I'm going to be buy a used 97-99 F-150 with the 4.2L for daily driving and I've been hearing about problems with gaskets going bad on them. How do I know that the engine has or hasn't had the gaskets changed? What is the maximum milage on a truck with a 4.2L I should even consider buying. About how many miles do they start having problems?

Thanks.

 

One more thing, is there any computer programer for a 4.2 that will increase its fuel economy?

 

Jan 15, 1998 was the last date of the old style gaskets. After that, all 4.2s got the improved gaskets and revised torque values.

If the gaskets were fixed at a Ford dealer, you should be able to find out at any Ford dealer by asking them to check the history of the VIN. I believe they can tell you by doing so. I'd call a Ford service shop and just ask if they can identify based on the exposed gasket surface if the gasket in question is the new or old style. I don't know for sure.
If the fix was done at a private shop or DIYer, then you'd just have to happen to find one where the seller can 100% confirm that the fix was done.

Why did you settle on 97-99 range? (just curious).

BTW, there is no 100% gaurantee of early failure with the 97-98 gaskets. They were just prone to early failure at a much higher rate than normal.

My 2000 made it to about 150,000 miles and then the new style gasket started to leak. I had it fixed at a local independent service shop. They replaced the gasket, bead blasted the inside of the intake, new EGR, new thermostat and the total was about $400. That was a deal in my book.

Thomas (Travlman) had about the same gasket leak on his 2000 model, but I believe his made it to about 170,000 miles. He fixed his and as far as I know, he's probably past 200,000 miles on his engine now.

The lower intake manifodl gaskets are just the weak link in this motor. It's the way the block/head cooling passages are designed. There just isn't a whole lot of surface between openings at some points.

Aside from the gasket issues, these engines seem to be poised to give a long life.
When I sold my 2000, it had almost 170,000 miles on it. And to be honest, you could have set the odometer to 25,000 miles and nobody would have been suspicious. The truck ran like new, burned no oil, etc.

Anyways, I wasn't too concerned as I bought a 2005 with the 4.2.
I expect (assuming I keep it that long) I'll pick a day long about 150,000 - 160,000 miles and drop it off to have the gaskets replaced. Cheap insurance against the chance of hydrolock and a damaged engine.

I happen to like the 4.2. I guess largely because it comes in a high quality truck, that suits my needs just fine, and all can be had at a very reasonable price.
My 2000 was $16,500.
The 2005 was just under $15,000.

The lowest priced 2005 they had on the lot with a V8 (4.6) was around $21,000.
Just wasn't worth it to me.

Oh, you asked about the highest mileage you should consider. That largely depends on the history.
I'd take one well cared for with 100,000 miles long before I'd choose one abused and neglected with 50,000.

With proper maintenance, 100,000 miles is nothing for today's autos.


Thanks for stopping in the 4.2 forum.
Stay in touch and keep us posted on your search.

 

I don't know if I'm going to be getting the truck I was looking at with the 4.2L. I found one with the 4.6L for the same price, a little bit more miles and has more options and newer.

 

BUY IT!( the 4.6) Dont even look back! BUY IT!