Thick Yellow Foamy Substance in my Oil Cap

[halo434321]

I was doing a general check of fluids today and found a thick yellow tinged foamy substance in the oil cap. I don't think that it is a head gasket problem because I am not blowing smoke from the exhaust and the oil down in the pan off of the dipstick is celan yellow with no tinge to it or bubbles. Is this just a bad cap or is there more to it like maybe another gasket is letting water into the to of the block? I have yet to disassemble anything and am looking for some advice or prior knowledge to this issue. Thanks.

[randomxzero]

check your coolant for any signs of oil..

[halo434321]

Coolant is clean although maybe I can have it checked for purity at an Autozone? As of right now it looks clean (or I should say that it doesn't look out of the ordinary or smell different). Thanks.

[MR JAS]

im having this as an interesting problem since i rebuilt my engine
i used all new gaskets had the head and block surfaced etc the water level doesnt drop at all after 3 months and no oil in it but i get white under the cap not much but about 4 mm deep after 2 weeks but i only drive my car 10 mins either way to work if i drive a decent distance of like 60km or so it comes back clean and statys that way for a week its almost as if theres condensation forming in the block its going into summer now so i will see if it continues with warmer weather

[halo434321]

That is about the depth of my problem inside my cap as well. I drive 1.5 miles to work each way so on and off the car goes with it barely getting warm. I am not seeing any drop in performance. I think I am going to clean what I can see, change the oil again and get a new oil cap. I will start there and see what happens after a few weeks unless someone else has any suggestions?

[GENESIS]

That could be a head gasket going bad or maybe just condensation?I too had the same issue on my n/a,but I did a compression test,coolant pressure test,and everything is fine.It might just be a slow leak?

I think its just condensation mixed with regular oil under the cap coz I don't have have that problem anymore I have been using synthetic oil and it still looks clean under my oil cap so i guess synthetic doesn't give you that milky crap.I was worried when I saw that milky crap under the cap but i drove my car hard and autox for a while and nothing happened.

[halo434321]

OK. So I was freaking out since the last post. I went out and checked my radiator fluid and it is brown. FREAK OUT TIME right? Well, maybe. I understand that Toyota uses some sort of reddish antifreeze because it has less synthetics in it which supposedly aides in a longer life for aluminium parts such as the radiator. My oil is clear yellow and without bubbles at the dipstick but does not feel as viscious as a synthetic oil should. I have not lost any oil and there is no funny smell of antifreeze in the oil either. But the thinned out oil could be due to antifreeze in the system? Also, I found a loose (not even hand tight) retaining ring on the #4 spark plug. After researching 'brown antifreeze' I found that the argument is this:

1. cracked head or blown head gasket
2. red Toyota antifreeze, water, condensation (rust from somewhere other than the aluminium components) and possibly some idiot who mixed green antifreeze in with the Toyota OEM stuff rather than doing a full flush or possibly a radiator stop-leak additive put in the mix.

I have not yet done a compression test so I don't know if it is good or not. In addition to that compression test, I have a question:

What are the numbers supposed to read on a healthy system with a compression test?

[Sh0ty]

What do you mean "not as viscous as a synthetic oil should [feel]"? Isn't the viscosity determined by the XW-Y? seems like conventional and synthetic oils of the same rating should have identical viscosity.

[GENESIS]

Originally Posted by halo434321

OK. So I was freaking out since the last post. I went out and checked my radiator fluid and it is brown. FREAK OUT TIME right? Well, maybe. I understand that Toyota uses some sort of reddish antifreeze because it has less synthetics in it which supposedly aides in a longer life for aluminium parts such as the radiator. My oil is clear yellow and without bubbles at the dipstick but does not feel as viscious as a synthetic oil should. I have not lost any oil and there is no funny smell of antifreeze in the oil either. But the thinned out oil could be due to antifreeze in the system? Also, I found a loose (not even hand tight) retaining ring on the #4 spark plug. After researching 'brown antifreeze' I found that the argument is this:

1. cracked head or blown head gasket
2. red Toyota antifreeze, water, condensation (rust from somewhere other than the aluminium components) and possibly some idiot who mixed green antifreeze in with the Toyota OEM stuff rather than doing a full flush or possibly a radiator stop-leak additive put in the mix.

