Hey I need some help, this 3406b has oil in coolant. I removed oil cooler pressure tested @ 110psi in 170°f water bath and not a single bubble. So I went to the air conpressor and pressure tested the Coolant side to 50psi (accidentally, I only meant to go to 10 but whatever) it held just fine. I also vacuum tested the Coolant side of air compressor to 25"hg and that held just fine. So i checked radiator with sealed check valve tube for compression getting into radiator, again no bubbles even at operating temp. What am I missing? Theres no Coolant is in the oil pan. Is there a possibility of head gasket failure between oil and Coolant passage ? Any advice is appreciated
With the oil drained and thermostat removed, pressure test the cooling system. (NAPA and others carry the tool,) If coolant is running into the pan, my guess would be bad head gasket or cracked head.
Just by chance does this truck {if it is a truck} have a coolant type transmission cooler mounted on the transmission? So we get that possibility out of the way. Is the oil in coolant black or brownish color?
No it is only an air cooler on the transmission. Oil in radiator was black
No other auxiliary comes either.
This is where ruling large items out starts. IMO-others may disagree which is fine but If it were me I would drop the pan pressurize the cooling system to 15 psi and look for leaks from the bottom up with rocker covers removed.
I may do that, but my thoughts are at 15psi it may not be leaking. It may only leak at 40psi+ and at operating temp. I don't want to give a false positive test. But my options are limited from my understanding at this point
Well at operating rpm {idle} oil pressure would be 40 psi and 55 to 60 at 1700 rpm. So the oil pressure will overcome the coolant psi of 10 psi at hot working. With engine off at 15 psi on the cooling system you may have a chance finding it. On E models when injector sleeves leak it pushes fuel into radiator while running and coolant into fuel when off till engine cools and radiator pressure drops.
Ok ill give it a shot. Thanks
We don't want another B model thread like the last one without proper trouble shooting. IMO
I did test a engine oil cooler like in first picture in green tub, and it had no leaks for 3 times of off engine in tub. But was putting oil into coolant when running. It was leaking only with vibration. It finally appeared in tub leaking but would not with 20 PSI.. Very hard to diagnose if only vibration will get it leaking. That is my experience. Simon C
That's a good point, one thing on those coolers that needs to be checked is where the tubes are vulcanized around each other and to the main housing. If the rubber between those tubes and body is coming apart or deteriorating it's a bad sign.
Do you have any photos of what the cooler end plates look like.?
I don't Nige- but when those go bad it's easy to spot because the sides of some tubes are more exposed than others plus the material sealing the tubes kind of turns to a goo.
I don't know of anyone around here that even bothers testing an oil cooler when they have a radiator full of gravy. Not saying it's right, but when the black is getting into the water, a new oil cooler gets put on, system gets flushed, and back to work. I have never heard of anyone hunting for a leak anywhere else.... ESPECIALLY on a B-model. Never. Cats and ISX seem to have oil cooler trouble the most.
Need a end view of tubes please.
That where you are and yes there are other places to leak. Always.
I'll have to get a better picture tomorrow off the ends
Sorry for the confusion Mike. My question was directed at the OP. Since he had the cooler off for testing I thought he might've taken some photos of it looking from the direction of the water bonnet rather than in through one of the oil ports. EDIT: Is dem cracks that I sees..??
Yes but it held at 170°f at 110psi
Hey I resent that Although it is completely true
One issue with any testing is being able to duplicate actual running conditions. Expansion, vibration under psi is tough to do. And there is a high probability it is the cooler, because of the fact it's where both fluids come in close proximity. Even the B model manual in trouble shooting section is vague at best. Remember it's a old engine that has gone through how many expansion/contraction cycles in it's life? One thing about dropping a pan to check it's only oil and a gasket, but it offers other insights about the inside--like finding a broken lifter clip in bottom of pan, hopefully not.
I never used to check em til an ACERT burned me, now I ck em all before I replace it. Still haven't found the leak on ACERT. I have B-model I'm rebuilding now I cant find anywhere oil is getting coolant but found liner orings ate thru on #1 letting coolant in the oil