Engine 351W coolant drip


Active Member
Jun 17, 2016
My 351W was are rebuilt. It has a TF upper intake and TF heads. There is a very slight trickle/drip of coolant that forms where the head meets the upper intake. Driver's side front corner. It then pools on top of the water pump area. Maybe like 1-3 ccs. Not much really. Previously, like maybe 2 months ago, I retightened (not crazy tight, don't want to strip the aluminum head) the intake bolt that threads into the head, and the leak stopped. Yesterday it was doing it again. I retightened that bolt and I think it may have stopped the leak again. Maybe I should try some blue locktite? I'm not sure if that bolt is walking out slightly over time or not. Is it a huge job to remove the upper intake and reseal or regasket the intake-heads area? Thanks.
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Active Member
Jul 12, 2018
That’s unfortunate .
Shop assemble the entire top end? If so, this should be their problem, not yours.
If not, skip loctite, the bolt isn’t going to back out under tension. I’d pull that bolt & verify it’s not bottoming out & causing torque reading errors. If that’s the case, it’s unlikely the only one. Chase the threads with a bottoming rap, or run a shorter bolt.
I Install a lot of TF top ends.
Brand new, I disassemble any new heads & check everything. Setting an aluminum intake or head down on a hard surface may cause a raised area on either end of a head or intake that prevents full seal surface contact once assembled.
The head may shift slightly due to a loose dowel. I set down the intake on the heads when heads are hand tight & look for gaps, intake bolts hand tight when I torque them.
If you over-torque the intake you can peel a head once it starts cycling hot & cold, or bend the intake flange if there’s a raised area. If it’s not the Bolt bottoming out, the only right thing to do is tear down & find the error.
No, it’s not difficult at all. Pull the battery terminals & bleed the fuel rail with the shraeder valve, drain off a few quarts of coolant, after that, it’s nuts, bolts, connectors. Take pic’s as you go, if you forget something you can later reference it.
You don’t want to start a fresh motor with a handicap, things like this don’t tend to improve over time.
If you have any questions, feel free to ask!
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