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73-87 Chevy _ GMC Trucks => Engine/Drivetrain => Topic started by: bigben5054 on October 08, 2018, 10:08:58 AM

Title: Is my engine dead?
Post by: bigben5054 on October 08, 2018, 10:08:58 AM
Hey all.  Bought a 79 K20 2 weeks ago.  Has a 350 SBC and 4-speed manual.  Previous owner told me they put new gaskets in the motor.  I thought that was odd.  Who pulls a motor apart just to do gaskets?  It has a Holley carb and Flamethrower HEI.  Anyway, first issue is with starting.  It would start to crank, then make this horrible grinding noise and it almost looked like it spun the engine back the opposite direction for a second.  It would do this quite a bit, but every so often it would crank normal and start right up.  Once running, it seemed to idle fine, but had zero throttle response.  Hit the gas and it would just bog down.  However, if you very gradually increased throttle and got the RPMs up, then snapped the throttle, it had pretty good response.  I thought the issue was timing, so I set the timing yesterday.  I set it about 10 degrees advanced.  It wasn't that far off to begin with.  However this did not fix the problem.  I also noticed that the big red power cord going to the starter had been laying up against a header pipe, melted, and grounded out.  At the time I saw it, it was not actually touching the header pipe, but pretty close.  Assuming this is why the battery kept draining on me.

I also noticed, after having run it a while, that the passenger side exhaust seemed to be spitting more water than it should, and actually you could see a little bit of steam (like in winter time, except its not cold here).  After a while, the garage windows near that exhaust pipe actually starting steaming over.  As if all that wasn't enough, I took a squirt bottle and shot a stream of water on each of the header pipes right by the head.  All would evaporate within seconds, except cylinders 2 & 3, which took noticeably longer (and I conclude were not firing).  I would think the steam and the misfire might be related on the passenger side bank (blown head gasket, cracked head, cracked block?), but not the driver's side.  Thinking I just need to pull it and go through it at this point?  Or could it be as simple as a blown head gasket?  I appreciate any input on where to start here.     
Title: Re: Is my engine dead?
Post by: Rapid Roy on October 08, 2018, 11:17:40 AM
Welcome.
Title: Re: Is my engine dead?
Post by: JohnnyPopper on October 08, 2018, 01:41:55 PM
Welcome.

Do a compression test first. Remember to keep the throttle wide open while cranking.

Title: Re: Is my engine dead?
Post by: Captkaos on October 08, 2018, 05:57:56 PM
Water is the expected output of a good running motor.  which side is putting out more?
What do the plugs look like?
I wouldn't question a refresh if everything else looked ok and it was leaking..
I would check the plugs and as above do a compression test.
Title: Re: Is my engine dead?
Post by: bigben5054 on October 12, 2018, 10:38:57 PM
Seems like passenger side is the steamy one.  Plugs looked pretty sooty.  Couple were oily.  Compression test as follows:
#1 - 120
#2 - 120
#3 - 0
#4 - 120
#5 - 120
#6 - 120
#7 - 120
#8 - 140

