Pour cleaner into PCV hole to reduce baffle blockage? 1mzfe 2002 Sienna.

[MrPlow]

Hi there,

I purchased a used 2002 Sienna with 220,000 miles on it a couple of months ago. I want to make sure the PCV system is running properly, but don't wish to spend the time and money getting to the rear of the engine to swap out the valve cover for the updated baffle and PCV mounting design. I will wait until the spark plugs need to be replaced before digging into the rear engine mess.

I have read of a couple of people pouring engine cleaner into the PCV hole and letting it soak into the valve cover baffle to help clean up the PCV venting holes, which are prone to clogging. Someone apparently used amsoil powerfoam to do this. I am a bit skeptical of putting something meant for the intake system, into the crankcase, even if doing an oil change soon after. Any thoughts on if this is a bad/good idea? Should I use Seafoam instead, as it is actually proven to work in the crankcase without destroying the engine? Any other product that might do a good job cleaning carbon and sludge from the baffle holes?

I am not looking to get the baffle factory fresh, but I think since it would be so easy to pop the PCV out (which needs to be done soon, along with grommet) and dump some stuff in there, then any gains in PCV venting would be nice.

Thanks!

 

[Lubener]

I wouldn't do that. I doubt that your actions would clean it.

 

[Imp4]

I am not looking to get the baffle factory fresh, but I think since it would be so easy to pop the PCV out (which needs to be done soon, along with grommet) and dump some stuff in there, then any gains in PCV venting would be nice.

Thanks!

The PCV and grommet on the 1MZFE is a particular pain in the rump. Located just in front of the passenger fire wall, the grommet typically hardens over time and needs to be cut out of the valve cover in little pieces.
Definitely a job that requires patience and is easiest done with the VC removed.

 

[AutoMechanic]

Seafoam would work for that most likely I use Seafoam in my cars and it always keeps them clean. You could also go to the store and get some Gum Cutter that stuff works good too to clean the PCV valve but the Seafoam would be easier to use so you won’t have to take the PCV out.

 

[MrPlow]

Thanks for the replies.

I was able to pop out the old PCV valve and the grommet didn't seem too burnt. Pulled the valve out and put it back quite easily with a bit of twisting. PCV grommets are pretty easy using a small, sharp knife to cut it into 2-3 chunks and then removing them without breaking into smaller pieces that fall into the valve cover. Done it on other Toyotas in less than a couple minutes, even my 200,000 mile 22RE grommet which was rock hard.

Regardless of everything else, would pouring something into there actually work at all? Would seafoam sprayed into there and let to soak melt out some of the carbon and sludge that is notorious to build up in the poorly designed baffle holes? I would of course be doing this right before an oil change.

Here's a post by someone with the same engine, different car.

"I had almost no labor as I used the PCV hole without removing the cover to fill the baffle with Amsoil foam cleaner three times before my oil changes and Seafoam "foam" cleaner the last time before the final oil change. The foam fills the baffle and the gunk/sludge melts away."

 

[AutoMechanic]

Thanks for the replies.

I was able to pop out the old PCV valve and the grommet didn't seem too burnt. Pulled the valve out and put it back quite easily with a bit of twisting. PCV grommets are pretty easy using a small, sharp knife to cut it into 2-3 chunks and then removing them without breaking into smaller pieces that fall into the valve cover. Done it on other Toyotas in less than a couple minutes, even my 200,000 mile 22RE grommet which was rock hard.

Regardless of everything else, would pouring something into there actually work at all? Would seafoam sprayed into there and let to soak melt out some of the carbon and sludge that is notorious to build up in the poorly designed baffle holes? I would of course be doing this right before an oil change.

Here's a post by someone with the same engine, different car.

I’d just pour the Seafoam in where the oil goes then it will clean the whole system and the PCV valve.

 

[PimTac]

Not some I would do but if you are bound and determined to try this then I would wait until just before you change the oil next time.

