Im doing an oil cap poll...

Greasygreg said:

My oil cap is always full of sledge.I would really like to know what the inside of YOUR oil cap looks like.I dont want someone to tell me that this is normal or to send my oil out for analysis,I want to see if all the other people with 4.7 engines are experiencing this too.I can clean it all out,drive 20 miles,and look again and find more sledge.PLEASE go out and look,just unscrew the cap and look inside and post what you see.thank you

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This was common on the 4.7s. I called California one time with a customer complaint and they said the reason is the moisture that accumulates in that long filler neck. I've seen it on about every engine I've touched.

My 2005 4.7 is clean-clean under the cap. 22,000 miles on engine, oil changes annually, mixture of short and long trip driving. Have used Chevron Supreme, Coastal Synthetic and currently Havoline. I would recommend a UOA if you even slightly suspect coolant in the oil. It is more likely to be a PCV (breather system) issue.

Thank you for your replies,I would like to hear more.I marked my collant overflow bottle about a month ago, and I think the only antifreeze im losing is from me obsessivly opening the radiator.Honestly believe the water is coming from thin air,but unsure.Thats alot of sledge in there.47,000 on the clock and the pcv valve rattles as it should.Heres a question,pcv is drawn from engine manifold vaccum.small tube into airbox supplies clean air to manifold.I live on oregon coast and its been wet here,front lawn is 80% moss. Should i try a push in breather in lieu of an oil cap to let the water OUT of the engine?

Normally, the moisture in the engine is not from the external environment but a product of combustion in the blowby gasses.

CnHm + (x)O2 --> CO2 + (z)H2O

At 47k you should not have excessive blowby.

I have an 06 with the 4.7 and have noticed a brown sludge on the cap when I change my oil. I change it every 3K miles, and have never had any water in the oil when I drain it. My daily commute is 4 miles each way, so I never really get the engine warmed up. I kind of chalked it up to that.

I dont totally follow what Nikita is saying with his xyz formula.What i do get however,is that he thinks that the moisture comes from what goes on inside the engine,and outside humidity is less relevant.He also says that he uses synthetic oil, and his cap is clean-clean.Im gonna try synthetic and see if that changes anything.I'll post results

If u make a bunch of short trips try cleaning it and driving for about 20 miles or so and see if it goes away.Mine is clean but have heard of people who live close to work having this problem.Engine has to get up to operating temp in order to burn off this moisture.

Greasygreg said:

I dont totally follow what Nikita is saying with his xyz formula.What i do get however,is that he thinks that the moisture comes from what goes on inside the engine,and outside humidity is less relevant.He also says that he uses synthetic oil, and his cap is clean-clean.Im gonna try synthetic and see if that changes anything.I'll post results

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Yes, water is a product of combustion but I have re-thought this a little and realize that outside air is drawn in from the airbox while the engine is running, so ambient humidity could also be a problem.

My point about oil is that I have used name brand conventional or store brand synthetic with the same result. All were purchased on sale for about $1 a quart. If you can find an oil with API CF rating as well as SM, it might have a greater dose of dispersant additive, that could help a little. I think Mobil "Clean" has that rating.

Well, two nights ago I cahnged the oil,using valvoline 5-30 synthetic,and also added a can of"restore"which claimed to fight sledge as one of its selling features.I looked in the cap at lunch and its just full of white milky sledge.so is the filler neck, and i mean bad,if it was yours you would be tripping out like i am, I mean there was no sledge IN the oil while I let it out,yes I did sit there and watch it drain,drip drip drip,but if you look in the cap you would swear the gaskets were blown or something, still no movment on the overflow bottle.The radiator is full too.Yes, this is really stressing me out!:whatthe:

Greasygreg said:

Well, two nights ago I cahnged the oil,using valvoline 5-30 synthetic,and also added a can of"restore"which claimed to fight sledge as one of its selling features.I looked in the cap at lunch and its just full of white milky sledge.so is the filler neck, and i mean bad,if it was yours you would be tripping out like i am, I mean there was no sledge IN the oil while I let it out,yes I did sit there and watch it drain,drip drip drip,but if you look in the cap you would swear the gaskets were blown or something, still no movment on the overflow bottle.The radiator is full too.Yes, this is really stressing me out!:whatthe:

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Relax, man. I've seen hundreds of these engines with that goop in the filler neck. The shape of the neck traps all the moisture in one little spot, it mixes with oil and turns milky white. I've had dozens of complaints, some of which had field techs and reps from Torrance involved. Your engine's fine.

when switching to synthetic oil. do you just switch it over or do you need to slowly switch it over. i heard that your not supposed to drain regular oil and then just put the synthetic.??????????