Obviously, #3 is a problem.  Any thoughts on most likely culprit?  This is a real bummer. 
Title: Re: Is my engine dead?
Post by: VileZambonie on October 13, 2018, 07:25:18 AM
Pop the valve cover off and look for a bent pushrod or rocker issue, or maybe a wiped cam lobe, etc. If you have have access to a cylinder leak down gauge, put #3 on TDCC and see what the percentage of leakage is and where it is escaping.
Title: Re: Is my engine dead?
Post by: bigben5054 on October 13, 2018, 12:10:05 PM
Pulled the valve cover and looked things over.  Everything looks good - but I did not remove the rocker arms and pull the pushrods yet.  I bought one of those valve holder hoses that lets you pump air into the cylinder from a compressor.  I turned the engine by hand until I was sure #3 was at TDC.  Put about 15 pounds of air into it.  No noise from tailpipe, nothing from dipstick tube, but air was absolutely coming up through carb.  So I've got it narrowed down to the intake valve on #3.  I'll check the rocker arms and pushrods before I pull the head, but looking like I'll need to pull that head and check out what's going on.  At least I dont have to pull the whole motor...yet...*knocks on wood*
Title: Re: Is my engine dead?
Post by: VileZambonie on October 14, 2018, 08:11:00 AM
Are you sure you're on tdc compression? Both rocker arms are up? If so, back off the nut on the intake rocker are and see if it makes a difference. Just count the # of turns you loosen it so you can put it back.
Title: Re: Is my engine dead?
Post by: bigben5054 on October 14, 2018, 04:04:15 PM
Well, too late.  I pulled the driver's side head last night.  Based on the photo, I guess it wasn't TDC, but I watched the valves very closely while turning it by hand and I'm certain they were both closed.  Great.  So now I can't be sure it was the intake valve?  At least I know its not a hole in the piston.  And it it were piston rings, I would have gotten some compression on the test, not 0, right?  Ugh.

Anyway, pistons look ok and considering how much cleaner #3 is compared to the others, I'd say this problem has been going on a while.  The valves look pretty nasty, its hard to tell from just looking at them whether the valve isn't closing all the way.  That gunk all over the intake valve is hard as a rock.  Wonder what caused this?  Anyway, think I'll pull the other side head and take them both in to a shop for reconditioning.

I just hope I dont go through all this just to find out the problem is actually in the short block someplace.
Title: Re: Is my engine dead?
Post by: VileZambonie on October 14, 2018, 06:38:11 PM
Put the spark plug back in and prop the head so it's relatively level. Fill the combustion chamber with ATF and let it sit. See if any ATF leaks past the valves or combustion chamber.
Title: Re: Is my engine dead?
Post by: bigben5054 on October 14, 2018, 07:12:47 PM
Good suggestion; thank you.  I donít have any ATF.  Would engine oil work just the same or is there something special about ATF?
Title: Re: Is my engine dead?
Post by: bigben5054 on October 14, 2018, 08:41:47 PM
Yeah, I'd say the intake valve is the culprit.  Still curious as to what causes this mess.  Thanks for the help. 
Title: Re: Is my engine dead?
Post by: JohnnyPopper on October 15, 2018, 02:11:18 PM
Kind of odd, usually the exhaust valve goes... From your pics I can't see any scoring in the cylinder that might indicate broken rings.

Been some years since I tore down a motor, your pics are inspiring. Think a rebuild is in my future!  ;D
Title: Re: Is my engine dead?
Post by: VileZambonie on October 15, 2018, 02:40:14 PM
5w30 is fine. Pop the valves out, decarbonize it and inspect.
Title: Miles
Post by: JohnnyPopper on October 15, 2018, 09:06:04 PM
Do you know approximate miles on engine?
Title: Re: Is my engine dead?
Post by: bigben5054 on October 15, 2018, 10:02:38 PM
No.  I called a couple machine shops today to get a rough idea on cost to go through a set of heads and itís around $250-$350 plus any needed parts.  Seems a bit high for some bone stock heads.  Been looking into picking up a set of Vortec heads instead.  Can find decent ones for half of what machine shop wants to redo these.
Title: Re: Is my engine dead?
Post by: JohnnyPopper on October 16, 2018, 01:57:16 PM
Doesn't look like a heavy ridge at the top of the cylinder is why I asked. Maybe low mileage, but if you have access to a micrometer it might be worth checking just how much wear there is. You've gone this far. Is the engine out of the truck?

I have to say, I have been out of the loop on modern engines, couldn't tell you what a Vortec head is if my life depended on it, but they sure sound interesting. I must investigate... 
Title: Re: Is my engine dead?
Post by: bigben5054 on October 16, 2018, 02:49:46 PM
Motor is still in truck and I don't really want to pull it.  You can barely feel anything at the top of the cylinder and these pistons are stamped 30 over, so I'm guessing it doesn't have a ton of miles on the rebuild.  Vortec heads are a pretty good bang for your buck.  Need a Vortec manifold and centerbolt valve covers, but everything is easy to find and usually pretty inexpensive.  Most articles I've read say they are worth 20-40 HP over stock.
Title: Re: Is my engine dead?
Post by: JohnnyPopper on October 17, 2018, 07:26:02 PM
Okay, sound like you're in good shape on the lower end.

