cracked valve cover - common?
 

While doing an oil change this afternoon, I noticed that the valve cover on my '84 SD had a hairline crack running from the front to about 2/3's back pretty much right down the center...is this common? Anyone have an extra that they want to get rid of?

BH

I have never seen a bad MB valve cover. But its just cast alluminum and can crack it hit hard.

mine is cracked too. PO must have hammered it or something. But it's a hairline only a few inches starting from oil filler cap. I flushed it with isopropyl alcohol, pumped in some RTV from the top and it's holding great. All this on a complete rebuilt engine I did myself. Why? Just to see if the fix would hold. Now, if your engine is mostly beat and you have a lot of blowby, that may not work.

time for JB Weld or mabey a real weld and some grinding.

Mine has a hairline crack from in front of the filler cap to about halfway back.

It's not bad, but it seeps enough oil to be annoying. I'm not losing enough oil to need a top-off between 3k oil changes, and my mechanic isn't worried.

find someone with a junk engine to buy one from....thats cheaper than having it welded.

If you decide to have someone weld it make sure they know what they are doing and have the proper tools. It needs to be held so it can't warp when it's welded. I would try RTV or one of the other methods mentioned. To get it really clean you might be able to fit it in the dishwasher (just don't tell your wife/girlfriend/roomate/whatever:D ). Mine fit in my dishwasher.

Depending on where the crack is, you'd want to fill the crack from the inside of the cover because of the blow-by pressure. I've seen some covers that have casting cracks that look like real cracks but aren't. If there's oil seeping through, then it's real.:(
I like the dishwasher idea.:wacko:

Crazy Rays U Pull auto parts lists valve cover @ $10.

i think my cover is warped a lil from the oil seeping out in certain places after a new valve cover gasket was installed

Aluminum moves all over the place when welded. High heat will cause all kinds of distortion and stress in the cover.

The chances of welding the valve cover and being able to use it properly to seal with the gasket when you're done..........are zero.:mad:

Stop drill the end of the crack. Then fill the crack and hole from the inside with epoxy putty.

JB Weld makes an epoxy for aluminum that blends in really well.

Of course I am not sure if it comes in that "lightly oiled" color.:D

What are some good online used part sources for a used valve cover? I'm having the valves adjusted and the gasket replaced, and they said they'd put on a replacement valve cover for free if I supply it.

I remember browsing through one a year ago, that had them for maybe $30. Anyone know what the good sites are?

try sun valley dismantlers in sun valley, ca.

I don't know their URL but they have one.