Random valve clatter when accelerating

[dissturbbed]

I bought a 99 ford ranger 2.5L about a year ago and sometimes but not all the time the valves will clatter on acceleration. Some days it will sound perfect some days it clatters. Checked the oil level, no codes, everything has been kept up ie air filter and etc.

Added: Since it is random should that rule out oil pressure or something mechanical?

 

[alwaysFlOoReD]

I would consider timing. Perhaps you're using too low octane gas. What are you using, regular, mid-grade, or premium? Sometimes the engine cylinders get too much carbon in them and then there is a hot spot that causes pre-ignition, especially under load. In days gone by I would, while parked with the emergency brakes on, pour water down the carb while revving the engine to clear out the combustion chambers. Nowadays perhaps Seafoam?

 

[dissturbbed]

I would consider timing. Perhaps you're using too low octane gas. What are you using, regular, mid-grade, or premium? Sometimes the engine cylinders get too much carbon in them and then there is a hot spot that causes pre-ignition, especially under load. In days gone by I would, while parked with the emergency brakes on, pour water down the carb while revving the engine to clear out the combustion chambers. Nowadays perhaps Seafoam?

What about the days it doesnt clatter? couldnt be carbon deposits if it doesnt happen all the time. I might be mistaken

 

[RonD]

Welcome to TRS

Does it EVER make the noise when engine is cold?

If so then won't be pinging/knocking, and probably not oil pressure either since cold oil is thicker oil.

If it ONLY occurs after engine is warmed up and when accelerating then it is most likely pinging, pre-ignition.
And yes this can come and go because it is specific to cylinder temps, and could be from hot spots(carbon) but they have to be hot enough and the fuel mix lean enough to get self ignition.

Running a tank of 89 or 91 octane through to see if problem goes away or decreases alot would tell you if this was the noise you are hearing.

If your 2.5L has an EGR system then tube or valve can get partially plugged up so not enough exhaust gases are getting into the intake when accelerating, so cylinders are getting too hot.
Hot Exhaust gases cool the cylinders, yes, odd but true, it reduces NOx emissions but a side benefit is less possibility of pinging on Regular gasoline(87 octane) because cylinders are running cooler


Your oil pressure gauge is actually just an on/off setup
The oil pressure switch on the engine will be open(no ground) when oil pressure is under 6psi, and it will be closed(grounded) when pressure is above 6psi
The dash gauge gets power with key on but with open switch it has no ground, when engine starts and pressure is above 6psi then gauge is grounded so gauge shows whatever resistor setting Ford used, usually shows about 1/4.
And movement of the needle while engine is running is from electrical voltage change, not oil pressure.
But if it does drop to 0 then pressure is under 6psi, and if it gets down to about 4 psi you will get valve train noise.

 

[dissturbbed]

Welcome to TRS

Does it EVER make the noise when engine is cold?

If so then won't be pinging/knocking, and probably not oil pressure either since cold oil is thicker oil.

If it ONLY occurs after engine is warmed up and when accelerating then it is most likely pinging, pre-ignition.
And yes this can come and go because it is specific to cylinder temps, and could be from hot spots(carbon) but they have to be hot enough and the fuel mix lean enough to get self ignition.

Running a tank of 89 or 91 octane through to see if problem goes away or decreases alot would tell you if this was the noise you are hearing.

If your 2.5L has an EGR system then tube or valve can get partially plugged up so not enough exhaust gases are getting into the intake when accelerating, so cylinders are getting too hot.
Hot Exhaust gases cool the cylinders, yes, odd but true, it reduces NOx emissions but a side benefit is less possibility of pinging on Regular gasoline(87 octane) because cylinders are running cooler


Your oil pressure gauge is actually just an on/off setup
The oil pressure switch on the engine will be open(no ground) when oil pressure is under 6psi, and it will be closed(grounded) when pressure is above 6psi
The dash gauge gets power with key on but with open switch it has no ground, when engine starts and pressure is above 6psi then gauge is grounded so gauge shows whatever resistor setting Ford used, usually shows about 1/4.
And movement of the needle while engine is running is from electrical voltage change, not oil pressure.
But if it does drop to 0 then pressure is under 6psi, and if it gets down to about 4 psi you will get valve train noise.

Thanks!!

