351W lower head bolt coolant leak

[Timmy390]

At my wits end on this engine.

Correct me here but 94 plus 351w roller block head bolts do NOT pass into the water jackets?

I have a coolant leak that I tracked to the lower head bolt D side # 2 in the torque sequence. This is the only one leaking and you can clearly see coolant coming out as the pressure build when coming up to temp. It was leaking (left a puddle on my shop floor over night) with no pressure on it after filling the coolant system and sitting over night but I couldn't find where the leak was till I fired it up.

I'm looking at a cracked block or head correct? I JUST installed new head gaskets. Heads were magnafluxed and milled......

Possible to take just that one bolt out and put some sealer on it or is my 351W a boat anchor?

Tim

 

[Joe473]

Lower bolts on 302 roller blocks need sealant. I would expect the same on the 351.

Sent from my SM-G900V using Tapatalk

 

[Viperwolf1]

I have a '94 351w and all the head bolt holes are blind. You have something abnormal going on with the block, head or gasket. It wouldn't hurt to try sealant on the bolt but that's only going to help if the leak is in the bolt thread area.

 

[77RHINO]

Thats the reason I just pulled my motor, had a leak in the exact same area. I was also leaking at my F/R seals, so I went ahead and changed them all out. Have a tiny drip from the rear main, I'm hoping once it gets ran a few times it'll set better? I did look and my holes were blind, 96 block.

 

[Timmy390]

I cleaned the holes and chased them before installing the head gaskets and they appeared to be blind but I just wanted to make sure. This is the same cylinder #6 that was the issue before.

Guess I'm pulling it yet again.

Bout ready to just buy a crate and be done with this never ending nightmare of a 351W conversion.

Tim

 

[Nickm1024cobra]

That sucks man. Really does. Haven't followed your conversion so I am not sure where to start. You sure it isn't the intake? I just rebuilt my 302 and made sure i retorqued after a few heat cycles, 10 miles, and just now at 100 miles. They all loosen up. If its definitely the cylinder/block that really sucks. I just bought a 302 short block from late model resto for 1500. I imagine 351 short blocks are just slightly more. I can't even get machine work done locally for that.

Good luck. Worth doing a compression test and rule out head gasket failure?

 

[ScanmanSteven]

Tim, I'm ready to give up. I feel for you, gosh I'm frustrated and it's not mine. I have a 351 but haven't had any of your problems. Compression test might be the best, could point to that stupid head gasket again, IiRC.

 

[Timmy390]

It's not the intake I wish it was. It leaks with no pressure on it. The first drip happen over night while it just sat there after filling the system with coolant. I was hoping it was the intake. I watched it start leaking more as pressure built. Coming right out from around the head bold and washer.

This is the same area that was leaking before #1 and #2 head bolts. No leaks that I can find any place else. Last time it was leaking into the #6 cylinder and I had bubbles in the coolant reservoir. This time I didn't have any bubbles in the reservoir just leaking around the bolt. It's only had one heat cycle on it.

Heads have been checked and checked again and milled. Hard to get a good pic of it. You can just make out the green puddle below the bolt. Need to get the black light out and see where all she glows.

 

[Timmy390]

Put another heat cycle on it just now....Bubbles are back in the coolant reservoir.

Pulling it and possibly starting over. At some point I have to cut my losses on this thing. No way in hell anyone can screw up 4 head gasket installs in a row.

Tim

 

[NYLES]

Put another heat cycle on it just now....Bubbles are back in the coolant reservoir.

Pulling it and possibly starting over. At some point I have to cut my losses on this thing. No way in hell anyone can screw up 4 head gasket installs in a row.

Tim

Bubbles are WHAT??? Are You saying bubbles are back in reservoir engine cold and running?

