97 K1500 5.0 Coolant in Cylinder 1

[Trig]

Looking for some advice as to next steps on this thing - don't want to do something out of haste that I'll regret later.

Truck has been sitting for probably 3 years now after a front end rebuild went south after a shop mangled my LCA's replacing the bushings. Soured me on the project so it sat longer than it should have. When I finally got it back together I was careful to follow advice found here in various threads surrounding fluid changes and the usual suspects. I also removed all the plugs and squirted fresh oil in all the cylinders followed by hand cranking the engine prior to starting it up. Started up fine, maybe a little hesitation/rough running. I pulled codes and found some misfires (couple of cylinders and the various misfire code I believe). I didn't think much of it considering it hadn't ran for a minute so I cleared and started again and let it run for 30-45 minutes to come up to temp and then pulled codes again and there was nothing confirmed nor pending. Awesome.

Started a DIY alignment to get it close enough to drive to a shop, so it sat for about a week I guess. Tried to start and just a umphh sound like it wasn't getting enough amps. Troubleshooted all that mess and found corroded connections everywhere, along with an oil soaked starter that I replaced. Started up good. Sweet.

Go to back it out of the driveway, and find the brakes going to the floor. Think well it probably needs some fluid so I top it off and it goes to the floor again. F***. Get out, look underneath and see the puddle under the rear end. Replace all the brake lines with the 90-10 CuNi. Good deal.

So, it's probably been 3-4 weeks at this point since starting it last. At some point during this time I pop the radiator cap just because and find it an inch or so low - barely covering the tubing inside. I top it off and figure no biggie it's just air working it self out or whatever. Open it again a week later maybe and same thing, again I top off. Now, I somewhat remember this being an issue going back a ways but I never put two and two together as it's always held proper temperature and the coolant/oil has always looked normal. To this day that holds true.

Fast forward to this week, I'm at it again only to find it won't crank again. Starter makes a god awful noise when I hit it and I immediately stop. Give the motor a look see and try again same thing. I figure maybe it needs shimmed so I drop the starter and look at the flexplate and notice teeth marks but no broken teeth. I add a 0.030 thrust washer to the outboard bolt as that's all I had that was precision and in the ballpark and try again and get the familiar "umpphh". Solenoid pops but can't turn over.

I check the battery connections as the side posts are suspect on mine and find I can move the positives around a bit. I already stripped back the insulation from those as well as the battery terminals as they were in the way. Effed design but whatever. I took some 3/8 ss bolts I had and cut the heads off and bottomed out the studs, locked with a nut and then attached the leads with another nut. Very solid now. Btw, battery checked out fine during the diagnosis earlier.

So, before hitting the key I figure I'll try and hand crank to make sure. It moves but then gets really tight and won't move anymore. I figure compression as I didn't take the plugs out. Remove all the plugs and when I get to the #1 cylinder coolant starts pouring out when I remove the plug. 1/4 -1/2 cup? S***. Likely why it wouldn't crank - coolant hydrolock I believe I've seen but mainly by fuel from the threads I found.

I took a break, googled a bit and don't find a whole lot except probable head gasket. I hand cranked it again and it rotates fine - I noticed a few more TB of fluid came out when I did this. Rotated another revolution and no more fluid. Radiator level is again back to barely covering the tubes and holding.

Looked around the engine bay and noticed coolant sitting in the spot underneath the upper cooling connection where the thermostat is. Hard to see in there but it was wet and shiny like coolant I believe. I believe that is where the intake manifold interface is as to the right of the thermostat housing I can see a big wad of goop where the interface is like RTV excess maybe. I had the intake manifold gasket work done by a shop probably 12 years ago/24K miles. That excess looks odd to me but maybe that's how it's done I'm not sure.

She's never overheated and I've never noticed fluid on the ground or steam from the engine bay or tailpipe. Again, that was prior to it sitting for 3 years and since then I've described above.

Any thoughts/suggestions on where I go from here would be greatly appreciated. From what I gather compression testing is the next step, I'm mainly curious as to what's possible with the intake manifold issue and the coolant levels always dropping down to right above the tubing, which could have been going on for much longer than I think. Or maybe that's simply not possible and/or a separate unrelated issue and I should ignore those pieces of information for now.

Sorry for the lengthy post - last thing I want to do is waste people's time with incomplete information. Let me know if anything else is needed and I'll respond asap.

