N/T that will not start

[Dhan]

Again, sorry for the attn. grabbing title, I’m just getting frustrated with this damn car.

If you are feeling lazy, skip to the bottom of my post where the questions begin.

Otherwise, here's a little background. Got the car with 113Kmi. for $500 not running. Figured it would be a nice project that I could turn into a decent DD. I've been messing with it here and there for the last few months, but now that summer is ending I have some extra time so I can really focus on it.

All the car does is turn over. The previous owner claimed it jumped three teeth on the
timing. But staying hopeful, I figured it was a fuel problem. Checked with a pressure tester, it was getting plenty of gas though.
So from what I read on here and DSMtalk, I figured it probably was the timing. The cam
sprockets lined up perfect, so I removed the covering all the way to the bottom. Everything lines up perfect there too though. So, I'm not sure what the previous owner was talking about in terms of the skipped teeth, unless he realigned the cam gears himself.

So, now more lost, I did a compression test. Got 40-60 psi on every cylinder. Bad. Popped the valve cover off next, everything looked all right.

After a long wait, I was finally able to borrow a compressor to do a leak down test. Have like 90% leakage through where the exhaust manifold goes. I guessed this meant the exhaust valves were crushed. My motivation to continue was also crushed.

So now with a big long holiday and nice weather, I had a chance to remove the head. Now’s comes the part where I have to ask for help.

Question 1: The pistons all have marks on the tops where the valves must have hit. Or are all the 4G63s like this? Surprisingly, all the valves look okay. Like they didn’t smash into anything.

Question 2: There is some kind of buildup or deposit of gritty crap on the ends of the valves (the plunger end), but the cylinder walls have no scratches or signs of anything getting past them. So can I assume the rings are okay? Also, has anyone else ever encountered this buildup in their engine?

Question 3: The most important question. What do I do now?!! If the pistons and valves look okay, where is the leak and which direction should I head next?

Thanks in advance!!

 

[akira235]

whats that headgasket look like? 40-60 is EXTREMELY low, if its a 4g63 your compression when could should be around 140. also we need pictures of the valves and pistons.

 

[OneBad2L]

#1 - I know nothing about n/t's but the pistons for the 4g63t will have valve reliefs on them.

#2 - Carbon buildup is normal, they have 113,000 miles on them. No scratches on the walls is good valves still intact is good but this does not mean the rings can be 100% ruled out as the cause of your compression loss although 40-60psi across the board I highly doubt they are the cause.

#3 - Are you positive these valves are not bent? Take a real good look at them through the exhaust ports ect and make sure the valve stem is perfectly straight.

 

[Indian]

If you suspect the valves are bent,you can look to see if any of the followers are off. You should post a picture of the crank sprocket. I thought I had it lined up perfectly once to,but that wasnt the case.

 

[Dhan]

@akira235: Head gasket looks pretty worn but not blown. There's some kind of buildup on parts of it, like someone poured that syrupy water-leak-repair stuff at some point.

@OneBad2L: Every piston I've seen on 4G63s have those reliefs on them, but they're always for turbo models.
And I expected some buildup, but the stuff on my valves is almost like concrete. Difficult to remove.

I'm actually having trouble removing the valves. I have a tool to remove valves, but it doesn't fit the angle of my head.
Do I need the special tool that the manual talks about, or will Harbor Freight (or a similar store) have one that will work? What does everyone else do to remove valves?


UPDATE: I just so happened to look inside the intake manifold and the carbon buildup is extreme. More than I have ever seen. I think the car was running insanely rich and probably getting like 10mpg . Me thinks the previous owner was lying when he said 28+mpg. Am I reading this right?

 

[Indian]

There are different sized,and different style valve compressors. You need a larger valve compressor then what you have if its not working. Alot of places will rent one out. Also there is always going to be carbon build up no matter if its running rich,or not.

 

[Dhan]

So finally got the valves out. They're all a-okay, which I'm stoked about.

One thing I noticed though is that the lifters (lash adjusters in the manual) are all stiff and were keeping the valves open just a little. Could this alone have been the problem?