Ferdinand Posted September 20, 2018 Author Share Posted September 20, 2018 Evening Gentlemen, SO here is the latest. Still trying to track down this leak: Engine is dry around the intake, block is dry on the sides and the front. But I cannot figure out what could be causing this leak. Any thoughts? Here is a 16 second clip of the leak with the engine running: Link to comment Share on other sites More sharing options...
Rembrant Posted September 20, 2018 Share Posted September 20, 2018 Engine is dry around the intake, block is sry on the sides and the front. But I cannot figure out what could be causing this leak. Any thoughts? Well, I don't think there's anywhere for coolant to leak from the back of the engine block, unless it is cracked. So...for a moment, leave that as a worse case scenario. Likely cause imho would be a leak between the intake manifold and cylinder head(s). Most common SBF coolant leaking area imho. If not from there, then I'd be checking the head gasket(s). Gary or one of the other guys on here can confirm...but I know on the 302, the later versions of these blocks (1984-ish and up) the head bolts thread directly into the coolant jacket of the block, and special thread sealant must be used during assembly. The earlier blocks had blind holes for the head bolts, so it was a non-issue previously. However, I'm not sure if this is an issue that is specific to the 302/5.0 or not. It may be the exact same thing with the 351 as well. If not one of the head bolt threaded holes, then maybe a head gasket. If not a head gasket, then maybe one of the press in plugs on the back of either cylinder head. (This seems the most unlikely to me, but worth checking anyway). If it was me leaning over your engine bay, this is what I'd do. Make sure the area at the back of the block above the bell housing is spotlessly clean and dry. Spray brake cleaner around if need be and let dry. Get some dry powder of some kind (like talc maybe?) and sprinkle a little bit around back there. Get a coolant system pressure tester (rent, borrow, or purchase?) and test. Look for wet spots. If everything above the bell housing checks out as dry and leak free, then I don't think you have much choice after that point but to pull the transmission or pull the engine. I'm certainly no expert, so one of the other guys on here might have better ideas on next steps. Link to comment Share on other sites More sharing options...
Gary Lewis Posted September 20, 2018 Share Posted September 20, 2018 Engine is dry around the intake, block is sry on the sides and the front. But I cannot figure out what could be causing this leak. Any thoughts? Well, I don't think there's anywhere for coolant to leak from the back of the engine block, unless it is cracked. So...for a moment, leave that as a worse case scenario. Likely cause imho would be a leak between the intake manifold and cylinder head(s). Most common SBF coolant leaking area imho. If not from there, then I'd be checking the head gasket(s). Gary or one of the other guys on here can confirm...but I know on the 302, the later versions of these blocks (1984-ish and up) the head bolts thread directly into the coolant jacket of the block, and special thread sealant must be used during assembly. The earlier blocks had blind holes for the head bolts, so it was a non-issue previously. However, I'm not sure if this is an issue that is specific to the 302/5.0 or not. It may be the exact same thing with the 351 as well. If not one of the head bolt threaded holes, then maybe a head gasket. If not a head gasket, then maybe one of the press in plugs on the back of either cylinder head. (This seems the most unlikely to me, but worth checking anyway). If it was me leaning over your engine bay, this is what I'd do. Make sure the area at the back of the block above the bell housing is spotlessly clean and dry. Spray brake cleaner around if need be and let dry. Get some dry powder of some kind (like talc maybe?) and sprinkle a little bit around back there. Get a coolant system pressure tester (rent, borrow, or purchase?) and test. Look for wet spots. If everything above the bell housing checks out as dry and leak free, then I don't think you have much choice after that point but to pull the transmission or pull the engine. I'm certainly no expert, so one of the other guys on here might have better ideas on next steps. I agree with Rembrant. The idea of using a pump up tester is an excellent one as it will work quickly and will keep things cool and easier to work on. But you might consider adding a dye to the coolant. Here's one at Amazon: https://www.amazon.com/Interdynamics-Certified-Engine-Cooling-Systems/dp/B002M4E0VC. They allow you to find a leak using UV light, which sometimes is the easiest and fastest way to find a leak. Link to comment Share on other sites More sharing options...
