4.7v8 low comp
#1
05-21-2009, 05:38 PM
Join Date: Apr 2009
Location: alexandria La.
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4.7v8 low comp
We just rebuilt 4.7v8 sohc heads , normal : Clean Heads
Press.Test for Cracks {ok} , ck'd vlv. guides 'ok', Ground Valves & Seats , Surfaced Heads [0.004] , Mech. took heads put on block , now he has [pass.side]head w/low comp. #2 & #8 cyl.s said he did 'dry/wet' comp. test & get aprox. 50-75Lbs & when puts [alittle] in spark plug hole only comes up
{15-20 Lbs} , we did not replace any valves/guides or springs . put heads on the Vacuum tester [both were where they should be] made sure no light shines past valves {ok} , this was all done before gave to mech 1st time ! mech. says he pulled vlv cover & all vlv.s look like moving up/down with no problems said he can't see anything wrong , when go down highway , runs good , but @ idle can feel alittle miss & worst under a LOAD? mech is wondering if could be anything they could ck & change/replace without having to pull head???? says he has ck'd injectors & fire .
PLEASE somebody HELP
THANKs
butch @butch's auto & diesel
Press.Test for Cracks {ok} , ck'd vlv. guides 'ok', Ground Valves & Seats , Surfaced Heads [0.004] , Mech. took heads put on block , now he has [pass.side]head w/low comp. #2 & #8 cyl.s said he did 'dry/wet' comp. test & get aprox. 50-75Lbs & when puts [alittle] in spark plug hole only comes up
{15-20 Lbs} , we did not replace any valves/guides or springs . put heads on the Vacuum tester [both were where they should be] made sure no light shines past valves {ok} , this was all done before gave to mech 1st time ! mech. says he pulled vlv cover & all vlv.s look like moving up/down with no problems said he can't see anything wrong , when go down highway , runs good , but @ idle can feel alittle miss & worst under a LOAD? mech is wondering if could be anything they could ck & change/replace without having to pull head???? says he has ck'd injectors & fire .
PLEASE somebody HELP
THANKs
butch @butch's auto & diesel
#2
05-22-2009, 01:47 PM
Join Date: Apr 2009
Location: alexandria La.
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new add-on to low compression
{05/22}
Just talked to our cust.[4.7v8 sohc] dodge , says that they got eng. running & noticed that {believe he told me : 1int. vlv.[slight leak] #2 cyl. & the #8 cyl.
shows that the int. & exh, valves are showing a slight
leak, the way [mech.] is talking , these valves are going up & down valve guide OK but , are not sealing off completely[guess enough to cause a miss?? & he was wondering & hoping[along w/me] that there MAYBE a way to cause these valves to seal???? without having to pull the [1] head back off > the Mech. & i realize that we're asking for a miracle
BUT , hey anything is possible???? isn't it ?
the mech. is waiting to hear from me ,so if anybody has an idea PLEASE get back w/me today[if poss]
thank U for any miracle out there
butch
Just talked to our cust.[4.7v8 sohc] dodge , says that they got eng. running & noticed that {believe he told me : 1int. vlv.[slight leak] #2 cyl. & the #8 cyl.
shows that the int. & exh, valves are showing a slight
leak, the way [mech.] is talking , these valves are going up & down valve guide OK but , are not sealing off completely[guess enough to cause a miss?? & he was wondering & hoping[along w/me] that there MAYBE a way to cause these valves to seal???? without having to pull the [1] head back off > the Mech. & i realize that we're asking for a miracle
BUT , hey anything is possible???? isn't it ?
the mech. is waiting to hear from me ,so if anybody has an idea PLEASE get back w/me today[if poss]
thank U for any miracle out there
butch