Hi,

the discovery today started shaking at idle. Felt like a vibration coming from under the seat. However the UG showed idle RPM to be constant. No Check engine light, but pending codes are P0150 P0327 and P0174. I also noticed a bit of smoke coming from the exhaust. (although hard to tell since it is cold and night time)

I had to go eat dinner, so went inside. Went back out again to drive the car a few hours later. Drove it for 15 minutes. The vibration at idle was gone, but still seemed like there was some smoke. There was also a faint smell of fuel or something, but very faint.

The P0327 (knock sensor) has been coming up as a check engine problem every once in a while in the past 2 years. I've just been clearing it and it goes away for months at a time. It last came one as a code on sunday.

The other codes I've never seen before. Again, these pending still.

Any ideas? Since the bad knock sensor code, has been thrown before, I am leaning towards replacing that as a first step. Can a bad knock sensor cause vibrations at idle? I'm guessing the P0174 (lean bank) is just due to something else. P0150 is 02 sensor, but that has not tripped yet.

Thanks!

 

update: the problem appears to be low idle RPM. When the car warms up the idle dips from the mid 700rpms to very low 600's and some smoke starts to come out. When driving there is no smoke or problems. This car has been idling even when warm at around 740rpm since I got it, so the 610 or so RPM it idles at now does not seem normal.

What could cause the low idle? I have a new bosch knock sensor on order. Anything else I should be looking at?

Thanks!

 

whenever a LR doesn't run right check the coolant

 

coolant reservoir is full. Is there something else I should check?

 

what color is the smoke, is the smell kind of sweet

 

I'd have to check it again. Still was dark this morning and there isn't very much of it, but it seemed white. I did not detect sweet smell. Was not too smelly, but smelled of typical engine smoke.

This is funny, in my learning journey to be competent shade tree mechanic, I'd never thought I'd have to learn how to smell the "bouquet" of smoke

 

If you smell fuel coming out the exhaust, injector issue

 

so the check engine light turned on today with a P0150, 02 sensor fault. . landroverparts has this kit:

Oxygen Sensor Kit - Land Rover Discovery 2

and amazon sells this single sensor:


any opinions? Can I just get away with changing the one sensor that is sending the fault?

 

Thats what I would do. Make sure your electrical connections are clean and free of oil.

 

I decided to buy the two front ones from amazon. They are bosch and a bunch of threads suggest replacing in pairs.

So this weekend I will: Change front 02 sensors, changer driver side knock sensor and clean out the IACV which I read can affect idle. Wish me luck