Loud fan / engine noise with minor acceleration

[deeman]

I just got my truck last night and really like it so far. I wanted to ask you guys about an engine noise. I have an auto transmission and when I put the truck in drive from park and barely touch the gas pedal I hear a pretty massive engine revving noise, like an 18 wheeler, lol. It's like something is spooling up. I just wonder if this is normal.

Thanks

 

[RonD]

No, not normal

When engine is cold, after sitting 5+ hours, open the hood and try to spin the fan, should be hard to spin
Start engine, you should hear the fan noise for less than 10seconds then it should get quiet, wait 30seconds and shut off engine
Try to spin fan again, should spin easily, if not you will need to replace the fan clutch, it has failed in the lock position, which is called the "fail safe" mode so engine won't overheat, but they can fail in unlocked mode as well causing higher engine temp when driving slow or stopped

Fan clutch is a fairly common failure on all vehicles after 10+ years of use

 

[deeman]

Hmmmm. Great advice, I will check it. Oddly enough the PO said the coolant was changed about 10,000 miles ago and yet I found the coolant reservoir empty and the rad was low by about 15 ounces. Wonder if something is going on.

 

[RonD]

Most likely you have a leak, and in a warm area so it evaporates as it leaks out and never drips to the ground, assuming you haven't seen any obvious leaks

You can rent cooling system pressure test kits
These are basically a rad cap with hand pump and pressure gauge attached
You pump up cold cooling system to say 20psi and watch for pressure to drop, which means a leak somewhere, then start looking for coolant coming out

 

[deeman]

Okay thanks again! Do you see any relationship between the low coolant and the cooling fan issue or are they not related?

I did fie up the engine and as soon as it's on, the fan runs at full speed. After 5 mins of idle the fan never slows, stops or changes speed, just full speed. Once the engine is off the blade is pretty east to move by hand.

 

[RonD]

Possibly, but would be result of engine overheating from low coolant, no direct relationship

Fan clutches do just wear out, and at 12 years old a little extra heat might cause a failure a year or two early

Test has to be done as described
Cold engine after it sits overnight
Open hood and spin fan
Start engine and let it run for 30second, shut it off
Spin fan again should be a BIG difference on how it spins, if not replace fan clutch

The fan always spins when engine is on

 

[deeman]

So I just ran your test and it failed. Before starting the cold engine I rotated the fan blade - it would allow me to rotate it by hand with some force. Started the truck, let it idle for 30 seconds turned off and the tension / resistance on the fan blades were the same as before. I will plan to replace the fan clutch. Thanks for your help.

 

[fastpakr]

So I just ran your test and it failed. Before starting the cold engine I rotated the fan blade - it would allow me to rotate it by hand with some force. Started the truck, let it idle for 30 seconds turned off and the tension / resistance on the fan blades were the same as before. I will plan to replace the fan clutch. Thanks for your help.

The good news is that it's a relatively cheap and simple fix. And it didn't take you long at all to diagnose the problem. Good job!

 

[Uncle Gump]

Isn't owning a Ranger... wonderful!

 

[cbxer55]

I've had mine for 21 years. No intention of selling it. Wonderful!

I'll have to check my fan clutch when I get the truck back. Far as I know, the fan spins easily in all the modes that RonD described. But, never had an overheating condition either. Maybe the 180 thermostat is helping with that.

 

[RonD]

No, thermostats have no effect on overheating
The 10 or 15deg difference between a 180 or 195 t-stat would be used up in under 10seconds if there is a cooling system problem
T-stats only control minimum temp, can't control maximum
The benefit of the higher t-stat rating is better MPG, cleaner emissions and cleaner oil, there was a study back in the 1970's by S.A.E., after it was released car makers started switching over to the 190-195 t-stats

 

[deeman]

Well as as I mentioned I just got this truck this week. I am almost having buyers remorse but will work through it. As you know the used truck market is insane. Cars and trucks are overpriced and selling in hours not days. I found this from a local guy who owned it for 10 years. When I got there he mentioned he had two other people coming to look at the vehicle later that day and I desperately needed a vehicle. So I looked pretty good at the underbody and it looked good. Now that it's sat in the driveway I now think there is a coolant leak, a leak in the brake line - I may have figured out where it is - and all the shocks are garbage - which I saw and felt that was the only repair needed. So I will replace the fan clutch, have someone fix the brake line issue and hopefully find the coolant leak with a pressure tester. I hope this is all it needs.

It is very reassuring to have this forum so I am super grateful for the advice from you guys!

 

[RonD]

Well a 12 year old vehicle will need some work

Even a brand new vehicle usually has to go back to dealer 3 times in the first year for repairs, and maybe 2 times the next year, yes, under warranty but still a pain in the butt to drop it off and pick it up, its a friggin NEW car for goodness sake, lol

You are probably close to end-of-life for its 2nd battery, unless its on its 3rd now
Upstream O2 sensors are due to be changed, only sensor that "wears out"

 

[deeman]

I hear ya Ron! I know the battery was recently replaced so I should be safe. I will deff replace the upstream O2 sessor based on your input. I spent a little time reviewing the maintenance schedule, but is there anything else you can think of to replace now with 120k on the odo? I don't recall, is there a timing chain on the 3.0? Thanks again, you are all a great community!

 

[RonD]

There is a timing chain on the 3.0l Vulcan, but it was never an issue, doesn't even use a tensioner

Keep an eye on front tire wear, if you notice more wear on the inside tread then its time to replace ball joints
Oil changes and transmission service

If you don't have an OBD2 code reader, a Bluetooth OBD2 reader is under $20 and works with any smartphone, iOS or Android, APPs are free, or $5 for more advanced features
These work on ANY 1996 and up vehicle sold in the US or Canada, so not a Ranger or even Ford specific tool
You can watch Live Data as well which it "neat" but also a good diagnostic tool