cylinders - SRT Forums

tim421165 · 08-10-2009, 08:02 PM

ok , this has been a 3 month project and can someone please tell me why after i did the head and headgasket my number 4 cylinder has no compression , i did the timing like 20 times today thinking that was the problem then decided to do a compression test and 1 -3 have just over 130 psi and # 4 is at dead 0 didnt even move the needle , any help would be greatly appreciated ?

nutz · 08-10-2009, 08:06 PM

sounds like a stuck valve, do a leak down to find out what side its on (intake, exhaust) and yake off the valve cover and look for something outa wack, you probibly gonna need to pull the head

mrj82 · 08-10-2009, 08:25 PM

Did you put cams in it? Sounds like a bent valve, or a hole in a piston, surely you would have seen that.

chuck's_srt-4 · 08-10-2009, 08:31 PM

Check your rocker arms, and make sure they are positioned properly. Might have one of them wedged in there keeping a valve open.

Other than that, Timing!

tim421165 · 08-11-2009, 07:28 AM

Quote: Originally Posted by chuck's_srt-4

Check your rocker arms, and make sure they are positioned properly. Might have one of them wedged in there keeping a valve open.

Other than that, Timing!

timing ? is that possible could maybe i be off 180 would that make only 1 cylinder come up with 0 , i have pulled this head off 3 times and not looking forward to doing it again , i have played with the timing for 2 days before i decided to do a compression check , so if thats possible maybe i was just off with timing but idk let me know?

tim421165 · 08-11-2009, 07:30 AM

Quote: Originally Posted by nutz

sounds like a stuck valve, do a leak down to find out what side its on (intake, exhaust) and yake off the valve cover and look for something outa wack, you probibly gonna need to pull the head

how is a leak down test done ?

toyoguru · 08-11-2009, 04:11 PM

leaktest is done by putting the cyclinder being tested at tdc and applying air pressure (70-80psi) using a leak down tester which has two guages on it..one for incoming air and the other showing the percentage of leakdown....

I think with 0 psi, you should be able to pull the valvecover and see an obvious problem without needing to do a leakdown check.