I have a lot of residue by this. Does not seem to be sitting flush
This picture is not my Lx, but from another vehicle.
This picture is not my Lx, but from another vehicle.
Is this the PCV valve
- Thread starter MadKel
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nukegoat
Should have bought a Jeep
Yeah. Check out this website i found where you can type in stuff like "2uz pcv valve" and itll show you pictures of them:
www.google.com
www.google.com
That be the pcv hose, the valve snaps into a rubber grommet in the valve cover. Maybe a leaky grommet or one that isn't fully in the valve cover. Sequence I used was to remove the hose from the valve, and then pull the valve straight out of the grommet...pull gently and be aware that the valve cover side of the valve can break off and drop into the valve cover...amhik. 
Once that's done, you can remove the grommet and "reassemble in reverse order". I'd definitely use a new grommet. A bit of silicone grease on everything makes assembly a breeze and maybe disassembly later on.
hth
Once that's done, you can remove the grommet and "reassemble in reverse order". I'd definitely use a new grommet. A bit of silicone grease on everything makes assembly a breeze and maybe disassembly later on.hth
Question: what does this valve?
nukegoat
Should have bought a Jeep
It helps the
2001LC
SILVER Star
PCV (positive crankcase ventilation) valve is retain by a rubber grommet in the 98-02 100 series.
The grommet is better changed out with new OEM grommet sooner rather than later.
03-07 PCV are threaded into head cover (no grommet).
98-07 have PCV hoses on both side of engine. PCV valve is only on LH side.
PCV system pulls crankcase gasses from engine block oil pan/crankshaft cavity. These gasses (if not pulled out) build up pressure and blowing gasses along with oil out anyway it can find, blowing out seals and blowing passed piston oil rings (head cover gasket, spark plug tube seals, cam seals, crank seals, rear main seal, etc..).
Vacuum (low pressure) within intake manifold pulls these gasses out of crankcase and burns them in cylinder heads. If hoses or grommets bad/leaking/cracked, intake looses some vacuum and gasses are not effectively pulled and burned off. So engine not only builds up gasses/pressure in crankcase it affect manifold vacuum.
The PCV valve controls/meters vacuum. If stuck shut we don't remove gasses. If stuck open we may pull to soon, loosing some manifold vacuum.
The grommet is better changed out with new OEM grommet sooner rather than later.
03-07 PCV are threaded into head cover (no grommet).
98-07 have PCV hoses on both side of engine. PCV valve is only on LH side.
PCV system pulls crankcase gasses from engine block oil pan/crankshaft cavity. These gasses (if not pulled out) build up pressure and blowing gasses along with oil out anyway it can find, blowing out seals and blowing passed piston oil rings (head cover gasket, spark plug tube seals, cam seals, crank seals, rear main seal, etc..).
Vacuum (low pressure) within intake manifold pulls these gasses out of crankcase and burns them in cylinder heads. If hoses or grommets bad/leaking/cracked, intake looses some vacuum and gasses are not effectively pulled and burned off. So engine not only builds up gasses/pressure in crankcase it affect manifold vacuum.
The PCV valve controls/meters vacuum. If stuck shut we don't remove gasses. If stuck open we may pull to soon, loosing some manifold vacuum.
Can this cause misfiring?
2001LC
SILVER Star
In severe case, I'll say YES!
It can cause oil to pass oil ring and carbon up compression ring and foul spark plugs. Even before that it may blow oil into spark plug tubes, filling them with oil. This may affect temp of coil and spark. Vacuum leaks will alter manifold pressure. So YES, a number of issue can result.
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Checked the PCV and it still rattles so it is not stuck.
2001LC
SILVER Star
Rattle is good. But test is if air passes in one direction only, out!
Misfire is often a bad coil or weak one not yet setting of a CEL.
Is engine tuned:
Tuning the engine includes getting all vacuum lines & hoses in good service. Also disconnecting battery for 20 min to reset ECM and cleaning & grease post. While cleaning throttle -body. Also all spark plugs should be cleaned and inspected. Coils may need replacing or just coil boots. Oil & filter and air filter. If still have a miss to a compression check.
Misfire is often a bad coil or weak one not yet setting of a CEL.
Is engine tuned:
Tuning the engine includes getting all vacuum lines & hoses in good service. Also disconnecting battery for 20 min to reset ECM and cleaning & grease post. While cleaning throttle -body. Also all spark plugs should be cleaned and inspected. Coils may need replacing or just coil boots. Oil & filter and air filter. If still have a miss to a compression check.
