Well, I've got a 1988 E250 with a 5.0L V8 that had the coolant freeze in it....
An expansion plug(aka freeze plug) popped out on each side....

It was the plug on both sides that's tucked above the motor mount and under the exhaust manifold where you've got no room to work without removing one of those items... I chose to remove the motor mounts, and freeze plug replacement was completed successfully.

Now, however there is another issue. I've got a stream of bubbles coming up in the radiator while cold. The van starts and runs well, the oil and coolant both look fine with no obvious cross-contamination. There is no smoke apparent at idle, but a small quantity of white smoke at higher RPMs.

I'm wondering if the head gasket is messed up, or if it's the block/head that's cracked instead. I'm inclined to think that since the defect doesn't seem to be producing too many big symptoms usually associated with serious damage or even a really bad headgasket blowout (ie coolant in the oil, oil in the coolant, huge clouds of smoke, very poor running, etc) that maybe I got lucky and it's just the gasket.

I know that these old iron heads and blocks were considered to be pretty tough. Hopefully I don't have a "go get a new engine" issue here.

My question is..... Anybody have a perspective on the likelihood of headgasket damage vs a cracked head/block from this kind of scenario?

Also, is the headgasket and the cylinder head itself the same part on both sides of the engine. IE there's only one part number??
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I had bought the van on the spot during a chance encounter with a stranger who was "down on his luck" and needed money "to get Pop in to see the doctors" etc etc etc and I'm now having the fun time of getting to discover all the issues which were not immediately apparent like a pinhole leak in the heater core which takes a couple hours to fill the hvac housing enough to leak onto the floor (which was why they had watered down the antifreeze)

My crucial mistake was looking in the radiator and seeing/smelling that green obviously antifreeze containing liquid and not realizing that it had been excessively watered down.

I'm looking at pulling the engine for a total rebuild/overhaul in a month or so, but I need it on the road for the next couple weeks even though it won't see 500 miles between then and now. If I replace the headgasket and the issue is still present, it will be time to sell the van and get my money back out of it while it's still running well, to someone with the interest in replacing the engine. I mainly bought it because it has a custom high-top which along with the particulars of it's setup (panel van, auto tranny for the wife, 302 engine is well matched for our use) is perfectly suited for what we needed the vehicle for.

It has a very recently rebuilt transmission in, and I was just planning on rebuilding the engine since before I bought it. I only paid $600 for the thing, so I figured that even if I spent $1000 in parts I didn't mind doing the labor in order to get the thing totally up to scratch for our use.

Thanks a lot guys!!

 

When coolant is allowed to freeze in an engine, I'd expect a block to crack before the head. Wouldn't usually suspect head gaskets, if filled with "green obviously antifreeze containing liquid". Only if coolant was rusty brown & smelled of exhaust.

The "scenario" that would interest me is just how "excessively watered down" the antifreeze was & how cold/how long did the E250 get to sit & freeze? Weak antifreeze is often enough to create slush & stave off freezing solid, if not to cold, for to long.

Having "freeze plug(s) popped out on each side" means ice expanded inside block/water jacket. Suggests that antifreeze was very "watered down" & E250 sat in sustained freezing temps.

IMO needing to replace "popped" freeze plugs, b/c of a wicked Cold Snap, is a bit of a gamble. Ice expansion exerts quite a bit of force driving out freeze plugs installed 25 years ago. They've saved many blocks, but not all of them.

Did you see the 'bolt in place' replacement freeze plugs? You can often install these expanding plugs quickly in difficult spots.

 

When I got the van I removed the radiator cap and checked to make sure that there was the proper level of coolant. It was at the proper level and it was green like antifreeze and smelled right, and it honestly didn't occur to me "Hey, I wonder if this is watered down??"

It did fine for a week or two of use, then we had a few days where the nights were down in the 10-15 degree Fahrenheit range over and over, and I hadn't used the van in a few days....... The stuff froze solid, popped the plugs.

I'm aware of the rubber expansion plugs, but in the particular location that I'm looking at, I'd have to remove the motor mounts or exhaust manifolds in order to install them anyway, and they're more expensive than the metal ones, so they didn't seem like an ideal option.
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I am going to try and find the time tomorrow to replace the head gasket on which ever side is having the issue (OH HOW I HOPE that it's only one side)
as determined by my compression gauge.

While I've got it off, I'll inspect the head and TRY to look in the block to see if I can identify a crack.

If I replace the head gasket and the problem still exists, or if the compression reading doesn't identify a weak cylinder then it'll be time to find a replacement engine at the pull-a-part to rebuild.

I am hoping so much that this is just a head gasket issue and not a cracked block/head............... I thought it might be a good sign that the oil and coolant look fine and that the only symptoms are exhaust going into the coolant and a little white smoke at high RPMs....

Who knows.........

I really appreciate the advice

 

Oh, and just to clarify..... There is definitely a smell of exhaust in the radiator, it bubbles up vigorously while the engine is running if you remove the cap.

 

what i would do is use a leakdown tester, but turn it up until you get air in the coolant. if a leakdown tester isn't available, rig something up to connect a supply of compressed air through a regulator and a valve into the spark plug holes (one at a time), and see which one blows bubbles.
its usually much easier to get definite answers this way than using a compression tester

 

Hey dustmote, I would have bought that one to...LOL frezzing all those heater lines and hoses plus a bad heater core....I would think the system is (suckng air) causing the bubbles, maybe? If its running good (not missing) a tear down would be the last thing on my list.....Good luck!

 

Ok, well heres the update!

I went out today and warmed the engine up in order to do a compression test on it. As I warmed it up, I left the radiator cap off in order to see whether bubbles came up....

There were no bubbles at all..... As it cranked, idled, I opened the throttle, and still not a bubble..... It got up to normal operating temperature and the thermostat opened, and then the coolant level slowly started to rise until it began to come out the cap, but there was still no bubbling at all.....

There was no smoke either, except for the normal initial puff of light blue smoke that it always puffs when I start the engine after it's been sitting. It stops after a couple seconds as usual.

I'm wondering now what's going on?
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I had to let the engine cool just enough that I could bear to remove the plugs and screw in the compression tester without burning myself on the exhaust manifolds.... I realize that the compression test is supposed to be performed with the engine at normal operating temperature, but there is simply no way for me to do that with the engine in the vehicle.... I'd burn myself like crazy trying to get all those plugs out.

The compression readings were 160 PSI plus or minus 10 PSI for seven of the eight cylinders.... One of them however was only 90 PSI.

I waited another twenty minutes or so for the engine to cool a bit more, then tested again and found the readings for the seven "good" cylinders to be basically unchanged, BUT the 90 PSI weak one had gone up to 105.

I'm going to pull the head on that side tomorrow (Thank the Lord it's the driver's side and easy to reach everything!!!) and inspect the head and replace the gasket to see if that cures it's low compression and questionable status.

I unfortunately may or may not be able to inspect the inside of the block very well at that cylinder, since it's the one located farthest from the cabin and it's engine cover, where I will be working.

I'm hoping that changing out that head gasket will straighten out this issue....
I'll let yall know how it goes.

If anyone has anything else helpful or interesting to say, I'm all ears!

 

Also, I'm thinking that the ~160PSI readings may not have been quite that high if the engine was fully hot like it's supposed to be, in either case, seems like good compression all around except for the one trouble spot.

The spark plugs all looked good too except for the light coat of oil, presumably from old valve stem seals..... This engine doesn't consume oil, nor does it consume coolant at a noticeable rate.

Just thought I would add that info, in case it rings any bells for anybody.