I have not yet done a compression test so I don't know if it is good or not. In addition to that compression test, I have a question:

What are the numbers supposed to read on a healthy system with a compression test?

About your radiator being brown I was in the same situation too thats why I assumed that I had a bad gasket or cracked head,It took me 9 coolant flushes for everything to turn green again,The previous owner of my car never did the coolant flushes.A year past my coolant is still green.

Its so crazy I buy my mr2 15k miles later I see (the white foamy film of doom) under the oil cap, Then checked the coolant that turned brown got stressed out though I needed a head gasket job and turned out I just needed to flush the coolant 9x whooo.Just to make me feel better I got a coolant pressure test.

I used this Prestone anti rust additive and it work great!though time It help get the brown crud out of the water jackets.I know this coz every 15k I do my coolant flush at least until its perfectly clean "I would get this nasty brown crud floating when I open my radiator cap".

Get your car tested or flush your coolant until its green again and see what happens it might just be dirty, Toyota engines are bullet proof especially 5sfe,3vzfe,5vzfe,22re,My uncles 22r engine has past 1million miles and my grandmas 5vzfe just hit 296k w/no leaks.

[nocashrider]

there is a good possibility that it is condensation building up if you are not really driving the car that far. i would suggest taking it out twice a week for a drive for at least 20 min to get it nice and warmed up and see if that makes a difference after a while

[randomxzero]

go to your local autoparts store and ask for the antifreeze tester to see if you have gases or oil i believe in your antifreeze.. use it on your car to determine if you do or you dont.. should help you keep peace of mind to determine for sure if your hg is bad or not..

[halo434321]

Thanks to all. Randomxzero, nocashrider, Genesis. I will continue until this is corrected and I will take ALL advice seriously from you guys. Sh0ty, there is a difference on the molecular level and you can feel the difference and although two cans may say the same thing, it is not precisely true.

"Synthetic oil is also created in a similar manner to a conventional engine oil, using a base oil combined with a series of additives. The difference lies in the fact that synthetic motor oils are created utilizing a specially "synthesized" base oil where the size of the oil molecules are all of an ideal weight and of a consistent size. While a conventional motor oil, despite the refining processes, is made up of different molecule sizes which are mixed together, along with various waxes and impurities, a fully synthetic oil is made to provide a much purer base oil, with less waxes and with a uniform ideal particle size to help increase the oils viscosity level. Added to this ideal base oil is a combination of more technically sophisticated additives than are used with the conventional oils."

Regardless of the viscosity proponent of this equation (which I believe is an important one), the problem still remains until I kill it.

[halo434321]

OK. I replaced my valve cover gasket, bought a new oil cap, did another oil change and resealed the #4 sparkplug retainer ring. I also had a coolant flush, detergent scrub and reservicing done. At this time I didn't have the equipment to do the full flush by myself and the temps dropped with rain over here which would have made that job a freekin nightmare so I opted to pay for it this time. After looking things over in the engine compartment, I am getting upset because I want to do a full engine bay cleaning but I know that is going to have to wait until the spring. So, with these changes and some monitoring, I will see if my fears were just that.

[nocashrider]

nice that should definately have fixed it

[randomxzero]

hopefully its all good from here.. good luck man!..

[te51levin]

Originally Posted by GENESIS

That could be a head gasket going bad or maybe just condensation?

It's just condensation. Don't worry about it unless you see other signs of trouble. My engine has always done this, and it's healthy as a horse, with 27K miles on it.

[MR JAS]

Originally Posted by te51levin

It's just condensation. Don't worry about it unless you see other signs of trouble. My engine has always done this, and it's healthy as a horse, with 27K miles on it.

do you think this would get any better if i put a breather on mine?

[te51levin]

It might get a little better if you put a catch can on there. My little air line separator does catch a fair bit of foam, which is a booger to clean out, but I suppose it's better to collect it in the separator than to leave it in the engine.