3rd gen issues

[JohnMc]

That does look like engine oil, not trans fluid.

In order of likelyhood:
- bad HG
- bad oil cooler
- cracked head
- cracked block

HG is the most likely culprit, it's not *always* associated with coolant getting into the oil, or compression leaks. But either of those things would certainly solidify the diagnosis.

The oil cooler is a little coolant/oil intercooler down by the oil filter/alternator - I'm not really sure I've ever heard of them failing on 4Runners, but I've seen it happen on other cars with similar coolant/oil cooler setups.

 

[thegipper]

A compression test on all cylinders is what you need to do next.

I've seen some filthy, nasty coolant that was nearly as brown as that (same with tranny fluid).

Start there and report back.

 

[dustin3006]

A compression test on all cylinders is what you need to do next.

I've seen some filthy, nasty coolant that was nearly as brown as that (same with tranny fluid).

Start there and report back.

I called my local mechanic and asked for pricing on a compression test, didn't even want to talk about it or give me a price kept insisting it was the oil cooler. Now I'm getting more confused haha

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[dustin3006]

That does look like engine oil, not trans fluid.

In order of likelyhood:
- bad HG
- bad oil cooler
- cracked head
- cracked block

HG is the most likely culprit, it's not *always* associated with coolant getting into the oil, or compression leaks. But either of those things would certainly solidify the diagnosis.

The oil cooler is a little coolant/oil intercooler down by the oil filter/alternator - I'm not really sure I've ever heard of them failing on 4Runners, but I've seen it happen on other cars with similar coolant/oil cooler setups.

Yeah called a local mechanic to do a compression test. Insisted it was my oil cooler. Might replace that and the radiator at the same time.

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[thegipper]

You can buy a compression tester for cheap (under 40 bucks) and do it yourself.

Replacing your radiator isn't a bad idea at all but if your engine is shot (HG or cracked head) and you don't want to fix it, you'll be out the money for the radiator as well.

you're call but I'd do a compression test first.

 

[phattyduck]

Yes they were just wiped from the lipsticks and you were right about the fluids. Here is a picture of me rolling the paper towel and letting it soak for a second

That's old Toyota Red mixed with Green.

Flush it and you are all good.

This is what oil in the coolant looks like:

-Charlie

 

[alumarine]

I'd just flush the current rad and run straight water in it to to get a handle of what's going on.

 

[Scramble]

I dont know anything about the 5VZ oil cooler. Didn't even know they had one honestly because I never see them mentioned. The oil cooler on the 3RZ doesn't go bad but the O ring & gaskets do. If the 5VZ is the same it's a cheap fix. $4 O ring & $8 gasket. No need to replace the whole thing, there's no moving parts, it's just a pass through.

 

[muellernautique]

I'd just flush the current rad and run straight water in it to to get a handle of what's going on.

would be easier to distinguish what else is getting in there. but remember - distilled water only. you don't want the minerals and fluoride and crap they put in tap water.

 

[dustin3006]

Hey everybody turns out it was red and green mixed together. However this has scared me into replacing my oem rad with either a stock or koyo. If I replace the rad do I still need to bypass with a oil cooler ? Quite confused by this situation and reading all the threads saying all the different answers dosnt help .

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[dustin3006]

Correction I think I have a stock oil cooler so may replace the o rings and gaskets? Trying to prevent a milkshake

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[Koko4]

Correction I think I have a stock oil cooler so may replace the o rings and gaskets? Trying to prevent a milkshake

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To really prevent the pink milkshake problem, I would get an external transmission cooler, which will completely separate the coolant and transmission fluid systems. The problem is that the small barrier inside the radiator wears out over time, and that's when the coolant / transmission fluid mix together. From what I've seen, the external transmission coolers are only $30-$40 and are easy to install. Luckily I have a 5-speed so I don't have to worry about that!

 

[4Runner4Leon]

Hey everybody turns out it was red and green mixed together.

yep, that's how my coolant looked after years of neglect and mixing of green and red.

However this has scared me into replacing my oem rad with either a stock or koyo. If I replace the rad do I still need to bypass with a oil cooler ? Quite confused by this situation and reading all the threads saying all the different answers dosnt help .

You're mixing a few terms here. You do not bypass the engine oil cooler, just leave that be. Now, if you want, you can bypass the transmission fluid cooler that is built into the radiator with an external one, to avoid the risk of the pink milkshake.

However, if you're getting a new radiator, you are probably risk-free from the pink milkshake for a good 100+k miles. So I would just use the transmission fluid cooler in the radiator - and if you want to, you can augment (not bypass) the radiator cooler with an external transmission cooler (that's what I did).

Does that help?

 

[thegipper]

I would completely drain the system and buy some of that radiator flush product (I used the Prestone stuff). Buy a bunch of distilled water and fill the system back up with the water and the flushing product (follow the direction). Let your rig warm up to operating temperature and drain it again. Repeat this a few times until the straight water that is coming out is clear and not nasty looking (it will never be crystal clear).

Once your cooling system is cleaned out, then drain it again and install a new radiator. Fill your cooling system back up with the correct Toyota red coolant (diluted properly).

No need to touch the oil cooler at all.

 

[phattyduck]

However, if you're getting a new radiator, you are probably risk-free from the pink milkshake for a good 100+k miles. So I would just use the transmission fluid cooler in the radiator - and if you want to, you can augment (not bypass) the radiator cooler with an external transmission cooler (that's what I did).

Does that help?

To second this, I disassembled my original radiator at 270k miles last year and it was still perfect inside (I ripped the bottom tank apart to check). Regular coolant and trans fluid changes keep the internal corrosion at bay. There is a near zero risk of pink milkshake when maintenance is kept up to date.

-Charlie

 

[Denis_Ruso]

Correction I think I have a stock oil cooler so may replace the o rings and gaskets? Trying to prevent a milkshake

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I keep seeing this. Make sure that you are not confusing the engine oil cooler with the transmission oil cooler.

The main one on our trucks is the Transmission oil cooler that needs to be addressed. The stock transmission oil cooler is built into the stock radiator and shares a wall which can corrode to causing fluids to mix thus the "pink milkshake". This is addressed by installing an external transmission oil cooler as described above.

The external transmission oil cooler prevents the transmission oil from being in the radiator.

There is also an engine oil cooler which generally does not fail and only needs the gasket replaced. (also as mentioned above).