3.0L cold ticking

'93 Grand Voyager 3.0L, under 120k miles (190k kms). This winter it fairly
suddenly developed a very loud ticking sound when cold. It goes away after a
few minutes when it warms up. I switched from 10W30 to 5W30 "winter oil"
synthetic blend hoping to quiet it down a tad with no change at all. I would
say sticky lifter but I'm not sure if this thing even has lifters (as far as
I know it's overhead cam, right?) or an exhaust leak at the heads. Any
advise?

 

Yes it has lifters. They are located in the tip of the rocker arms. Sounds
like you may have something in one of the lifters (debris) that is holding
the valve open. You might try some of the detergent you can buy for the
oil. I believe that CD2 used to make a material like this. Good luck.

 

They are more "correctly" referred to as "lash adjusters" in that
geometry (i.e., when not directly in the path of the valve stem, or in
the case of a push rod engine, in the path of the push rod - all lifters
are lash adjusters, not all lash adjusters are "lifters" as the term is
technically used). I know I'm being picky - please don't take offense.
Not a big deal when people call them lifters - just thought I'd
point that out.

Actually, when a lifter/lash adjuster is "sticking" or "collapsed", it
is the opposite - rather than a valve being held *open*, the valve is
*not* opening, or is not opening enough. The noise in that situation is
due to the excessive gap between rocker and valve stem or rocker and
lifter/lash adjuster (goes along with the term "lash adjuster").

It could be an exahust or intake leak that closes up with heat, but
you're right - if it's a lifter/lash adjuster, some cleanout additive
could "unstick it" - MMO, Sea Foam, or ATF are known to work well.

Also, the anti-drainback valve in some oil filters is not as good as in
others - they can leak down and you get more dry-run time on startup.
The OP might review what filter model he is using and possibly change to
one that is known to have a good ADB valve (one made of silicone - not
nitrile - rubber).

Bill Putney
(To reply by e-mail, replace the last letter of the alphabet in my
address with the letter 'x')