Sticking valves

Thread view:

Enable EMail Alerts

Start New Thread

Thread rating:

Ryan Underwood - 12 Oct 2004 21:40 GMT

Well, I think my rough cold-start issue made itself more apparent today.
Today I was clearly able to hear valve ticking for the first time, which
made the other things that were going on a bit more obvious and simple to
explain - a valve is sticking.

Once I figure out which valve it is, what is the usual remedy? Ignore it
until rebuild time?

I've never done valve clearance on this car. Would it help or hurt at
this point?

Is it possible to hurt the camshaft or lifters by revving the engine in
the morning to get the valve un-stuck? Once it's un-stuck, it's fine for
the rest of the day.

I read some anecdotes about pouring 1/2 qt ATF or Marvel into the oil, but
I'm rather skeptical that putting anything but oil in there would be a
good idea.

I don't change my oil very often (4-6 months on average), but I drive less
than 1000 miles in between changes, and use non-synthetic brand name
5W-30. I'm not sure if this is something expected with high mileage or
if I should be blamed for improper maintenance.

Reply to this Message

MCL - 12 Oct 2004 22:57 GMT

If the valve & only one valve, is sticking there is no reason for an
adjustment. If it goes away as you said then it's sticking not out of
adjustment. And YES revving will send it to an early grave: cam, lifter,
pushrod, rocker & valve depending on the car can all be damaged. Skeptical
about putting anything but oil in, it's called Marvel Mystery OIL & it works
great for your exact sticking problem. I've used it for years on older high
mileage Chevys that usually get a valve tick. Try it, it's been around for
longer than I can remember.
Mike

> Well, I think my rough cold-start issue made itself more apparent today.
> Today I was clearly able to hear valve ticking for the first time, which
[quoted text clipped - 19 lines]
> 5W-30. I'm not sure if this is something expected with high mileage or
> if I should be blamed for improper maintenance.

Reply to this Message

Ryan Underwood - 13 Oct 2004 02:34 GMT

> If the valve & only one valve, is sticking there is no reason for an
> adjustment. If it goes away as you said then it's sticking not out of
> adjustment.

Well, it un-sticks, but the ticking stays around for a little bit until
things warm up. This is just observation from driving around today
because I haven't heard the ticking before.

> And YES revving will send it to an early grave: cam, lifter, pushrod,
> rocker & valve depending on the car can all be damaged.

Ouch. Well, I don't "race" it. Usually getting it up around 2500-3000
clears it up. (Or just getting on the road.) Hopefully that's not a big
deal, though warning heeded.

> Skeptical about putting anything but oil in, it's called Marvel Mystery
> OIL & it works great for your exact sticking problem. I've used it for
> years on older high mileage Chevys that usually get a valve tick. Try
> it, it's been around for longer than I can remember.

Excellent! Thanks for the feedback; I'll give it a try. This is a high
mileage car (18xxxx) and I've only owned it for the past 7 years. Who
knows how the previous guys took care of it.

Reply to this Message

Brian - 13 Oct 2004 15:03 GMT

If the car is new enough to have hydraulic valve lash adjusters, then
probably they are leaking down between running sessions. A sticking valve
(where the valve actually sticks in the guide) doesn't normally tick, it
hits the piston and bends. Changing the oil will help, running 10W oil may
help, MMO may help, etc.

Brian

>> If the valve & only one valve, is sticking there is no reason for an
>> adjustment. If it goes away as you said then it's sticking not out of
[quoted text clipped - 19 lines]
> mileage car (18xxxx) and I've only owned it for the past 7 years. Who
> knows how the previous guys took care of it.

Reply to this Message

Ryan Underwood - 13 Oct 2004 23:36 GMT

> If the car is new enough to have hydraulic valve lash adjusters, then
> probably they are leaking down between running sessions. A sticking valve
> (where the valve actually sticks in the guide) doesn't normally tick, it
> hits the piston and bends. Changing the oil will help, running 10W oil may
> help, MMO may help, etc.

Hmm, well according to the teardown manual I don't have hydraulic
adjustments (they recommend a periodic clearance adjustment).

I bought some MMO. Should it go in the gas or the oil? If oil, how soon
should I change the oil afterwards to avoid complications?

Reply to this Message

MCL - 14 Oct 2004 00:48 GMT

You don't change the oil. The MMO stays in as regular oil. Use a quart in
replacement of a quart of regular oil & leave it in.

> > If the car is new enough to have hydraulic valve lash adjusters, then
> > probably they are leaking down between running sessions. A sticking valve
[quoted text clipped - 7 lines]
> I bought some MMO. Should it go in the gas or the oil? If oil, how soon
> should I change the oil afterwards to avoid complications?

Reply to this Message

Ryan Underwood - 29 Oct 2004 20:00 GMT

> If the valve & only one valve, is sticking there is no reason for an
> adjustment. If it goes away as you said then it's sticking not out of
[quoted text clipped - 4 lines]
> mileage Chevys that usually get a valve tick. Try it, it's been around for
> longer than I can remember.

Mike,

just to follow up. I put 6oz of MMO in a 10 gallon tank of gas. After a
week or so of sporadic driving, the problem (whatever it was) gradually
disappeared. It fires up smooth now. I'm not sure what it was (clogged
injector?), but MMO in the gas sure did the trick this time. Maybe some
of it leaked down into the pan and ended up doing some other cleaning too.

Thanks!

Reply to this Message