Noticed coolant leaking from the passenger side of the engine. Attached a placeholder image for now, but wondering if anyone has dealt with this before? What should I be looking at?
I had the exact same issue. The problem is usually the manifold. The plastic wears out where it connects to the passenger side of the crossover thermostat. It’s not the gasket—it’s just the plastic giving out.
For reference, the crossover thermostat is bolted underneath the air intake manifold. A bit of a hassle, but just so you know how it’s set up. I replaced mine with a Dorman intake, and it’s been great—better than the original, actually. I’d recommend getting the one with the crossover thermostat already installed.
The whole job took me about 5 hours, and I did it alone. While you’re at it, I’d suggest replacing the heater hose that runs across the top of the engine and adding new clamps. Makes sense to handle it all at once.
@Torin
Thanks for the help! Have you noticed any change in power since switching to the Dorman intake? I read somewhere that you lose around 20 horsepower, and that’s kind of a big deal since the 5.4 only has about 250 horsepower stock.
@Torin
My old intake had a crack that was messing with performance, so the new one has definitely been an improvement. I also added an aftermarket cold air intake with a big air filter, which boosted power quite a bit. Next on my list is a performance throttle body—BBK makes one, but it’s pricey, around $300–$400. Could be worth it, though.
@Torin
One more thing: the Dorman intake leaves the engine gallery more open, which seems to help keep the engine cooler in the summer.
@Torin
Interesting. I’ll take mine apart and see if there’s a crack. Hoping there isn’t, but we’ll see.
@Torin
If there is, it’s usually on the front, top seam. A tip: take pictures while disassembling. You’ll be removing a lot, and photos can really help when putting it all back together. Use zip ties to keep heater hoses and wires out of the way—it makes the work much easier. Cut them when you’re done. Good luck, and if you run into problems, just ask!
@Torin
Thanks for the advice! I’ve already prepped Ziploc bags to organize the bolts when I take everything apart next weekend.
@Torin
Good call! I did the same. Let me know how it goes once you’re done.
Just a heads-up: when you install the new manifold, use a good torque wrench. Follow the torque sequence and specs closely to make sure everything is done right.