mazdaverx7

As most of you guys know, I have been redoing the top end on my 86. I replaced a lot of large parts to include:

-cylinder head
-water pump
-belts
-all top end gaskets
-balance and crankshaft seals
-plugs
-cam box, cam, and seals
-thermostat and o-ring

I got it all together last night and got it started. It ran and idled well for a little bit. Got a couple of coolant leaks buttoned up on the block off plate on the water pump. Decided to let it idle a little longer and warm up as I was bleeding the cooling system. I continually checked the coolant temp gauge and it got as high as 3/4 during the bleeding cycle but the engine was turned off when I saw that. At that time I noticed that the cooling fans were not kicking on. I let it cool down for a little bit and started it again. As I was letting the engine idle I noticed that white smoke began coming from the exhaust and the engine began to stumble a little. I backed the car out of the garage and the smoke amount increased. I thought maybe it was just burning coolant off the inside of the exhaust. Took it up the road and it filled the roadway with clouds of white smoke. Temp gauge was half way during the drive and with the amount of white smoke bellowing from the car I decided it was time to return to the garage. I parked it and felt so dejected and disappointed. I followed every Clark's Garage procedure for install. Followed all torque settings, used all high quality parts, spent hours cleaning and making sure everything was perfect. for install. I went to bed last night and decided to sleep on it. I haven't ran a compression test yet or pulled any of the plugs to see if they are wet. I'm assuming that something with the head sealing is wrong. The gasket is not sealing properly I suppose. It almost seemed as if the coolant was being slightly pressurized by the compression from the engine. It took forever to bleed and didn't seem as though it was bled completely. Its just frustrating when I have tried so hard and spent so much time and money to make the car right. Makes me wonder where I went wrong. Any input would be greatly appreciated. In the mean time I will run a compression test and see what I have.

cruise98

Sorry to hear about your trials. Pull the plugs and do a leak down to figure out which cylinder is bad. You will have to remove the head at a minimum. Did you put a straight edge on the block to make sure it is not warped? Who did the head work for you?

mazdaverx7

I didn't straight edge the block. I had a very reputable shop rebuild and surface the head. I bought the car with bent valves. Guy's story checked out that the belt skipped and bent valves. Ended up being a bad cam gear and sheared woodruff key. So, since it wasn't overheated, I hadn't checked the block. Perhaps I should have. I will pull the head and redo the job if need be. Its not a terrible job and everything has been apart and will come right apart again. Plus, I won't have to redo the front seals ad water pump and such. Would just be a simple head job...hopefully.

Noahs944

I feel for you brother... time is something that once its gone its gone forever. But the good news is you have lots of new parts that are re-usable & you have a lot of familiarity with this car. I know it's hard but you will find the answer.

It has to be: unseated or damaged gasket, cracked head or block. Could it be anything else?
How else can the coolant get in the exhaust?

Sounds like a second issue with the switch or fans.

You would be best off to diagnose both things as best you can while the car is intact. Then pull the engine apart to confirm your suspicions.

What was the torque on the head studs? I know there is some variations. Perhaps someone can confirm yay or nay.

In the heavy duty truck world we might pressurize the coolant res (not exceeding the cap limit) and wait like 30 mins (usually plugging the block heater in to help raise the temp (towards operating temp) and then look for leaks. In this case the only place I can think to look is with a boroscope into the cylinder after you pull the spark plug... looking for coolant.

Just thought I'd offer another angle.

Don't worry. You will get it!

944Ross

Sorry for your troubles... Any milkshake? Did you fill with antifreeze or plain water?

raleighBahn

Nevermind. Just re-read. Sorry for your troubles!

Van

I use 1st stage, 15 ft/lbs; 2nd stage 90 degree torque angle; 3rd stage another 90 degrees torque angle.

I wonder if your head didn't sit properly on the dowel pins, or if there was some part of the old gasket still on the block deck or cylinder head. These have to be cleaned off very thoroughly.

When you take the head off, look VERY carefully for cracks in the casting - I've heard of that happening with other engines. This could let the coolant get into the combustion chamber even if the head gasket is good.

lart951

It's possible that when the PO bent the valves the block could have been fractured, those cracks are almost invisible and hard to detect.

mazdaverx7

I guess the plan is to first pull the plugs and see which ones are wet and do a compression test if need be. Then when I tear it back down and check I can check block and check the head in those particular areas that I find to be faulty. I may take the head back to the machine shop and have them check for any warpage or any defects at all. If the block turns out to be bad then I guess I will source a good used block and reuse my rotating assembly and install new rings and rod and main bearings.

mazdaverx7

Van, how long are you waiting in between each torque sequence?

Van

I do them all in a row. No wait time between.

mazdaverx7

Ok. I have heard that you should wait some time in between each torque cycle. Perhaps that is not a critical step in the torque process.

Noahs944

No, but torque sequence (something close to factory if not exact) is important. Also when removing the head & gasket, do it with extreme care, so you can inspect the gasket for any flaws, scratches. (Just like when you install new gaskets-inspect them before hand).

StoogeMoe

Hmm...interesting on the torque angle method. I followed what was in the Factory manual (even though I think it mentions both). Three stage of 20 - 50 - 90 Nm, with waiting in between. I think you're supposed to wait around 10-15 minutes between each stage, but I was impatient, and only waited a few minutes. No problems after 100k miles.

Van

In later parts of the FSM (e.g. turbo section) the head gasket torque was updated to 20 Nm (15 ft/lbs) then 90 degrees and 90 degrees.

That's actually a more accurate way to do it. Because the thread pitch is a known quantity - M12x1.5mm - a half turn on the nuts after snug (initial torque) will put 0.75mm of stretch in the head studs. If all head studs are the same material and same diameter, the same stretch will make for a very uniform force. This eliminates any friction drag between the nut and washer or washer and head from the equation.

Another thing to mention, when you take a head off, you want to do it in the reverse torque pattern.