Recently, an oil leak caused my engine to explode. It was a stock d15 in a 95 Civic DX and it was replaced with the same type of motor, but when I sit at 40 mph in 5th gear just on daily drives, the car starts shaking like I just hit several bumps... It also does this starting out in 1st gear... And when the car is started with a cold engine, instead of just idling, it revs up and down until the temperature of the engine is normal...

I have absolutely no clue what could be causing all of this to happen, but those are the symptoms and any insight on what could be the problem would be appreciated. Thanks in advance.

 

is your check engine light coming on? the heater might be out in your main oxygen sensor, what kind of shaking do you get? like the front end shakes, or it feels like the motor itself is causing shaking?

 

The surging of the rpms at cold start is probably the IAC (intake air control). It's known for them to go out on honda's. It uses your coolant temperature to adjust your idle accordingly to compensate for fast warm ups on colder coolant temps by raising the idle speed a little. It's located on the back of your intake manifold right by the throttle body. It's a pretty simple install.

You'll have to be a little bit more detailed about the shaking. Does the whole car shake or do you just feel it in the steering or in just the foot pedals? Considering that this is has a newer motor did you replace the clutch when you had the swap done and resurface the flywheel? If the clutch cracked and a piece broke off than it could cause the whole motor to be out of balance. This is considering of course the car is a manual. Post more specific details about the shaking please.

 

Try cleaning the FITV and bleeding the cooling system. You might also check the 2-wire coolant temperature sensor under the distributor. How do the plugs, cap, and rotor look?

 

im taking a wild guess that the steering wheel shakes but also you can feel the vibration in the front end as well. that sounds like a really bad 1/2 shaft or the wrong shaft. if the steering wheel doesnt shake ..i would assume this is some chatter in the clutch/trans area. manual?


some other issues are:

wheel about to fall off...loose lugnuts. check this first please. wheels had to be off to do the swap.
out-of balance tires.. but this would vibrate at 60 plus. you say low speed (1st gear)
snow in tires..see above
bent rotors...but this would vibrate while braking
slipp belt in tires..this would be a "wobble" at low speeds.

idle revving up ad down while cold... i know it sounds weird but check coolant level first. its more then likely a sensor of somesort.. coolant temp sensor, intake air tempature sensor, intake air control valve or even the idle is not correct. like stated above..any CEL's?

 

^^^It feels like the front end shakes.

^^^No, I did not replace the clutch during the swap, and yes the car is a manual. The shaking feels to be in the front of the car.

^^^Plugs, cap, and rotor seem to be in order.

 

thank you guys for your help so far btw