Have you popped the valve out? I think I have a spring compressor, but haven't seen it for years. Curious as to why such a loss of pressure when there's no visible crack/hole.

I'm really surprised that just changing your heads can deliver that much more horsepower! Thanks for the info, now I'm really interested.
Title: Re: Is my engine dead?
Post by: bigben5054 on October 18, 2018, 07:05:35 AM
I did the loan-a-tool at Autozone last night and popped out that intake valve.  It just looks covered in carbon build up.  Its clearly unable to close completely at this point because of the carbon buildup, but I still dont have an answer as to why it possibly got stuck open in the first place.  I'll take them all out and spend some time with the wire wheel this weekend.   
Title: Re: Is my engine dead?
Post by: JohnnyPopper on October 18, 2018, 12:27:03 PM
I don't know if I would pull them all out.

I think I would clean that one and take it to the machine shop (call first) and see if they have a vacuum tester. (old school) See if it is still leaking.

Strange that conditions of excess fuel and/or poor ignition would cause such a buildup that produced no pressure. But it sure looks that way.

The rest were straight up 120. did you take Vile's advice and look for a sheared lobe on the cam?
Title: Re: Is my engine dead?
Post by: bigben5054 on October 18, 2018, 01:33:14 PM
Good suggestion, thanks.  I did not look for a sheared cam lobe.  I suppose with the intake off, I can crank the engine by hand and watch the lifters.   
Title: Re: Is my engine dead?
Post by: JohnnyPopper on October 18, 2018, 02:41:18 PM
Yeah, I'd start there.

Sometime rebuilders aren't aware that the have to break in a new camshaft.

Hope it's something simple like carbon...
Title: Re: Is my engine dead?
Post by: bigben5054 on October 19, 2018, 10:58:47 AM
Last night I took off the passenger side header and pulled the valve cover (I have limited wrenching time during the week).  There was a small pool of antifreeze in the back corner of the head (above #8 cylinder).  Note from my original post that all cylinders compression tested at 120lbs except #3 (zero) and #8 (140).  Also recall that I thought the passenger side exhaust was a bit steamy.  I'll get that head pulled tonight, but I suspect I'll find some coolant in #8.  In my limited experience, this means 1) bad head gasket; 2) cracked head; 3) cracked block; 4) cracked/leaking intake.  I know that some cracks can be hard/impossible to see with the naked eye, but I'm not crazy about the idea of paying a shop to magnaflux the heads or the block (I'm still holding out hope I don't have to yank the whole engine).  What sort of things should I be looking for when I pull the head that might give me a hint as to how that water is getting in there? 
Title: Re: Is my engine dead?
Post by: bigben5054 on October 19, 2018, 11:12:24 AM
Or...maybe they failed to put sealant on the head bolts when they "regasketed" this motor.  Let's hope for that one. 
Title: Re: Is my engine dead?
Post by: JohnnyPopper on October 19, 2018, 02:15:30 PM
So the puddle of anti-freeze was sitting under the valve cover, and you saw it when removed? That's troubling if true.

Sometimes it leaks into areas when you take things apart if the block wasn't drained to a point below the water pump ports, but I can't say how it got under the valve cover.

A Far reach is that the head gasket is bad, and it came in through a head bolt. Did you see any A/F in the oil?

I recall the steam question and the answers that stated somewhat normal when first getting warmed up. Did it continue steaming after reaching operating temp?

I think it points to a cracked head. You'll know if the combustion chamber is squeaky clean.

