What to do first?

[h2odrx]

ok have problems? presure in coolant, no oil in water or water in oil, gets hot sometimes, like i posted before. A) should i pull the heads and go from there? B)do a compression test? C)pull the motor and buy a new one?
i'm not sure where to start?
thanks for the help

 

[argve]

First I would do troubleshooting before going and replacing the engine...

What I would do is get an adapter to so thatyou can put pressurized air in each cylinder then watch for bubbles or rising coolant so that you can figure out which cylinder is the offender then go from there.

The adapter will go in the hole for the glow plug - just have to yank the glow plug and hit it with air. I guess a guy could shove a rubber tipped air gun in the hole and shove like a son of a *BLEEP* (I do this when testing cylinders after I rebuild them) but trust me with somewhere in the ball park of 100+ psi you gotta shove and shove hard to keep a good seal. Just make sure that when you do the test that both valves are CLOSED and the cylinder is at the bottom of it's stroke - that way you can test the entire lenght of the cylinder...

Now once you find the cylinder then we need to determine if it's cavitation or just bad head gasket... How to do that is run the cylinder up to TDC with the valves closed and hit it with air again but you will need to keep the engine from turning over - if you still get rising coolant then you know it's a head gasket - if the rising coolant stops then you know it's in the block and it's cavitated.

If cavitated then get a replace long block is my vote or at least a short block. I have done both, Rebuild from scratch and installed a replacement long block - once you get done and total up the bills from both you will have same money invested in both... Been there done that...

Or get a replacement drop in engine from a junk yard or such that you know the engine is good - it's a lot of work to install an engine just to find out that it's not good to go...

 

[h2odrx]

if it was the big "C" would i not have hydrolock? or water in the oil? the gp's are a fine thread? i guess i need to call the guy i got the rad from he said he had 6.9 and 7.3's he wanted to sell? he said $1500 for the 7.3? i wonder if he might take a core?

 

[dsblack]

"c" begins before hydrolock. But it could come to that. This sounds like a good atack plan.
Let us know how it goes.

 

[h2odrx]

but from day one i was seeing extra presure in the rad, and with the cap off it would push water out. then it got real hot and had no water in it? time is a problem right now, so i guess i will have to check each cyl with air, then maybe compression test? it turns over so easy, it should right? i mean not like my 400 husky that you had to turn to a sweet spot then crank or you could break a leg, now that was compression!

 

[clorine12]

earlier you said that you have to make sure that the valves are closed when pumping air into the cylinder how do you do that

 

[Agnem]

You could pull the valve covers and remove the rocker arms, OR, you can try to figure out which cycle that particular cylinder is in which will be pretty easy if you have presurized air going in. The engine will try to "run" as it were when all the valves are closed.

 

[h2odrx]

You could pull the valve covers and remove the rocker arms, OR, you can try to figure out which cycle that particular cylinder is in which will be pretty easy if you have presurized air going in. The engine will try to "run" as it were when all the valves are closed.

"run" ? you mean turn over quick?

 

[clorine12]

alright thanks how much pressure will i need to use

 

[dsblack]

This happened to me on the first 6.9 I owned. Turned out to be cracked heads. I would use a lot of water in my normal driving, but not a lot on long trips. It had to do with the cracks in the head leaking when it was warming up.

Doug

 

[h2odrx]

where was the water going?

 

[Mr_Roboto]

Don't get too worked up yet. It could be as simple as a leaking head gasket.

I'm sure I'll get shot for this, but I *personally*would use ceramic block sealer to see if the leak will seal before fooling with anything. What can I say, I'm lazy. I had a 351W that overheated quite a bit after I lost the fan belt, it was burning coolant like crazy. I ran the ceramic block sealer that stopped the leak, drove it for 6 more months with absolutely no issues then sold the truck.

 

[h2odrx]

i tried the block seal but it did not work? there is more pressure so sealer will not work? i was going to get my money back cause it didn't work?