Regards,
Chad

 

[Schurkey]

Vortec intake gaskets were a big problem when these were new. The gasket set has been updated at least once and maybe more than that. Modern intake gaskets should be OK.

Even if the intake gasket leaked, it'd be unlikely that it'd fill #1 with coolant, rather than puking it on the ground or into the oil.

Probably not intake gaskets.

A faulty head gasket is pretty likely. A cracked casting is a real possibility. You won't know for sure until you take it apart.

You could pressure-test the cooling system. What that's going to tell you is that you've got a coolant leak into #1. You already know that. I wouldn't bother--although it might tell you that you've got more than one coolant leak.

Similarly, you could perform a cylinder leakdown test. What it'll tell you is that you've got a pressure leak into the cooling system. You already know that. HOWEVER, you might find that you've got leakage past the intake or exhaust valve, or excessive leakage past the rings. That might change your mind about doing the only thing that makes sense--ripping the head off to inspect for head gasket problems or a cracked head or cracked block.

If you perform a cylinder leakdown test on all eight cylinders, and they're all good except for the one known coolant leak, you wouldn't have to remove the other head; and you might not need a valve job on the head you do take off. Maybe you get lucky and just replace the one head gasket and you're good-to-go. Maybe you have to plane the head to get it flat again, replace the gasket, and good-to-go. Maybe it's cracked, or maybe the block is cracked. Maybe you have more than one problem--bad gasket, AND cracked head. Or something. It's possible--not likely--that the hydrolock bent the connecting rod. Or broke the top ring. Or distorted the piston so that the ring-land pinches the ring.

But you won't know until you take the head off. Be sure to turn the crank so you can compare #1 piston height at TDC with the other cylinders, (to see if the rod is bent) and look for signs of ring problems. (Good luck.)

And if one head gasket popped...the other has the same mileage on it; in the same driving conditions. "I" would replace them both.

If you remove the distributor to remove the intake manifold, you'll need a scan tool to get it back in proper synch with the crankshaft sensor.

You should probably flush the cooling system including removing the block drains--a regular plug on the left side, I think; and the knock sensor on the right side. The knock sensor needs thread sealant and a specific torque to reinstall. A regular plug should have thread sealer, and reasonable tightness. I like the Prestone "Flush and Fill" kits, and Long-life antifreeze. I buy FULL STRENGTH "Global/Universal Lifetime" from Peak, and a couple gallons of distilled water.

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There's a jillion competing products. With the cooling system drained, that's a perfect time to replace ancient radiator and heater hoses, too.

The replacement head gasket ought to be the same thickness as the original, which is probably thinner than the typical ~.040 composition gaskets. I bet the original is more like .028.

How much money do you want to stick into a 5.0? A "good used" 5.7 might be more work, and some more money, but pays rich power dividends.

 

[Trig]

Thanks for the reply - appreciated. Unfortunately I don't know what gasket was used when the shop did the intake manifold. For that matter I can't say for sure if the lower was done either. I was ignorant of the details at the time and it wouldn't surprise me if all they did was the upper. Like you said, it doesn't much matter either way at this point most likely.

Well, I'm going to have to push this six months most likely due to an impending move North. Will likely haul behind a moving truck on a dolly if possible. Any guidance on what I should do to the engine/truck to limit further corrosion/damage would be appreciated. New territory for me. I'm not afraid to tackle this, even if am engine swap is the final outcome - just not going to happen for 6ish months until I get settled again.

Ty!

 

[stutaeng]

I would agree about confirming it's a head gasket, but probably not worth it since you have coolant in the cylinder.

Drain all the coolant out of the block and drop some oil in the cylinders, with plenty of oil in the suspect cylinder to limit corrosion. But if you are doing a 5.7 swap, maybe it's not even worth it? I don't know.

Maybe you'll rebuild your engine, so seems easy and cheap to do that until you get to that point.

 

[Trig]

Just to reiterate in case I wasn't clear, the cylinder filled with coolant just by me topping off the radiator with no engine rotation. That seems significant but likely I'm grasping at straws and/or it doesn't matter at this point like you guys have said. Figured I'd check on that before draining the coolant and prepping it for another day.

Thanks guys

 

[Trig]

Finally getting back to this thing. Got the manifold off and here's what I found. Think I'm done for today so was mainly curious if I should proceed with getting the heads off and/or maybe someone sees something I don't have the experience to notice. Thanks in advance!

