Hey guys!

New to the forum but I thought I would post a thread on what I think is a fairly odd problem.

(note: my 66 delta ran and drove quite well before all this)
a few weeks ago I finally decided to pull the heads off my daily driver 425 delta 88. I took the heads to a local reputable machine shop to get them freshened up. According to them, they were quite tired. Valves, Valve seats, guides, mating surface were all worked on. While waiting, I scotch brite and razor bladed off the old gasket from the block making sure it was quite clean. The shop called me and I got them back about a week later and they looked great. I painted them up, gathered some new gaskets (head, intake, exhaust) and started reassembly. I was sure to use fel-pro head gaskets and new arp head bolts, torquing them in sequence to 70 ft lbs as recommended by arp. As for the intake, New fel pro 2 piece gaskets with some rtv around coolant ports for good measure. (I used the same intake gaskets as the last time I replaced them a couple years prior) after putting it back together, double checking the head bolt torque specs, I finally was able to start her up. It spun to life very quickly and so I was already impressed.

it was at that moment, I noticed a large cloud behind the car. My heart sunk. White smoke pouring out the tail pipe! It was really puffing it. Between the green puddle on the ground and the sweet smelling smoke, I knew i had a coolant leak. One thing I noticed was after letting it sit for a bit and then starting it again there would be no smoke out the tailpipe, but if I let it run for a few minutes it would gradually start puffing the white death out the tailpipe again. Defeated and puzzled, I started going
over the engine.
When I Pulled all the spark plugs, none of them looked white or very clean as evidence of coolant in the cylinders. However, the dipstick showed a murky color in the oil indicating coolant. When I opened the rad cap there seemed to be a lot of air pressure in the cooling system. (Could this be because of air pockets?)

All of this told me I should take the engine apart again. I knew I was looking for an Intake mani coolant leak or a head gasket leak. Pressure in the rad would have me leaning toward the head gasket failure. I tore the block apart again. I removed the intake and the heads and for the life of me It did not seem like anything was out of the ordinary. I decided to replace both intake and head gaskets just in case I had a faulty one or something. I bought new fel pro performance head gaskets and intake gaskets. Upon re-assembly, taking the same steps as the first time, everything went together quite smoothy. I changed the oil, and even left 90% of the coolant out of the engine. Again, same problem. I fired it up and within minutes It felt like a group of teenagers were hot-box vaping my entire shop. Coolant out the tailpipe, white smoke, murky oil again, rad pressure.

I decided to inspect the mating surface areas on the head and block. Using a machinist ruler, it did not seem obvious to me that the freshly resurfaced heads or block had any kind of warpage. I could not see any light gaps through the surface that the ruler was on. I was also using a .006 feeler gauge that was not even close to fitting in any gaps. I will try a .002 thou feeler tomorrow.

Im sure somebody will have a solution.
if anybody has any opinions or questions please feel free to reply!

Thanks,
Troy

 

I am going ask a few things.
1. Did you spill antifreeze down the exhaust manifolds when you removed the heads the first time ?
2. When you removed the intake manifold, did some antifreeze get into the valley and flow down into the oil pan ?
3. How much antifreeze was on the floor ?
You may have got the exhaust system hot enough to starting cooking antifreeze in the exhaust system from the first time you removed the heads.
You may have spilled antifreeze into the oil when you cracked the intake manifold loose.
Radiators are designed to be pressurized.
Look at the exhaust manifold holes and tell me you capped those before you removed the heads.
You may have done everything right to put it back together.
............Just my two cents worth.



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Thanks for the quick reply!

just a few things to add:

I changed the oil after re-assembly to avoid possible coolant in the oil during startup.

I did not cap off the exhaust manifolds. Would this cause thick white smoke for 10+ minutes out the tail pipe? I remember seeing I did spill abit in there when i took the heads off. However it seemed to be much worse when I revved it up and it seemed to come and go occasionally if I would let it cool for a bit. How long do you think it would be smoking if there was a small amount sitting in the manifolds upon re-installation?

Thinking of having the block surface decked.

thanks

 

Change the oil again, just to make sure there was leftover coolant in the oil pan. It will take a while to blow all the coolant out of the exhaust system. Whatever coolant was in the pipes probably got blown thru the mufflers when it started, only to get stopped where the exhaust goes up over the rearend. I wouldn’t be surprised if it takes several miles of highway speed to get the exhaust hot enough to burn all of it out.

