dwimbugh

I have antifreeze pooling in the center of the Vblock. I saw this when I changed out the water pump last October because the auto shop told me that's where the leak was coming from. Well that' didn't fix it because my pump wasn't leaking in the first place. I knew I should have looked more closely into the antifreeze in the middle of the block, but I didn’t know if I had spilled it there when I was pulling everything apart. The leak has gotten so bad (about a pint a week) that I have reason to believe it has damaged the knock sensor wire and it's now shorting out (check engine light coming on). It’s a code 52 which is apparently a short in the knock wire, bad knock sensor or bad ECM. The engine runs really poorly when this code is picked up by the ECM. I looked under the air chamber between the 4th and 6th fuel injectors to find the connection from the knock sensor to the wiring loom (which runs down somehow to the middle of the block and connects to the sensor) and I can see where I think the hot head and antifreeze have essentially melted through the wire a little. I'm not %100 sure of this because it's really tight in there. It kind of makes sense to me because when the vehicle has sat for a little while I think the antifreeze dries up on the wire and then when the engine is started it runs nicely until it's up to running temp when the antifreeze starts to leak from wherever it's coming from and causing what I think is continuity (a short) between the exposed knock wire and surrounding metal through the fluid contact. I could be completely wrong about all this but this is what I think. I'm also getting a code 14 which has to deal with IGF and/or IGT between the Igniter and the ECM. At least until I trace these lines, I'm going to attribute this error to the antifreeze leak as well because I think those wire run around the front to the engine on top just in front of the air chamber.
I'm thinking my leak is coming from the water-by-pass pipe that runs under the intake manifold down the middle of the Vblock - a freaking pain to get to. It must have corroded where it connects to the block and is now leaking out and could have possibly caused damage to the knock sensor down there because I think it’s actually connects to the block or intake manifold somewhere in that general vicinity. I'm working with a lot of theories here. But, it’s also possible the leak is coming from that rectangular opening in the front of the intake manifold that connects to the pipe that leads out to the pulley (behind timing cover) between the cam pulleys in the middle of the timing belt. I guess my question is do I have to remove the timing belt to remove the intake manifold? Is there a way to hold the timing belt in place to remove that pipe/pulley I’m talking so that I don’t have to screw around with the timing? I’m wanting to remove as little as I possibly can to get this leak fixed. I’ve purchased a new knock sensor wire and a new knock sensor but I will test the old one to make sure it is working and I might not use the new one because it’s so freaking expensive $159. But then again, if I’m all the way down there, I might as well replace it also? I also have a new water-by-pass pipe just in case it’s that. But I really think it’s that union between the front of the intake manifold and that pulley pipe. Is there a gasket there or jut RTV sealant? I had come to terms with removing the top part of the engine but once I realized I would need to redo the timing as well, I got a little depressed (actually a lot). Any help would be greatly appreciated because I want try and get this stupid thing fixed this weekend. Also, do I have to completely take apart the fueling rail or can I just disconnect it where the fuel comes into it and remove it with the intake manifold (still connected that is)?

bugs1961

Yea, you'll have to disturb the timing belt to remove the intake manifold. The upper idler pulley for the timing belt is part of the water outlet mounted to the intake. You don't have to remove the belt but you will need to loosen it to take the idler off. Relative to the whole job, the timing belt is fairly minor. Removing the plenum, fuel injection, and the wiring harness is a bigger job. This would be a good time to replace the timing belt, water pump, belts, hoses, and other top end gaskets while you're at it. Look at as an opportunity to get everything up to speed and prevent any further problems for a long time. Take care,
Bugs

dwimbugh

Thanks for your help bugs1961!

Does anyone know where the wires are I need to disconnect to start the process of relieving pressure in the fuel line?

bugs1961

The pressure will only be maintained for a couple of hours at the most but I recommend you let it sit overnight and the pressure will be gone by the morning. You want to work on a cold engine anyway. Drain the coolant overnight and it will be ready in the morning also.

jasonbrink

Make sure you (or your neighbors) don't have any pets that can get near/drink the coolant while it's sitting there! They will die

Jason

Innervision

I replaced the bypass pipe without removing the belt (or the fan, rad..ect.). I just used some C clamps to hold the belt tight to the cams. I did not remove the belt tensioner. I did mine this way and did not have any issues. But I may have gotten lucky. But most people will tell you to at the least, remove the tensioner. Most people I talked to said they would have never attempted to replace the by-pass hose without removing the belt.

Good luck, its deep down in there. And a PITA to get the new one to fit back in the block.