 

[MrPlow]

I’d just pour the Seafoam in where the oil goes then it will clean the whole system and the PCV valve.

Sure, but if the baffle vent holes are already a bit clogged (which is pretty much 100% certain with these engines with high miles) would the seafoam ever get there? Also, if I dump it into the PCV hole, the area that needs the most cleaning would then get a 100% seafoam concentration compared to diluting it in the oil.

I've been doing 1,000 mile OCI with Pennzoil Platinum (2x now) to clean up the rest of the engine.

 

[AutoMechanic]

Sure, but if the baffle vent holes are already a bit clogged (which is pretty much 100% certain with these engines with high miles) would the seafoam ever get there? Also, if I dump it into the PCV hole, the area that needs the most cleaning would then get a 100% seafoam concentration compared to diluting it in the oil.

I've been doing 1,000 mile OCI with Pennzoil Platinum (2x now) to clean up the rest of the engine.

Well the PCV hole goes to the same place as the oil hole does lol if you are pouring it in the hole on the valve cover. But I think the Seafoam would clean those blocked passages and benefit the entire engine. Just my opinion. But if you feel better about poring it into the PCV hole then that’s fine.

 

[MrPlow]

Looks like I will just use the Seafoam spray and hit it a few times before the next oil change. Thanks for the help, folks.

Wish I could document if this actually does anything for the baffle holes. Too bad the PCV valve isn't on the front cover, then I could do more an actual before/after test. Then again, I would just take the valve cover off and clean it properly or replace it if it was that easy of a job and not bother with dumping it down the PCV hole. LOL

 

[AutoMechanic]

Looks like I will just use the Seafoam spray and hit it a few times before the next oil change. Thanks for the help, folks.

Wish I could document if this actually does anything for the baffle holes. Too bad the PCV valve isn't on the front cover, then I could do more an actual before/after test. Then again, I would just take the valve cover off and clean it properly or replace it if it was that easy of a job and not bother with dumping it down the PCV hole. LOL

Do they make it in a spray bottle? Usually it’s a bottle you pour in. If they do make it in a spray let me know that might be handy if you are just trying to get a little bit in there.

 

[MrPlow]

Do they make it in a spray bottle? Usually it’s a bottle you pour in. If they do make it in a spray let me know that might be handy if you are just trying to get a little bit in there.

They sell a seafoam spray which is often used for the intake. I just did it a couple of weeks ago on my 1993 Yota Pickup 22RE intake. Comes with a really long spray tube. Perfect for the 1mzfe engine which is a bit cramped in the back where the PCV is located. I guess I am just assuming the spray is mostly similar or the exact same stuff as the regular seafoam, just in a spray can, and hopefully doesn't make my engine explode if dumped into the crankcase. LOL

 

[AutoMechanic]

They sell a seafoam spray which is often used for the intake. I just did it a couple of weeks ago on my 1993 Yota Pickup 22RE intake. Comes with a really long spray tube. Perfect for the 1mzfe engine which is a bit cramped in the back where the PCV is located. I guess I am just assuming the spray is mostly similar or the exact same stuff as the regular seafoam, just in a spray can, and hopefully doesn't make my engine explode if dumped into the crankcase. LOL

LOL. It shouldn’t. I always pour mine straight in the oil works fine for me and keeps the engine clean. I haven’t ever seen the spray so that’s cool.

 

[Oro_O]

I have been able to remove the PCV valve on 1mz-fe's with the intake in place - sounds like you did, too. If you work carefully with long-handled pliers, it's not that difficult. Like these:

https://www.harborfreight.com/20-offset-45-angle-long-reach-pliers-2-pc-64090.html

The 2002my had the revised valve cover design and the pcv blockage is not a big issue like it was on earlier models, though of course at 220k maintenance is important there. Just cleaning the valves isn't adequate as I've both been told, and experienced, that even if you can shake them and they rattle, they can still not operate correctly - spring weakens. I'd want a new one.

