Last year I was about ready to throw in the towel in on my Aerostar. Every year it was something that seemed goofy to appear after my once-a-year run up to the middle of my province and back again - about 400kms each way. Once it got back to regular "soccer dad" status daily duties, it behaved for the most part just fine.

My mechanic of 25 years, like a dog with a juicy bone, didn't want to give up on this, so in a last-ditch desperate attempt, spent a lot of time (and only charged me $250) to replace just about every rubber hose under the hood, vacuum and otherwise, even those that looked just fine.

Well, my sometimes spongy brakes are now wonderfully tight, the Heater now miraculously works better, the shifting is silky-smooth and gas economy and get up and go have increased tremendously (before I'd take a tank to get to the destination, then a tank back - I now can do it on 3/4 of a tank each way).

To my mechanic's amazement, some of my hoses were the originals. (@ 320Kms!). I also treated it to a set of new spark plug wires and now I'm all set. This year, I just came back from the long journey (oh, and I also tow a 2000lb trailer while doing this BTW) without 1 incident, no mysterious "check engine" lights, nor an "abs" light either.

Maybe this going-over might be worth your while, too....since the youngest Aero is 12 years old...

 

I'm wondering if you can get heat resistant silicone hoses to replace the rubber ones. I know silicone would be an upgrade for the vacuum lines.

 

Not exactly silicone hoses, but much stronger than stock rubbers:

http://www.summitracing.com/parts/GTR-65074/

The silicone hose sets are usually made for specific models of cars. Ford had Goodyear make a set of silicone hoses for their special service (police) cars, and released them through their SVO and Motorsports outlets. So guys like me with Mustangs were able to get a set for their cars. I installed my set 20 years ago, and they're still in great condition when I checked them out a couple months ago.

This spawned an aftermarket of makers of other "silicone" hose sets in brilliant blue and purple colors. These are especially popular among boy races in the Sport/Compact car market. It might be possible to find silicone hoses from these sources that would fit the Aerostar.

 

bah on rice boys. i've been thinking of just dropping the engine out this fall to replace everything w oem parts (all new seals, gaskets, full tune up, valve adjustment, timing stuff, etc.). i think i'll try replacing my hose's tho, might help

 

I have a feeling that many OEM parts were the cheapest that will allow the car to survive the first year/12000 mile basic warranty, and some not even that. Specifically on gaskets and seals, a lot of what Ford used just do not compare against offerings from a good aftermarket company like Fel-Pro. Aside from the quality of the materials, sometimes the stock design just did not work well, and the aftermarket would avoid the same mistake. The best example I can think of is the lower intake manifold gasket; the stock is one-piece covering both sides, and the normal stresses that the engine parts experience cause it to easily fail. The replacements (from Ford as well as aftermarket) that are in two pieces worked much better.

Similarly, for cost reasons, most auto makers do not use silicone rubber hoses. When the standard rubber hoses fail, they can easily lead to engine overheating, which is much more costly than just the hose failing.