4.6's Tend to Throw Rod Bearings??

[stangin]

I remember reading a couple of posts on various boards mentioning the tendency of 4.6L's to throw rod bearings? Is this true?? Could they be talking about pre 03 Cobra engines or does this apply to 03 Cobra engines as well? I have also heard the location of the wrist pins causing the motor to be weak? I dont know this for a fact and would like to hear more on the subject. Has anyone heard of this? I have not heard of engine failures other than caused by a lean tune or bashing the oil pan.. due to being lowered. Just trying to gather facts.

Thanks

 

[jeffsvt]

I had a 99 GT and gutted all the rod bearings in it . Don't know how one day when changing my oil I noticed metal shavings in it and I was hearing a weird knocking noise at certain rpms . I wasn't loud at all very quiet knocking . I took it in a sure enough the dealership pulled the engine apart and just about all the rod bearing had been gutted . The dealership told me it was a common problem and they have had several in there for the same thing . They said since there is such a small gap for the oil to get in to lubricate the bearings and people using to heavy of an oil causing it .

 

[Shadowgray03]

Originally posted by jeffsvt
I had a 99 GT and gutted all the rod bearings in it . Don't know how one day when changing my oil I noticed metal shavings in it and I was hearing a weird knocking noise at certain rpms . I wasn't loud at all very quiet knocking . I took it in a sure enough the dealership pulled the engine apart and just about all the rod bearing had been gutted . The dealership told me it was a common problem and they have had several in there for the same thing . They said since there is such a small gap for the oil to get in to lubricate the bearings and people using to heavy of an oil causing it .

Interesting, I guess all the more reason to go with a full syn oil?

 

[stevieb]

When I told a friend of mine who happens to be a service manager at a Ford dealer that I was going to buy a 03 Cobra, he told me the 4.6 is known to have rod failures around 70k miles and highly recommended the extended warranty.

 

[94SVT Coupe]

Yes, The Ford mod motors tend to spin bearings. 5.4's do it too. I change my oil every 2500 miles. Tryin to keep those babies intact.

 

[venom279]

From what I understand, it is the 2-valve 4.6's that have had the rod/rod bearing problems?? I haven't ever heard about these problems on the cobra's or lightnings??

:beer:

 

[norcal_cobra]

Originally posted by venom279
From what I understand, it is the 2-valve 4.6's that have had the rod/rod bearing problems?? I haven't ever heard about these problems on the cobra's or lightnings??

:beer:

Isn't the Lightning a 2v 5.4L?

norcal_cobra

 

[venom279]

Originally posted by norcal_cobra
Isn't the Lightning a 2v 5.4L?

norcal_cobra

Yes, it is a 2valve, but it's a 5.4 that's built for a blower, I was referring to the 2v 4.6.

:beer:

 

[norcal_cobra]

:beer:

-norcal_cobra

 

[stangin]

Originally posted by jeffsvt
I had a 99 GT and gutted all the rod bearings in it . Don't know how one day when changing my oil I noticed metal shavings in it and I was hearing a weird knocking noise at certain rpms . I wasn't loud at all very quiet knocking . I took it in a sure enough the dealership pulled the engine apart and just about all the rod bearing had been gutted . The dealership told me it was a common problem and they have had several in there for the same thing . They said since there is such a small gap for the oil to get in to lubricate the bearings and people using to heavy of an oil causing it .

I suspected this:

"small gap for the oil to get in to lubricate the bearings"

as I once changed the gfriends oil in her 94 explorer and used 20/50 as I used to use in all my cars in the mid 90's and it then started to have a slight knocking/tapping noise, switched to 10/30 and it went away again. Now I use 10/30 during summer and 5/30 in winter in all my cars. I agree, must use a thinner oil in newer cars, oil holes are probably smaller due to cost cutting measures??

I am not convinced of syn oils, guess I am an old timer at 36 lol.. but I do feel that changing the oil often is the key. Since the Cobra is run hard I think I will go 1500 miles or so between changes.

I am hoping for more info on the 4.6 spun bearing issue and hope that these issues only apply to the "pre - non blown" 4.6 engines. Anyone else?