A word of caution - do not use the front bank plugs as a proxy for the condition of the rear. I have seen more than once (and on our car, too) that mechanics change the front plugs and skip the back. When I went to change ours, I found the back were not only NOT iridium like the front, but were plain copper. They were gapped out to who knows what, and the center electrodes looked like ski slopes. They did have a perfect burn pattern on them, though. The funny thing was, putting in fresh Iridium plugs didn't make much of a difference at all to the performance, mileage, or idle characteristics.

Our 1mz-fe has 320+k on it and runs like a champ, uses about 16oz of M1 10w30 HM every 7,500k OCI (when the rear valve cover gasket is not leaking, then it's more like a quart), is smooth and still delivers as-new performance and mileage. All I think I've done to the engine is timing belt changes, plugs, valve cover gaskets, a PCV valve and both cam timing solenoids (VVT valves), periodic flushes and high quality synthetic oil. Amazing engines. I have the weird feeling if I keep doing the same maintenance it will run another 300k just fine.

 

[MrPlow]

The 2002my had the revised valve cover design and the pcv blockage is not a big issue like it was on earlier models, though of course at 220k maintenance is important there. Just cleaning the valves isn't adequate as I've both been told, and experienced, that even if you can shake them and they rattle, they can still not operate correctly - spring weakens. I'd want a new one.

I think it was 2003my where they went with the redesign (manufactured in 2002). Mine is 2002my and does not have the threaded PCV like the redesigned ones. The updated valve cover can be added to all VVT-I models though, but costs around $200+.

 

[Oro_O]

I think it was 2003my where they went with the redesign (manufactured in 2002). Mine is 2002my and does not have the threaded PCV like the redesigned ones. The updated valve cover can be added to all VVT-I models though, but costs around $200+.

Lexus got them in 2002 (my) I know for certain. However, Lexus usually gets new engines, transmissions one to two years before it goes into the Toyota line.

I assumed it was across the whole line since this was a critical change and the engine had already been in production six years at that point. I haven't looked at a 2002 Toyota to be 100% certain so maybe it was 2003 for Toyota vs. Lexus.

 

[LeakySeals]

I've been blasting throttle body or carb cleaner down the PCV tube or take it off and shake it if I can for years on my different vehicles. Then change the oil. Nothing broke. And I've never replaced the PCV valve.

 

[JC1]

I had a 98 Sienna. What a pain to access that PCV valve. I would replace it since you don't know when it was last done and then use some spray cleaner on the hose to clean out the rest and then reassemble.

 

[doublebase]

Regarding seafoam or any other cleaners used to clean carbon...it really depends if the carbon is more of a stain/sludge or if it actually hardened. Because if it hardened - and I find that it usually will with time and heat cycles - you aren’t getting that off with seafoam, no matter how much you dump down in there. Heck, I’ve used CRC, sprayed an entire can directly on to hardened carbon on a valve and it did NOTHING. I then let the valve soak in an entire can of seafoam for two hours, and it did NOTHING to hardened carbon. So, then I took that valve, heated it up to engine operating temperature, with the seafoam solution soaked into it, and then sprayed another entire can of CRC intake cleaner directly on to that valve...and it did next to NOTHING. Maybe a few tiny little minuscule specs came off, but nothing worth talking about. 2 entire cans sprayed directly onto the carbon, and one bottle of seafoam soaked for two hours, and then heated up the valve to operating temp (lucky I didn’t blow myself up, surprisingly it only smoked).

Unfortunately if it is hardened carbon you’ll need to replace it or scrape it.

 

[MrPlow]

I decided against the idea once I saw the crud sitting on the baffle while changing out the PCV and grommet. My thinking is that if the holes in the baffle are not clogged now, then dislodging stuff might drain it down and clog those holes. It's a terribly designed PCV system. Also, the majority of the stuff I saw down in there was super soft and not hardened much.

My only good choice now is to get the upgraded valve cover with vastly better baffle and breather system when it comes time to replace the gaskets and spark plugs.