Hi,

My 2001 Honda CRV had a burnt valve and I bought a JDM motor with about 55000 miles on it and had my mechanic install it. All seals, gaskets, belts, etc. that were on the outside of the engine were replaced and the valves adjusted. He did perform the CKF Bypass Trick and it fires right up with no codes etc. But the car is vibrating pretty badly. I haven't driven it yet, just fired it up in neutral and it get's louder and worse when you give it more gas.

He at first thought it was a motor mount going bad, but the engine itself doesn't seem to be vibrating hardly at all when I put my hand on the valve cover but inside the car is shaking pretty badly and is very loud. He put a large soft piece of wood on a floor jack and put it under the motor and applied a little pressure to take the weight off the mounts and the noise is the same.

I'm thinking one of a few things:

• Something to do with engine timing
• Fuel injector issue, possibly wiring related due to CKF Bypass
• Exhaust issue

Any other things we should look at? What should we check?

Thanks!
Brian

 

I've been running a CKF bypassed B18C for years. You can probably take that off the list unless he did it wrong. Your other ideas are all culprits. The mechanic could have botched the valve adjustment. Were all the engine mounts replaced? Or were any damaged on the install? Over stock stiff mounts would cause this. Could also be a mount under stress because it was tightened before engine was completely mounted. I leave everything untorqued and let the motor rest where it wants to with all mounts installed before torquing them down.

 

Also check your ignition timing

 

Thanks!

Here's a link to a video of the motor running -- I'm at home, will try to go back to the shop soon

Any hints in the motor noise?

Engine Running Video

 

The mounts were not replaced during the install -- any good suggestions on tests for the motor mounts? He used a floor jack + a large soft piece of wood under the mounts

 

They should have been inspected when the motor was out. You'll need to crawl around and look at each one. Look for cracks or rips. It's not always obvious. Have someone else flex the motor while you look at them. Check your ignition timing first.

 

Yea he did a visual inspection on them before installing the motor and said they looked fine so we didn't put them on the list of things to replace -- can you make heads or tails of anything from the sound in that video link I posted?

 

Sounds rough incorrect Ignition timing, failing ignition component, bad connection, bad distributor are my guesses. Engine mounts dont cause a rough idle. Were all ignition components changed or inspected? Could be fuel system related. Injectors, fuel pump or fuel filter. Diagnose and test. Don't throw parts at it

 

Yea that was my thought too -- it's new distributor/wires/plugs -- I'll ask him to go through timing again first

Thanks!

 

Talk to your seller, the one who sold you the engine. Thats all I can say. Thats not vibration, thats engine noise.

 

Thanks guys -- here's an update:

Ok -- timing, etc. was double checked and all of that seemed right. After the car warms and idle drops to 750 RPM it's smooth and quiet, no vibration at all. It's when you give it any gas you can really here the noise, sounds like a jet engine

We also checked the exhaust for leaks, there seems to be a leak in the last flange just before the muffler, not giant but you can feel it pretty clearly. I drove the car around and power, etc. seemed fine, no trouble with RPMs, good power, acceleration etc. very consistent just LOUD

We then tested the motor mounts by putting it in gear with the brake on, both forward and reverse and the motor twists forward or backward pretty significantly (more than 1 inch movement) which leads to believe motor mounts

I took another video of the car from the inside, the car is running from the very beginning and you can hear almost no noise at idle and then very loud as I give it gas -- I'm thinking it's the rear mount where it ties into the chassis against the dash and that it's just transmitting vibration through the car body, but mounts are expensive! Can you give this a listen and see if that seems logical (I know you can only tell so much)

Engine sound inside car

 

In case that link didn't work to the video try this one