Cracked block

 

[Timmy390]

Bubbles in the coolant reservoir is what I've been chasing since day 1 with this build
http://classicbroncos.com/forums/showthread.php?t=266011

No bubbles on the first fire up with this set of gaskets (4th set) but today there were bubbles when I fired it up. Bubbles don't seem to start till things come up to temp but then there's a constant flow.....Rev it up and you get more bubbles.

Tim

 

[NYLES]

Same leaky spot on gasket every time?

 

[Timmy390]

Same leaky spot on gasket every time?

It appears to be the same area. Last time it was not leaking externally only internally. #6 had clear signs of water intrusion and even had some rust on the head surface inside the chamber. Then again, I wasn't looking for a leak externally. It took me a bit of time to find the leak this time so it's not an obvious "there it is" spot. Headers in the way among other things.

Talked to the machine shop this afternoon as they did the block and the heads. Going to clean it up and black light it (dye already added) to make sure it's not leaking from a crack above the bolt and running down from behind the bolt. They said they have seen issues with SBF heads cracking in that area. Not common but they have seen it.

Also taking out to then to look it over while it's in the truck (see the bubbles in the coolant reservoir and the drip. Showed them some pics of the area and they're stumped.

They said they would make it right if it was something they missed i.e crack in the block, heads or other) and I knew they would. This is a stand up shop with a stand up owner.

Tim

 

[Nickm1024cobra]

Im not sold on the lower bolt holes being blind on all 351 blocks. Many mustang guys use sealant on the roller blocks and claim they are in the water jackets. I don't know for sure. Just for sh$ts and giggles, did you use thread sealant on the lower bolts? Before I pulled it I would definitely back out that bolt, thread seal it, and heat cycle it a few times. Whats the worst that could do? Nothing but keep leaking.

 

[NYLES]

Crack in one of em I read your other thread glad your shop gonna check it out for you. I don't think the thread sealer thing would work I think it would only force the water thats getting into that cylinder to find another escape route.

I got one for ya, disconnect #7 injector wiring, pull the spark plug, crank it, slip a piece of paper down there and see what's coming out of that cylinder while it's running and see if the bubbles stop while that plugs out. Don't do this if it's still carbed or TBI only if you can cut the fuel to that cylinder. I'd also do 6 or 8 whichever the two that bolts between. Yea I'm ready for the bashing I'm am about to recieve!!!

 

[Timmy390]

I got one for ya, disconnect #7 injector wiring, pull the spark plug, crank it, slip a piece of paper down there and see what's coming out of that cylinder while it's running and see if the bubbles stop while that plugs out. Don't do this if it's still carbed or TBI only if you can cut the fuel to that cylinder. I'd also do 6 or 8 whichever the two that bolts between. Yea I'm ready for the bashing I'm am about to recieve!!!

I like it....Have heard/read about the paper trick before. Think it was on a YouTube video. Had forgotten about it till you posted.

Running Ford EFI so I'll have to remover the upper to get to the injectors on the D side but that's no thing......

Tim

 

[NYLES]

I like it....Have heard/read about the paper trick before. Think it was on a YouTube video. Had forgotten about it till you posted.

Running Ford EFI so I'll have to remover the upper to get to the injectors on the D side but that's no thing......

Tim

Be careful! Conway? Don't you know John and Bubba?

 

[Tiko433]

This really sucks for you Tim !
I hate when you take the time to do something right and it still is not . Ok to all thinking about this , I'm thinking the block has a crack down in the threads . I hate to think the worst but if you figure it out at least you will know
Good luck find us posted

 

[Timmy390]

Be careful! Conway? Don't you know John and Bubba?

I've meet a few guys from this area over the years.

Tim

 

[Timmy390]

This really sucks for you Tim !
I hate when you take the time to do something right and it still is not . Ok to all thinking about this , I'm thinking the block has a crack down in the threads . I hate to think the worst but if you figure it out at least you will know
Good luck find us posted

I'm on a "Vision Quest" at this point. I/we will find the problem come hell or high water and I'll let everyone know for sure.

Tim