Ferdinand Posted September 20, 2018 Author Share Posted September 20, 2018 Excellent thoughts gentlemen. Thanks for brainstorming this with me. I'm no "mechanic" by any means, but when I rebuilt my '82 F150 I didn't have any of these problems! 🙃 I will keep you posted. Link to comment Share on other sites More sharing options...
Ferdinand Posted September 20, 2018 Author Share Posted September 20, 2018 I agree with Rembrant. The idea of using a pump up tester is an excellent one as it will work quickly and will keep things cool and easier to work on. But you might consider adding a dye to the coolant. Here's one at Amazon: https://www.amazon.com/Interdynamics-Certified-Engine-Cooling-Systems/dp/B002M4E0VC. They allow you to find a leak using UV light, which sometimes is the easiest and fastest way to find a leak. Side note, I must not be holding my tongue right... I have tried about every version of Width = "100%" I can think of and I cannot get it to work. It it maybe a MAC thing? Link to comment Share on other sites More sharing options...
Gary Lewis Posted September 20, 2018 Share Posted September 20, 2018 Side note, I must not be holding my tongue right... I have tried about every version of Width = "100%" I can think of and I cannot get it to work. It it maybe a MAC thing? Don't put the spaces in. It should be: width="100%" Link to comment Share on other sites More sharing options...
Ferdinand Posted September 21, 2018 Author Share Posted September 21, 2018 Well last night's investigation left me with what I feared the most... Here is a 20 second clip of the motor running with the leak active at the lower bell housing as in previous posts, but no leaking at the freeze plugs in the rear of the heads or the rear of the intake. -Sorry for the crazy angle You will see a little bit of dried coolant in the valley of the intake. That was a small weep from a plug on the top front of the intake just behind the thermostat housing that I have since tightened. I did most of the leg work last night. So, hopefully with 3 more bolts to remove, the transmission and transfer case will be down and out tonight. Anyone have any advice on the things I should investigate/replace on the C6 auto while I have it out? The NP Transfer Case is also leaking a tiny bit at the case halves and I thought about trying to fix that but I am not sure if that is opening up a can of worms or not. Thoughts? Link to comment Share on other sites More sharing options...
Ferdinand Posted September 21, 2018 Author Share Posted September 21, 2018 Don't put the spaces in. It should be: width="100%" Thanks Gary, I will keep picking away at it! Link to comment Share on other sites More sharing options...
Ferdinand Posted September 21, 2018 Author Share Posted September 21, 2018 Here are a few progress pics of the night I finally set the motor. Man was I glad not to be tripping over that thing anymore!! (My space is limited, but I am thankful for the garage! My '82 F150 rebuild was outside in the winter, laying in the snow!) Link to comment Share on other sites More sharing options...
Gary Lewis Posted September 21, 2018 Share Posted September 21, 2018 Here are a few progress pics of the night I finally set the motor. Man was I glad not to be tripping over that thing anymore!! (My space is limited, but I am thankful for the garage! My '82 F150 rebuild was outside in the winter, laying in the snow!) Gary, I finally figured out the "100%" edit. Thanks!! Truck is looking good! I watched the video and didn't see anything that was suspicious. Did I miss something? On the C6, if it is working well I'd leave most things alone. However, if you haven't changed the fluid lately I'd drain it, which is likely to cause a BIG mess, pull the pan, and replace the filter. Then, while you have the pan off, add a drain plug to it so you can change the fluid next time w/o causing such a mess. On the t-case, I've not rebuilt one of them. But the issue may well not be with the t-case. Instead, it may be with the seal between the t-case and the tranny. There's lots of fluid there, coming from the tranny, and unless that seal is good you'll have a leak. The factory used a gasket, and I've used a gasket/RTV combo and I've gone back with just RTV. Either work. Link to comment Share on other sites More sharing options...
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