"Conventional" oil today is really semi-synthetic anyway and all additives are similar, so it is a myth that mixing is a problem. I have switched back and forth with no issues. Dont expect full-synthetic to perform any miracles. I keep very careful records and there is zero difference in gas mileage. Since additive formulations in API-rated oils are similar, there will be no benefit as far as low-temperature sludge formation is concerned. Full syn is only a benefit for cold starting in arctic conditions and, if you can bring yourself to do it, extended drain intervals due to slightly better resistance to shearing and oxidation.

nikita said:

Full syn is only a benefit for cold starting in arctic conditions and, if you can bring yourself to do it, extended drain intervals due to slightly better resistance to shearing and oxidation.

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Yep, that why I use it 12 months or 25K miles between intervals only requires me to change the oil once a year . Oh yeah and the other question: my oil cap is clean no noticable brown slude on my 03 Tundra with 57K miles.

so is there any reason to switch to synthetic or reg. oil is fine? unrelated to oil. when i get in my truck and go reverse, then into drive and start to drive theres one click that i can hear and feel on my foot on the gas peddle, but only when start my truck. otherwise thats it drives great. any ideas????????

Hey GreasyGreg, I am not sure what the temperature is like in Oregon. I live in Iowa where temp can fluctuate greatly and I have noticed in fall and spring that this white, tan thick mucas tends to more prevelant than in summer or even winter when temperatures are consistently cold.

I got real frustrated with the problem because my main reason for buying the tundra was due to the reliability record. I am very diligent in changing oil and it ticked me off. But, toyota is also very diligent in acknowledging problems like the camry's with oil sludge problems.

This problem you are experiencing is nothing to worry about. I noticed mine is also more prevelant during the fall and spring because the vehicle is not warm and I don't warm it up like in the winter. Likewise, I only drive 1.5 miles to work. (I would walk, but I have to pick up my daughter after work).

Your tundra has a great warranty, I would be the first to sell if there was a problem.

The Camry problem was different, high temperature oxidation. I notice that our 1999 Camry owners manual calls for 7500 mile change intervals with API SJ oil. The 2005 Tundra calls for 5000 miles even though API SM is more oxidation resistant. I think Toyota Motor Sales USA overreacted to the Camry problem, but I do understand why.

1980's and even early '90's vintage 5W-30 and 10W-40 used to oxidize so badly that the resulting sludge was called "black death". Oil chemistry has come a long way in the last few years. A byproduct of "synthetic" diesel and jet from natural gas is cheap synthetic motor oil. Plants are under construction now.

sold the 04 tundra with 59k and sledge filled filler.got an 00' with 140k now and its doing it too.IThink i live too close to the ocean.50' elevation,100% humidity.succs!:facepalm:

Not an issue. You can always shorten your oil change interval.
If you take many short trips, you need longer trips to cook away any moisture.
Make sure the PCV is working. Replace it every 5 years/50k if in doubt. Same can be said about the thermostat. If it opens too early, stays open... might not let engine get to temp. So, give the thermostat a time/mileage change interval since it doesn't last forever. Stick with Toyota parts.

You could always pull a valve cover off for inspection. What you see on the oil fill cap is NOT what you'll see in the engine. Whats on the oil cap is not an issue.

I've got it pretty bad in the filler neck and cap too. It doesn't matter if I'm driving short trips or a thousand miles--It still builds up even with regular trips of 400 miles or more. I've been using Mobil 1 synthetic for the oil and it seems this is a common issue for Toyota trucks. Apparently, it has mostly to do with the fact that the filler neck is constructed of "plastic" and won't allow the heat dispertion as well. Your motor is fine. It's really just a minor, common inconvenience with the design on these engines.