Question for the 300 Gurus
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From: Renton, WA
Question for the 300 Gurus
Just got me an 88 F-250 with a 300 and wether or not it goes to parts or back on the road depends on fixing this motor, here's what's going on;
Previous owner said he over heated it, that temp fluxuated and was out of coolant.
When I got it the oil was milky from water in the oil, only ran it a couple min.
When got home I changed the oil and ran it with no pressure cap. So far no more water in the oil that I can notice, but can't even drive it around the block without it boiling half the coolant out of it.
So I need to decide wether or not to fix it, common sence tells me it looks like a blown head gasket, that the cumbustion gasses are boiling out the coolant. But the water in the oil causes questions, blown head gaskets don't usually do that unless REALLY REALLY blown or something else is also bad, cracked and or warped.
I just don't want to waste time and money trying to fix a motor that is too far gone to be worth the effort.
So here's my question, what usually goes bad on these motors, is water in oil common with just a blown head gasket or is that telling me that it's something bigger?
If/when I take it apart what should I look for, where are cracks common, etc?
What else do I need to consider that I haven't? do the head bolts fail, are they torque to yeld, etc?
Thanks in advance
Previous owner said he over heated it, that temp fluxuated and was out of coolant.
When I got it the oil was milky from water in the oil, only ran it a couple min.
When got home I changed the oil and ran it with no pressure cap. So far no more water in the oil that I can notice, but can't even drive it around the block without it boiling half the coolant out of it.
So I need to decide wether or not to fix it, common sence tells me it looks like a blown head gasket, that the cumbustion gasses are boiling out the coolant. But the water in the oil causes questions, blown head gaskets don't usually do that unless REALLY REALLY blown or something else is also bad, cracked and or warped.
I just don't want to waste time and money trying to fix a motor that is too far gone to be worth the effort.
So here's my question, what usually goes bad on these motors, is water in oil common with just a blown head gasket or is that telling me that it's something bigger?
If/when I take it apart what should I look for, where are cracks common, etc?
What else do I need to consider that I haven't? do the head bolts fail, are they torque to yeld, etc?
Thanks in advance
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Joined: Oct 2008
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From: Renton, WA
Well now you can't run it like it is, correct?
Can you pull the head off it? It could be a cracked head, or a gasket.
If you had oil in the water, they would tell us pressurized oil (engine running) is being forced into the water jacket. On this motor, that could only happen in the block.
Water in the oil, that tells us pressurized water--engine running and hot engine off--is going into the oil. Could very well be the gasket, as there are drain back passages from the head to the block that are sealed by the gasket. Warped head or cracked head also gives the water ways to get to the oil.
So, get your tools out and pull the head.
You will only find your answer that way.
At the very least, pull the valve cover and pressurize the cooling system with a testing pump. You can probably borrow one from a parts store. If it's cracked it may show under the valve cover.
At the very, very least, run it till it's hot, then pull the oil fill cap and look for steam in the valve cover. Eye protection recommended!
Can you pull the head off it? It could be a cracked head, or a gasket.
If you had oil in the water, they would tell us pressurized oil (engine running) is being forced into the water jacket. On this motor, that could only happen in the block.
Water in the oil, that tells us pressurized water--engine running and hot engine off--is going into the oil. Could very well be the gasket, as there are drain back passages from the head to the block that are sealed by the gasket. Warped head or cracked head also gives the water ways to get to the oil.
So, get your tools out and pull the head.
You will only find your answer that way.
At the very least, pull the valve cover and pressurize the cooling system with a testing pump. You can probably borrow one from a parts store. If it's cracked it may show under the valve cover.
At the very, very least, run it till it's hot, then pull the oil fill cap and look for steam in the valve cover. Eye protection recommended!
Runs fine but boils all the coolant out.
Can pull it apart of course but don't want to unless rather sure that I can repair it cheaply.
Of course there are passages for oil in the head mating serface but head gasket blowouts are very rare between coolant and oil, unless there is something common with this motor I'm unaware of. So where is the most likely/common place water leaks to oil in these engines?
Don't take this the wrong way, but I'm not here just to be told to take it apart to find out, I can do that, might as well tell me to open the hood. What I need is to decide if it's worth the effort. Or if the odds are too high that the problem is more then just a head gasket, BEFORE I turn a wrench on it.
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"Can pull it apart of course but don't want to unless rather sure that I can repair it cheaply."
There is no way of knowing that unless you tear it down or at least remove the head. The odds are you are going to find a problem. What it is and whether it is worth it or not (that's your call) cannot be determined over the internet by someone for you.
There is no way of knowing that unless you tear it down or at least remove the head. The odds are you are going to find a problem. What it is and whether it is worth it or not (that's your call) cannot be determined over the internet by someone for you.
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