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Discussion Starter · #1 ·
manual boost contoller- 10$
adams chip 60$
socket to install chip 1$
have a guy put in the socket 20$

raising the boost to blow your engine pricless.


well yea, i didnt blow it yet, but we were doing compression yesterday, and i got 150-150-140-125, YAY

started on the leack down test, so we tested cyl #4 and air was coing to the crank case, YAY. so there is in no way im raising the boost on my engine, to go faster.

im surprised how bad cyl #4 went that bad in 5 monthes, last time i did a copression test #'s were 155-150-145-150

so cyl #4 went from 150-125 in 5 monthes, YAY, i wonder were it will be in 5 monthes more.
 

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A bad head gasket will cause air to flow down into the crank case. I would check that first.

~Chris
 

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well iam not sure if you have bad rings if you are that sucks. but it looks like you might have a bad head gasket . but ethier way it still sucks good suck man
 

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Ya, check that headgasket...........these engine are strong as hell

I met some guy at a car meet. he got his 89 Probe GT for free. Some guy bought it before him and he wanted to see if he could blow it up. This guy had it for 3 years, non stop taking it to redline plus he didnt change the oil. The guy that bought it said when he changed the oil it feel out in clumps. 225,000miles later........still runnin great with 3 bolts holding the exhaust mani on:p

Of course he replaced all fluids and gaskets. I think that says alot of this engine.
 

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Discussion Starter · #5 ·
what kind of tests can i do to check for a head gaskets, last time i did compression, and leak down test, we came to a conclusion with bad rings on cyl #4.

also how could air gto from the combustion chamber through the head gasket to the crank case??
 
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What percentage of leak did your leakdown test say?

A bad headgasket can allow the compression to go down the oil channels in the head, into the crankcase.

When you did the leakdown, did you remove your intake boot and feel to see if it was coming out of your valves?

Or, feel at the end of your exhaust?
 

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Discussion Starter · #7 ·
no, i took the oil cap, and listend for air leaks, and i was hearing it loud in there. i forgot what the #'s were. i would have to check on it again.
 
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Mazda_MX6_Turbo said:
no, i took the oil cap, and listend for air leaks, and i was hearing it loud in there. i forgot what the #'s were. i would have to check on it again.
:shrug: That would more likely be your valve stem seals.
 
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I've heard of putting oil in your spark plug hole and when you turn your motor over the oil will create a seal on your valve seals to eliminate that as an issue. If the oil is in there and it's low, then the valve seals are not your problem.
 

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Discussion Starter · #10 ·
hmm ooks like im gonna be doing more testing this week end again then guess.
 

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FlySwat said:
:shrug: That would more likely be your valve stem seals.
Um no, valve stem seals have nothing to do with compression. If it's coming out of the crankcase then it is most likely bad rings, the air goes past them and pressurizes the crankcase.
 

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My compression gauge instructions say to add the oil, and if the pressure goes up, then it's the piston rings. If it doesn't change considerably, then it's the valves.
 

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I think that's kind of what 1Badmx6 was saying. The oil helps troubleshoot the possibilities.
 

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Could be worse, I did a compression test over the weekend and got 60-95-95-105. It has 1800 miles on the motor since I last rebuilt it. It still puts down 180whp at 13 psi though...
 
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rebel2k4 said:
Um no, valve stem seals have nothing to do with compression. If it's coming out of the crankcase then it is most likely bad rings, the air goes past them and pressurizes the crankcase.
We are talking about a leakdown test, he is pressurizing the cylinder with an air compressor. IF the valve stem seals are bad, the pressure will leak through them, and into the valvetrain, which would obviously be felt and heard through oil cap.

Consequently, cars with bad stem seals leak oil into the combustion area, if it can leak oil through, then compressed air can go back up.


I've heard of putting oil in your spark plug hole and when you turn your motor over the oil will create a seal on your valve seals to eliminate that as an issue. If the oil is in there and it's low, then the valve seals are not your problem


Actually, the extra oil will "temporarily" seal your piston rings like a band-aid. It will not affect the valve stem seals.


With Flyswats guidance, I performed my first blinker fluid flush this weekend
Don't forget to bleed the air out of the blinker line, otherwise you might get a spongy feeling blinker level :lol: :shrug:
 

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FlySwat said:
We are talking about a leakdown test, he is pressurizing the cylinder with an air compressor. IF the valve stem seals are bad, the pressure will leak through them, and into the valvetrain, which would obviously be felt and heard through oil cap.

Consequently, cars with bad stem seals leak oil into the combustion area, if it can leak oil through, then compressed air can go back up.



[/B]
No, the valve seats seal the compression, not the stem seals. Have you ever looked? The valve stem seals prevent oil from entering the port through the valve guide.
For pressure to come through the valve guide, past the stem seal, and into the crankcase is impossible. It would first have the be the valve seat with the problem for air to even enter the port. It would take the path of least resistance and come out either the intake manifold or exhaust manifold. That would be if you had a bad valve seat, NOT stem seal. I think you have them confused.

So, lets review:

  • Valve stem seals are located in the head on the valve guide. They are rubber and prevent oil from going through the guide and into the port. They have nothing to do with compression.

    Valve seats are machined into the head and valve and prevent compression from escaping past the valve when it is closed. If these are bad, you will have compression problems.
 
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rebel2k4 said:
No, the valve seats seal the compression, not the stem seals. Have you ever looked? The valve stem seals prevent oil from entering the port through the valve guide.
For pressure to come through the valve guide, past the stem seal, and into the crankcase is impossible. It would first have the be the valve seat with the problem for air to even enter the port. It would take the path of least resistance and come out either the intake manifold or exhaust manifold. That would be if you had a bad valve seat, NOT stem seal. I think yuo have them confused.

So, lets review:

  • Valve stem seals are located in the head on the valve guide. They are rubber and prevent oil from going through the guide and into the port. They have nothing to do with compression.

    Valve seats are machined into the head and valve and prevent compression from escaping past the valve when it is closed. If this is bad, you will have compression problems.
I stand corrected. I've never actually done a valve job. Thank you for the information.
 

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FlySwat said:
I stand corrected. I've never actually done a valve job. Thank you for the information.
youre welcome, my friend :)
 

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Discussion Starter · #20 ·
yes it is the rings, i had my teacher look at it and test it today in my auto class. he said, rings it is, Weeeeeeeee
 
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