97 4.0 SOHC Cam guide recall questions

[toms97xlt]

Hi all,

I’m sure this is not the first time this topic has been covered so please bear with me. I have read a lot of horror stories about the Explorer 4.0 SOHC engine on this and other web sites.

We own a 97 Explorer with the 4.0L SOHC engine. It has about 64,000 miles on it. It has been in the shop for the last week for repair to the front overhead cam chain guide. It developed a “Hard Knock” last week and has been having gradually worsening ratting sound on cold start-up for the last year. The dealer told us the front cam chain guide broke into 3 pieces.

So far the dealer has been pretty good about getting parts replaced under the extended coverage program for this engine. (He showed me a list of about 10-15 parts today that they are going to replace for no charge.) One component he says that MAY not be covered is the “intake plenum?” (I think that’s what he called it – is this the same as the intake manifold? And is it really plastic?) He said it’s a high-density plastic part that has to do with the air intake but I’m not sure what exactly he was talking about. Anyway, he says it’s cracked and a new one costs about $750.00. He has also found a used one locally for about $250.00.

The questions I have are:

-Is this cracked plastic “Intake plenum?” likely related to the the front cam guide breaking ?

-Are there any other things we should be sure to have checked while the dealer has the top of the motor apart?

-Anyone else been through this with their 4.0 SOHC engine? Good - bad experiences?

-Can we trust this engine to take us up to 100k miles or more after these problems have been fixed?

Other than this problem we have been really happy with this vehicle. Good Mileage reasonably reliable and comfortable to drive.

Thanks, Tom Hopkins
Bismarck, ND

 

[TPLYNCH]

A cracked intake plenum should not be related to the Tensioner problem. It is the (from my understanding, and anybody with more experience please correct me) the piece on top of the engine that runs from your airbox to the throttle body. If it is cracked, it will cause your engine to run improperly because more air in negates the readings from the Mass Air Sensor. $750 for that sounds a little steep to me, however. I would ask the dealership to show you the crack. You may even just be able to fix it yourself with a sealer..... alot cheaper than $750.

Also, have they done the lower intake manifold O-rings yet? That's under warranty as well. If not, have them do it and take care of everything at once.

 

[toms97xlt]

Thanks for the input TPLYNCH

I looked at the intake plenum today and a molded vacuum fitting on the bottom if it had broken right off. My wife (She fights my fights) is going to stop there tomorrow and see if perhaps the mechanic didn't accidently break it when he took it off. That thing had been running pretty well before we took it in otherwise.

The dealer had a used plenum on hand. A new one would run around $720.00 with tax and all

Has anyone else run one of these SOHC engines for a lot of miles after these kinds of repairs have been made? We are really concerned about the long-term reliability of this motor.

Thanks, Tom