Older guy, older truck (both with problems) <g>

[PeterLindquist]

We previously owned an '87 Bronco II, a delightfully straightforward vehicle.

We purchased our '91 Explorer last year. Very clean overall, with just a few minor issues along the way since purchase.

My wife had the truck the other day. She said she drove (slowly) through a flooded section of road as the only unusual occurrance. But when she parked at home, ignition off and keys in her pocket, she heard a repeated 'clicking' from under the hood (~1 per second?), lasting a minute or so.

I started the truck a couple of times, idling in place, but no recurrence. Then I drove it a couple of miles on local side streets, and when I parked it I heard the sound. Opening the hood, it sounded like it was coming from the front part of the engine bay. Additionally, putting my hand on the engine I could FEEL an impulse with each 'click', which indicated a solenoid to me?

My _only_ thought, was that it might be related to the transfer case? I again drove (slowly) around the block, and cycled the '4WD' and 'Hi/Low' buttons (our indicator light for the latter does NOT work BTW), and when I parked again, the noise did NOT reoccur.

I'm NOT especially savvy about this cars mechanicals. Does the mechanism for the 4wd system draw power AFTER ignition is off?

I can take it to a local Ford shop, but I'd like to be able to either reproduce the problem reliably, or at least talk intelligently about the symptoms. <g> Any thoughts, informative musings, or embedded links to articles I desperately need to read will be most appreciated.

Thank you all for your time spent reading all this.

 

[Heath]

Welcome to EF.... I don't know the answer to your question but I'll move this to the first gen forum for you so you'll get more exposure...

 

[Roadrunner777]

You have to be stopped and in Neutral for Hi/Lo to work... No clues to your actual problem, unfortunately.

 

[BWTGUY]

Where is COBB, CA? I'm in La Crescenta, CA about five miles north of Glendale on the 210 Fwy. I can help with the 4X4 stuff but have never experienced the "clickies" you are having. Oh yeah, I have a 92' Eddie Bauer + a ton of Explorer tools. I am also an "older model".

 

[GuardianSport]

Um? Pixkthx

 

[FIND]

The clicking sound (and feel) is most likely from metal expanding and shrinking from heat soak as coolant and oil stops circulating and your exhaust manifold shrinking as it cools. This is a very normal condition and many vehicles do it. It is more common among vehicles that use a mix of aluminum and cast engine parts since the parts expand at different rates , this is probably why you have never really noticed it before on older vehicles you have had.

If you like, I can try and find another vehicle that does it so I can replicate the sound and you can compare the sound to the sound coming from your engine, but from your description, I would almost bet that that is what you are experiencing, especially since you can actually feel it when you place your hand on the engine. Basically, if you have ever lived in a house with steam heat, you remember the pinging sound that your radiators and pipes would make after the boiler kicks off? Yeah, it sounds a lot like that if this is what you are experiencing.

Hope this helps you out.

 

[huntman58]

Find said what I was thinking as my 93 seams to do this more then almost any auto I have owned before. Like you I have even felt it with my hands. now when I lived up in Idaho it seamed to be a bit louder at times then it has here in Calif. now if Cobb is were I think (close to Clear lake) its were an Uncle had a cabin and it can get cold up there and the weather we have had this winter it would also seam to reason it would make the sound a bit more being motor heat and colder out side air temps almost give a faster cool down and thus popping snapping sound. Now to tell you how sounds can trick you I had the windows down in a car one time that had given me lots of problems and when I came around a corner I heard a chirping sound nice and load so I stop the car pop the hood and started to check it out and that’s when it came to me the dang chirping was crickets along the road side and this was on a road I had drive for years and never heard them before. so may be what find and I are say is all it is and we can hope so but just keep an ear out and see if its there all the time or just with temps being colder then normal or your healing is tuned to listen more being the truck is new to you.

 

[PeterLindquist]

Update to thread

Thanks to all who've contributed.

First, I do know the sounds of thermal contraction, and of my vehicles normal sounds in general. This was a new, distinct anomaly. I spent a day and a half trying to isolate the cause, narrow the behaviour parameters, and in general do anything I could to AVOID having to hand it off to someone who'll take WAY too much of my very limited funds.

Idling the truck, for 10 minutes or more, would NOT reproduce. Driving a mile or so, at VERY mild throttle even, would. The noise could be heard and (borderline) felt while driving, and leaving the engine running while popping the hood would let me narrow the search area to the front half of the engine bay.

I finally DID take it to the local Ford shop, primarily because I wanted to insure that they would have all equipment necessary to check ALL data ports if required. I had to demonstrate the problem to the service writer. He in turn demonstrated it to their LEAD mechanic. That was on Friday, late afternoon. The mech felt he had a possibility, which he will investigate first thing Monday. The only feedback I received, second-hand, was that he believed it to be related to the _thermostat_? I don't think I would have gone in THAT direction on my own anytime soon. WE did have the water pump replaced recently, but that was more than a month ago, and we've put at least 2k/miles on it since then with no problems, including multiple commutes up and down a mountain chain.

When I get the truck back, I intend to grill the mech for the exact details, and I _will_ post for everyone's benefit. Thanks to all.

 

[Roadrunner777]

I thought of something to try. I'm too late, I think, and I'm anxious to hear the outcome. But, you said it can happen after you park and shut it down. What I would have liked to have tried is to disconnect the battery and see if the tick/click stops. That would indicate or eliminate electrical, I think. Anyway, sounds like you are on your way. Look forward to the results!