Oil burning after new PCV valve

Has anyone had trouble with the 4.0 burning oil? I just recently replaced my pcv valve with the oem part and now it's slowly burning oil. There is some smoke coming out the exhaust and the oil level is lower. Trying to get it fixed and be done with it. Engine has 91k. Thank you

 

What made you replace the PCV valve?

 

Engine wasn't running the best and had trouble accelerating and was sucking gas more than normally. I inspected the old one and it was dirty and clogged. I read online for our trucks they need to be replaced every 30k and I know mine has never been replaced.

 

That's odd to have those issues at only 90k. Sounds like something else is wrong. Did the truck throw any error codes when it was running rough?

 

^ I agree. Got ~96k on mine and not a single drop of oil between changes.

Did the oil burning start when the new PCV went in?

 

Where did you read it needs to be replaced every 30k miles?

It's easy to check, take it out and shake it if it rattles it's probably still good, alternatively though I don't recommend it as it is combustion fumes but you can suck on the line and if you can pull through it it's venting then try to blow through the line and if it stops the back floe it's good.

I replaced mine last over 60k ish ago, still good.

 

Absolutely no codes. Still runs fine but it's a little concerning. Still runs fine.

 

Just because you changed the PCV doesn't mean that is the cause or if you even have a problem. Install the old PCV and see if the "oil burning" stops.

All engines burn some oil.
How much oil is being burned between oil changes? Be specific.
What do the spark plug tips look like?

 

This was the first time it's ever burned it. And I only assumed it was the valve because whenever I replaced it I saw bits of smoke coming out the exhaust even though the motor was warmed up. It hasn't ever done it before to my knowledge until I changed that valve. At first I assumed it was carbon build up but it seems much more than that now

 

I’d dive for a week. Keep an eye on the oil level. When you changed the PCV maybe it is flowing better. And the oil that makes it’s way in the line had “built up”. Maybe you just need to drive if for awhile?

Some guys go as far as installing an oil catch can. I myself don’t find it necessary on the 4.0. At least not yet. As I haven’t had any issues with excessive oil build up in the intake as far as I know.

 

If the truck is blowing smoke and eating oil I personally would not recommend driving it until you get it sorted.

 

Lets try this again:

How much oil is being burned between oil changes? Be specific.
What do the spark plug tips look like?

 

I checked it later today and the level is fine. Not low. It just seems to smoke a lot more so I'm guessing it's old oil and moisture built up flowing freely. I've only driven like a total of 100 miles with the new valve. Maybe it needs to be fully broken in or so. It mainly does it when it's cold started and once it's fully warmed up it doesn't do it anymore. It does it whether it's cold or hot.

 

If I'm being honest, I don't think it's burning but I think it is burning bits of oil built it from the clogged pcv valve. Spark plugs look good. Changed them 8k miles ago with oem plugs.

 

Let’s try this again “between oil changes” so if he’s running synthetic that will be 20,000 miles. So for now he’ll pull the spark plugs and then drive 20,000 miles to answer your question. Maybe you should try this again and you should be more specific. You sound fun to hangout with.

 

synthetic oil change interval isn’t 20k. Toyota recommends 10k or 12 months which ever comes first if your vehicle requires synthetic from the factory. If your vehicle requires dyno oil from the factory (all second gens) Toyota recommends sticking to 5k/ 6 month intervals regardless of what oil is used (dyno or synthetic). To say some people don’t stretch intervals would be a lie. Some people suggest 10k. I haven’t heard 20k recommended yet. Ive run full synthetic since I purchased my truck and change it every 5k no questions. Doesn’t mean my intervals are correct however it is what Toyota recommends and gives me peace of mind. Oil and filters are cheap compared to the alternative.

https://www.whiterivertoyota.com/blog/toyota-synthetic-oil-change-intervals/

Asking how much oil is being consumed between changes and if newly changed plugs are oil soaked provides additional insight to suggestions.

 

I meant 20,000k as in 2 oil changes

 

A faulty PCV valve will not cause oil loss in the manner you describe. It can cause oil leaks if the valve, or PCV hose, is plugged due to buildup pressures, but not oil burning. Blue smoke out the tail pipe, more so at startup after a few days sitting, is more indicative of worn/torn valve stem seal(s). It’s a costly repair if that is the diagnosis. If oil burning is not great, there are oil additives that may help. Some also recommend going to thicker oil, but with the low mileage you have, I wouldnt do that.

 

Never replace a cheap part because someone said it’s a good idea. Where in the manual does it recommend a PCV replacement at scheduled interval? Put the old one back in and chug along. Test the original part if you are doubtful, sometimes people create their own problems.

 

For what it's worth, cleaning or replacing the PCV at a regular interval isn't something that @Mattsyota529 made up. @BlackBeerd's 2nd gen maintenance guide calls for this to be done every 30k-50k miles. While this isn't a manufacturer manual, the guy knows his stuff and surely based this figure on some sort of documentation from Toyota.

https://www.tacomaworld.com/threads/2nd-gen-diy-maintenance-quick-reference-guide.438945/

I replaced mine at 50k miles, and plan to again at 100k miles. Anything to keep the engine purring along.