Random Timing Chain Failure = Disaster!

Discussion in 'SN95 4.6L Mustang Tech' started by silverbullet221, Jul 26, 2014.

  1. Hello StangNet!

    I hope I am posting this in the correct section. Anyways I wanted to get your guys input on this matter. I own a 2000 Mustang GT with approx 153,000 miles on it I take very very good care of this car. I usually do oil changes about 3,000 miles with Mobil 1 High mileage synthetic oil. Well about 2 weeks ago I drove to my parents house car was running great no noises or issues running at all. I decided to upload a SCT tune that I have been using for over 4 years or so. While the tune was being downloaded one of the little kids I was watching accidentally pulled the cable from the SCT tuner that was plugged into the ECM with their foot. Long story short The car immediately started having issues starting. So no big problem I decided to restore the car to stock and still had issues starting it would crank but just would start.

    So I kept trying to upload another tune that has worked for me before, still cranking no start. At this point it seemed very serious the car was backfiring and sounded horrible. Time to take it in to have it looked at. The guy I took it to told me the engine is getting spark but no fuel so I will need a new fuel pump. So I said ok if thats what the issue is lets go for it. So he changed the fuel pump and guess what same issue $465 dollars later. He also checked all the fuses, Shut Off Pump in the trunk, and fuel components. He was confused and was unsure what to do so he called me for more info I told him the story of the tuner and thats what seemed to start all these issue's. So then he immediately thought the car's computer was messed up and to have it reflashed. So guess who went to FORD to have their car's ECM reflashed? Cost me $120 because FORD said I needed it even though at this point the car's original software was already put back on the ECM. Guess what the car still did not start so they told me they pulled a spark plug and they where filled with gasoline and to have those replaced as well. So I agreed to have those replaced and in the process of replacing those they decided to do a compression test they came to the conclusion that on the driver's side I have 0 compression and that the timing chain may have jumped tooth. They wanted to charge me $600-$700 to just take a look at it no promises this is what it could be and that they could not promise it would run.

    At this time I am thinking this is getting very costly and it's time for a second opinion so I took it to another place they pulled the valve cover's and told me a chain has snapped, hit a piston and broke several rocker arms and it is not even worth fixing and to just buy a remanufactured engine for $4,700 parts and labor. I am thinking at this time holy hell the car was running great and now all of a sudden all of these issues?? There where no sign's when I tried turning over the car when the tune happened I heard no chain or anything break.

    What do you guys think about this? Is something like this possible? and if so would it do that much damage without me hearing a thing? What are your suggestion? Also sorry for this being soo long.
  2. If the chain breaks while the engine is running, yes it can. The 4.6L is an interference engine so the chain breaking would allow the pistons to hit the valves which would cause a lot of damage depending on how fast the engine was running. Did they physically show you the damage?

    I guess if it's time to get a new engine then it's a good time to upgrade.

    I totally feel for you. I have never seen a chain snap on the 4.6 or really ever heard of it happening to anyone. I have had a car that had a guide break and caused bank 2 cam to skip a tooth in timing.

  3. Hey 1987stangman thanks for the reply. Yeah I saw the engine but never heard anything break which is really strange to me I just drove it to my parents and it would crank but wouldn't start. I guess I am one of the luck ones! Haha.
  4. Is $4,700 for just the 4.6L engine block No Intake Manifold, Air Intake, Wires, Tubing Spark Plugs, etc and labor really high or is that just me?
  5. It better have NO miles on it : ) Seems high if its just a reman or if it is not that's definitely to high. See how many hours they are quoting you on labor too.

    Be careful at what they are using as a replacement engine. Some shops use salvage yards and their networks to find engines. Make sure that it is a PI motor if used and verify the mileage. Expect them to mark it up over what THEY paid for it even if its NEW. If it is new make sure you know where they are getting it from and get the warranty in writing.

    These days there are good premium salvage yards you can find good running engines. There is one near me that does all Ford and they get all the good insurance total loss cars. I have quite good results with them over the years replacing engines, 2 of those in my own families car and truck.