I have coolant in my cylinders. Poor compression with compression test. Leak down test was not great, heard air leaking from the oil dipstick hole and valve covers. Its not a blown head gasket. A little discouraged, probably leaning towards a rebuild, been trying to diagnose it for a bit. Any last suggestions or guesses what it might be before I go for a full rebuild?

 

Sounds like a head gasket or cracked block and rings may be worn out.

 

Can you please elaborate how you know the head gasket has not failed? If you're getting coolant in the cylinders, a bad head gasket is a likely culprit. Next would be cracks in the block or head(s), but such cracks typically don't lose much coolant. Which leads me to further questions:

Which engine?

Which cylinders have coolant in them?

What were the results of the compression test, cylinder by cylinder?

 

it’s a 351w and I just replaced the head gasket. Did the same problem.

 

Did you have the heads checked out by a machine shop ? They could do a pressure test on them to find cracks or leaks.and verify they are flat.

 

Could you do me a favor and step outside, or at least stand by a window? I’m doing my absolute best to read your mind to understand what’s going on with your engine. I even took off my tinfoil hat, but am not getting a very strong reading.

The preceding was industrial grade humor. Just trying to get the point across that we’re trying to help but need your assistance to do so. I had asked a bunch of questions in hopes of working through the clues and getting your truck back on the road with minimal expense. So in the kindest, gentlest manner possible to ask, please answer all of the questions so we can help.

Back to your new head gasket. If you didn’t check the head and block for flatness, you may be spinning your wheels. It’s highly probable the head is warped enough so the new head gasket can’t seal properly. Or maybe the bolts are bottomed out against debris on the threads inside the block. Either way, the new gasket can’t do its job. Did that happen? Can’t tell from here, but it’s very likely.

Re: the other questions. That wasn’t me being a pest. I’m trying to get a feel for the overall condition of the engine, and whether a repair or rebuild is a better option. Sorry if I sound cranky. We’re all just trying to help but we can’t do it without your assistance.

 

Even if you don't have a machinist check the heads for cracks you can do it at home with a dye penetrant kit.

 

351w, as far as I could tell, basically all of them had coolant in them when I took off the heads (I drained the radiator beforehand). Compression results were around 110-115 on cylinder 1and 4. 120-125 on 2 and 3. All the others were 140ish except cylinder 8 which was 110 ish

 

I have not done that yet. That will probably be my next move

 

Unless you drain the block before unbolting heads, there will be a lot of coolant still in the heads to pour into the cylinders when you crack them loose. Even if you do drain the block you will still get an ounce or two of residual coolant. I sop the very small amounts of coolant from the cylinders with Bounty towels then spray in WD-40 and sop that out to prevent any flash rust.

Before unbolting the heads, either remove the block drain plugs to complete the draining or remove one of the lower head bolts and siphon off remaining coolant from each side.

 

So the engine failed the compression test and leak down test, so you replaced the HG's hoping those would fix it ? (maybe I'm reading more into post 1)

You have to rebuild the engine and heads. Tell the machine shop what you found. Yes, some coolant will get on pistons when you remove the head.

 

Does it have to be Bounty? Would other brands work?

 

I don't feel so bad peppering you with so many questions. I wish you had mentioned this earlier about coolant in all the cylinders, not just one or two. As the others have suggested, this is almost certainly spillage from when removing the heads. I bet we could have saved you a lot of aggravation.

Think about it. If coolant was indeed leaking into the cylinders while running, it would have quickly turned to vapor and escaped via the exhaust. You'd have to have a MAJOR gusher for coolant to remain a liquid in the cylinders while running. And then across all 8 cylinders at the same time?

Backing up some more, what were the symptoms prompting you to tear apart the engine? The compression numbers weren't stellar, but I bet it would have run okay like that. Heck, I ran my 351W for years with 7 cylinders in the 120-140 range, and one at 60. It ran fine like that, and I work the truck hard. It wasn't until two adjacent cylinders dropped to 30 that I pulled the engine. Even then, the engine was running pretty well with just a slight vibration at low RPM.

 

It's the quicker picker upperer!

Don't you watch TV?

 

Agree, Bounty or nothing... LOL

But I like to use my shop vac to suck coolant out of the engine. We would use vacuum to remove water from the items we used to pressure test at work.