[owensmat]

Hi Guys,
Over the past four months, I've been redoing my GLH-T. I recently installed a completely overhauled 88 Daytona Shelby 2.2 T2 engine and bathtub head. Everything is back in the car and looking great. Here's my problem. When I added coolant, I noticed a leak coming out of the backside of the engine, in the area of the passenger side firewall. When I got a mirror and a flashlight in there, I saw the apparent source. It appears that coolant was coming off of the far right exhaust manifold bolt nut. There was no apparent coolant anywhere above the bolt, to the right or left, it seemed very clearly to be coming out of the bolt, accumulating on the nut and then dripping off the nut, rolling down the exhaust manifold and dripping onto the power steering pump bracket and ultimately onto the ground. It wasn't pooring out, but rather came out about one solid drip every couple of minutes. Keeping in mind that at that rate with the engine having never been run, it will probably lose coolant very quickly once the engine is warmed and over time. It may be helpful to know that when we were putting the engine back together, we put the threaded exhaust manifold bolt in and then used new brass manifold nuts. The mechanic that I'm working with says the brass one's have just as much clamping power and they were the smallest diameter to best fit into those little slots. Also, all new gaskets, etc., were used. So, here's my questions: 1. How is it possible that coolant would come out of an exhaust manifold bolt hole? Has anyone ever seen this before? Depending on the answer to #1, what do I do from here? Any help would be appreciated!!

 

[Turbomini]

did you make sure it was tight? and on that same note did you over tighten it? becuse the one bolt goes right into a water port.

 

[owensmat]

Hi there, Thanks so much for the reply. When we put the engine together, we hand threaded the exhaust manifold bolts in until they were hand tight. Then, once the manifold was on, we put on the brass manifold nuts to hold the manifold in place. The brass manifold nuts are an o-ring type of nut that is supposed to first fully tighten the manifold bolt and then thread on and tighten to hold the manifold in place. I don't recall using any excessive force when tightening the nut. What I do understand from what you are saying, is that one of the exhaust manifold bolts threads into a coolant cavity? Is that correct? This is the exhaust manifold bolt, from memory last night, that is closest to the passenger side shock tower. If my understanding is correct, in that this bolt could be the one that threads into a coolant cavity, it would make sense that if left not quite tight enough, that coolant could come across the threads and off the bolt/nut. It just seems odd to me that an exhaust manifold bolt would also serve as a coolant plug? Is that true, or would it be the case that we punctured or cracked a coolant cavity? In other words, if I were to never had put that specific exhaust manifold bolt in and left it with nothing in it, would I have expected to have coolant poor right out of there? Sorry for the frantic presentation of this question. Its just that unfortunately, I'm already 10k into this car and while it will be sweet done, I'm afraid of having to dump more into it. Thanks for your help!

 

[rx2mazda]

take the stud out, put teflon tape or sealer on the stud, screw it back in and tighten.

 

[patrickjengram]

Coat the threads with blue or black rtv silicone sealant, then torque it back in. It will leak unless you do this.

 

[owensmat]

Hey guys, thanks for your responses. Obviously I'm a novice. I will do as you suggest. What I'm wondering though is two things. First, is this normal? Is coolant supposed to come out of there, or did I jack something up? Second, won't the tephlon tape or silicone burn up from heat off of the manifold?

 

[roachjuice]

i use red loc tight on all manifold bolts. never had a problem but have heard of this happening. some of the thread holes went into the coolant passages of the head. shit happens all the time.