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  1. M

    2002 5,7 Mercruiser exhaust manifold keeps cracking - 5 times this summer

    Ok, so we had this one also in the correct place - now only thing to check is that water is flowing on all the pipes. Also ordered new thingy with small ball inside below the manifold where 2 pipes are connected - it seems that ball inside the connector was not moving freely. I am still out of...
  2. M

    2002 5,7 Mercruiser exhaust manifold keeps cracking - 5 times this summer

    Thank you! I am still confused as there are this statement: Purpose of the Restrictor Hole Design The purpose of the restrictor hole is to prevent the cold bypass water as it enters the exhaust elbow, from back-flowing down and into the manifolds. If the restrictor hole is positioned incorrectly...
  3. M

    2002 5,7 Mercruiser exhaust manifold keeps cracking - 5 times this summer

    I have the hose coming to the riser, should the restrictor be lower or higher from the hose?
  4. M

    2002 5,7 Mercruiser exhaust manifold keeps cracking - 5 times this summer

    Hi I live in Estonia, Northern Europe, it is a small country just a bit south from the place where Santa Claus lives :) Hence we do not have much US origin boats here and Mercury is not the most popular brand on engine. I do hope that my mechanic is the best one in the country, but having a...
  5. M

    2002 5,7 Mercruiser exhaust manifold keeps cracking - 5 times this summer

    One more question - I have dry joint risers and need to verify where to put seal with the small hose? I watched several videos and it stated that it should be below hose coming in? Anyone has a good drawing on how install those, please?
  6. M

    2002 5,7 Mercruiser exhaust manifold keeps cracking - 5 times this summer

    I would exclude the muffler part - during the run and different check, elbow is always cold, meaning that muffler is not restricting it, still seems to be linked with water flow thru the manifold himself
  7. M

    2002 5,7 Mercruiser exhaust manifold keeps cracking - 5 times this summer

    My boat mufflers and exhaust outlets are looking like this, so sudden stopping is not bringing wave to the engine. I will be checking the whole waterflow in and out on that side of the engine - can also compare to starboard side, if there is any differencies.
  8. M

    2002 5,7 Mercruiser exhaust manifold keeps cracking - 5 times this summer

    Risers and elbows are not original, when I got the boat, all risers and elbows were changed to new better ones. Cylinder heads went to the shop and were checked and refurbished - no issues there. Engine oil this 5th time is still clear as engine was stopped before it was filled with water, all...
  9. M

    2002 5,7 Mercruiser exhaust manifold keeps cracking - 5 times this summer

    We assume that it is linked to the water flow thru the exhaust, just can not find the issue, last time engine and all the piping was outside the boat and we did not see any issues (to be frank - we also did not look any closer on piping) SeaRay mufflers are rather big bulky ones and there is...
  10. M

    2002 5,7 Mercruiser exhaust manifold keeps cracking - 5 times this summer

    Winter maintenance was done in the boat and last renovations I was the delivery guy to and from the garage - engine is mine :)
  11. M

    2002 5,7 Mercruiser exhaust manifold keeps cracking - 5 times this summer

    My setup looks very similar to the drawing attached - will go over it pipe by pipe once in the boat. Thanks! Cyclops - Searay has rather big mufflers and it is not the issue with fast stopping, I am sure I have the issue with water flow around this one exhaust manifold - it started after the...
  12. M

    2002 5,7 Mercruiser exhaust manifold keeps cracking - 5 times this summer

    Hi I have sea water cooling and I do not know the serial number of the engine. While driving all numbers are fine on numbers, water pressure, water temp, oil pressure etc. Water coming out from the sides of the boats are normal temp, if the manifold would get really hot, it should burn the paint...
  13. M

    2002 5,7 Mercruiser exhaust manifold keeps cracking - 5 times this summer

    Hello everyone! I need help diagnosing the issue I have been fixing 4 times this summer, without much success sadly! After doing proper maintenance last winter and taking the engine off for small oil leak fix, I have had a 5 exhaust manifold cracks on port side engine and port side manifold...
  14. M

    2003 Mercruiser 6.2 MPI Exhaust Manifold cracks

    I have now reached to the point where I have replaced manifolds four times and each time I hoped that I found the reason for it.. Firstly I blamed old age of the engine and put new manifold, after 2 hours of driving, another crack, then changed the provider .... and after another crack also...
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