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[Schurkey]

Just to reiterate in case I wasn't clear, the cylinder filled with coolant just by me topping off the radiator with no engine rotation. That seems significant

Yes, it's significant. You have a BIG leak. There's a real danger of hydraulic-locking the cylinder and causing VERY EXPENSIVE damage--broken piston, cracked block, bent connecting rod, etc.

Finally getting back to this thing. Got the manifold off and here's what I found.

1. That Fel-Pro intake gasket looks much worse than I'd have expected. It's got some serious distortion around the water-jacket openings, and some distortion around some air/fuel ports.

2. Yet, I don't see a coolant path from the water jacket opening to the intake port on #1. I don't think that gasket--damaged/distorted as it is--is the source of your coolant-in-#1-cylinder.

3. Which means you need to remove AT LEAST the left cylinder head. As I said in previous post, I'd pull them both AFTER doing a leakdown test to verify valve seal and ring seal. Even if you don't use a leakdown tester gauge system, and just pump compressed air in the spark plug holes, then listen at the tailpipe and the intake port for sounds of escaping air. No audible leakage in the intake or exhaust in any of the cylinders means you would not "have" to have the valves ground and seats cut. There WILL be audible leakage past the rings, and with the intake manifold off, it'll be hard to separate the noise from ring leakage from the noise (or lack of noise) from the intake-valve leakage. Be careful. Also, remove the rad cap before pressurizing the cylinders--you'll pressurize the cooling system through whatever is leaking, and you don't want to pop the radiator if the rad cap can't release pressure fast enough.

4. Probably want to haul that intake manifold to a machine shop after you remove the spider, coolant temp sensor, EGR valve, etc. so that it can be appropriately cleaned. Check (or have the machine shop check) the intake manifold gasket surfaces for flatness/warpage.

5. The left cylinder head (and probably the right as well) should be checked by the machine shop as well. I'm kinda guessing you're going to find a head gasket in bad condition, but you might have a cracked head, cracked block, or both. Point is, you don't want to slap a new gasket in there, and find out later that you've also got a cracked casting. And again, the head(s) should be checked for flatness along with having them look for a crack(s).

6. There's been discussion on this very forum about whether the head bolts are re-usable. Based on the service manual info I've seen, they are. But a guy posted a photo of a used bolt compared to new bolts, and the used bolt is obviously stretched. So I don't really know what to tell you. New bolts are not terribly expensive, unless you're buying ARP. I think I would risk re-using the old bolts IF they appear to be in good condition, (properly cleaned, threads sealed with Loctite/Permatex 592 "PST", and whatever lube the service manual specifies under the bolt head.) I don't know that you should risk it. Stretchy bolts can be "felt" if a person has appropriate experience. Not everyone has experience.

 

[Trig]

Good stuff - thank you Schurkey.

After cleaning up I poked around a little more. Here's two more photos of the front side of the heads (bumper) after I peeled away the gasket.

It's possible that the front (bumper side) four bolts of the intake weren't torqued properly -- I say that as visually it seems like the intake is "cleaner" on that end (washed/steam from the leak?) as well as the those bolts were easier to break compared to the rear four. Not great evidence admittedly, and I'm not sure it changes anything regardless. I may as well remove both heads since I'm this deep already.

I'll take your advice and acquire a leakdown tester and do that prior to taking them off. Good call on that - it had not occurred to me. Ty!

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[L31MaxExpress]

That is how the gaskets looked on my 97 van back in 2004 with 57K miles, when it exploded from hydraulic locking #2. The Felpro rubber gaskets are equal garbage. The only thing I will use now is the composite fiber paper ones.

 

[Schurkey]

I'll take your advice and acquire a leakdown tester and do that prior to taking them off. Good call on that - it had not occurred to me. Ty!

If you can borrow one, fine.

If you're going to buy one, get one with a Master Orifice. That allows you to "test the tester"; calibrating your expectations.

I bought this one, a decade ago. The Master Orifice is calibrated to Continental/Teledyne aircraft specs; it's a little too "generous" for performance automotive use. Not a big deal, I use the Master Orifice to give me a "worst-case" pressure, and then hope things are significantly better than the Master Orifice pressure.
I just looked at the web site to get the link, and the thing is even on sale. It includes an 18mm spark plug adapter, when I bought mine I asked for the 14mm adapter instead. That was a no-extra-cost swap.

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