Dear Forum,
I own a 97 Ford Ranger 2.3L 4 cylinder with the 5 speed. The truck has 83,000 miles on it and always been maintained. This truck has not been beat on. The only problems I have had with it were the FUEL PUMP and the INTAKE GASKET.
The check engine light went on the other day, so I brought it to the dealership. They discovered that the aluminum intake was warped, cracked, and the gasket blown. The Ford technician stated that this is a very common problem in these trucks. They also found two fuel injectors leaking fuel after the truck has been shut off. Had those replaced too. But the key to this is that it was caused by a BAD THERMOSTAT. The thermostat was staying open, the truck was not getting up to operating temperature, the cylinder head(cast iron) was expanding at a different rate than the aluminum intake, which caused this problem. I was planning on replacing the thermostat, but did not get to it soon enough. Of course the crappy "gauges" that are in the dash did not show that the truck was operating at a low temperature, maybe they could have warned me of impending doom.
The moral of the story is, a $2.50 part cause over $1500 in repair costs. Please service your cooling system and replace those thermostats. Keep up on those coolant services especially if your engine has ALUMINUM parts.
Please learn from my mishap. Thanks, 97Rangerspl

 

Interesting info. Aluminum parts on a engine make me nervous.

 

That is odd. I've heard from MANY people, including mechanics and consumer reports, that the 96-97 Rangers were the most reliable ones ever made. Sorry to hear that all happened to yours. I too am a firm believer in regular maintainence, I think lack of maintainence is the #1 cause of break-downs.

 

Sorry to hear about the problem with your 4 banger.

I understand the part about the aluminum intake and cast iron heads expanding and contracting at a different rate and causing the gasket in between to fail But the part about the aluminum intake cracking confuses me a little. Where did it crack? Along the bolt flange(s)? The cracks and warping could not have been from heat ...you said yourself the motor was running cool, and the intake usually runs cooler than the heads do (right?). So the damage must have been a result of the difference in movement between the two metals when they expanded and contracted at different rates. Where the two metals are bolted together, I would think, is where that stress would be.

The heads checked out OK?

 

I would be more willing to place the blame on a crummy gasket or bad gasket installation than the aluminum itself...unless the intake was overtorqued.

The days of dissimilar materials raising a red flag are over. Well, as long as the gaskets are of quality and the coolant is in good shape, I am not sweating it. The early 80s and the Caddy 4.1L with iron heads and aluminum block are long gone.

Oh yeah, every so often I supposed a crummily casted piece can come from the factory.

 

First off I think the dude that told you this is a common problem is full of Guacamole dip.
Second most thermastats that I have used are designed to stay open when they go bad. This way you don't have a overheating problem which actaully causes the alum heads to warp.

 

My old Toyota had a cracked head that was allowing exhaust gas into the coolant. To help it from overheating as quickly, I pulled the thermostat completely out. I haven't seen or noticed any damage thus far, and it's a cast iron block with an aluminum head going into a cast iron exhaust manifold. Doesnt' get much worse than that with mixing of metals. I agree with greenpus, that mechanic was full of it.