a few questions

[snomaker321]

im debating trying to fix my truck, more for the learning experience than anything but i wouldnt mind selling it for a bit more $$.

I was having misfiring problems and took it to a mechanic who told me that there was no compression on cylinder 4. I was misfiring in 1, 2 and 4.

Im trying to figure out if cylinder #4 is firing now or not. It completely melted the plug so i threw and old one in. Can I tell if its firing by the plug?

Also, could a blown head gasket cause a cylinder to have zero compression? I think im burning some coolant too but im not sure if its just a head gasket among other things or something completely different.

Where's the best place for me to start? thanks

 

[Big Jim M]

Oh wow snoguy

im debating trying to fix my truck, more for the learning experience than anything but i wouldnt mind selling it for a bit more $$.

I was having misfiring problems and took it to a mechanic who told me that there was no compression on cylinder 4. I was misfiring in 1, 2 and 4.

Im trying to figure out if cylinder #4 is firing now or not. It completely melted the plug so i threw and old one in. Can I tell if its firing by the plug?

Also, could a blown head gasket cause a cylinder to have zero compression? I think im burning some coolant too but im not sure if its just a head gasket among other things or something completely different.

Where's the best place for me to start? thanks

No compression means really bad internal things... NOT just plugs!
If the compression check was done by a professional mechanic, then your answer is at the very least a burnt valve and burnt headgasket..
Could be a cracked head. Also could be a ruint piston.

If it was here at my shop I'd pull the heads and get really personal with it. I'd make up my mind if the engine had any hope at all. Then I'd look at the vehicle and make up my mind as to wheather or not the vehicle was worth the amount of money it would take to repair it.

Judging from you saying you had others to do the compression check I'd venture that repairing this vehicle is above your pay grade.
Big JIm

 

[snomaker321]

No compression means really bad internal things... NOT just plugs!
If the compression check was done by a professional mechanic, then your answer is at the very least a burnt valve and burnt headgasket..
Could be a cracked head. Also could be a ruint piston.

If it was here at my shop I'd pull the heads and get really personal with it. I'd make up my mind if the engine had any hope at all. Then I'd look at the vehicle and make up my mind as to wheather or not the vehicle was worth the amount of money it would take to repair it.

Judging from you saying you had others to do the compression check I'd venture that repairing this vehicle is above your pay grade.
Big JIm

I know its not plugs. I just wanted to know if there was a way to see if the cylinder was firing again by looking at the plug. Like maybe the valve was just stuck or something. idk

He said probably a burnt valve but digging deeper into it = more money.

The biggest reason we took it to a mechanic was just to diagnose the problem. I didnt have the time to mess around with it and we couldnt find our compression gauge. The plan was to have him find the problem then i was gonna bring it home and fix it.

Right now I figure its not worth much as it is so what do I have to lose really? Use it as a learning experience.

The engine still runs but has no power. shakes at idle but if you give it a little gas it smooths out to the point that you dont notice it, although it is still misfiring.

I guess the biggest question was could just a blown head gasket cause zero compression in a cylinder, or do i definitely have another problem?

 

[Redwood650]

absolutely no compression in the cylinder? Thats bad. I had 80 in cyl 2 and I am in the process of swapping the heads myself. Not fun but it beats the $800 in labor it would cost me at a shop.

My compression problem is a burnt exhaust valve seat. At least that is what these damn things are notorious for. I got 2 heads for $220 to my door complete.

 

[sloth69mustang]

i had this same problem. i took the heads off and they looked ok for the most part. i took it to a machine shop and had them clean them up. cost me about 175 bucks put them back in and this was at 112k miles. now it runs perfect and i am now pushing 180k. it ended up being a sticking valve. it just depends on the truck. it could be anything. head gasket, head, valve, piston.

 

[snomaker321]

absolutely no compression in the cylinder? Thats bad. I had 80 in cyl 2 and I am in the process of swapping the heads myself. Not fun but it beats the $800 in labor it would cost me at a shop.

My compression problem is a burnt exhaust valve seat. At least that is what these damn things are notorious for. I got 2 heads for $220 to my door complete.

Thats what the mechanic told me. I dont know what went down in there but it melted a practically brand new spark plug. The engine still runs if that rules anything out, it just has even less balls than a good 3.0. alot less.

 

[Big Jim M]

Howdy snoguy

Thats what the mechanic told me. I dont know what went down in there but it melted a practically brand new spark plug. The engine still runs if that rules anything out, it just has even less balls than a good 3.0. alot less.

AIR! Air is what went down there. An intake leak or even an exhaust leak can ADD more air to the fuel mixture and that extra AIR makes the flame so hot that it actually MELTS the valve or even the valve seat that gets in it's way!
In a common torch that cuts metal we have a flammable gas in one tank and the other is oxygen.. When we want the torch to cut thru metal we increase the amount of oxygen.. this makes our torch hot enough to cut right thru metal. The same thing happens when we have an air leak in our engines.
That's what happens when we run our engines and fail to keep them up to specifications...
Big Jim

 

[snomaker321]

AIR! Air is what went down there. An intake leak or even an exhaust leak can ADD more air to the fuel mixture and that extra AIR makes the flame so hot that it actually MELTS the valve or even the valve seat that gets in it's way!
In a common torch that cuts metal we have a flammable gas in one tank and the other is oxygen.. When we want the torch to cut thru metal we increase the amount of oxygen.. this makes our torch hot enough to cut right thru metal. The same thing happens when we have an air leak in our engines.
That's what happens when we run our engines and fail to keep them up to specifications...
Big Jim

well when i first started having misfiring problems i checked for vacuum leaks but couldnt find any. anyways, do you think its worth the effort to tear into it and see what up?

 

[Big Jim M]

Sno.. It's no good to you unless you do tear into it.. You already know what is wrong with it. You have at least one burnt valve and maybe a headgasket leak.. Maybe worse.
Big JIm

 

[snomaker321]

Sno.. It's no good to you unless you do tear into it.. You already know what is wrong with it. You have at least one burnt valve and maybe a headgasket leak.. Maybe worse.
Big JIm

well i meant more fix it, replace the engine, or junk it. I think I want to fix it but i'll have to convince my dad to let me tear into it.