Help with internal block leak - not head gasket.

IdahoDoug

 
 
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Looks like the culprit letting coolant into the oil is not the head gasket I just replaced. I've waited a bit to confirm this before posting, but my problem lies elsewhere. Oil/water emulsion in the oil cap, and now I can see it on the dipstick.

Somehow coolant is getting into the oil internally to the tune of a half pint a day. Seems like I heard someone who had coolant in their power steering oil or something? I'm trying to figure out where else in the block an O ring or gasket between the oil system and the cooling system would allow this.

For purposes of discussion, let's rule out the head gasket, and cracked block or head. These are highly unlikely and I have the feeling it will be simpler.

I see one possibility in the block's oil cooler which is a finned affair the oil passes through that's in the block's water jacket on the right side. I see another in some of the timing cover seals though I am unfamiliar with this area and don't know if there's coolant flowing in this area - anyone? The water pump seems to share no seals with the oil system, so no worries there.

Seems to me someone once posted a strange 'coolant leak found' in an unexpected place. Hmm. Thoughts??

DougM
 
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If it's not block, head, or head gasket, then probably no better place to start than the oil cooler.

I do believe that I read one posting of the oil cooler being filled with goo from a coolant leak.

With respect to the power steering, you are probably recollecting reports of the power steering fluid being pumped into the crankcase due to a leaking gasket or seal.

I reckon you must just about have had your fill of dealing with this issue.
 

landtank

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Doug have you pulled the drain plug? The coolant should be the first out. And I suspect that the oil level is also increasing daily.
 

e9999

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oh, no!
sorry to hear that. Is this all in the more recent truck or your old one?
at least you have the good HG now
good luck
 
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and you have no oil in your coolant? it would seam that a leaking oil cooler would let more oil into the coolant than coolant into the oil, oil pressure in the cooler is much higher than the coolant pressure arround it. but stranger things have happened.

water gets from the water pump thrrough the timing cover and into the block somehow. I dont know how that connection works. CDan posted pics of the timign cover when he had the major oil leak but I cannot find those now
 

CJF

 
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Question from a 1 :banana: mechanic; please excuse if it's a dumb one:

Does the oil system have a "low" side, like the power steering? Maybe from the filter back to the pump, or something like that? (In which case if the coolant and the oil were near each other at that point...)

Curtis
 
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CJF sort of, the return or low side of the oil system is the crank case and it works by gravity, oil is sucked out of the sump (bottom fo the crankcase ) by the oil pump and then pushed through the oil filter, oil cooler and then on to many lubricated parts. after it does its job its flows out into the crankcase and makes its way back to the sump via gravity.

from the pump to the part being lubricaed is high pressure, the crankcase is low pressure.
OilSystemS.gif
OilSystemRs.gif
 
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IdahoDoug

 
 
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OK, some great suggestions. No, the head was not checked for either flatness or cracks as I was replacing the HG for a coolant-to-oil leak and not for blown HG with attendant overheating. Ditto the block.

I've been pondering this thanks to Raven's comment about oil in the water for awhile and need some logic checks. His point speaks to the fact that 12psi water vs 15-40psi oil should favor oil in the water if there's a leak between the two pressurized systems. This and a conversation with my Pop who reminded me that not all the oil in the engine is pressurized led me to again look at the oil flow diagram in the Engine section (lube system section) of the FSM. You guys just took me a ways on eliminating things.

For one, I can eliminate a leak between oil and water systems anywhere the oil is pressurized as I would definitely have oil in the water. I don't. So, from looking at the engine oil diagram it appears the oil is pressurized in the oil cooler and everywhere in the block until it's lifted up and dumped into the valve train atop the engine at the front of the engine. From here it basically floods the valve train under no pressure - flowing all over the spinning camshafts under the valve cover. It then freefalls by gravity through a half inch hole at the rear of the valve train back to the pan - passing through the head/gasket. It also free falls through the large rectangular opening the timing chain passes through and back to the oil pan - again passing through the head gasket.

So. The #1 culprit has again become the head gasket, which I can live with as it simply means another replacement and the head work (checking for flatness) I opted out of. Obviously, this still leaves a cracked block or head in the mix but I consider that a flyer - no way to find it.

If it's the HG again, I can simply pull the valve cover and pressurize the cooling system while staring down the rear oil hole and the timing chain rectangular opening with the UV glasses and light (I have the UV die in the coolant already). No coolant dripping out there? The block's toast. Coolant? New head gasket and head/block work.

What say ye?

DougM
 

landtank

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Doug, a 1/2 pint a day for how many days? You would have something like a gallon of coolant in your oil pan.


HOW OVER FULL IS THE DIP STICK READING???????????
 

semlin

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doug this is bad news

were you/are you overheating? would overheated coolant be at higher pressure?
 

IdahoDoug

 
 
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Rick,

Actually, the oil level's not going up - it's evaporating off during operation and getting sucked out the PCV tube just like condensation would. I can see a faint line on the dipstick where there must be a thin layer of foamed emulsion sitting on the oil. But with such a long oil pan and 8 quarts, the half pint is relatively small and as I say it must be evaporating off at a high enough rate that the level seems stable. Just so you know, there is no doubt in my mind at this point that it's getting into the oil. The quantity of emulsion in the oil cap is far larger than it was before I did the HG, and I can see milky oil on the 'step' inside the oil cap opening. The half pint a day is my estimate - it's actually about 3/4 of an inch daily drop in the overflow which I've guessed is about a half pint.

This mirrors what happened before the HG as well. The dipstick did not notably go up. What'cha thinking??

DougM
 

IdahoDoug

 
 
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No overheating. The engine purrs like a kitten, and pulls like a freight train. Starts instantly. Totally no hint of the maelstrom going on within.

DougM
 

landtank

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I'm thinking that this residue is just normal after the HG job. A half pint a day is a lot of coolant to evaporate especially since it's sitting under 8 quarts of oil in the bottom of the pan. I'm thinking you have a leak somewhere from the job itself. I had 3 when I was done and I also feared the worst. I'd try and put the HG possibilty way out on the back burner and start to look closely at the usual suspects. The first leak I found was the PHH hose of all things.
 

Gumby

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I remember you saying in the other thread that you changed the oil after the head gasket, right?

If so, something is not right.

If not, you dump a fair amount of coolant into the oil while changing the HG. It might be a seperate leak.
 

4WD Toyota Owner Magazine

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Have you had any problems with emissions or O2 sensors going out? Sometimes chemicals in the coolant (if leaking into your engine's innards) will kill cats and 02 sensors.

Dave
 

IdahoDoug

 
 
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Hmmm. Residual water, eh? Well, I drove it about 50 miles after the HG was changed on the old oil (pre HG), then hot changed it - meaning I pulled in the garage with the oil stuff laying out and had the drain plug out within 2 minutes. Then I refilled with Mobil 1 (whoops - there's another forty clams). Man, you had me thinking positively there for a few seconds, but there's just too much water evidence in the oil. Too much - looks worse than before the HG actually. RaddCruisers did have all kinds of steam and odd running after his HG until his cleared out, but his was a classic failure involving water in the exhaust, cylinders, etc and it took awhile to stop steaming.

Exhaust is not smelling like coolant, and no steam from the exhaust, however I now feel it was my imagination that it did pre HG. This is based on zero evidence of water in any cylinder, or exhaust manifold during the teardown. I have a good nose and it MIGHT have been a whiff from the coolant contaminated oil burning off as piston blowby.

No lights or codes.
 
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