When motor is cool, strange tapping noise from under valve cover

[Machinator]

The only time this happens is when the motor is cold and I take off gently and at 2200 to 3000 rpms I hear what sounds to be cam/valve tapping sounds coming out of the valve cover on the driver side. When it gets warm it all goes away. Somebody explain this, is something wrong?
Scott

 

[I8URZ28]

maybe fuel injector noise :shrug: are you sure it isn't from both sides? or coming from underneath the car --may be exhaust noise also my GT's exhaust would make a slight ticking noise that would radiate from underneath the car when it was cold

 

[FireRed04Vert]

Boy...that sure sounds like piston to me. This was very prevelant on the 01 model...and is one big reason the pistons are so tight on this car. If it is a piston, normally it's nothing to worry about other than it's annoying. But these cars shouldn't do that. The fit is too tight. In this case, I might be concerned I've collapsed a piston skirt or hurt one in some way. Of course, if it's in the valvetrain, you can ignore all this!!

 

[Hye]

I've heard what your experiencing.

Most people with offroad pipes and loud c/b's on their cobra would never even hear the noise. And I have to hear the noise with the windows up to help keep the sound inside the car, atleast it helps. Soon as I quieted down my exhaust i heard what you are talking about. When the car is fully warmed the noise goes away, same as me. I think that's the important part here. I think it's just more noises the car makes under the hood, hopefully just valvetrain noise.

 

[CobraBob]

Did the noise just start? And it doesn't make the noise at idle?

 

[Patisi]

The only time this happens is when the motor is cold and I take off gently and at 2200 to 3000 rpms I hear what sounds to be cam/valve tapping sounds coming out of the valve cover on the driver side. When it gets warm it all goes away. Somebody explain this, is something wrong?
Scott

You are correct, that is what it is. The oil circulation is not at full volume and the mechanical parts in the valve train need to lubricated and warmed up as well. My practice is to allow the motor idle from cold start when ever possible for say 5 mins, and also never to gun the motor from a cold start either. Along with this you may also find that the gear engagement is not always as smooth until the tranny fluid is warm and properly circulating.

This behavior is more noticeable in the winter months, and it also depends on the oil weight that you use in the vehicle. Mobil 1, has a 15-50 fully synthetic Wt Oil that I have had success with So Cal, this grade appears to be suitable for me year round. The light weight (15), in the winter months allow for faster circulation and warm up and the heavier weight (50) allows for longer viscousity in the warmer summer months. Just my $.02

 

[WDW MKR]

15W-50 is way to heavy for the oil passage and bearing clearances in these engines. Do not use anything that heavy!

Mach, I wouldn't worry too much if it goes away when warm. It's the hot noises that give reason for concern. Just make sure you never romp on the car until oil (not just coolant) temperature is warm. Starting from that high of an RPM seems a bit much, too.

 

[I8URZ28]

general rule of thumb never race a "cold" engine --on a cold day my car sits for 5 min @ idle --I learned that from driving my chevelle(it didn't like the cold) in all acutallity on newer motors letting the car warm up for 1 minute is probably plenty due to quicker pressurization

 

[WDW MKR]

general rule of thumb never race a "cold" engine --on a cold day my car sits for 5 min @ idle --I learned that from driving my chevelle(it didn't like the cold) in all acutallity on newer motors letting the car warm up for 1 minute is probably plenty due to quicker pressurization

You still can't beat on it. It takes several driving minutes for oil to come up to temperature in warm weather, so it's even worse in the winter. Cold oil will not flow and you will break something.

 

[I8URZ28]

right I was just saying that overall pressurization of the system on newer motors happens quicker then on an older motor--by that i mean oil is circulated throughout the engine but it still isn't at temps for a few minutes

 

[Machinator]

Hey guys thanks for the input, I am just glad it goes away when it gets warm. I dont romp on it till I am sure everything is at operating temps. I first noticed this a couple of weeks ago, it doesnt do it at idle and only for the first 2 or 3 minutes of driving.

 

[ChicagoMike]

Going to agree there, 15W50 oil is psycho. You should not use anything greater than 30 viscosity. Not only are you hurting the motor, but 15W50 is robbing horsepower.

10W30 and no more is what you should use.

95% of us use 5W30 full synthetic. The other 5% still use 0W20/30 or 5W20.

 

[ugotbit03]

Yup 15-50 is alittle THICK for 03-04 Cobras, and never beat on a cold car thats how things break...

 

[brownbootsracin]

Going to agree there, 15W50 oil is psycho. You should not use anything greater than 30 viscosity. Not only are you hurting the motor, but 15W50 is robbing horsepower.

10W30 and no more is what you should use.

95% of us use 5W30 full synthetic. The other 5% still use 0W20/30 or 5W20.

It's a toss up. The heavier the oil, the better the heat soak and heat dissapation, the lighter oil, the better the flow freeing up HP.

I like ams oil 5w 30 myself. full synthetic...

 

[broke7]

I have had the same issue since for a LONG LONG time on my car. It sounds like a damn diesel in the winter when it sets overnight and it gets cool, and lil less noticeable in the summer now that its warming up, but the noise goes away within 15 seconds on start in the mornings. The car has 37k on it now, was beat very hard since day 1.

i ran synthetic for the longest time 5w/20 mobil1. I swapped to 10w30 penzoil and Lucas heavy duty oil stabilizer about 12k ago and the sound is alot less noticeable, but it is still there very very very faintly when its warm like it always has been, but you really have to know what your listening for. Its only audible at nuetral throttle application at 2000-2300. Not on the accel or decel.

 

[random--strike]

ive seen lots of pistons break skirts when ppl stomp on it when cold

 

[Steeda30]

I just start mine and rev it to 6-6.5k and, off the throttle to 4k and rev it back to 6.5k at WOT - repeatedly for about 2 mins.

It's what the F1 cars do to warm up, so I figure it works for me too. :shrug:

 

[djtyau]

I granny shift the crap out my car early in the morning until I reach optimal temperature. If I shift above 2000 rpms I hear a lot of piston slapping. It definitely goes away once the car is warmed up.

 

[03yellow]

your joking.... right?

I just start mine and rev it to 6-6.5k and, off the throttle to 4k and rev it back to 6.5k at WOT - repeatedly for about 2 mins.

It's what the F1 cars do to warm up, so I figure it works for me too. :shrug:

 

[03yellow]

Sounds like a sticky valve. Put some fuel additive and oil additive for sticky valves/lifters. See it quiets down some. Run it through you system for awhile then change your oil; run the recomended motorcraft syn. blended oil.
Make sure you run 93 oct fuel.