2001 Mercury Mountaineer Knocking Noise

Tiny
VIPER22656
  • MEMBER
  • 2001 MERCURY MOUNTAINEER
  • V8
  • 2WD
  • AUTOMATIC
  • 158,000 MILES
I had taken my truck on a 250 mile trip pulling my 2 jet skis which weigh around 2,000 lbs. I was about 20 miles from my destination when I felt some knocking coming from the engine. When I arrived and the put the truck in park the knocking was very loud. I immediately turned it off and had it towed to a local mechanic. They measured the oil presuure and it was at 14 psi and should be a at lease 40 psi. They dropped the oil pan and found alot of metal in the pan. They said the crankshaft bearings were gone and needed to be replaced. They said the crankshaft looked good so the bearing and a new oil pump should fix my problem. They installed all the bearings but had a problem with one that was up higher. They damged the new bearing trying to put it on so they had to order a new one. After 4 days and $1300.00 they said it was perfect and ran all there tests and had no problems. I got home with no problems the truck runs great. But now there is a slight knocking when I first accelrate or when I'm driving a slow speed. Once I'm on the freeway I can't feel anything or hear anything. I can feel the knocking in the pedal when it occurs. I put in a oil treament that suppose to seal the rings and it seems to help a little. I'm wondering if maybe they didnt replace that one bearing and that whats causing the problem or if its something else. What do you think?
Sunday, May 9th, 2010 AT 11:08 PM

3 Replies

Tiny
MHPAUTOS
  • MECHANIC
  • 31,937 POSTS
Hi there,

Did they pull the crank shaft out to replace the main bearings did they flush the oil galleries of any metal from the failed bearings? Did they actually measure the crank shaft journals for wear before replacing the bearings?

Mark (mhpautos)
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Sunday, May 9th, 2010 AT 11:42 PM
Tiny
VIPER22656
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No they didn't. They said the cranshaft looked in good shape. No they didn't flush it. I'm going to replace the oil and but a 300lb magnet on the oil filter.
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Monday, May 10th, 2010 AT 3:34 PM
Tiny
MHPAUTOS
  • MECHANIC
  • 31,937 POSTS
Hi there,

keep in mind that the crank can only be -002" under size and you can have oil pressure problems, the metal thats they talk of is bearing metal, and this is no ferrous and non magnetic,

Mark (mhpautos)
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Monday, May 10th, 2010 AT 6:05 PM

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