Ford Ranger loses power

[pacem]

170K miles, 5 speed, 2.3L 4 cylinder

It has been slowly getting worse over the last few weeks. Serious loss of power when starting out in 1st and also weak at low RPMs in 2nd. Lacks power in all gears apparently, especially low RPMs.

Hasn't had a tune up in a long time. What could it be? Plugged up fuel filter? Spark plugs? Fuel pump going?

 

[Colt45ws]

What is a long time for a tune up?

 

[mcrn]

What year? They had two different 2.3's?

 

[Greggy_D]

Clutch slipping?

 

[mcrn]

What year? They had two different 2.3's?

 

[jhs914]

Clogged catalytic converter?

 

[pacem]

Actually I think it's a 2.5L.

The clutch - diagnosing it via this method, it seems fine. I have a hard time getting the RPMs up.

http://www.wikihow.com/Diagnose-a-Slipping-Clutch-in-Your-Car

I am borrowing the vehicle so I have no idea about maintenance / tune-up history. The air filter looks pretty dirty, I would say a year on it or two easily.

 

[widman]

Clogged air filters, like clogged gas filters, show resistance to high rpm's. If it does ok at high rpm, discard those as causes.

One of the first things I could recommend is a bottle of Techron to clean things up.

 

[HM12460]

Sounds like a good complete tune up is due. If no improvement, maybe a wet and dry compression test.

 

[mcrn]

If its the 2.5 then its the Lima engine......they are very slow any ways. I had the 2.3. Great truck but slow. Do you know the baseline for this truck? It might be ok?

 

[pacem]

Yes, it's the 2.5L.

 

[Roadkingnc]

Low power was standard equipment with that engine with a 5 speed, excellent mileage though

 

[pacem]

It has lost power.

 

[Roadkingnc]

Does it run smooth?

 

[Kuato]

A stretched timing chain will cause those symptoms.

 

[01rangerxl]

Could it be losing power at all RPM, and just showing it at lower RPM since the engine's peaks are fairly high up? TQ peak is 3K RPM, HP peak is 5K RPM.

Also, like Roadking mentioned, how does it run? Smooth? Sputtering? Does it detonate, misfire, run rough? If so, at what RPM?

I am assuming there is no CEL on?

What kind of driving does this truck see? All around town? Limas need to be run hard every so often, it won't hurt them.

If the truck is overdue on maintenance, catching up on that is a good place to start. It will help rule things out and if the truck isn't up to snuff on maintenance, that will just contribute to the root problem.

Plugs are mildly challenging since there are 8 and the intake side ones are knuckle busters. Inspect the two coil packs for cracks. Fuel filter is super easy, but would likely cause higher RPM issues. Replace the air filter if it is dirty.

A clogged cat could cause this issue, but I would expect noticeable symptoms at high RPM like detonation and/or misfiring...though if it has trouble reaching high RPM, that makes it suspect.

 

[Kansas_Ron]

Timing belt replacement per manual is at 120,000 miles. I'm guessing yours not been changed. Most likely it has jumped and your timing is off.

 

[01rangerxl]

^ That is a possibility and something that needs to be looked into. If the t-belt has never been changed, it should be done. It is just about the cheapest/easiest t-belt job out there. It is a non-interference engine, so it's not a big deal if it breaks, but I wouldn't want to run on a stretched out 170K mi belt.

 

[dishdude]

If you are on the original t-belt, it's time. A buddy of mine has a 2000 with the 2.5, a couple years ago the original belt sheered off a few teeth sitting at a light around 180k. Of course no damage to the engine, but inconvenient to wait for a tow truck in the middle of an intersection. I warned him about it a few years before that.

That truck is still going strong, I think he has about 230k on it now. He's good about changing the oil, but nothing else gets done until the truck stops moving under it's own power.

 

[pacem]

I just realized it's a 2001.

Anyway, I pulled the plugs and #3 is soaked in oil, on the business end. Seems the valve cover gasket is leaking. No spark obviously and it's apparently running on 3 cylinders.

How much work would it be to replace the valve cover gaskets?