 

[tomw]

I would add that if you are going at a steady speed, and you start to hear pinging(clatter), but can get it to stop by pressing a bit more on the gas pedal, you have a pre-ignition problem. You can try cleaning the combustion chamber with gas additives, spritzing water into the engine running at a FAST idle, or running higher octane fuel 87/89.
I had that in an 85 2.3, and it was apparently weather dependent. On cool humid days, early in the AM on the way to work, I could turn the ping OFF by accelerating a little, and sometimes easing off back to cruise, it would not return. I don't think I ever did anything other than wait for the weather to change.
If that is not your experience, then you would likely have valve 'clatter', from lifters/supports that have collapsed due to low oil pressure & flow, more when the engine & oil are hot, and the viscosity reduced(thinner oil when hot).
Last call is two: coolant system needs preventive maintenance, leading to a hotter running engine, or the fuel system is causing a lean mixture that is more prone to lighting itself off, causing pinging or knock.
tom

 

[RonD]

Yes, +1 ^^^, cold air is "heavy air", i.e. "Hot air rises", because it is lighter

So cold air needs more fuel added to it or air/fuel mix gets Lean, and Lean can cause pinging, stepping on the gas pedal adds more fuel so Richer mix and less or no pinging.

Most fuel injected engines have an IAT(intake air temp) sensor to compensate for that

MAF sensor should also do that because it tells computer air Flow and Weight
MAP sensor didn't

 

[dissturbbed]

I would add that if you are going at a steady speed, and you start to hear pinging(clatter), but can get it to stop by pressing a bit more on the gas pedal, you have a pre-ignition problem. You can try cleaning the combustion chamber with gas additives, spritzing water into the engine running at a FAST idle, or running higher octane fuel 87/89.
I had that in an 85 2.3, and it was apparently weather dependent. On cool humid days, early in the AM on the way to work, I could turn the ping OFF by accelerating a little, and sometimes easing off back to cruise, it would not return. I don't think I ever did anything other than wait for the weather to change.
If that is not your experience, then you would likely have valve 'clatter', from lifters/supports that have collapsed due to low oil pressure & flow, more when the engine & oil are hot, and the viscosity reduced(thinner oil when hot).
Last call is two: coolant system needs preventive maintenance, leading to a hotter running engine, or the fuel system is causing a lean mixture that is more prone to lighting itself off, causing pinging or knock.
tom

Nope its not pre ignition, if i give it slightly more gas or nail it it becomes worse. It is definitely valve clatter and not pinging or pre igniting the gas. I think one of my roller arms have slightly locked up since it seems it is coming from one cylinder and not all four.

 

[RonD]

Good work on eliminating pre-ignition

Looks like valve cover will need to come off

 

[Mark_88]

Unless you know how to make adjustments on the valves or plan on replacing parts under there I'd avoid removing the valve cover for a bit...

there is nothing to see in there folks and it can lead to oil loss if you don't seat and seal the valve cover properly...plus the cost of the gaskets and all the farting around removing the upper intake...

The valves on my 88 (with a 91 head and roller cam) first started clattering and I decided to have a look to see if I could adjust anything...

Without knowing what i was looking for I ended up putting it back together and developed an oil leak from the poorly seated valve cover...and had to replace the rubber gasket that cost $50...cork are cheaper but still an added expense unless you are going to do something.

I would suggest just run it for a bit first and see if it goes away. As long as you are not losing power completely or the engine develops severe power loss it is probably best just to leave it be and let it work itself out.

I ran some Lucas Oil Treatment in mine (among other things) and rarely had any clatter as long as the oil was present...

If you know what you are doing...disregard this message...lol

 

[tomw]

If you remove the cam cover to inspect, be prepared to replace a cam follower or lifter(support) that may be apparently bad. The lifter could be jammed, and fail to extend enough to hold up its end of the cam follower. The cam follower could be damaged, or have a bad 'roller', or ???.
If you have a spare on hand, you can swap then and there. If you suspect more than one noise maker, either have more on hand when you open it up, or be prepared to remove the cylinder head for repair work.
If the noise comes and goes as it pleases, you could have a lifter/support that needed cleaning. They'll leak down quickly if a speck of carbon or ?? gets stuck in the check valve, and make noise like they're on their last legs, but can be repaired by cleaning or replacement. To find the leaker, you'd have to shut it down when it's noise-making, remove the cam cover, and then try to wiggle the cam followers. The loose one is the suspect. The others should be pretty tight against the cam, with very little play.
tom