Cylinder compression test question

Lincoln LS

  1. AmsterDutch

    AmsterDutch Dedicated LVC Member

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    So the Shop called me today and said that the car doesn’t have a vacuum leak, the fuel pressure is correct and the cylinders on both banks are pushing 235 PSI they said that doesn’t rule out the exhaust cam compression so they have a “Hunch” that because the car is running rich on one side and lean on the other the timing chain skipped a tooth...I called my trusted Mechanic ( this Mechanic diagnosed my previous 2001 Lincoln LS when it had a torque converter transmission code and could show me with proof that my Over-Drive was out) who normally works on my cars and told him all the information ...he said that 235 psi sounds awful high but he would have to double check the engine again because he works on so many and can’t remember off the top of his head if this is a high compression engine and that it sounds like there is carbon built up in my valves ...So if anyone can tell me if the cylinder compression test is normally around 235 psi I would greatly aprreciate it
     
  2. AmsterDutch

    AmsterDutch Dedicated LVC Member

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    Jun 16, 2012#3
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    04_Sport_LSDedicated LVC Member
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    “Are all of the cylinders that are reading low compression, the same ones that showed a misfire? Are all of these cylinders on the same bank, (head)? If so, you may have had a cam chain slip, and one, or both of the camshafts on that bank have jumped time. This seems to be a common issue with these engines. Especially 2000-2002. I don't have the actual spec in front of me, but most, (not all), engines today run 160-180 psi per cylinder. I'd guess the 3.9 runs closr to 190-200 psi. Google for the cylinder compression on this engine, and you will probably find your spec. Someone else may chime in too, that knows more than I.“
    Finally found the thread I’m looking for I think ...thanks 04’ Sport
     
  3. joegr

    joegr Dedicated LVC Member

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    Yes, 235 PSI is within range, and yes it is a high compression design, around 11:1 I believe.
     
  4. AmsterDutch

    AmsterDutch Dedicated LVC Member

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    Sounds good.. I am just a little suspicious of this new shop... because like I told my regular Mechanic (Ron) over the phone my LS doesn't have any symptoms of a skipped tooth (other than the Rich and Lean codes) ...the car fires off perfect ...it has plenty of power...and even with the misfires on three different cylinders after it warms up to optimal temp the idle smooths out and she runs and drives perfect...I'm taking the car to Ron's Shop tomorrow, now that its deemed safe to drive the distance which is about an hour away...I would have brought it to him first but thought I better be safe and bring it to the Shop a few blocks from my house ...big mistake... and I'm out $185 dollars and found out everything I already knew..... What do you think about that Mechanics theory when he said this doesn't rule out the Exhaust Cam Compression? I mean I hear what I think is a slap[ing chain on right side but ...I KNOW ...I KNOW ..until I rip this thing apart and look at the chains I will never know...if there is oil getting into the cylinder would that make a higher compression? I mean could the main culprit still be leaking Valve cover gaskets all this time which in turn allowed misfires which would cause plugged cats and carbon in the valves?
     
  5. AmsterDutch

    AmsterDutch Dedicated LVC Member

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    I just received the print out and bill from Autotronic Of Saint Peter this is an AAA APPROVED AUTOMOTIVE SERVICE CENTER and claims ( should I say even boasts ) there an AAA "TOP SHOP" Award Winner...I say what a JOKE! So I got the bill today $185.00 for them to tell me everything I told them before I left the shop...I told them I did a vacuum test with propane and found no change in Idle...When I asked them how they did the vacuum test they said they used Propane and the idle didn't change....I told them my fuel pressure seems right on the money so they tested the fuel controls by forcing the system RICH and Forcing it Lean and they found the fuel controls react like they should..Fuel pressure sensor is reading 40p.s.i. They tested the engine vacuum at idle and at 2000 R.P.M. They said they observe 15 to 16 inches at idle and 20 inches at 2000 R.P.M. Vacuum at idle should be 18-19 inches They removed the ignition coils and spark plug from each bank Test compression on cylinder #2 and the #5 cylinder they find 235 LBS. of compression on each bank...They say they suspect the exhaust cam on Bank One has Jumped...The real kick in the head is that I told them I wanted my Alternator replaced and they didn't even attempt to replace it because they said there is no point due to my timing chains
    These mechanic shops are straight criminal ...
    Today I took the LS to my regular mechanic and he used his stethoscope on my engine and said it doesn't sound bad at all and then looked at me and said well you probably already know this but I'm going to let you know anyway and with 100% confidence ...you need new valve cover gaskets and all new COP's and Plugs ...he is also going to replace the alternator for $100 ...I'm writing this post in order to help the new Lincoln LS owner avoid a hole in there pocket ...before going to a Mechanic ...I say this with the utmost sincerity ...make 100% sure ...I say again MAKE 100% SURE THE MECHANIC and/or SERVICE CENTER HAS WORKED ON THESE CARS!!! Otherwise be prepared to flush your hard earned money down the toilet
     
  6. Jtown

    Jtown Active LVC Member

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    With so few of these cars around, it's tough to find a shop with LS knowledge. I even question the dealership.
     
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