Engine cold, started with the cap off. It bubbles like it's boiling. The higher the RPMs, the faster the bubbles swirl.

 

thats an indicator of a blown head gasket...the "bubbling" could be air making into the water stream. it could also be some sort of internal block damage, but most likely a blown headgasket.

 

^^ x2

 

Exactly what I was thinking, checking compression in each piston now...what should they be at? Just did cyl. 1 and got 130.

 

The value isn't as important as having them all the same.

 

Okay. I know you're supposed to do it with the engine warm but I've already screwed up my hands enough with hot manifolds. I think it'll be okay doing it cold as long as I'm just looking for similarity in numbers rather than focusing actual engine compression.

 

Can I pull out all 8 spark plugs and crank the engine with the 2 fuel inj. fuses pulled + ign. coil wire disconnected to check for coolant spitting out of the heads?

 

Not really

 

Alright what about putting 15 PSI on the cooling system using the a pressure tester and then trying after a few minutes to allow coolant to seep into the cylinders and THEN cranking with the plugs out to check for coolant spitting?

I pressure tested all cylinders. Six of them are at 150 PSI while cyl. #1 is 155 PSI and cyl #3 is 145 PSI. I'm going to pressure test those two again to make sure the numbers are right.

Other than a cylinder leak down test *i don't have an air compressor* I don't know what else I need to do to test for a blown gasket, or a warped or cracked head.

I started up my engine and revved it some and saw fresh splatter marks out behind my exhaust. My coolant spins and bubbles in my radiator when I rev my engine with the rad cap off.


I'm about to just replace the head gaskets and have the heads machined because I'm not sure how many more signs of a blown head gasket I can have. I'm not sure how else to check for "some sort of internal block damage" as mentioned by travis401.

Please - any input is appreciated.

 

Better, but it still might not find your problem. You have exhaust gas at several hundred PSI getting into your coolant, you might not have coolant at 15 PSI getting into your chamber.

 

I believe what he meant by internal block damage would have to be a cylinder wall cracked through to a water jacket. Unless you have a 400 or a 350 bored considerably, I doubt that. Problem is with a cold compression check, the metal isn't warped like it is when the motor is hot, which is when your coolant is bubbling. If you have damage beyond a head gasket, I would think it was the head that is either cracked or the mating surface is pretty messed up. If the head is cracked, you would have an easier time finding it with a warm engine, as the crack will open up when hot.

This being said, it appears to just be the gasket. Replace it and machine the heads if you think they need it. AFTER A HOT COMP CHECK

 

Last week on a trucks episode I saw this kit you can purchase where you add this blue fluid to a small plastic (clear) cylinder and then you place it over the radiator cap hole and let the gasses from the radiator enter the cylinder. On the show the blue fluid turned yellow indicating C02 which meant a leaking head gasket. I don't know where to get the kit but I saw it used on one of the weekend car shows. I think it was trucks.

 

since you already have a pressure tester. put the tester on the radiator and start the engine. watch the pressure and see what it builds to. it should go to about 15 psi in a normal rate of time. should take a while. if it builds quickly and keeps building then there is a leak. i usually put them on and put 5 psi on the system. then start the engine and see how fast it builds.

 

Thats what I was refering to by internal block damage. which I also said isnt very likely, but it can happen. The only realy reason youd have a warped or cracked head is if it ran the car for a while AFTER it started over heating. most likely its just a head gasket that gave up the ghost.

 

Agh...I guess I'll have to wait until tomorrow then. There's no way I'm going to try pulling plugs out of a hot engine without my gloves. Those exhaust manifolds are killers


And at this point am I just doing a hot compression check to see if I can find the weak spot? Because even when the engine is cold it runs funny with bubbles in the rad and if I'm replacing one gasket I'm most likely replacing the other while I'm at it...

 

Not seeing bubbles in rad with belt disconnected

 

thats because the water pump is not turning. you need to take a picture of it.

 

A picture of the bubbles? I have a vid if you want

I thought if I had a blown head gasket or warped or cracked head the exhaust gases would get into the coolant passages regardless.

The reason why I did it without the belt is because I was reading my book today. I was reading a section

"Diagnosing Head Gasket Failure"
Bubbles in the Coolant.
Remove the coolant pump belt to prevent pump operation. Remove the radiator cap and start the engine. If bubbles appear in the coolant before it begins to boil, a defective head gasket or cracked cylinder head is indicated. - don't have that problem unless belt is on.



I'm not sure how else to diagnose this. I have the problem when the engine is cold, so I pressure tested cold. Maybe a cylinder leakdown test?

 

show us the video.

 

I have had same exact prob for about a year. Though I don't drive. But motor doesn't overheat either. I have only broke one head gasket that I was sure of and it overheated very quickly. I am more thinking perhaps small cracks in a head . What heads you have? Stock?

 

It will, but the bubbles will just rise instead of being entrained in the flow. They'll collect at the highest point available in the cooling system, and you'll get displaced fluid overflowing the filler neck, but won't see any bubbles for quite a while.

A leakdown test is the best way to diagnose a leaky cylinder.

 

I have no air compressor at my house so no leak down test just yet. Bought one of those combustion testers with the blue fluid and it was pretty much blue the entire time but I think I did suck in a tad bit of coolant so I'm going to test again.

What is this hose?

Goes from under the throttle body to the heater control valve and down to a T where the red hose goes to the radiator and one down under the car

 

heater hose and diverter

 

Should that red hose be constantly shooting coolant into my rad? It's a steady stream, like a garden hose.

 

Yes, that's what it's for, it's routing water from the intake that goes either through the heater core or bypasses it and returns to the radiator