I too heard that the higher performance 3.8 liter engine had some reliability issues.
I have VERY good engine experience with a 1985 Taurus Company car and this 1987 Taurus Station Wagion that I later bought BOTH with the 3.0 liter engine. I drove the Station wagon until it had 156,000 miles and the enginer was still running well when I traded it in. The transmission was on it's last legs at that point with poor shifting and sometimes slipping.
I would buy a car with that 3.0 Liter engine again in a heartbeat. It looked good, ran smoothly, had good performance, was low maintenance, was easy to maintain, got 22-26 mpg and was reliable. What's not to like?
i've worked on these type of parts for 20+ years and the requirements for corrosion have evolved due to technological advances in surface chemistry, litigation from accidents due to corrosion, and overall advancements in customer expectations of quality.
i'm sure the dfmea process was done and the vehicle level testing was done by ford, but sometimes this type of corrosion doesn't show up until some time has elapsed. hence the galvanized washers added as a recall.
i think you will find that designs over the last 5-10 years are much more robust due to the lessons learned on these previous models
i'm glad you were not driving when the mounts failed.
I drove a car with that engine for six years and never had problems with it -- maybe I didn't own it long enough. I liked the engine. I chose it instead of a 3.8-litter because I heard the 3.8 had head gasket problems.
As a kid in the '80's, we had a Chevy Citation which had its share of issues, but the main thing we saw was that after the first few years, there was a spot in the center bottom panel of the driver's side door that would rust out every year before the annual inspection requiring a fiberglass patch. The next year, the patch would be gone and you would need a bigger patch. In watching the car run, there was just enough room beneath the front mud flap for a small stream of rock salt to hit the exact location of the rust spot. The solution was longer mud flaps for our car, but I remember seeing a lot of similar Citations with the same rust spot.
Ironically my experience with automotive floor pan rust was usually from the inside out. either the windshield frame would rust until it leaked or window seals would leak.
Cars with carpeting would get wet carpet then dry-out. Cars with rubber matting would get wet and stay wet until the floor pan rusted out (from the inside as I said with my experience).
And yes, newer cars seem to do much better with rust-proofing. I don't know if it's from the body design or processing with an immersion pool of rust proofing primer or zinc/cold galvanize, but most cars have better rust performance since the late 1970's.
It is interesting that in the automotive world that this type of FMEA is not done more completely. As Beth mentions, quite charitably, the process was not as "robust" as it should be.
Some of your examples ring very familar, although most of my early experience was with small British sports cars. My first car had a leak on one side of the oil pan (the passenger side). That side had no rust. The other side had rusted through and a previous owner had used some old road signs to replace the rusted out floor pans. As this was under the carpet, I didn't see it at first.
I do notice cars I have bought in the last decade or so have much better corrosion resistance, and I live further north where they use lots more salt.
Great real-world example showcasing the need for engineering teams to seriously address Design Failure Mode Effects Analysis--a process that perhaps isn't as robust as it should be on many a development effort. You were lucky that you had enough ingenuity and engineering smarts to troubleshoot and handle this problem on your own. Most people wouldn't be so lucky.
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