When I first start my engine, the oil light is on for a second and I can hear the engine chortle like a diesel during that second, then the oil pump kicks in and all is fine. Is this an indication of the oil pump going bad or is it normal? I have good oil pressure otherwise while it's running.

 

If the motor is sitting, the oil has drained down and the noise you hear could be lifters. When the oil is circulating, the motor is quieter. If you have normal oil pressure when driving, it is not the oil pump. If is was "sticking, there would be other problems. To change the pump on a 300 6, the engine must be removed. I changed the pump on mine when the motor was out for cleaning, just to be safe. If the truck continues to run real rough after it is started, it could be timing, ignition, plugs or carb problems that need to be checked.

 

The biggest problem you have here is oil starvation when cold. The noise you hear is lifters and bearings before they get pressure. Older engines start doing this due to clearances opening up in the bearings and lifters. If it's only a second Ok. If it's 5 or 6 seconds thats BAD.

Because the oil filter sits horizontally AND most of the filters have crummy anti-drainback valves (or lack there-of) all the residual oil in the gallery's drains back into the pan. The oil pump is working to get the oil up the gallery, thru the filter and then to the engine parts. If the anti-drainback valve is good there tends to be oil in the filter and gallery which will pressurize much faster. If bad then the pump has to FILL and pressurize the whole system.


The easiest change you can make is to use a MOTORCRAFT oil filter (1st choice) or a Purolator(2nd choice). STAY AWAY FROM FRAM!
Also use the lightest weight oil you can get away with, ie:5W-30, 10W-30, no heavier than 30W. The 1st # is cold viscosity number and you'll get less knock/rattle/bang when you start up cold due to the oil flowing easier.


Larry

 

Cgfiend , What model yr is your truck ? If its a later model then Ford has a tsb dealing with the startup noise . It replaces the oil filter adapter with one that has a check ball & spring . I suppose by the design of the engine , enough oil can drain from the oil filter even using Motorcraft oil filters . When the engine is shut off the check ball stops any oil from draining from the filter & the startup noise is gone . The part number is E4TZ 6890 A .

 

Thanks for all the replies. Yes, it's only a second when the engine starts. Maybe it's a cheapy filter. It's a 1980 Ford F-250, but the engine was replaced with a crate motor, I think. She only has about 8000 miles on her. Hard telling. I suppose I will try a different oil filter and not worry about it until it becomes a problem. The engine gets good oil pressure.

 

[QUOTE] Cgfiend , What model yr is your truck ? If its a later model then Ford has a tsb dealing with the startup noise .


I don't normally get the noise, but wondered if my '95 300 I6 is addressed by the tsb you refer to?

Thanks

 

TallPaul , Yes , The Tsb I mentioned goes up to the 96 model yrs . It will stop the noise , but the part is about $80 . Hard to believe a small piece of metal with a steel ball & a spring can cost that much .

 

How easy (or hard) is it to install?

 

Its easy to remove & install . Use a pair of Vise Grips ™ to remove the old adapter , the new adapter has a hex than can be tightened with the appropiate socket . After that just install a new oil filter & you are done .

 

Paul,

Do you know if Ford associated the noise with any damage to the engine? Mine only lasts a second, so it's not like it's going to cause major wear. Also, do you know a way to identify the year of the engine? It's not the original year, so I need to figure out if it's a newer one. The truck is 1980. If the same year engine is in it, then were the 80 engines afflicted with this same problem?

 

Id say beyond the noise very little damage or wear would occur over the life of the engine , I think its more to quiet the engine when starting . There may be some casting numbers that may lead you to ID the engine model yr , but I dont know of any way to tell .