Car always rumbling/shaking at idle

2001 HONDA CIVIC
168,000 MILES • 1.7L • 4 CYL • 2WD • AUTOMATIC
Avatar
BUSINESSFRED
  • MEMBER
  • 96 POSTS
When i bought this car a few months ago i replaced the spark plugs , intake manifold gasket , and adjusted the valves which rid me of 2 misfires.

The spark plugs i replaced had white tips as if they were running hot.

The car always shakes at idle
Has good compression give or take 170 on each cylinder

Also doesn't consume much oil.
And almost no coolant at all .

What can be a reason why these issues may be occurring?

Have also replaced the ECT sensor once a while ago as well
Nov 12, 2020 at 6:18 PM
Advertisement
Avatar
KASEKENNY
  • ✓Experienced Mechanic
  • 18,907 POSTS
Assuming you have no codes, the most likely cause would be a vacuum leak or possible air flow sensor. I would suggest checking thoroughly for a vacuum leak because not only is that the most likely cause but often missed causing people to chase their tail for other things.

Here is a guide that will help:

https://www.2carpros.com/articles/how-to-use-an-engine-vacuum-gauge

Let us know what you find. Clearly checking around the engine with parts cleaner is a good way but if you have a vacuum gauge that will tell us the story. Thanks
Nov 13, 2020 at 12:39 AM
Avatar
BUSINESSFRED
  • MEMBER
  • 96 POSTS
If i am not mistaken i think that mine does not have a mass air flow sensor.

This is the American version
DX trim . Also does not have the EGR Valve

I will check with the vacuum gauge is there specific port i should check through?
Nov 13, 2020 at 4:00 AM
Avatar
KASEKENNY
  • ✓Experienced Mechanic
  • 18,907 POSTS
You are correct. It does not have a mass air flow sensor but it still has to know how much air is coming in and it does this through a MAP sensor. That is a manifold absolute pressure sensor. Basically it tells the PCM what the negative pressure is in the manifold and it can use this to calculate how much air is coming in.

You can use any vacuum line on the engine and just use a T fitting if needed to keep the vacuum line connected but you can still monitor it.
Nov 13, 2020 at 9:07 AM
Join 2CarPros for free, one of the most advanced car repair communities on the internet. From first-time drivers to seasoned mechanics, everyone is welcome to reply, share details, and get better answers. You can add a temporary image or video first; uploads are limited to 20 MB.
Ask a Free Question
Repair Safety Notice: This information is for general instructional purposes only. Vehicle repair can be dangerous. Verify all information, follow manufacturer service procedures, use proper tools and safety equipment, and consult a qualified repair shop when needed.