Fault codes?

[markwillenbrock]

We've plugged my dad's '97 Exporer into a fault code reader and it's come up with three fault codes. Can anyone suggest a fix?

P0171,P0174 are left and right banks running lean. An inlet manifold air leak? The car runs perfectly bar the first minute after a cold start, when it stumbles then revs.

P0705 is a transmission range selector malfunction; and the car is sometimes difficult to move out of position 'P'.

Any ideas?

 

[dogfriend]

P0171 and P0174 usually are caused by vacuum leaks at the intake manifold. There are other possibilities as well, see this thread:

http://www.explorerforum.com/forums/showthread.php?t=145587&highlight=p0171

Also, the SOHC engines are known for having issues with the intake manifold o-ring seals, so intake leaks are a strong possibility.

For the P0705 code, the manual indicates that it is a fault with the DTR (digital transmission range) sensor. Fortunately, this may be repairable without removing the transmission.

 

[markwillenbrock]

Thanks for that; it sounds like the inlet manifold gaskets are the way forward. Not too difficult...?

As for the transmission, I presume this is the lock that means you can't get out of P without your foot on the brake. Presumably pulling a wire or shorting a relay would get rid of this?

 

[dogfriend]

Here is a thread on replacing the o-ring seals on the SOHC motor.

http://www.explorerforum.com/forums/showthread.php?t=222851

The DTR sensor basically tells the PCM what gear you have selected. The P0705 code indicates some type of electrical fault with the sensor or the PCM or the wiring connecting the two. The PCM is usually very reliable, so the fault is most likely with the sensor or the wiring.

 

[markwillenbrock]

Which intake gaskets

I've had a look at the Rockautos catalogue for intake gaskets and they show a one piece gasket with six staggered square ports..

I thought the ohc motor used 6 separate O rings?

Does anyone have an idea of what the correct gaskets look like?

 

[Howard]

The Inlet manifold has two sets of gaskets. 6 individual round 'o' rings on the bottom and 2 3 port odd shaped ones that go between the upper inlet manifold and lower inlet manifold. It is usually the 'o' rings that leak.
Rock Auto do a kit Fel Pro MS90890 for $13.33 which has both upper and lower. Remember our SOHC engine is code E.

 

[markwillenbrock]

Thanks for that. I'd presumed the more powerful ohc per bank was the X engine - no idea why. It is indeed E.

The link shown above on this thread mentions a chain tensioner as well, and mine is often noisy - particularly with one's head in the right hand (from the drivers seat) front wheel arch.

Any tips?

 

[dogfriend]

There was a field campaign by Ford (00M12) to replace the o-rings and the timing chain tensioners on early (97 - 98?) Explorers with the SOHC (E) engine. It was covered under extended warrenty for the affected vehicles. I am virtually certain that the warrenty has since expired.

The reason that the tensioner and o-rings are described in the same thread is because the Ford kit included both.

I have the OHV (X) engine, so I don't have any practical experience with the timing chain, but I believe it is a common issue.

 

[markwillenbrock]

Oh for that nice simple pushrod lump. A had 2.9 in a TVR years ago, and it was indestructable; it froze and boiled more often than I can remember. Definitely the best bit of that pretty dreadful car.

I wonder how one can tell whether the chains have been 'done'? Expensive Mobil 1 (0-50w) makes the chains very noisy. Cheap monograde 40 and they're quiet but it burns oil at a litre every 1500 miles.