Hi, new member here. A lot of stuff on this website just blows me away. You guys are serious!

I have a 1999 E250 with the 5.4L V8 EFI SOHC engine, the 4-EOD and a limited slip 3.73 rear end. I don't have the knowledge, talent or tools to do serious work on it, so I end up paying someone else. The van has 130,000 miles on it, and this spring it seems to have developed an exhaust leak on both sides from broken manifold studs. When the manifolds heat up the noise from the leaks stops. What kind of damage will happen, and how quickly will it happen if I do nothing about the leaks? What are my long term options?
Any thoughts on this would be very helpful, thanks.

 

Hi outsider and welcome to the forum
I doubt that any serious damage will happen due to the leaks.
I've seen people drive vehicles for many years with manifold leaks and not have any problems.
I've replaced lots of broken studs on 5.4's in trucks and it isnt too bad but I dont think I've done any in a van. I've done manifolds on other engines in vans though and they arent much fun but can be done. Dont be surprised though if the bill is pretty big when it's finished.
Options are probably limited to paying to have it fixed or driving it until it drops, providing you dont mind the noise. I dont think I've ever seen one with more than 2 studs broken per manifold so it might not get much worse than it is now.
Is the engine in good shape otherwise?

 

Racerguy:

The engine has had it's (not synthetic) oil changed every 3000 religiously. There have been a couple of service light repairs at Ford dealerships which I've taken care of asap. Absolutely no other problems - (except for that annoying tick at startup which I could hear when it was new but no Ford dealer could hear until it crossed 36,000 miles, and then they wern't sure what it was.) It's really been flawless otherwise. Even has the original serpentine belt (I hesitate to tell the truth about that, but the belt still looks pretty good).

With the exhaust leak I was worried about burning a valve. And I was thinking if I ask someone to drop the motor down to replace the exhaust manifold studs on both sides, I might as well replace other stuff that's due to wear out soon at the same time. Stuff like the power steering pump which has been whining pretty loud for the last 30,000 miles, but doesn't lose fluid. The transmission has been great too (no service yet).

When things go perfect, how many miles is this engine good for? I can live with noisy manifolds at startup.

 

Something Needs to be mentioned here. If you have heard vehicles with bad exhaust leaks you typically here a backfire right?

That obviously a bad leak on a loud vehicle typically. The point that I'm making is that the pop sound you here is cold air rushing in to balance the pressure in the system.

The same thing will happen at the manifold/head except it will possibly go into your engine and very rapidly cool valves and heads which will cause warping eventually, possibly sooner than later if you live in a cold climate. Just had to mention this because I've heard it said many many times. Not sure on how much damage could actually occur your call.

 

One thing that I don't understand: With respect to an exhaust leak and in-rushing air - How do the forces compare between cruising on a flat highway say, versus backing off the throttle completely going down a big hill with a load?

Thanks to you both for your valuable insight about my issue. I'll be paying attention to the sound as we go through the summer. I guess the conclusion I've come to is that the cost of repairing just the manifold studs is so high that I'm just going to drive it this way for as long as I can and eventually probably replace the whole motor.