5.7 tbi bad valve spring and one fouled plug

[Chaz]

My truck started running really bad so I pulled the plugs. The first cylinder on the left hand side spark plug was totally fouled, caked over with something it didn't look like oil because it was dry but was told its oil fouled. And its only the one plug that looks that bad. I did install new plugs and it does run ok with new plugs but the spark plug dosent look good out of that cylinder.

So I pulled the valve cover just to look inside and I found a broken metal ring down around the bottom of the valve springs where the oil puddles. It looks like it came off the top of the exhaust valve spring, first one towards the front of the motor. Its the same cylinder that is fouling the plug. Should I pull that one valve spring and replace it along with the seal or should I just go ahead and pull the whole head and take it to a machine shop???

 

[Chaz]

Does anyone know if that ring on the top of the exhaust valve spring is a critical part?? Im about to pull the cylinder head off this thing,,,,don't want to because I don't know how to set the valve lash when I put it back together,,,

 

[foamypirate]

@HotRodPC

HotRod, you're pretty good with engine internals. What do you think is going on here? Put those paragraph writing skills to work!

 

[Chaz]

Im gonna have it off tomorrow,,,Im thinking im gonna just count the turns on each rocker arm bolt and then put it back together exactly the same way,,,,depending on what there gonna do to the head,,,,im pretty sure theres something wrong with the valves on that #2 cylinder,,,

 

[Chaz]

Ill bet the other piece of that busted cockring is in my oilpan,,,,

 

[firebane]

Spark plug chart :

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[HotRodPC]

Are you having any backfiring problems? Some kind of valve train failure happened there. It is part of the spring cover or part of the spring dampner inside the spring? Makes me wonder whatever went wrong, did it destroy the valve seal and or valve guide and you're getting alot of oil on that plug and it's getting baked on the plug.

Do you over rev it by any chance and ever float the valves?

 

[Chaz]

Ive been having a really minor missing on acceleration,,,intermittent,,,,with yeah it backfired maybe 3 times total after I put a new muffler on it,,,,I think the last time I changed plugs that #2 was the worst,,,,,and ya I drove it home from work really hard because I was late to take kids to school,,,and when I got home it barely ran,,,,don't think I over reved it because I never take it over 4k but I drove extended on the fwy at about 70-75 which is about 3100 rpms, I don't usually drive it hard but I did that day,,,

 

[HotRodPC]

NO, you didn't over rev it then. Stock OEM valve springs will handle 5,000 rpm easy. I was just wondering if you might have floated the valves a time or two. And the backfire doesn't seem to be consistent enough for permanent damage. So the valve face and valve seat should be undamaged at this point the way it sounds. You just have an issue with that one valve and it's components. I'd probably fill that cylinder with some small rope and bring the piston up to TDC so that the valve can't fall down in the cylinder, then remove that valve spring assembly for inspection and go from there. The valve guide might be worn, but for a patch job, replace the valve seal with one of the better umbrella type seals while you have it apart and that will work as a band aid for quite some time.

 

[89Suburban]

Sure is clean under that valve cover!

 

[Chaz]

I have everything off the motor right now. Intake is unbolted just haven't pulled it off yet. I was gonna pull the head,,,,but I think ill just throw the dizzy back in,,,rotate it and pull that valve spring,,,Ill post some pics of it when/if I can get spring off,,,thanks for the replies,,,,,

P/O said motor was rebuilt,,,I thought he was bs,n me,,,but it does look clean inside from what I,ve seen on the internet,,,

 

[Chaz]

Tried the rope trick,,didn't work for me,,pulled the heads and took em in to the local machine shop,,,pulled the valve spring and there was NO SEAL on the exhaust valves,,,there were seals on the intake valves only. Mech said sometimes they don't put valve seals on the exhaust valves because they don't usually leak. So hes gonna rebuild the heads, 70 bucks each + parts (new seals).

Another question I asked him was about the blocked off coolant ports on the intake manifold gaskets. I was thinking that's why my heater dosent get very hot because the ports are blocked off. Machine shop guy said they have to be blocked off or the heads will overheat??? Dosent make sense to me cuz why would they put those ports there anyway.

 

[HotRodPC]

hmmm well, there's lots O' info here I think I'd have disagree with. I'm easily corrected if I'm wrong so if a few disagree with me, I'll take as I'm wrong.

#1, no seals on the exhaust valves because they don't leak? ******** IMO. Any oil that's in the top of the head is subject to ride down the valve stem into the combustion chamber. Valve seals have nothing to do with compression or holding back compression, and they are not to keep spent gasses out of the crankcase. Their main purpose is to keep oil from riding down the valve stem and entering the combustion chamber causing you to burn oil. Valve guides are a different story. Usually when your valve guides go bad, you can certainly lose compression out and around the valve stem and that hot compression will usually cook your valve seals in short order and blow them away. So yes, IMO, no valve seals on the exhaust valves is a problem. Minor as it be, still a problem. I'd be pist if I didn't have exhaust valve seals.

#2, Not blocking off the intake water ports WILL NOT cause your heads to overheat. You don't have to block them off, but I would. Now there is likely some truth to maybe having better water flow to the heads if it's blocked off, but it's not going to cause head overheating. And NO, that being blocked off is not why your heater doesn't work. That has nothing to do with your heater core flow at all. What the hot water crossover to the intake manifold is for, is for cold motor operation, warming the fuel and also some intakes have choke stoves. If you have that blocked off and the heat isn't detected by the choke stove, your choke may stay on longer than needed. For an emissions motor or OEM daily driver ride, you'd probably want to have it open or restricted to allow some water through. If you don't have tailpipe emissions testing in your state I'd block it off. Have you ever heard of a Cool Can where a coil is ran through a can and people put ice or dry ice in it to chill the fuel for better performance? What this does is the opposite. It heats the fuel believed to vaporize the fuel for cleaner burn, cold starts and better running until the motor warms up being that most people make short trips and rarely get to full operating temp. Like running up the grocery store real quick and coming right back home. It's more of an emissions thing more than anything. I'd block it off to keep the fuel cooler and better performance. And yes, it could potentially help keep the heads a couple degrees cooler maybe. Sounds good in theory but I doubt it's that much different.

 

[Chaz]

Well im tellin ya there were no seals on the exhaust valve stems,,,,,some ******** put my heads together that way prob causing the fouling plugs. If they were blown away I would think I would have found some debri from the destroyed seals. I found metal shavings in the corner of the head near that spring that had the busted ring on top. Anyway Im pretty sure someone put it together like that. The machine shop guy said my valve guides were good. And that intake gasket has one small hole in each side where the coolant block off is at,,,I was thinkin that it prob reduces flow to the heater core since the hose fitting is right above the crossover on the manifold,,,,but if you say its ok not to open it all up ill just use the gaskets as they came with the crossover blocked,,,,thanks hotrod I really appreciate your knowledge,,,

 

[Chaz]

And just thought I'd throw this in here and ill be damned but I ended up pulling the exhaust manifolds out so I could access the lower head bolts easier,,,and I noticed it said "Made in China" on the back side of one of the cast iron exhaust manifolds,,,,Thats gotta be an aftermarket replacement part right,,,,,prob lcmc,,,,???