I've reinstalled the COPs and plugs but didn't screw down the COPs. This will cut a lot of time off when I go to pull the plugs again. I've started the engine to warm it up. During the warm up, I squeezed both the upper and lower radiator hoses (cap off). Alot of air worked out of the system and I'm getting plenty of hot air coming from the vents. When I get through running the kids to their lessons, I'm going to redo the compression test, but I'm wondering if the root of the problem was a stubborn air pocket in the coolant system. During the engine warm up, the O2 sensor reset itself and the exhaust is clear. I also forgot to mention that the needle did not leak back during the first compression test. Well, after three days of working on this, I've at least ruled out the water pump and the windshield washer fluid.

 

The air pocket doesn't explain your coolant loss though.

 

Well actually it kind of could cause the coolant loss. It gets hot pressure builds up in resovour(sp?) coolants comes out. These cooling systems can be a pain in the tail to get them to bleed all the air out since you dont even have the rad cap to work with. 02 sensors dont clear or reset themselves, if the light goes off then that means the computer didnt recognize enough faults with it in the last so and so warm ups. It might be a case were the 02 sensor isnt bad, but the truck is runnin rich or lean, so it throws an 02 sensor detects rich or lean condition.

 

I know the O2 sensor doesn't "reset" itself. I guess I need to better explain myself. When I monitored the O2 sensor voltage, it definately lags behind the amount of time to go from low to high and hight to low compaired with bank 2's sensor. You're more accurate then I was when you said the fault condition didn't exist. I'm sure if I scan it again, I would see the fault code learking in the background just waiting to jump out when it sensed I was having a good day.

Here's the results of the latest compression test with the engine hot (I've got the burns to prove it): All cyclinders were within +/- 5 psi of 200. The interesting thing about this latest test was that I had fuel (I think, I didn't taste it) blowing out the spark plug ports as I cranked the engine. There was also a loud popping under the valve cover when the pressure cross about 175 psi.

You may be correct that the coolant is escaping from the resevoir cap. When I restarted the engine before pulling the plugs, I noticed that the upper radiator hose never got hot. The pressure in the resevoir was also high and this was before the thermostat opened. The heater hoses were hot and I had plenty of hot air coming from the vents. Could I have a blockage within the radiator itself?

 

This "fuel" that you had blowing out of the port, I realize you didn't taste it however did it smell like gasoline ? I'm wondering if it couldn't have actually been coolant. Also did you have this blowing out of all the cylinders ? I'm not sure what the loud popping was that you heard. I think it very unlikely that your radiator is blocked, usually build-up would plug off your heater core before plugging your radiator. As far as your compression test, it looks good this time, all within acceptable limits. As far as coolant out your reservoir cap, I would think if you were losing coolant out the reservoir cap you'd see some signs of it and your system wouldn't be holding pressure if you had a leaky cap.

 

The fluid came out of every cylinder. I'm going to check it in the morning to see what it is. The compression test I did last night was without the throttle being open so no fluid. I replaced the resevoir cap a week ago when I noticed it seeping. At the time I didn't realize I had such a build up of pressure in the system. I still don't understand why the upper radiator hose didn't get hot but was definately pressurized. I need to quit for the night. I already blew a battery fuse (175 amps) when I wasn't careful disconnecting the starter jumper.

 

I cranked the engine with the plugs removed and the throttle blocked open. There's a spray of fluid coming from the #1 cylinder. There's little to no odor to it and it doesn't burn so I guessing it's coolant. If I don't block the throttle open, there's very little if any fluid coming from the cylinder. Any ideas?

 

I think we're back to the head or head gasket. Or you said you changed the intake gasket right ? You could have a coolant leak there also getting into the cylinders that way.

 

Too many signs pointing towards the head or head gasket so thats what I'm going after. Thanks for your help.

 

Well if you had this same fluid coming out of all the cylinders like you mentioned in your earlier post, it could quite possibly be your intake, cracked or bad gasket. If it's localized to one cylinder then I would suspect head gasket.

 

I just turned over the engine one last time before I start. I only see fluid coming from the #1. So, I'll only be pulling one head unless someone thinks I should go ahead and do both.

 

Well if that's the case that's probably what it is, you're going to have to do the intake gasket anyway if you pull the head. I'm sure you already know this but be very careful setting the head, and intake back on the new gaskets so you don't ding them up, and be sure to torque them properly. Let us know how things turn out when you get it done.

 

I would seriously consider getting the head checked for flat and milled if necasary if you pull it off. If it has overheated that can warp the cylinder head. The last time I had any done it cost $90 for a set of heads for a V-6 to be machined.

 

I have no doubts the heads have been over heated. So, I will do as you suggest. If I find the right side to be warped, then I will pull the left one and have it checked. $90 sure beats the cost of new heads.

Hey Madonp, I'm dying out here its 74 degrees out.

 

Very good point. They may be able to check it for cracks also.