Sorry for the off forum post but I really trust you guys more than blindly posting in another forum....

My daughter has a 99 mustang with the 3.8l v6. One of the lifters is noisy for a couple of minutes after starting. I have pretty much verified it is not an exhaust leak. I can feel it thru the valve cover.

I need to change the oil, so....would a thicker oil help quiet the noise? or should I go with a thinner (even synthetic) oil?

The noise takes care of itself after a couple of minutes but if an oil weight change would help I would do it.

Thanks for your help.

 

Just my 2cents.

Run a can of Seafoam through the oil pan prior to the oil change. Then change the oil with a multi weight synthetic.

I had a 5.0L but had a similar issue. Buy 2 oil filters, 1 cheap and one good. Pull the old oil filter off (without draining the oilpan). Install the cheap filter, add a can of seafom to the crankcase. Run the engine for 10 or 15 minutes. Then do a normal oil change with a new filter. The cheap filter will catch all the crud that may come out during the seafom treatment.

As far as oils, for full synthetic i use Mobil 1 high mileage, Royal Purple or Castrol.

 

What oil have you been running?

I had a stcky lifters in my 302 and tryed all kinds of additives. Nothing worked and was a waste of time and money. You know what finally made a big diffference? Synthetic oil (no particular brand) and miles of driving.

 

I have always used Motorcraft semi-synthetic 5W30. The previous owner was a Ford Service guy so I assume it has had the same oil it's whole life.

It needs an oil change now. I was hoping that a little thicker or thinner might keep the lifter primed. Maybe it just needs the extra cleaning that a full synthetic would give it.

I am leery of using seafoam in the crankcase but it seems fairly common.

 

I'd retain the 5w-30 and just go with a synthetic oil. You don't have to spend a lot either. One of the oils I use the most is Pennzoil platinum which is now $25 for a 5 quart jug. I'm not a fan of all the miracle additives on the market, never impressed with any of them.

 

Thanks dkf. I'll give the Pennzoil a try.

 

If it's the old 3.8 pushrod motor, pull the valve cover and find out why it's making noise. If you can feel it through the valve cover, it's not the lifter but more likely the rocker arm pivot. If the ball or rocker arm is worn, replace both and be done with it.

In my opinion, never ever run Seafoam or any other "cleaner" through an engine that you want to keep. If it's a last-ditch effort and you're already looking at replacing the motor, what the heck... but if it's just a single rocker arm or even collapsed lifter, just fix it

You could try running 10W40 in it and see if that helps the noise - just as a test.

 

Good advice Art.

I need to do an oil change anyway so I will try either the cheap synthetic or a little heavier oil. If that doesn't do it, I might pull the valve cover. It seems like if the rocker was loose or worn it would make the noise all the time. The fact it goes away leads me to believe that it is a priming issue.

The daughter is moving out next year and I will probably help her get a different car. The stang is a convertible and that worries me a little when it sits outside in the dorms / apartments.

 

could it be a piston slap?

 

Good point on the piston slap - my wife's '97 Cougar has/had piston slap, and at times it really sounded just like a lifter.

But in this case, I'm willing to bet that as the engine heats up, the pushrod expands and takes up whatever slack in the valve train there is. How long does it take for the ticking to go away, right away within a few seconds, or a few minutes ?

 

The noise usually goes away in about 2 minutes.

I just came in from changing the oil with Pennzoil Platinum synthetic. Even on a cold start after changing there was no noise.

I will post back after several cold starts to see if it went away.

It seemed to definitely be an upper engine noise but I have never owned anything that had piston slap. That is more of a Chebby thing?