#4 0 Compression pulled head (pictures) what happend?

[Boosted98RS]

Well first off I'm not the greatest when it comes to engines but I can read and do things from there. But as far as knowing what I'm doing internally I have no clue. I just know that the car has 0 compression in cyc #4 so I was told to take the head off and look at the valves.

I don't even know how the work really? So like #1/#3 will open 2 valves each at the same time and then #2/#4 correct? But anyway I pulled the head off and it looks like the #2 valves opened and then #4 are open just a little. Not very much at all. Would this cause 0 compression? Also, how do I know if the bottom end is good? Take a look at these pictures please.

#1

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#2

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#3

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#4

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[kingjust]

Did you make sure that the cylinders that you were checking were at TDC? That's when the valves are closed and proper compression can be read. Try again...

 

[danl]

Those pictures aren't very good, hard to tell what is going on. However you are going to want to see if any of the valves are bent and not seating correctly. You can check this by removing the cams and putting mineral oil in the combustion side of the head with the cams facing down. If it is leaking you have a bent valve or two. Also you are going to want to make sure the cam lobes are actuating the valve properly and causing it to open and close which you have already verified (I think).

That #4 piston looks very clean, like the HG is leaking into the cylinder. You might have a HG leak but you usually can build just a tick of compression with a HG leak.

Last check that the piston is moving up and down, but you would know if that wasn't the case with the hole in the block.

 

[Boosted98RS]

Did you make sure that the cylinders that you were checking were at TDC? That's when the valves are closed and proper compression can be read. Try again...

I checked the compression when the motor was still in the car. Does that make a difference? I did everything and all the cylinders were near 180 except #4 and it was 0. I didn't see if they were at TDC though I have no clue how.

Those pictures aren't very good, hard to tell what is going on. However you are going to want to see if any of the valves are bent and not seating correctly. You can check this by removing the cams and putting mineral oil in the combustion side of the head with the cams facing down. If it is leaking you have a bent valve or two. Also you are going to want to make sure the cam lobes are actuating the valve properly and causing it to open and close which you have already verified (I think).

That #4 piston looks very clean, like the HG is leaking into the cylinder. You might have a HG leak but you usually can build just a tick of compression with a HG leak.

Last check that the piston is moving up and down, but you would know if that wasn't the case with the hole in the block.

I took the pictures with my phone. I can try and get a camera but didn't have one at the time. I'll have to check this I just didn't know what my next step was. I was just going to bring it to the machine shop and let them take care of it???

 

[BoredDSM]

Yea #4 does look slightly cleaner than the other two which would lead to the headgasket pushing coolant. Did the car have trouble running? Looks like you have forged pistons and aftermarket valves. Have you had prior engine work done before? Should bring the head to a machine shop and have it checked out.

 

[Boosted98RS]

Yea #4 does look slightly cleaner than the other two which would lead to the headgasket pushing coolant. Did the car have trouble running? Looks like you have forged pistons and aftermarket valves. Have you had prior engine work done before? Should bring the head to a machine shop and have it checked out.

Well the car really didn't have problems running but the previous owner said it had no IAT sensor on the throttle body so it took a minute to get idle but then it ran fine. I didn't even really get to drive it much before it crapped out on me. But from what he said it was supposed to have Wiesco pistons and I think Eagle Rods. I figured my best bet due to inexperience would be to just bring the head to a machine shop? Or should I do something else beforehand?

So I have a question so when I drop it off at the machine shop what exactly do I say I need done? Do I need to take anything off? Do I just leave the cams in there or what? I haven't ever had to do this before so any help will be appreciated.

 

[BogusSVO]

well depends on what you want /need done to the head
and find a shop that understands DSM and/or alum DOHC engines in general

ask them to just clean the head and check for bent valves,(appox $30) and then call you! this way you will not end up with work you do not need /want or can not afford

it looks like a few valves made contat just from the way the carbon pattern looks on the valve heads.

 

[Boosted98RS]

well depends on what you want /need done to the head
and find a shop that understands DSM and/or alum DOHC engines in general

ask them to just clean the head and check for bent valves,(appox $30) and then call you! this way you will not end up with work you do not need /want or can not afford

it looks like a few valves made contat just from the way the carbon pattern looks on the valve heads.

Ok, great. So when I find out if there are bent valves should I just replace the ones that are bent? Trying to do it on a budget so keep that in mind. Where is the cheapest place to buy new valves?

 

[delta448]

I can tell you have aftermarket pistons and valves, so that engine has certainly been opened up before.

The intake valves appear to have all been kissed by their pistons, whether they are bent or not isn't absolute, but pretty likely.

Make sure the piston to valve clearance gets measured when you put it all back together. Some issues may quickly arise when using aggressive cam lobes, higher than stock CR pistons and a head that has already been shaved a couple times.

 

[BogusSVO]

boosted... the price of valves will depend on what valves you have and what brand

if the valves are bent past a point, the guides crack, so they will need to be replaced if that is the case you will need a full valve job.

http://www.dsmtuners.com/forums/newbie-forum/341218-how-change-valve-guides-4g63t-head.html

but as delta said, you need to clay the top of the pistons and chek the piston to valve clearance...
this is a bit more advanced than a basic head swap

 

[Boosted98RS]

I'm not very well versed when it comes to checking clearance and all of that and rather have all of that looked at. Should I bring the whole short block to be checked out also? I'm not sure if there is anything wrong with it but I have no idea. I just dropped the head off a few minutes ago.