Sudden onset rattling noise front of engine, diagnosis?

[cobrajocky]

I've got a '97 4.0L V6 Xtra Cab 2x4 Mazda B4000SE (same as a Ranger XLT). It's only got 98k miles, yeah I hardly drive it.

I've got a "sudden onset" (like a heart attack) rattling noise, sounds more like the connecting rod rattle in a 57 Chevy I had in High School. I heard the faintest of this sound starting maybe a month ago (less than 40 miles ago - said I don't drive it much). Oil is clean and full, I run 10W-30. The AC compressor went out last year, seized after a leak when the original hoses deteriorated enough to let the system go dry without any warning.

I'm not seeing any coolent leaks in the driveway, I'm thinking water pump? It's original on this engine. I've listened to the noise from both the left and right sides and it sounds like it's coming from the front of the motor, though I can't tell if it's internal or not.

Anyone recognize these symptoms??

One more thing, this winter (here in So Cal near the coast) when it's wet wet air or raining, the engine just does not want to start. Dry air, no problem, starts immediately.

Appreciate Pro or Home Mechanics thoughts both. Thanks.

I just turned 70, I thought this Jap branded Ranger would outlast me, now I'm wondering!

 

[Uncle Gump]

As far as the wet starting issue... I would say the plug wires are suspect.

For the noise making issue... I've had belt tensioners make some strange sounds. I would take a long... really long screw driver and start touching different components while running with your ear to the other end of screw driver and listen. It will help you narrow down where this noise is coming from.

 

[RonD]

When engine is Stone COLD loosen and remove fan belt from crank pulley

Start engine, you can only run it for max 2 minutes with no water pump, so be quick
Battery light will stay on, no alternator either.

With no fan noise in engine bay any engine noise should be easy to track down
If no noise then shut off engine
Start spinning each fan belt pulley by hand you will find the bad one

 

[cobrajocky]

@ Uncle Gump and RonD,

[slap forehead] Well Duh on me! I had read somewhere that the Ford 3.0 and 4.0L V6's had a issue with pully/tensioner failures / problems, but I guess I buried that too deep in my old brain to think about that. Maybe the failure of my AC compressor last year brought on a failure in a pully or tensioner bearings?

RonD, I'll try your testing methodology to see if that's a way to eliminate or point to where the noise is coming from.

How many pullies does the 4.0L V6 on a late 90's Ranger (Mazda badged) have that could be bad?

Thanks guys. to you

 

[RonD]

Idler pulley
Tensioner pulley
Those are most common to fail

But........
AC compressor
Alternator
water pump
and even power steering can fail

You can spin test all except power steering pump

 

[cobrajocky]

Idler pulley
Tensioner pulley
Those are most common to fail

But........
AC compressor
Alternator
water pump
and even power steering can fail

You can spin test all except power steering pump

@ RonD - Thanks for the followup reply.

The AC Compressor already failed just before summer last year (figures).

I listened to the Alternator using a long screwdriver a few days ago and the noise isn't coming from there.

So that leaves either those two pulley's or the water pump or PS pump. My PS is not exhibiting any problems, I would think I would feel something in the steering "action" if the pump was already going bad.

Thanks why I most concerned about it being the Water Pump. It's been a couple decades since I had a WP go bad and can't remember if they make a mechanical "racket" when about to fail. I thought it was always a "screaming" sound when the bearing on the impeller dies. At least that's what happened on the Datsun 240Z, 280Z, 280ZX's and Mustangs I used to race (IMSA) in the old days. I just don't remember a mechanical almost "knocking" kind of noise from the water pumps or power steering pumps either.

 

[cobrajocky]

Follow up. -
Didn't need to take off the serpentine fan belt after all. On a quiet morning, it was easier to determine that the "noise" - a mechanical "chuga chuga" rattling type sound - was only coming from the drivers side of the front of the motor and up high. That meant either the AC compressor or the power steering. I already immediately suspected the AC Compressor since it seized internally last late spring due to deteriorating 22 year old hoses (obviously, I don't turn on AC any more). Wth a very long screw driver against the two housings I listened for which had the loudest same "chuga chuga" noise and it was the AC compressor. It think after watching it for a while that the AC Comp Clutch is failing too and that noise is metal to metal noise.

Fortunately I found a great deal on a new US made aftermarket AC "Kit" that includes everything but the up and down hoses. Ford no longer makes those and that kept me last year from having the AC kit put on. All the Pressure Hose repair facilities around here wanted way too much to make me hoses. Again fortunately I found a new set made by a S Korean company with very high review grades at a great price ($75) for both up and down. So now all I need to do is find a mechanic in Orange County to put the kit and hoses on and charge it without ripping me off with an absurd labor charge. I may take a shot at installing it myself and just buy a Freon Recharge kit off EBay or Rock Auto.

 

[Bgunner]

I would recommend installing it yourself to save money and have a shop vacuum down the system and check for leaks and charge it while it is there. IF you are not replacing everything in the system make sure you flush out the components and be sure to change the orifice tube. Any time you change the compressor you really should flush the system to remove any metal shavings that may have come from the pump.

Don't forget to add the proper oil into the system before sealing it up to be vacuumed down.

 

[cobrajocky]

Bgunner, thanks for the advice, and I was considering just doing that, but I watched a couple video's on YouTube doing a near complete AC system replacement on a 4 cyl and a V6 Ranger and doing the "Dryer" / hose / filter pull would be beyond my capabilities at 70 yrs old. Just don't have that dexterity and strength anymore. The rest I could easily see tackling. I have a new compressor, dryer, new rings and filter and all the replacement hoses. The only thing I'm not replacing is the condenser assembly / those hoses. Besides, I have none of AC tools to do a proper job.

One of the community colleges I used to teach at has a Auto Tech degree / certificate program. I think I'll call over to the dept head and ask if they'd like a AC job for the students to do for a retired senior Prof. that needs some help.

 

[cobrajocky]

Turns out that the noise was coming from the AC Compressor pulley, apparently the Compressor Clutch specifically is the culprit. The Tensioner Pulley was fine.

Thanks for everyone's advice.

 

[alwaysFlOoReD]

Thanks for the update.