I have a '98 Ranger with the 4.0 v6 and am experiencing a lower end engine knock when at idle. It almost sounds like I have a diesel under the hood. This is the third engine in this truck. All three have developed the same noise between 12 and 20 thousand miles. Ford has already replaced the engine twice but claims to have no idea about whats going on. They swear that this has been a good engine for them without many problems.
Anybody heard of this or have an idea of whats going on?
The truck runs great, gas milege is about what it is supposed to be and it has plenty of power........

 

CORanger,
I have the same knock sound at idle (at least I guess) as you.
Can you give more details? Do this knock appear with A/C on? Do the knock lowers with the engine temp higher?
My Ranger is a 98 XTL 4x4 OHV 4.0L
Mine noise is a diesel like noise, on idle, from the botton left of the engine. Its worst when cold get lower when hot.
I 'm looking for other people with the same probem... As I don't by dealers explanations.

 

My 2000 has the same noise . At first I even tried a heavier oil mobil 1 10-40. According to ford this is a known issue. Ford says to live with it and they are not sure what causes it. Ford service message #15226. I was pissed at first htinking it was the bottom end, but now I'm a bit more relaxed, still embarassed of having a new truck with a rattle that won't go away.

 

2000XLSEXPLORER,
I'm not sure if your truck have the same engine as mine and Coranger's...
I do believe that 2000 Rangers have the 4.0L SOHC engine instead of the 4.0L OHV... I read some posts reagrding SOHC's knocking and seens that is really something Ford is aware of but has no solution...
Anyway I don't buy the idea that a modern engine can knock without Ford knowing what is about...

 

Well the guy at Ford let me in on a little info, telling me Ford thinks the noise may be from camshaft endplay. As per the exact words from my Ford service:

Some 1998-2000 Rangers/Explorers equipped with the 4.0L OHV engine may exhibit an engine noise that is known as marble noise. High mileage studies show no adverse effects to engine life or performance.Marble noise is a characteristic noise of this engine.


And I say bullshi* to that be cause not all of the 4.0 OHV have that noise.

The 4.0L SOHC on the other hand has the timing chain tensioner noise which Ford will fix.

 

2000XLSEXPLORER,
Do you have the complete Ford description (email or sort of that) about this problem that you can e-mail to me?
Did u noticed that the noise is louder after a fresh oil change, and gets quiter with mileage?
Do the noise goes away with AC on (so the engine run on a higher iddle)?
Tks

 

I'm going through this currently and was just provided a copy of the special service messages (SSM) including 15526 ("4.0 OHV Marble Noise") after yesterday's service visit to a Boston-area dealer. The consensus on this forum/thread is that Ford doesn't know what the problem is (the SSM certainly doesn't explain it) but that it doesn't hurt engine life or performance - if they don't know the cause, how can they possibly claim this?

We'll be coming off the extended Ford warranty next summer on our '99 Explorer and I would like to get the regional manager involved in this and, at the very least, get this is writing. What I'd prefer is a new engine. Any advice from those who've gone through this would be much appreciated. Best, all!

 

The dealer I was at told em they put a new engine into an Explorer to get rid of the noise and they said teh replacement engine made even a louder noise than the origional. This is when Ford told them not to give out replacement engines becasue it's no big deal. I actuallt just sold my 2000 becuase I was dissatisfied with answers like that from a dealer.

 

Just an idea:

Waaayyyy back in the sixties, Ford of Germany added two more
cylinders to their V4 to make the 2000cc V6. This "Cologne"
engine later expanded to 2.3, 2.6, 2.8, 2.9 and now the 4.0.
But along this path, no significant changes to the bottom
end took place. The rod and main bearings on your 4.0V6 are the SAME SIZE as those used on the original 1400cc V4 engine! Those bearings have more work to do today.

Cheers, JT

 

I have two Ford trucks, well one pickup and one Explorer. My Explorer, like the others here has the 4.0 and has the marble sound when cold. The Ranger has the 3.0 but it does not make the noise the 4.0 does.
Has anyone successfully had a mechanic fix the noise?

I am thinking it is more upper engine as it sounds more list a wrist pin rather than a camshaft. It does sound like a rod bearing but several things do not point to it. Normally a rod does not get better as the engine warms up and oil pressure usually goes more to the low side if the source of the knock is lower end.

I am really curious if anyone has had success in truly finding and curing the sounds.

Thanks