Mercury Mountaineer Problems

Worn Timing Chain Cassettes May Cause Rattling Noise From Engine on Mercury Mountaineer

Problem Description and Possible Solution

A rattling noise from the engine may indicate that the timing chain cassette is worn. Our technicians tell us that installing an updated cassette and timing chain tensioner should correct this concern.

(51 people reported this problem)

Mercury Mountaineer Vehicles With This Problem

RepairPal Verified
Average mileage: 132,742 (45,000–200,000)
Engines affected: 4.0L V6, 4.0L V6 SOHC, 4.6L V8, 5.0L V8
10 model years affected: 1998, 1999, 2000, 2001, more2002, 2003, 2004, 2005, 2006, 2008
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Viewing 1-20 of 24 comments
My Mountaineer makes a very high pitched annoying sound when I start it and the noise level increases as I push on the gas pedal and accelerate. I have been so curious as to what causes this and how to fix it. I have taken it into a garage, but they have said they didn't know what it is. Sometimes the noise will subside and I won't hear it for a few days, but typically it is very loud.
loud tapping noise or ticking from engine. louder as I excellerate but does quite down some as the car warms.
Issue sounded just like a "spark knock" only under acceleration around he 2000-3000 RPM range. The easy fix of running a tank full of high octane gas made no change in the noise. I replaced the knock sensor to see if the engine timing was not being compensated correctly. This still made no change. To determine if it was a mechanical part in the engine, I dumped an entire quart of Lucas Engine Oil Treatment into the engine. As soon as I drove it for a test drive the "rattle" noise at the 2000-3000 RPM range was gone and the engine sounded very smooth. I drove the car very easy for the next few months to get past winter and progressively there began a light rattle at startup also which slightli went away a\s the engine warmed up. The startup rattle started to get louder and louder after the next few weeks to the point I decided to tear it apart (I dont recommend tearing it apart for everyone, I am a Journeyman Machinist and a master mechanic of 20 years certified with my mechanical engineering degree). After removing the upper intake plenum, the fuel rails and a few wires, I popped the passenger side valve cover and noticed the problem. The oil infused nylon that the tensioner shoe is made from was obliterated. I put some pressure on the cam to relieve the chain on the tension side and was able to pull a large portion of the broken tensioner shoe out with my fingers. The rest of it seems to of been ground into chunks and now lies in the bottom of the oil pan.

It works like a big speaker in theory. Right under the valve cover on the passenger side, as you are standing in front of the car looking at it, to the right of the cam gear their is a machined stud that is a funny looking shoulder screw. This shoulder screw is what the upper portion of the tensioner shoe hooks to. When the tensioner shoe breaks (as they all do), it falls off the shoulder screw allowing the timing chain to now slap around and ride very tightly against the bare steel side of the shoulder screw. The effect is like a needle on a record player making a very loud noise.

After a close mechanical assessment after replacing all of the timing chains and tensioners in the vehicle, I cannot see why there has not been a recall on this design flaw. I noticed that the majority of the issues listed through different dealers seem to be about 80,000 mile range. As this design was started in 2002 the vast majority of these cars did NOT reach the mileage point by the time the design was ended in 2006. I think FORD saw the "red flag" and re-engineered after 2006 after a bunch of repairs started coming in on vehicles that were still within the engine and powertrain warranty. The list of repairs for warranty was not enough to trigger a recall on the engineering and design although this is actually one of the most well known flaws and failures of design for an engine.
Loud rattling noise, definetley time and chain. Was told it was worn nylon on the time and chain, still haven't got it fixed
there is a rattling noise when it is just sitting after you first start it. and you also hear the noise at times when you come to a stop waiting for the light. also it sometimes will not start right away you turn it off. sometimes at least four tries.
Same issue here on the plastic timing chain guide. Mine has the issue on timing chain in the back of the engine. I was quoted $4400 for replacement engine. I'm looking to trade in now but I might try some additive to get me through winter.

Someone else mentioned the higher-pitched noise. Mine has that as well. I believe that to be the power steering pump.
Vehicle started making a loud ticking noise. The faster I went the worse it got.My mechanic told me it was timing chain slap, meaning I need a new one.Apparently these engines have plastic parts of some sort and if they break it creates this problem. Now for the verdict, to replace approx. $1800.00 and they do not recommend due to possibly doing damage to other parts, so, a rebuilt engine with a 3 year warranty for $2500.00.Still contemplating.
cassettes broke , brought it in and $4200.00 later its been repaired ,two year warranty,they claimed the oil viscosity was a fault, supposed to chain oil every two thousand miles now....
Ratle in the motor in morning seem to be worse then would quiet down after warmed up had it checked saying timing chain or guides or the tensioner looking at alot to fix I decided to put Lucas oil stablelizer in with a fresh oil change need to say it quiet down now don't here much not sure how long it will last but for now she's running good
Camshaft sensor check engine light is on after replacing camshaft sensor the check engine light is still on . hard to start when engine is warmed up . not accelacrating properly.