Title: Re: Is my engine dead?
Post by: bigben5054 on October 19, 2018, 02:27:43 PM
Yes, the antifreeze was there when I pulled off the valve cover.  I shrugged it off at first because you are right, I had anti-freeze all over the place from pulling the intake and other head.  But later I was thinking about it and thought hey, how did that get in there? 

The anti-freeze in there looked like it just came out of the jug, so clearly it had not worked its way up through the oil pan, oil pump, valve train etc.  I did a few Google searches and unsealed head bolts seem like a good lead.  But, how would the antifreeze get from on top of the head into the cylinder?  It don't see how it could.

As far as the steam, it got worse the longer it ran.

Part of me is starting to believe that the prior owner knew of the problem, thought it was a head gasket so he put all new gaskets in it, but turns out that didn't fix it, so he did something to temporarily hide the problem while he dumped the truck.

Hopefully I'll get time tonight to pull the head and I'll post what I find.
Title: Re: Is my engine dead?
Post by: bigben5054 on October 19, 2018, 10:29:08 PM
The head doesn't look too bad.  To the naked eye anyways.  But there was a good amount of oil in #8 (the one with 20lbs more compression than all the others).  The coolant may or may not have already been in there.  I made a mess pulling the head off.  That oil pooled in there is bad news though, yeah?  Thinking piston rings.  But if the rings are that bad, why would I get such good compression?  Would the oil in there act as a sealer for the bad rings?  Ready to scrap this thing. 
Title: Re: Is my engine dead?
Post by: JohnnyPopper on October 20, 2018, 08:56:20 PM
Wow, a stumper at the moment.

Unsealed or loose headbolt may have allow it up, but it would still need to make it past the head gasket and into that bolt passage. You said the former owner changed the gaskets- do they look new?

Do you have the lower radiator hose removed? It looks like there is/was a high level of A/F that leaked into cylinder in both 6 and 8.

Can't figure the oil in 8, especially looking at the exhaust valve, it was burning better than 4 and 6.

Start with the heads and a magnaflux inspection, if they check out, take a look at the block. May as well pull it, mark the components, and inspect.

We all feel for you, are you into the truck for much $?
Title: Re: Is my engine dead?
Post by: bigben5054 on October 20, 2018, 10:52:38 PM
I have read that the antifreeze can cling the threads and then come out under the bolt heads.  Thatís how it think antifreeze got under the valve cover.  And I think more likely than not, the antifreeze you see in 6 and 8 got in there when I pulled the head.  No, didnít remove lower hose.  Should have because itís a mess. 

Iím more concerned about the oil I found in the cylinder.  I figure it either came down through the valve guides or blew up past the rings.  I fear the latter makes more sense given the quantity of oil.

I appreciate all the advice.  Iím not into the truck much.  Paid $2k for it.  I havenít put a dime in it other than that.  What gives me the most pause right now is starting to pump $ into this motor.  I can find ďran great when pulledĒ small blocks all day long for $250-$300.  Of course, might just be buying another headache doing that. 
Title: Re: Is my engine dead?
Post by: VileZambonie on October 21, 2018, 07:07:46 AM
You should have drained the block before removing the heads, hence the mixing of the fluids when you pulled the heads off.
Title: Re: Is my engine dead?
Post by: bigben5054 on October 21, 2018, 08:47:21 AM
I've never pulled an engine on a manual transmission.  Aside from the bellhousing to block bolts, what else to I need to take apart between the engine and transmission to pull this thing? 
Title: Re: Is my engine dead?
Post by: Captkaos on October 21, 2018, 12:06:53 PM
Is is still in the the truck?
If not, I would pull the starter just because, otherwise nothing else has to be pulled between the 2.  The input shaft goes through the clucth disc past the pressure plate into the pilot bearing/bushing, so you will have to pull it straight back to get it off.
Title: Re: Is my engine dead?
Post by: bigben5054 on October 21, 2018, 12:18:34 PM
Yeah, still in truck.  So remove starter, remove bell housing bolts, remove engine mount bolts, then start lifting with picker and pull engine toward front to separate from transmission?  Sounds like it will be fun putting it back in.  Isnít there some linkage or something between clutch pedal and bellhousing that needs to be removed or disconnected?
Title: Re: Is my engine dead?
Post by: Captkaos on October 21, 2018, 12:32:33 PM
If it is manual trans there will be a Z lever on the driver side, you just unpin it from the clutch actuator lever and remove the springs. (it will fall out by itself) unbolt it from the frame side and remove it and unpin the clutch side lever.

