1FZFE valve cover design changes: (1 Viewer)

[Kernal]

Just tossing this out for discussion. There are apparently (at least) three different designs for the 1FZFE valve cover baffle (Parts gurus please chime in).

So the question is, why change the design of the baffle?

To decrease the amount of oil vapor being sucked up by the PCV system?

To increase flow (drainage) back out of the baffle?

Or more likely both??

What is not known (to me) is whether the design/flow inside the baffle box was also changed??

Here are some photos, the top photo is from TYM4FUN's build thread which shows a new valve cover (? most recent design) with a silver colored baffle, and an earlier version with the gold colored baffle.

Note the addition of a large rectangular ? drain hole in the newer valve cover (click on photo twice to magnify). But also note the squarish shields
over the vent (?IN) holes:

 

[Kernal]

And here's a photo of a valve cover from an early 96 model US Spec FZJ80/1FZFE.

Compare this valve cover to the baffle design to the others above.

There are apparent differences in the design of the shields for some of the vent holes along with smaller open flaps for the drain slots compared to
the larger rectangular open hole in the top photo above:

 

[Kernal]

So what's the point: Anyone who's pulled off their Throttle Body has probably found the same thing; a pool of oil in the intake plenum along with a ton of baked on oil/soot. Oil from the PCV, soot from the EGR system, together they make black concrete.

Seems obvious that a Toyota engineer decided the original baffle needed redesigning for ?? better ventilation, less oil being sucked into the intake, etc.

Question: is it possible/feasible to modify an older design baffle to work like the newer design? Just bend the tabs on the older design more open?? (IIRC that's been discussed). A catch can will trap some of the excess oil being sucked up by the PCV but then does the newer baffle design provide other benefits (better ventilation, less sludge)??

FWIW





key words for future searches:

1FZFE Valve cover baffle design changes oil mist catch can

 

[BILT4ME]

Also note that the spark plug tube seals changed from the old design VC to the new design. Somewhere late 97 or to 98. The OD of the seal is smaller on the new ones.

 

[TYM4FUN]

One thing I did not mention, Toyota uses an adhesive around the parameter of the spark plug tube seals on the new valve cover.

 

[OGBeno]

Also note that the spark plug tube seals changed from the old design VC to the new design. Somewhere late 97 or to 98. The OD of the seal is smaller on the new ones.

They are the same as the 2UZ-FE. Which makes sense.

 

[Kernal]

Edit: Factory sealant apparently is applied when the baffle plate is attached to the inside top of the valve cover (I've found it turned brown and cracking off around the edges of the baffle plate). FWIW

 

[TYM4FUN]

So the new smaller OD seals installed into a new style valve cover from the factory used sealant/adhesive around the perimeter of each seal ie: during installation? Anyone have a photo of that?

When replacing those smaller OD seals, if sealant/adhesive is required,
anyone have a TSB for that?

Interesting

So I thought. Looking closer, it is sealer for the baffle plate.

 

[Kernal]

OK, I've found that on two original valve covers but it had turned dark and was cracking off. When I recently cleaned out the inside of the baffle box a bunch of chips of that old sealant came out.

 

[Malleus]

So the new smaller OD seals installed into a new style valve cover from the factory used sealant/adhesive around the perimeter of each seal ie: during installation? Anyone have a photo of that?

When replacing those smaller OD seals, if sealant/adhesive is required,
anyone have a TSB for that?

Interesting

 

[flintknapper]

I've no idea the reason(s) for the design changes. I'm baffled.

But I DO know....any well maintained 1FZ-FE will go for hundreds of thousands of miles with any of the designs.

So.....just throw a catch can on it to help reduce the amount of oil vapor and call it good. Crank her up, drive it, enjoy life.

 

[Kernal]

So I did a little experiment: put the garden hose nozzle into the breather hose port on the valve cover, the water comes out of the open flap at the rear of the plate, same side. Putting water into the PCV valve port, the water comes out on the other side (same side as the PCV valve port), also at the rear of the plate.

Also when blowing air into either port it seems like most of that air
comes out the bent flap hole in the plate on the same corresponding side as the air went in, but there also may be some flow out the other ports?? Hard to tell, maybe someone can do a colored smoke flow test.

So assuming the breather hose/port airflow direction is IN to one side
of the baffle box, and the PCV valve flow direction is OUT the other side,
then there must be a connection for air/gases (and some oil mist) to flow between the left and right chambers of the baffle box. And subsequently the design of the baffle plate/box will determine the amount of oil mist that gets pulled from one side to the other. IMHO.


The question is, for those with the earlier style baffle box, could people adjust those bent tabs to the open holes, cut a new hole, or ??

Looks like the with the new design they added shields to holes on both side of the baffle plate/box, most likely to decrease the amount of mist sucked IN to the baffle box. But they also added a large open rectangular hole on the breather side of the baffle plate/box. So is that for better airflow IN, or was it put there for better drainage of accumulated oil OUT (or both)??

IIRC someone has removed that baffle box/plate but I don't recall seeing
a photo of the guts of a baffle box/plate, anyone have such a photo?

Or (if your head hurts after reading this) forget about it and install an oil catch can.