I've never found a definitive answer on whether these need to be replaced on 03+ trucks, and how to do it if so. I've read that the design improved from 03 on, but I have no idea if they're "good for life" or if they need periodic replacement. I have an 03 LX, FWIW.
2001LC
SILVER Star
If good oil change history with synthetic oil & filter and air filter, are done/used all it's life in a well tuned 2UZ engine. They can last what seems like forever. What usually happens is they gunk-up and valve fails. They are replaceable in the 03-07, they're thread on. Lock-tight is used during installing, so they're tight.
Rattle tells us the valve is free. Checking air follow tells use valve is working.
Rattle tells us the valve is free. Checking air follow tells use valve is working.
Awesome, thank you! Can you elaborate on how to check to make it rattle or how to check air flow? I'm not familiar with PCV systems.
2001LC
SILVER Star
Google videos for other ways on vehicle!
Looks like I'm in for some fun as I have a PCV that has never been changed....98 model.
I tried replacing mine but it was so dang hard to rotate that thing off even with the biggest wrench I got and cheater bar. It looks like these come pre-loctited and it's heavy duty! The early models are grommet and the newer models are screw on, mine is a screw on and boy it's tight...
I didn't want to damage things, so I'm just going to wait to do the PCV at a later date when I am disassembly the whole valve cover to do valve cover gasket replacement. My hoses and the foam were also in nasty condition, the foam is crispy and flaking and the hose clips were rusted and not really gripping anymore and the hose felt loose on the nipples. I wanted to wait for the new parts to arrive before I do a proper replacement. so might as well wait.
I made some notes on the part numbers for the hoses/foam:
1226150050 - hose with foam $13 partsouq
9046715021 - hose clips – 2x $0.5 partsouq
1223650010 - valve cover foam $2 partsouq
1223550010 - foam on top engine - $6, lexuspartsnow, partsouq not have
With valve cover off, the whole PCV is off the truck and I don't have things obstructing my bigger wrenches getting the PCV off. If I really have to I'll grind the plastic tip off and then use my big impact gun that I use to get out my crankshaft bolt.... Can't use that gun with all the other pipes and mounts blocking while the valve cover is mounted.
I didn't want to damage things, so I'm just going to wait to do the PCV at a later date when I am disassembly the whole valve cover to do valve cover gasket replacement. My hoses and the foam were also in nasty condition, the foam is crispy and flaking and the hose clips were rusted and not really gripping anymore and the hose felt loose on the nipples. I wanted to wait for the new parts to arrive before I do a proper replacement. so might as well wait.
I made some notes on the part numbers for the hoses/foam:
1226150050 - hose with foam $13 partsouq
9046715021 - hose clips – 2x $0.5 partsouq
1223650010 - valve cover foam $2 partsouq
1223550010 - foam on top engine - $6, lexuspartsnow, partsouq not have
With valve cover off, the whole PCV is off the truck and I don't have things obstructing my bigger wrenches getting the PCV off. If I really have to I'll grind the plastic tip off and then use my big impact gun that I use to get out my crankshaft bolt.... Can't use that gun with all the other pipes and mounts blocking while the valve cover is mounted.
2001LC
SILVER Star
03-up PCV valves are hard to remove, due to factory seal on threads. If engine run on synthetic oils, most of it's life, or very frequent oil service. They usually test good, so don't need removing. These, I like to add a little SeaFoam into.
Ones that I did remove to service. I've been able to get off with my tools. Which I do, head cover in place. Removing PCV valve, while head cover off head. Head cover, then need held. Which holding, would be difficult to distribute force equally around body of cover.
Addition, up to now. I just re-torque head cover bolts to 53IN.lbf. Rather than replace the gasket. The only HC gaskets, I've had to replace. Are ones that were not the factory installed ones. That is, ones some replaced already.
Ones that I did remove to service. I've been able to get off with my tools. Which I do, head cover in place. Removing PCV valve, while head cover off head. Head cover, then need held. Which holding, would be difficult to distribute force equally around body of cover.
Addition, up to now. I just re-torque head cover bolts to 53IN.lbf. Rather than replace the gasket. The only HC gaskets, I've had to replace. Are ones that were not the factory installed ones. That is, ones some replaced already.
