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Vehicle: Honda Civic 2004 1.4 liter engine

Question: I'm planning to replace my head gasket and have the head resurfaced because of coolant leaking into cylinders. I do not need to replace the timing belt as that was done a while ago. Do I need to time the engine when replacing a head gasket? Some people say that a first cylinder must be put to TDC by rotating a crank, some say it is enough to mark the timing belt tooth on cam gear and just loosen the tensioner, then slide the belt off the cam gear, without needing to remove the lower cover and front wheel. Which one is true? Thanks

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  • ... and some people say that reading the service manual for your particular car is a good start. This simple trick can save a good deal of swearing (and money, and time). Some engines have impressively convoluted procedure. An almost 10 year old mass-produced car is guaranteed to have the manual all over the net.
    – fraxinus
    Aug 10, 2022 at 15:06
  • @fraxinus I have Haynes manual for my car, it's just that it refers to the section of replacing the timing belt in cylinder head replacement section, while all I need is to replace the head gasket. I could not find instructions there on how to replace the head gasket without replacing the timing belt.
    – Mr. Engineer
    Aug 11, 2022 at 8:12
  • While I am not familiar with this particular car, if your engine is OHC=over head camshaft (and most modern car engines are, the fact that you have a timing belt is a good hint that the engine is OHC) you can't remove the head without removing the timing belt or chain first. This requires releasing the belt tension and implies losing the timing. No, you can't restore the timing reliably without being able to see the timing marks. And yes, contaminating your timing belt with motor oil is bad.
    – fraxinus
    Aug 11, 2022 at 9:21
  • @fraxinus I'm aware that timing belt needs to come off from cam gear, but retiming the engine is somewhat unclear. Here on this video they just mark the location of timing belt on the cam, and later slide it back on: m.youtube.com/watch?v=pm76KVI8uZQ
    – Mr. Engineer
    Aug 11, 2022 at 20:11
  • This may or may not work, depending on your experience and precision.
    – fraxinus
    Aug 12, 2022 at 5:50

1 Answer 1

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You do not need to have the #1 cylinder at TDC for head removal, but you should have it there when you put it back together. If you don't, it makes timing the engine problematic. You'll want to double check that for your engine, but most have the #1 cylinder at TDC for timing purposes. Look at the timing marks to be sure.

Note: While not required, it may be easier to align the timing marks to their correct location as if you were doing a timing belt before head removal. This will help you when you put it back together so you know what you're looking at. With the marks aligned, the #1 should most likely be at TDC.

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  • Can I do a head gasket job from start to finish without removing the lower timing belt cover and/or the left front wheel? It is my understanding that one does not need to touch the crank gear as it is enough to take the belt off the cam, then slide it back on in same position as it was. Is this correct?
    – Mr. Engineer
    Aug 10, 2022 at 10:52
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    You'll still need to set the timing when you put everything back together. If you can see all the timing marks without taking the wheel off or the lower timing belt cover, then no, you won't need to. The belt won't need to come all the way off, it would just need to come off of the cam gear.
    – Pᴀᴜʟsᴛᴇʀ2 ♦
    Aug 10, 2022 at 11:16

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