Well....its not fixed

[bcjjones]

Thought my problems were over. Had bad compression in three cylinders, thought I got lucky with a simple easy fix, but of course not. Symptoms went away for a day or two and they are back now. So im back to where i started, needing to take the head off to see whats goin on. Just dont have the time. Recently bought the car and the guy i bought it from said he had the head rebuilt proffesionally and had receipts saying so. Obviously something went wrong, but what i was doubting is the valve spring were replaced or even tested. Was curious if i can remove those without having to remove the entire head? Just to check them and make sure they are working properly. I'm thinking the valves arent closing correctly. Is that possible?

 

[demonic racing]

Ya you can pull the springs without removing the head and your valves can stick. I would say your problem is in your bottom end not the head.

 

[1457gvr4]

Might as well pull to the head to check for bent valves and/or blown head gasket.

 

[LiquidX]

Before pulling the head, I would at least to a leak down test to see where the issue is at.

 

[1457gvr4]

He said bad compression on 3 cylinders... Either way, the head has to come off.

 

[vinnio]

Yeah, I'm 100% with Zoott... I still can't read that name haha! LiquidX

Either way, a leak down test is the next step. Always figure out exactly what the issue is before removing or replacing parts. More so if you're talking about major engine work.

If you have a compression tester you can build your own leak down tester halfway easily. You use your hose from the comp. tester and just buy an air pressure regulator (and some random parts too) then go from there. You just have to remove the check valve from the comp. testers hose (same thing as a tire valve)

 

[LiquidX]

He said bad compression on 3 cylinders... Either way, the head has to come off.

Regardless if it will need to come off, it will at the least give him knowledge of what exactly is causing the loss of compression whether it's rings, valves, head gasket, or a combination.

It's always good to go in knowing what to assess than go at it blindly.

If you are going to pull the head first, here is a good way to test the valves without pulling them.
http://www.dsmtuners.com/forums/newbie-forum/420313-how-fluid-test-4g63-cylinder-head.html

Yeah, I'm 100% with Zoott... I still can't read that name haha! LiquidX

It's Scott

 

[pauleyman]

Regardless if it will need to come off, it will at the least give him knowledge of what exactly is causing the loss of compression whether it's rings, valves, head gasket, or a combination.

A leakdown test before teardown will point in the right direction first. It's not a bad idea. Leakdown will show a piston leaking or cracked ringland. It's difficult to spot this on a visual inspection. You'd have to do a complete teardown. I had the same issue long ago. No compresion on 1 cylinder. Leakdown cleared showed piston as the problem not valves. Visually it all looked good until you got the piston out of the bore.

 

[bcjjones]

Yea a leak down test was my other option then pulling the valve springs before removing the head.

I was looking at harbor freights tester and it's only 35 bucks. There are some negative reviews though. Has anyone on here ever uses one? If not where and how much did you get yours for?

Leak down test is my best option I think

 

[bryanwheat]

Valve springs aren't the problem. Even if the spring is a little worn, you will still have good compression. Where that spring will cause problems is when you are turning higher rpm's, it can cause valve float.