembu** » Sun Dec 02, 2012 5:49 pm

What is possible is that some coolant and/or oil got into to the thread holes of the cylinderhead bolts. This will let you torque the bolts but as fluid can't be compressed, it won't pull the head down enough. I've seen this only once but it is a possibility.

Post by **Toddstang** » Sun Dec 02, 2012 6:06 pm

Ian wrote:Is there a possibility that the car may have been over heated to where it may have warped the block or head(before the timing chain or after)

Did you check the block surface when you had the head off?

Also what did you clean it with?

This.

Post by **Ian** » Sun Dec 02, 2012 6:49 pm

There is the possibility that depending on what you cleaned the block with if it was abrasive enough that you may have created high spots and low spots on the block.

Looksdeadtome · Post by **Looksdeadtome** » Sun Dec 02, 2012 7:03 pm

You should have measured the deck to make sure you don't have any block warpage. Blocks will and can naturally warp over time and miles. What has probably happened is you have put a now true head on a uneven deck height causing a leak by somewhere. Hopefully it is just a cleaning issue but you will know when you pull it apart. Good luck!

Post by **justang1997** » Sun Dec 02, 2012 8:55 pm

Ian wrote:Is there a possibility that the car may have been over heated to where it may have warped the block or head(before the timing chain or after)

Did you check the block surface when you had the head off?

Also what did you clean it with?

I cleaned it with rags and brake parts cleaner. When I got the car back with the timing chain fixed it ran fine on all cylinders except for cyl 3 with the bent valve. It had no coolant in the oil. It has not overheated so im pretty certain its a gasket issue, I just need to know where I screwed the gasket up. Or maybe didnt get the torque right on the head bolts due to dirty threads. IDK. Its gonna bug me all week cause I cant work on it any more til next weekend.

Post by **justang1997** » Sun Dec 02, 2012 8:57 pm

Looksdeadtome wrote:You should have measured the deck to make sure you don't have any block warpage. Blocks will and can naturally warp over time and miles. What has probably happened is you have put a now true head on a uneven deck height causing a leak by somewhere. Hopefully it is just a cleaning issue but you will know when you pull it apart. Good luck!

At the machine shop the head was only cleaned and valve fixed and valve guide checked for damage. There was no resurfacing of the head needed.

Looksdeadtome · Post by **Looksdeadtome** » Sun Dec 02, 2012 9:38 pm

I would say that is where your problem lays then. I am not claiming i am a master engine builder, I have built a lot over the years, mainly race applications, but i have never put a motor together without checking the deck height or resurfacing the heads, reason being because you run into problems like you are having. Do you know if they checked the head surface? At the least it will need a resurface and check the deck height on the block, if not you will risk the same problem if all you do is put a new gasket on it. if the deck is checked/fixed if needed and head resurfaced your problems will probably go away. Good Luck man

Post by **Laurino** » Sun Dec 02, 2012 10:52 pm

Ulwembu wrote:What is possible is that some coolant and/or oil got into to the thread holes of the cylinderhead bolts. This will let you torque the bolts but as fluid can't be compressed, it won't pull the head down enough. I've seen this only once but it is a possibility.

It typically cracks the block before that happens.

Did you do the correct torque sequence? If it wasn't done correctly it can warp the head.

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Post by **etownguy** » Sun Dec 02, 2012 11:14 pm

Is the Motor a open or closed deck? Meaning are the cylinder walls open all the way around with coolant. Or is the top surface closed off with just holes for coolant and oil passages?

Post by **justang1997** » Mon Dec 03, 2012 8:18 am

I followed the torque sequence and torqued it down in 3 stages

It has passages drilled for oil and coolant but the right side is very open where the pushrods go.

There is what appears to be a coolant passage on the side where the intake comes in but this intake does not have a port in that location. So the intake gasket closes that port off. I guess that opens the possibility off the intake gasket too.

Post by **Jff24Gordn** » Mon Dec 03, 2012 8:27 pm

You would figure that someone who owns mustangs would be good at being a mechanic by now. :llama:

Post by **325MOUTguru** » Mon Dec 03, 2012 8:30 pm

I clicked on this thread thinking it would be a LR thread. :llama:

Post by **Ulwembu** » Wed Dec 05, 2012 4:46 pm

Laurino wrote:
Ulwembu wrote:What is possible is that some coolant and/or oil got into to the thread holes of the cylinderhead bolts. This will let you torque the bolts but as fluid can't be compressed, it won't pull the head down enough. I've seen this only once but it is a possibility.
It typically cracks the block before that happens.

Actually, it doesn't. I worked at an engine overhaul company so I kinda know what will crack a block or not. This normally doesn't.. If it does, more is going on (loose dirt in the threads for example which works itself between the bolt and the block).

Friend of mine had my above example happen to him on an engine of a Range Rover. He couldn't understand it untill I took the head off again and cleaned out the thread holes which had water/oil in them. Put everything back with a new head gasket and all was fine. Before taking the heads off I asked im if he cleaned outthe holes and he told me he didn't. Checked the bolt head rings and showed him some thhat were loose under the bolt. The tried to torque them down but they were at the torque force they should be at.
My friend did several head gasket changes after that to other cars he owned and he never made that mistake again

Post by **Laurino** » Wed Dec 05, 2012 5:19 pm

I don't doubt you a bit. But in my experience I've seen it happen mostly to aluminum blocks. I've also heard on many occasions of it happening to blocks like the 4g63. Which is in my car. I've always cleaned the holes before installing studs, or bolts. It just lessens the chance of a failure in any manner.

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Post by **justang1997** » Thu Dec 06, 2012 2:17 pm

Hopefully that's what my prob is. Just take head back off and clean the threads.

Should I have to use new head bolts? I mean I just bought these last week and put them in. I'm replacing the gasket just to be sure but the bolts are $27 and I'd hate to buy them again too. Maybe I should just to eliminate all possible problems.
Its my understanding that the torque to yield bolts have to be replaced after they are torqued but is that true if the engine hasn't even ran long enough to warm up?

Post by **burn360** » Thu Dec 06, 2012 4:22 pm

Yeah I think u have to replace them

Post by **Ulwembu** » Thu Dec 06, 2012 6:06 pm

Depends on the type of bolts. If they are designed to stretch when torqueing, they need to be replaced.

Post by **justang1997** » Sat Dec 15, 2012 2:46 pm

Welp. I got it fixed. Hot new gasket and new bolts. All the threads seemed clean but there was a significant amount of fluid in the headbolt holes. Took forever to get out using rolled up paper towels but I did it.
Tightened it all back down and checked it. I was then leaking some from the thermostat housing. Tightened it up a bit and promptly broke the housing.
Just got a new one tho. All fixed. Oil changed, and getting ready to do a second oil change to make sure all the coolant is out of there.

Post by **JustShootIt** » Sat Dec 15, 2012 3:07 pm

Good deal....

Post by **etownguy** » Sat Dec 15, 2012 6:10 pm

Next time use a air nozzle and blow the liquid out of the holes.

Post by **justang1997** » Sat Dec 15, 2012 6:18 pm

Thought about canned air. I don't use air tools and don't have a compressor yet.

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