TowndawgR50 Posted December 28, 2015 Share Posted December 28, 2015 Attempted to repair the coolant crossover pipe leak and failed. I was not able to reach the hardware for the pipe after tearing down the intake and valve covers. Even if I was able to reach it there no room to pull it away from the head off the studs. IF I was even able to reach the hardware you might cut the gaskets and slip them in while prying the pipe away from the heads but I would worry the mating surfaces would not be clean and prone to leaking again. Has anyone done this repair without dropping transmission? What exactly was your technique? Ive searched the net and read a few stories of people that say its possible but nobody ever said how. I only had a few hours in a loaner space so I couldnt get too deep into the project. Feeling pretty defeated but might just take it in to have it done at a shop. All power valve screws accounted for with new loctite applied This bracket on the rear of the the lower manifold was a paint to get to. Rounded out most inaccessible bolt. Ended up pulling lower mounting bolt and removing it together. Source of leak, passenger side head crossover pipe gasket. Link to comment Share on other sites More sharing options...
Boostedbc Posted January 1, 2016 Share Posted January 1, 2016 Is it bolted to the other side of the head like that? I don't know much about the vq35 but I do have over 20 years experience in the field Sent from my iPhone using Tapatalk Link to comment Share on other sites More sharing options...
94svt50 Posted January 3, 2016 Share Posted January 3, 2016 I got as far as you did and came to the same realization. I just put it all back together and since It hardly seeps a bit of coolant Im just going to let it go for know. Link to comment Share on other sites More sharing options...
TowndawgR50 Posted January 3, 2016 Author Share Posted January 3, 2016 Boostedbc- its bolted to both heads. See the pics below, although not from a pathfinder, the VQ's all share this setup. The first engine shown is probably from a right hand drive vehicle as the coolant pipe exits on the left side of the motor but it clearly shows the the crossover pipe design. Poor access is the main issue. Its so close to the firewall there is very little room to fit tools let a lone a hand. To compound things there is a set of tubes, vacuum or coolant, that cover the drivers side flange and bolts for the pathfinder setup. There should have been an access panel in the firewall, a relief...something to facilitate access. I thought about making an access panel in my firewall but opted not to. I was able to get an appointment with a local shop last week. They pressure tested the whole system and surprisingly it held. They recommended a bars leak sealer solution for now. Seems to maybe work but I'm reluctant to take a trip until i get some significant mileage on it without the continued leak. Mine wasn't leaving coolant on the ground but every time I park the truck I can smell it and I have to top the coolant off once in a while. I'm not willing to take a 1800 mile trip towing 5000lbs of trailer with the current issue. I may just suck it up and pay a shop to have it done. Not worth the risk on a long distance trip. Link to comment Share on other sites More sharing options...
mel.d Posted January 4, 2016 Share Posted January 4, 2016 I had the very same symptoms you were experiencing with the coolant leak. I could smell it at times and found coolant dripping down the back side of the block to the bell housing. I had done this repair roughly 3 years ago. I did not have to drop the transmission, just removed the top and bottom intake manifold. It was very difficult to do and I think I spent a couple of hours trying to figure out a way to clear the firewall. If memory serves me correctly, I had unbolted the crossover pipe and disconnected the hose from the secondary t-stat in order to get it loose. I wiggled it until it hit the firewall, but it would still not clear the mounting bolts. Using a pry bar, I pushed the pipe out while rotating it up and down, I was able to clear the top bolt by a few millimeters which allowed me to slide one side of the gasket on. I then did the same prying and rotating to allow it to clear the bottom bolt by a few millimeters which allowed me to put the bottom part of the gasket on. Looking at the last photo in your post, the head of the bolt looks like they could be removed with a special female star socket. Or you could put two nuts on the bolt, tighten them together and then use the bottom nut to remove the bolt. It would be more difficult to do with the little working room available. It may seem impossible to do, but I personally was able to do it. However my back was not happy with the several hours spent bent over on the engine. It's been a few years since I did the repair and it is holding up just fine. BTW, I don't recommend using Bar's leak or any other pour-in-the-radiator type repair. If left in the cooling system too long, it can clog your radiator passage ways and then you'll have overheating problems. Good luck. 1 Link to comment Share on other sites More sharing options...
TowndawgR50 Posted January 5, 2016 Author Share Posted January 5, 2016 Thank you for the info. What did you use? Socket or combo wrench? I have considered buying a long wrench and heating it with a torch to bend it just for this job. I have a set of three 1/4" tubes that look to be for coolant or vacuum covering the flange and bolts on the drivers side. How did you get around those? While i figured the prying method was the most realistic solution I didnt want to do it this way because the surface of the head and crossover pipe couldnt be cleaned, making sure the sealing surfaces dont have some kind of leftover material preventing a good seal. Although your repair seems to be holding fine after years so maybe i can get away with it. Wish there was just a little more room. An inch or so would make all the difference. Link to comment Share on other sites More sharing options...
mel.d Posted January 5, 2016 Share Posted January 5, 2016 I used a long handle 10mm or 12mm combo wrench. It sucked having to turn the wrench a quarter at a time, but with little room, it was the only thing that would fit. The three tubes you mentioned I believe are breather tubes for the differentials and tranny. If I remember correctly, they are attached to a mounting plate that is tack welded to the firewall. There was no way to remove them without breaker the weld. Since they are brass tubes, I carefully bent them out of the way and then bent them back in place when I was done. I don't remember the surface being too dirty, but I do remember using a small metal putty knife to scrape the surface smooth. 1 Link to comment Share on other sites More sharing options...
TowndawgR50 Posted January 6, 2016 Author Share Posted January 6, 2016 Great. Thank you for sharing. I might give this another go. Thinking it might be worth it to buy a long handle wrench and bend it for this job. Link to comment Share on other sites More sharing options...
jjonez Posted May 20, 2017 Share Posted May 20, 2017 Figured I'd ask here rather than starting a new thread. From your guys' experience would this repair be significantly easier with the transmission dropped? I'm planning to have a shop replace my clutch at some point (no slip, but pilot/TO bearings are making noise), and I'm wondering how much labor time it will add to have gaskets replaced at the same time. Thanks! Link to comment Share on other sites More sharing options...
TowndawgR50 Posted May 22, 2017 Author Share Posted May 22, 2017 Absolutely. If trans has to come out get done. Link to comment Share on other sites More sharing options...
onespiritbrain Posted May 22, 2017 Share Posted May 22, 2017 Can you not use a 12 point wrench to remove the studs? Sent from my iPhone using Tapatalk Link to comment Share on other sites More sharing options...
TowndawgR50 Posted May 22, 2017 Author Share Posted May 22, 2017 Sure, if you could actually get a wrench on them. The top two are possible, the lower two are not accessible. Link to comment Share on other sites More sharing options...
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