 

A1. And you checked the oil before you started tearing things apart ?
B1. I am guessing the antifreeze went down the exhaust manifolds and into the exhaust system. How much went down and how long it takes to boil it out is a guess. More comes out if you rev it up because more heat and exhaust are going through. If you let it cool for a bit, it condenses in the exhaust system.
C1. Decking the block won't hurt anything.

I think you got panicky when you saw the smoke and didn't realize the antifreeze got in the exhaust. After that, its trying to determine IF something got into the oil and filter before you started cracking things loose.
Others will chime in with wisdom and guidance.

 

If the plugs are clean, I’d be willing to bet your coolant leak into the oil pan is intake manifold gasket related. If it was head gaskets, I’d expect to find spark plugs with a greenish tint.

 

Compare all old gaskets to new for hole alignment.
Pressure test the cooling system and just use water for the first warm up.

Since none of the pistons look steam cleaned it is probably residual coolant in the exhaust.

Can you see coolant in the intake ports on the heads? If not that’s another good sign.

Good luck!!!

 

Don't put rtv on Fel Pro head gaskets, they are teflon coated. Your block surface doesn't look real good; perhaps scraping with a razor blade in a holder will help, or get it resurfaced very smooth. Use a new Fel Pro if that head gasket is your choice. If they dry out, they can leak through the filler material.

 

He's talking about RTV around the coolant ports on the intake gasket. And yes, I'd use FelPro blue head gaskets - they're somewhat more forgiving as to surface condition of the deck.

 

No RTV and torque to the factory spec of 85.

 

No coolant in the intake ports.
The pistons and spark plugs show no sign of steam cleaning.
head gaskets show no obvious signs of leaks

The only thing that confuses me is the amount of smoke that was out of the tail pipe. If it was residual I could see how it would be puffing a small amount. This was THICK white smoke with carbon black coolant on the ground under
the tail pipe. If it was residual, how long would it take for it to clear out?

thanks for the help guys!

 

I'll take a SWAG at this. Consider the interaction of water with carbon, or a substance made primarily of carbon molecules - not much interaction going on there. They will repel each other rapidly. And, the water will evaporate readily whereas the carbon requires enormous amounts of energy to vaporize - first having to go from the solid phase to the liquid phase to the gaseous phase (and, a very slow process, indeed).

On the other hand, consider a glycol (whichever you choose (propylene glycol or ethylene glycol). A glycol is oily and more viscous than water (in the liquid phase). While an alcohol will evaporate faster than water, a glycol (a double carbon double -OH group alcohol) will also adhere to (interact) with carbon compounds. The exact type of carbon compounds which you'll find in a muffler and coating the interior sidewalls of the entire exhaust system (including the engine). Therefore, IMHO, the glycol is going to hang around for quite some time before it is completely burned (enthalpy of evaporation) off. It'll hang onto carbon compounds with ease and it will break down carbon compounds. So, I'm thinking it will take awhile to burn off any residual glycol in the system and I wouldn't worry about the white smoke puke and the dripping carbon exuding from the tailpipe. It will clear eventually, just don't expect it to clear rapidly.

 

Best guess. Fifteen or twenty miles running at 65mph could be longer, could be shorter. Variables: (1) Type of antifreeze (propylene vs ethylene) (2) 50:50 mixture or otherwise (3) age/condition of exhaust system (mufflers hold a lot of carbon soot) (4) heat of exhaust system. Get that sucker toasty hot to remove as much as possible as soon as possible.

 

DD,
This brings back memories of a head gasket job I did on a mid 80's Olds Quad 4 engine. I ended up having to drive it almost 40 miles on the highway before it finally cleared up.

What head gasket did you use ?? If your bolts are the 7/16 ones then the 70 lbs is correct with ARP lube.

 

How much smoke did you have out the tailpipe? Did it gradually clear up? Was it worse when you revved it?

 

Enough that I was almost convinced I did something wrong or used the wrong gasket. It smoked terribly but was running fine so I drove it around a loop I had for breaking in new engines and by the time I went about 30 or so miles it finally was clean.

Did you use a metal head gasket ? Only reason I ask is because of the Copper Coat.

 

There are two ways coolant could get into the exhaust:

Spillage during disassembly, or
through the exhaust ports of the heads due to a crack or head gasket sealing issue.

If the exhaust ports are dry showing no signs of coolant then it is very likely residual spillage. How long does it take to burn off? A lot longer than you would expect especially at idle and the clouds can be significant.

Don't inhale that burning coolant, stay clear of the fumes.

Good luck!