You will want to lift up on the trans to get it out over the engine frame stands.  It will be a pain getting it back in.  You will need a clutch alignment tool to do it when you put it back together and assemble the clutch assembly.
Title: Re: Is my engine dead?
Post by: JohnnyPopper on October 22, 2018, 03:41:25 PM
2 grand is a good start, you have some headroom, that is if the rest of the truck is clean.

It's easier than it looks. Before you take the last bell housing bolt off, use the picker to elevate the block 2 inches above the unbolted engine mounts, then put a jackstand under the transmission to keep it elevated when separated from the engine.

Lower the two back down to the jackstand, and keeping tension on the engine chain, remove the last bolt. It will move forward and into your waiting engine stand, or block of wood or pallet, or...

otherwise the trans plops down when they separate.

If you can keep the truck in place while the work is being done, it will slide right back together, clutch alignment/ tool notwithstanding.
Title: Re: Is my engine dead?
Post by: Irish_Alley on October 22, 2018, 04:10:07 PM
i wouldnt worry too much about it if you didnt notice smoke when it ran.
Title: Re: Is my engine dead?
Post by: bigben5054 on November 09, 2018, 04:09:47 PM
Finally ready to pull the engine this weekend.  I decided to pull the engine with transmission.  I dropped the transfer case out already.  I'm going to rent a hoist from a local hardware store and buy one of those load levelers from a tool store.  The leveler will have 4 chain ends to bolt to the engine.  My question is that since the intake and heads are already off the engine, where would be the best places to bolt the 4 chains?  I am thinking where the head bolts went into the block, but I'd hate to strip those out.  Are they strong enough to hold the weight of the short block plus the sm465?  Is there a better option?
Title: Re: Is my engine dead?
Post by: JohnnyPopper on November 09, 2018, 04:35:51 PM
The head bolt hole are strong enough to lift the two, I would look for some shorter bolts in that same size so you don't have to use the actual head bolt, they might bend. Not too short... ::)

Find a point toward the rear of the block to tie down to. Maybe between cyl 6+8 and 5+7.

Lift and check balance before committing. Your block is heavier than the transmission.

Do you have the center core / radiator support removed?
Title: Re: Is my engine dead?
Post by: bigben5054 on November 09, 2018, 04:43:36 PM
Thanks.  No, I did not remove the core support or radiator.  Truck is lifted 4 inches with 35" tires.  Think I'll have trouble lifting the motor/transmission high enough to clear?  I figured it would be close and that if I had to I could take the front tires off and lower it to jack stands.  But if its easier to just pull the support and radiator, I can handle that too. 
Title: Re: Is my engine dead?
Post by: JohnnyPopper on November 09, 2018, 04:55:32 PM
I think your life will be easier with the tires removed. Try it without removing the center support, if it become a bear, then do it.

Wish I could be there to assist! Be careful...
Title: Re: Is my engine dead?
Post by: bigben5054 on November 10, 2018, 01:15:46 AM
Haha, Iíd buy the beer!  Got it pulled.  Wasnít a ton of fun, but itís done.  Ended up taking the tires off and it was still almost too high.  Couldnít use the leveler because I needed max lift from the hoist.  Planning to tear down the engine Sunday and see what Iíve got.  Hopefully just a good cleaning, honing and re-ring.
Title: Re: Is my engine dead?
Post by: JohnnyPopper on November 10, 2018, 05:27:47 PM
Good job! Hope it goes well.
Title: Re: Is my engine dead?
Post by: VileZambonie on November 11, 2018, 07:20:40 AM
For future reference you can just air down the tires.