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I have a 1994 ES300 and was going to change the spark plugs when I noticed there is a plastic valve that appears to work as an overflow that sits below the intake manifold and top of the engine block. I’m not sure what exactly it is for and I have had no luck identifying the part or finding a replacement other than finding one at a local junk yard. It is a pain in the neck to get this part out even when it was broken and I now have just a hose line feeding into when it was before. I believe it’s coolant or overflow run off valve but I just don’t know and don’t want to do any damage. Here is the photo
Given the age that grommet is probably going to crumble when you try and remove hit it with a heat gun and get it nice and toasty first.
edit - if some of the grommet falls inside the valve cover not the end of the world there is an oil baffle that will prevent the pieces from going into the engine.
I have a 1994 ES300 and was going to change the spark plugs when I noticed there is a plastic valve that appears to work as an overflow that sits below the intake manifold and top of the engine block. I’m not sure what exactly it is for and I have had no luck identifying the part or finding a replacement other than finding one at a local junk yard. It is a pain in the neck to get this part out even when it was broken and I now have just a hose line feeding into when it was before. I believe it’s coolant or overflow run off valve but I just don’t know and don’t want to do any damage. Here is the photo
Bolding mine. That there sir is your Positive Crankcase Valve mounted into the grommet on your rear camshaft valve cover.
The good news is the parts you're wanting to replace are freely available and quite cheap.
The 5 inch long hose which has a 90 degree bend in it is the part which tends to go super hard over time. Thankfully the grommet which inserts into the rear valve cover stays quite malleable and soft. Indeed there's a very good chance you wouldn't need to replace it.
In any event, you should seek to implement the PCV system correctly on your car. The PCV valve wears out over time, and contrary to popular belief, only opens under partial vacuum not under full vacuum at idle. The system allows combustion "blow by" gases to be get gently sucked back through your inlet manifold and it plays a major role in keeping your engine oil clean - but not at idle because then it would be acting as an unmetered vacuum leak.
Prior to the introduction of PCV systems, engines breathed blow by gases directly on to the road surface and there was no recycling happening at all under partial throttle. As a result, blow by gases had a LOT of time to ruin the engine oil, which in turn caused terrible sludge problems.
The 3VZ-FE and 1MZ-FE engines are inherently prone to sludge problems even WITH a correctly functioning PCV system.
I'm a big fan of the early ES300 cars, but they do require a lot of love now that they're hitting 30 years of age.
Do your engine oil changes every 6 months, and use a quality engine flush product immediately prior to draining your oil.
03-17-23, 07:18 PM
1st Gen ES300 part identifier (help!)
