I just did a service & tune on our 04 3.3L Grand Caravan including: oil change, air filter, oil pressure sending unit & r&r of the power steering reservoir. After doing the service, my wife & I noticed a squealing sound coming from the engine compartment that was not constant but intermittent. I figured had to be air in the PS system.. Jacked it up, blocked it & turned the wheels lock to lock approximately 100 times while checking the reservoir for bubbles. Some did escape so I figured had it handled. It does seem to have helped but squeal is still there. So I grabbed a stethoscope to hone in on the squeal. The PS system had no sound from reservoir, lines, pump or rack but the valve cover, specifically over cylinder 6 had the squeal. The only thing that comes to mind is rockers & or push rods not getting lubed? Am I on the right track here? My father, long time backyard mechanic suggested putting about a pint of ATF in the crankcase thinking if any type of carbon build up within the rods might get cleaned out, considering the highly detergent nature of ATF, therefor restoring any lost lubrication to the rockers. Wasn't sure if that would be something I felt comfortable doing to a late model engine, pre-90's I wouldn't have any problem but mid 2000's & I just wasn't sure of the impact to the sensors. Any help would be appreciated.

 

Anyone?

 

I see this has had 55 views, yet nobody has any advice or suggestions for me? I've always been fairly confident in my mechanical ability and now this problem pops up. I would just like some input. I'm kinda using this forum as a sounding board, if you will. Am I thinking correctly about the rockers & rods? Is ATF a good/bad idea? I know there are way more knowledgeable people on this forum, I've been helped many times before, just by browsing the q&a. Any help would be appreciated.

 

I do not think I would use the ATF in the engine. There should not be much of a build as long as you have been using a good brand of detergent oil.

The squeel could be a whistle caused be pressure or vacuum in the crankcase. I would check the PVC valve and the engine for blowby.

 

I second the PCV system. Could even be a pinhole leak in the valve cover gasket that is whistling. I'd pull the valve cover and see if it makes the noise with the cover off or just loosely sitting on the head. I haven't used ATF in the crankcase before but know people that have. I have used Seafoam in the CC and it seems to do something as the oil turns black really fast afterwards.