Honda Prelude Forum banner
1 - 6 of 6 Posts

·
Registered
Joined
·
14 Posts
Discussion Starter · #1 ·
Hi Everyone,

Working on a H22A4 engine in my garage. I mounted a recently done valve job/cylinder to the bottom block. Out curiosity I decided to a leak down test and I got 80 percent leakage on all 4 cylinders. I sprayed some soapy water in to the exhaust and intake ports and bubbles rapidly came out (also I am not sure how much is normal or if none is normal). I did not know what to do so I pulled the head off to inspect. I poured some water in to the intake/exhaust port and sure enough drops of water slipped through. I called the shop that did the valve job and they said they did a 20PSI vacuum test and it should be fine. I took the head back to the shop and the showed me how they did the vacuum test and sure enough it held 20 PSI.

I am thinking of just taking the head to another shop to get another valve job done. What is everyone else thoughts?
 

·
Registered
1999 Prelude. F20B/K20A hybrid rebuild
Joined
·
202 Posts
This might sound obvious but did you make sure to have the engine at TDC for each cylinder you leak down tested?
Other than that, if you poured liquid into the ports and liquid came out of the valves, that means they aren’t sealing correctly. Forget their stupid vacuum test, one of the best ways to make sure the valves are sealing is what you already did by pouring liquid (usually alcohol is best) and seeing if the liquid leaks through, if the liquid seeps through the valves then that means they aren’t sealing, no question about it. Their little 20psi means nothing compared to the 200+psi and crazy amount of heat that the cylinders go through. Sounds to me like they didn’t Lap (resurface) the valves correctly.
After i got my head from the machine shop, i put the head on top of paper and poured alcohol into each port, if there was any leaks then it would be easily seen on the paper below the valves, but luckily it sealed perfect and there was no leaking.
 

·
Registered
Joined
·
14 Posts
Discussion Starter · #3 ·
This might sound obvious but did you make sure to have the engine at TDC for each cylinder you leak down tested?
Other than that, if you poured liquid into the ports and liquid came out of the valves, that means they aren’t sealing correctly. Forget their stupid vacuum test, one of the best ways to make sure the valves are sealing is what you already did by pouring liquid (usually alcohol is best) and seeing if the liquid leaks through, if the liquid seeps through the valves then that means they aren’t sealing, no question about it. Their little 20psi means nothing compared to the 200+psi and crazy amount of heat that the cylinders go through. Sounds to me like they didn’t Lap (resurface) the valves correctly.
After i got my head from the machine shop, i put the head on top of paper and poured alcohol into each port, if there was any leaks then it would be easily seen on the paper below the valves, but luckily it sealed perfect and there was no leaking.
Hi. Yeah I cranked it TDC, then counter clockwise for Cylinder 3 (90 degrees), and again for Cylinder 4. All leaked :(.

Also I got like three leak down testers just to be sure. Calibrated and I tested leak down on a working car in the drive way to make sure lol.
 

·
Registered
Joined
·
24 Posts
When they showed you it held vacuum, did you show them it leaked liquid?

Sent from my SM-G965U using Tapatalk
 

·
Registered
Joined
·
14 Posts
Discussion Starter · #6 ·
Took the head to a new shop. Remounted it and now I am getting 60 percent loss compared to 80 percent loss. I poured some oil down the spark plug hole and now I am seeing 40 percent loss on all four cylinders. I am now thinking the piston rings are not seated because they are new?
 
1 - 6 of 6 Posts
Top