View Full Version : Valve/Head issues 351

07-07-2010, 09:38 AM
92 PS 351 Indmar. While replacing my valve cover gaskets a couple weeks ago I noticed the left #7 rocker arm was loose. All the others were snug. This one was wobbly. Tried to put a socket on it and tighten it but was afraid I'd break the stud. The engine is smoking off the port side. Blueish smoke. Not bad but not right. I can hear it clicking when I lift the doghouse. Here's my two questions...it seems to be running fine now.

1. Can I do any harm to my engine by continuing to use it as it? I'll take the heads off at the end of the season and get them re-done.

2. When you find a shop (Nashville) that can repair the heads what do they generally replace and what is a fair price to get both heads done?

Thanks. Kevin

07-07-2010, 09:50 AM
Was the nut backed off, or is it all the way down on the stud? If it didn't back off, you may have lost a lifter. I just had a similar problem on my '88 PS190, turned out I had a cracked valve. Can you do a compression check on the #7 cyl?

07-07-2010, 09:54 AM
Nut was tight. I'll see if I can borrow a compression gauge from a friend.

07-07-2010, 11:35 AM
was there lash in the pushrod? Grab on to the pushrod and see if you can spin it and/or move it up and down. If you can, pull that nut off and pull the pushrod out; check it to see if it is straight (roll it on a table or other flat surface) and if it is all there (missing an end?)

Simplest case: It sounds like you lost the lifter on that rod. That is fixable when you get the heads off, but installing new lifters without regrinding the cam is not a recommended "best practice".

Worst case: Your cam is damaged or busted, and the valves are not operating properly on the back side of the engine.

When you take the valve covers off, disconnect or ground out the distributor (or pull the plug wires if you dont want to mess around with the distributor) and turn the engine over a few times. You should be able to watch the valve intake and exhaust pushrods actuate the rockers in succession. You may be able to visually diagnose why you are getting smoke out of the #7 cylinder (or in fact, if it isn't the #7 cylinder)