Might be helpful so posting.
At about 120K 2012 LR4 HSE had an idle surge no matter temperature of the engine. Surged while crusing / accelerating as well. About 500 drop in RPM every 3-4 seconds.
1) Cleaned air flow sensors and replace air filters- no go.
2) Private shop said it was a timing sprocket issue. Complete tear down and fix cost $14k (included other things they found). I was lucky as i had 8 miles left on extended warranty when i brought it in. Still- No go.
3) Took it back about 6 month later as they warrantied their work and this time said it was most likely the air conditioning compressor putting an intermittent load on the engine. I didn't buy the explanation so made an appt with the dealer.
4) Dealer had it 3 weeks (I gave them all the paperwork associated with the previous work). Compressor was good. At week 3 they said it was LH Mid 02 sensor ($605 dollar part). They charged me 1 hour labor (or maybe they buried some of the labor in the cost of the part?) But regardless they solved the mystery. Thought it might be helpful. Good luck out there.
At about 120K 2012 LR4 HSE had an idle surge no matter temperature of the engine. Surged while crusing / accelerating as well. About 500 drop in RPM every 3-4 seconds.
1) Cleaned air flow sensors and replace air filters- no go.
2) Private shop said it was a timing sprocket issue. Complete tear down and fix cost $14k (included other things they found). I was lucky as i had 8 miles left on extended warranty when i brought it in. Still- No go.
3) Took it back about 6 month later as they warrantied their work and this time said it was most likely the air conditioning compressor putting an intermittent load on the engine. I didn't buy the explanation so made an appt with the dealer.
4) Dealer had it 3 weeks (I gave them all the paperwork associated with the previous work). Compressor was good. At week 3 they said it was LH Mid 02 sensor ($605 dollar part). They charged me 1 hour labor (or maybe they buried some of the labor in the cost of the part?) But regardless they solved the mystery. Thought it might be helpful. Good luck out there.
