'91 4.0L OHV chattering on cold start

[SouthernWheelin]

Ok here is my problem;

When the engine is cold it makes a chattering sound like it coming from the lifters or the rocker arms.

After warm up it smoothes out and purrs at idle but when the engine is revved the sound comes back only not quite as loud as when it is cold.

The previous owners are friends of mine and they noticed the problem too when they purchased it used. They had sprung for the Wynn's Warranty for used cars and had the top end rebuilt under warranty, only to get it back sounding the same as when it left.

I would not guarantee that it actually got rebuilt but they were told it was.

I have heard another X from the same year make the cold start noise also. I have been told that this was a Ford design flaw in that the oil channels were too small and therefore insuficient oil was reaching the top of the motor.

Is this the case or is there a way to remedy the chattering?

I am happy with the performance of this motor, it has 160k miles on it now, other than this annoying sound.

Any thoughts are greatly appreciated

 

[ajevenson]

Sounds like lifter clatter to me. You may be able to remedy the problem by installing a new oil pump as your old one might not be doing the job. A cheaper cost solution is a product like STP oil additive which is like molasses and you add to your oil and it makes the oil really sticky and viscous when it cools. That way the oil doesn't drain out of the top of the motor when you shut the engine off.

I had the same problem on my S-10 and the STP worked for about 8 months before the engine blew up due to a bad oil pump. Those are my thoughts...

 

[SouthernWheelin]

Well, I read through the oil filter study and found out that the filter I am using and have always used is one of the worst filters to get. The Fram Extra Guard.

Will change it over the weekend to either Mobil1 or Motorcraft. If it helps any I will post back here.

 

[sharonis3]

Clatter

I had same thing. Clatter on startup. Read same report and stopped using Fram. Put on a Purolator and never heard the noise again.

 

[SouthernWheelin]

I changed the oil filter with the one from Motorcraft. Didn't notice much difference in the ticking sound.

I decided to go ahead and try the STP treatment. It helped some. The ticking is not as loud as before but it is still there and very noticable.

The performance of the engine doesn't seem to be affected by this so I am not going to lose sleep over it.
I think I will try some heavier wieght oil next change and switch to synth as well. Currently I use 10w30 QS.

Does anyone know if replacing the lifters, rods and rocker arms will solve this prob or is it just buildup? Would I benefit from flushing the engine next oil change?

Thanks for the tips guys!

 

[Raceit]

I had the same problem. I tried everything in the book to try and fix it. But it turned out that about half of my lifters had collapsed.

Below is a picture of the valve cover that's been removed. If you look at the assembly with the red paint on the sprint you'll see a gap between the valve it self and the rocker arm. That's what was causing the noise on my engine. It might be worth picking up a couple valve cover gaskets if you want to check those if nothing else is working.

Dead Link Removed

Here is the complete write up and some more pics....

Dead Link Removed

 

[SouthernWheelin]

Thanks Raceit. That was just what I was looking for. Nice write-up and pics of the job. It will be very helpful. I will probably take a look under the valve cover this weekend.