I opened valve cover

[86bayliner]

My mechanic didnt have any numbers for me , he said the clylinder had compression of about 125, ??umm i think he just told me that. Could have come out better doing the stupid compression test myself, but as you will see even without doing a full compression test i found an obvious problem.<br />Im still getting around to the test, gonna do it anyway. before and after i work on it, i promise.<br /><br />I removed valve cover and cranked engine. I watched all the rocker arms move except the very last one. Number 7 does not rock like the others. This is the one on the end, not sure if its the intake or exhaust of 7, but its definitely the one on the end. I turned engine off and walked back to rocker arms to study further. I felt each one to compare to the other with my fingers. The #7 rocker (one on the end)arm has a good bit of slack or play, its not tight like the others. The nut that holds the arm in place seems tight like the other arms nuts, except i can wiggle it around a bit. the push rod has just a tad play in it too. more than the others.<br /> <br />any thoughts while i look for some oil to squirt down the valve guide. should i hit with a hammer.?<br /><br />thanks, <br /><br />86bayliner<br />Norcross, GA 30071

 

[prockvoan]

Re: I opened valve cover

First off,what engine?

 

[Alumarine]

Re: I opened valve cover

Does the push rod go up and down on #7? btw shouldn't the very last one be #8?

 

[Bondo]

Re: I opened valve cover

Your description Sounds like a "Wiped-Out" Cam Lobe,...........<br />In other words,...... There's No Bump left on the Camshaft............<br /><br />It's already been mentioned before,... But,....<br /><br />Your Best Way Out,.. At this point is to go get a Junkyard 350 Chevy, out of a Truck,.......<br />Strip it down to the "Long-block",+ Install ALL of the assessories from the Broken Motor you have Now,..........<br /><br />Then Go Boating,+ Have some Fun...........

 

[86bayliner]

Re: I opened valve cover

Originally posted by Bondo:<br /> Your description Sounds like a "Wiped-Out" Cam Lobe,...........<br />In other words,...... There's No Bump left on the Camshaft............<br />

all my accessories from my 305 will mount up with a 350? what do i expect to cough up for soemthing like that from a junkyard?<br /><br />for u others , im sorry for not mentioning the engine, its a 1986 305 5L v8 Volvo Penta Aq225e<br />and its the exhaust rocker if im not mistaken from what my what the manual says<br /><br />so i can loose "bump" over night? I was hauling across the lake just three weeks ago,<br />jeeeeez.........<br />and thanks for all the ideas?<br /><br /><br />86bayliner<br />

 

[searay3]

Re: I opened valve cover

Pull the rocker off the suspected valve and inspect further. Possible bent push rod? I have had that happen before on chevy v8's. Could mean a head re-do. I have also seen where the hydraulic lifter has collapsed. I'm not sure what the budget is, but if you have head/valve damage it probably will end up a motor swap or rebuild anyway if you have want to have confidence in the motor.

 

[rodbolt]

Re: I opened valve cover

yep now its time to inspect installed valve stem height. if its low the #7 EX valve is stuck open. if its within specs its time to measure cam lift. measure two or three other ex valves at the top of the pushrod travel and compare it with #7 ex. if the travel is much different its time to look at lifters and cam lobes. normally a wiped lobe will show up as mettalic engine oil. all that metal has to go someplace.

 

[Bt Doctur]

Re: I opened valve cover

id say theres a chance #7 exaust valve took a dunp from a leaky riser and stuck a valve bending/breaking the push rod.On a gm head the valve sequence is: EIIEEIIE E-exaust,I intake

 

[86bayliner]

Re: I opened valve cover

i cranked it up again, i noticed the rocker moving , but only a little. i pushed down on the rod with my finger, felt nothing pushing it up, then i put my finger on the other rockers and i can sure feel the power of the rod going up and down.<br /><br />Im gonna have to pull the head off regardless arent I?<br /><br />thanks for your input<br /><br />86bayliner

 

[Haut Medoc]

Re: I opened valve cover

Yes, you will. If you are lucky it might be a collapsed lifter. If you have that "metal sheen" in your oil, (you can't mistake it), then you have a bad lobe. They wear out quick once you get past the hardened metal.....JK

 

[86bayliner]

Re: I opened valve cover

it is a 20 year old boat, ive been doing alot of reading, Im gonna open her up and im gonna stop playing and im gonna fix it. one way or another. <br /><br />i know you can replace lifters, pushrods and have valves machined, but if i have the problem of a worn lobe is the cam replaceable while i have her opened up? if not could i, "jerry rig," the rounded lobe? <br /><br />so worst case scenario for me then would be as follows:<br /><br />3 things<br /><br />(a) being the worst to me anyways but i'll manage.<br /> a worn or (rounded)lobe on camshaft<br /><br />b)failed lifter, possible reason- since engine was running great before oil change and over fill of oil due to my neglect of about a quart. if lifter failed for another reason, it is unknown as of now.<br /><br />c)Exhaust valve guide is bent or in need of machining and or replacement? by george do i finnally get it. Ive narrowed it all down.<br /><br />you guys helped me out alot, really apreciate it , ive been on this for weeks now,<br /><br />let me know if you think i got my problem understood <br /><br />Would the above be correct for my situation,<br /><br />thanks. <br /><br />86bayliner<br />Norcross, Ga<br />

 

[imported_scott_m]

Re: I opened valve cover

If I understand your post, you're seeing 125PSI of compression in number 7? If that is indeed the case, then you do not have a bent/broken exhaust valve and the head is probably fine. You can replace the cam and at the same time, you'll want to do all the lifters. The rest should be fine. Even if it is 'just a bad lifter', I'd probably go ahead and stab a new cam in at the same time so it wears evenly. If she did eat a lobe, I would not run the motor a whole bunch until you can get thru a couple of oil changes to get the metal out of the oil.

 

[rodbolt]

Re: I opened valve cover

have a leakdown test run on #7. if it passes the valve is ok. then pull the intake and check the lifter. use a dial indicator or calipers to check the plunger depth and the lobe lift. compare one to another. the cam and lifters are replacaple without pulling the head if the hull allows access.

 

[86bayliner]

Re: I opened valve cover

oh cool, ok thanks<br /><br />--------------------------------------<br /><br />86bayliner

 

[Alumarine]

Re: I opened valve cover

You can replace the cam in the boat if you have 2 ft. or so of space in front of the engine (the cam is the same length as the block).

 

[86bayliner]

Re: I opened valve cover

jeeez..........<br /><br />dont think i have the room but will investigate further when i can get this stupid intake off,<br />Please tell me a way to pry the intake off with out killing it, i have all the bolts removed, distributor and throttle linkage pushed aside everything i can find. and its seems like a stuck bi...?????<br /><br /><br />thanks, <br /><br />86bayliner

 

[86bayliner]

Re: I opened valve cover

im praying its not the cam then

 

[86bayliner]

Re: I opened valve cover

ok i got it off yeah

 

[86bayliner]

Re: I opened valve cover

now im messed up cause i thought i was going to be able to see the lobes when the intake came off, jeeez, ok now im gonna pull the head off, is it a requirement to pull the riser off when pulling a head, ill be digging in my book while a wait your answers <br /><br />thanks,<br /><br />86bayliner and now that i got the intake off, looks like everythings intack. <br />ill have to read these other threads again to learn how to test the lifter

 

[86bayliner]

Re: I opened valve cover

appears to be no metal in the oil<br />just eagar to now what to do next.