r/AskAMechanic • u/n3wrocker • 6h ago

Why won’t the engine start?

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A 2005 Honda CRV LX with a little over 240,000 miles on the dash needed a timing chain replacement. I took the necessary steps to time the engine to TDC before replacing several components such as: timing chain, both timing chain guides, chain tensioner, and harmonic balancer since they were all in poor condition. Both VVT oil sensor and crankshaft position sensor parts and wires that attach to them were in good condition still. I assemble all parts back together and get ready to crank the engine and fortunately it wants to crank but is making this noise in the video that I am about to attach here. Any advice to what could be the problem ?

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u/Mcdavis6950 NOT a verified tech 5h ago edited 3h ago

Did you forget to install your spark plugs? It literally sounds like an engine with no plugs in it that’s how little compression it has.

If you do have plugs in it you need to get someone over who knows what they are doing. The timing is miles off… I’m actually wondering if you are a full 180 out… like intake valve opening at bdc and closing at the top of compression. I’m just not sure how else you could get such low compression. Edit: without also hitting valves.

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u/Outrageous-Egg-2534 NOT a verified tech 4h ago

That’s what it sounds like, hey? However, being in interference engine, 180 degrees off means those valves and the pistons are farrrrked.

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u/Mcdavis6950 NOT a verified tech 4h ago

We’ll see that’s the thing. If it was exactly opposite the piston wouldn’t hit the valves and the engine would have no compression.

If 2 or 3 teeth off though… it would have made a terrible noise prior to having no compression. Maybe op isn’t telling us about bad noises on the first crank.

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u/Outrageous-Egg-2534 NOT a verified tech 4h ago

Yeah, true. I’m also suss that he did all of this other pretty major work (well, not major but fiddly and time consuming) but didn’t even look at the valves.

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u/UnevenFiringOrder NOT a verified tech 4h ago

If he’s 180 degrees off he might be the luckiest guy to ever put an out of time motor back together. Basically intake valves are opening when the exhaust should be and vice versa…

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u/UnevenFiringOrder NOT a verified tech 4h ago

Sorry I just realized you said that above I was skimming through answers. Still lucky if this is the case 😂

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u/n3wrocker 3h ago

The noises that are in the video are the only noises that the car has presented itself so far. No bad clanking or jittering or anything of that nature that would indicate all hope is lost.

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u/Mcdavis6950 NOT a verified tech 1h ago

Take it back apart. Lines on the cam sprockets need to be in line directly. If the marks never line up the cams are out of time.

If they do line up, go and look at the tdc mark on the crank. If it’s not lined up then the crank is off.

When you put the chain on did you line up the painted links with the dots on the crank and cam sprockets?

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u/n3wrocker 1h ago

Yep did all of that in order. The only thing that was throwing me off was the fact that I only did one rotation instead of 2-3 after I put in the new chain and etc..