cracked head?

[tuck817]

so my exploder (dora) was running the best it ever ran for about three weeks but then last week sh8e started to get hot on me so memorial day i decided to replace the cat because it needed it and the radiator when i took the old radiator out the lower hose leaked out hard rusted particles i did get the cat replaced first but when i put the new radiator on and fired her up she shot water from the exhaust junction right before the cat any thoughts or suggestions would be greatly appreciated :exp:

 

[Iron Weasel]

Pressure test the cooling system. You might be able to rent the kit at places like Autozone, or take it to a shop and have them pressure test it. A compression test might be a good idea as well.

Otherwise, there are always the old fashioned ways.
Check for bubbles in the radiator while the engine is running.
Check for coolant in the oil - see if it looks like a milkshake.

The end all test would be to take the heads off, have them hot tanked and then magnafluxed. That will tell you with 100% certainty if it's cracked or not.

 

[wood1]

If it wasn't a lot of water and your coolant level is not dropping then it is just water produced as a byproduct of combustion. And you have an exhaust leak. (Hope that's all it is)

 

[tuck817]

it poured water so i shut it off didnt want to hurt it any more should i try and start it again

 

[wood1]

if you are saying that it was basically pumping water out of the exhaust I would think it is a very bad head gasket. Do a compression check, I wouldn't start it at this point.

 

[Roadrunner777]

I don't know a lot about hydro-lock, but I'm wondering if I would even do a compression test at this point. I think I would start turning bolts.

 

[tuck817]

where can i get a compression tester does autozone or oriellys loan them

 

[wood1]

You will be fine as the engine is not running while you do a compression test. Make sure you pull all your plugs and unplug your coil(s). When you pull your plugs you might find a cylinder with water in it or a really clean plug compared to the others. That's likely your suspect cylinder and I would check that one first.

Sorry, forgot to tell you to disable the fuel pump, don't need gas washing down the cylinder walls messing with your results. You can either pull the fuel pump relay, or trip the roll-over safety switch.

 

[tuck817]

how do i turn the fuel pump off

 

[Roadrunner777]

Open the power distribution box near the battery and locate the fuel pump relay. Pull it out, voila!

 

[tuck817]

ok compression is as follows #1-120#2-120#3-110#4110#5-80#6-100 should i change heads or get a running used motor from junkyard

 

[Iron Weasel]

You should figure out why you have low compression on cylinder #5.
Do a "wet test" and see if the compression comes up. Squirt a small amount of oil into the cylinder through the spark plug and then redo the compression on that cylinder again. I don't expect the numbers to come up significantly, but you never know.

Next step I would take would be to perform a leak down test.

You'll need an air compressor and a leak down tester which you might be able to rent as well. If you don't have access to an air compressor, you might want to see how much a local shop would charge to do a leak down test on it. They'll also be able to interpret what's happening.

All in all, it could very well end up being a blown head gasket and not a problem with the cylinder head itself, but you need to diagnose as much as possible BEFORE you go tearing into it that way you have a better idea of what's going on with the engine.

 

[tuck817]

this is my daily driver how do i tell if its just a head gasket or a head or both w/o tearing in to it and doing a wet test wont damage the gauge

 

[Iron Weasel]

A wet test won't hurt the gauge any. You need maybe 1 tablespoon worth of oil, not much.

A leakdown test will give you a better idea of where the problem is. If you do one and there are bubbles in the radiator, then you probably have at least a blown head gasket. Either way, if you get bubbles in the radiator, the heads are going to have to come off.

 

[tuck817]

well then i guess theyre just gonna have to come out do i have to take both heads off or can i just change one side

 

[wood1]

Imagine if the other one you don't do goes months later and you have to go back in to fix it. It wont add that much time or expense to the job to do them both.

Hope it is a gasket and not a cracked head.

 

[tuck817]

got my fingers crossed ill tear into it next weekend

 

[wood1]

Let us know how you make out dude.

 

[tuck817]

oh did the wet test just on #5 it went up to 95 but dropped after that to bout 75 what does that say and my battery went dead

 

[wood1]

Your piston rings seal much better with the oil but it gets scraped away and your reading goes back down again.