How JustAnswer Works:
  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site.
    Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.
Ask Gary Your Own Question
Gary
Gary, Technician
Category: Infiniti
Satisfied Customers: 15726
Experience:  GM master tech for 15 years/ASE master tech for 20 years
19513769
Type Your Infiniti Question Here...
Gary is online now
A new question is answered every 9 seconds

2006 Infiniti M45. Did an oil change to Mobil1 synthetic and

Customer Question

2006 Infiniti M45. Did an oil change to Mobil1 synthetic and now the car is making a loud knocking sound at startup. 170K miles
The car have been maintained accordingly by the dealership.
Submitted: 5 months ago.
Category: Infiniti
Expert:  Gary replied 5 months ago.

what oil was being used before and what weight oil ? was it full synthetic ?

what weight synthetic oil did you pout in it ?

Customer: replied 5 months ago.
Dealer normally used Mobil 5w30I tried Royal Purple 5w30 for the first time.
Expert:  Gary replied 5 months ago.

if your using the correct weight oil which you are can you tell me how long will the knocking sound last ?

Customer: replied 5 months ago.
When I start the car it is very loud and doesn't stop. So I haven't let it run for more than 2 minutes.
Expert:  Gary replied 5 months ago.

what brand filter vs what the dealer is using for an oil filter ? and the oil is full on the engine oil dipstick i am assuming ?

Customer: replied 5 months ago.
Oil level is fine. Always checked normally. K&N Oil Filter.Oil level is full. No engine lights or sensors are blinking, but is sounds just like this link
https://www.youtube.com/watch?v=A32KioBnvlc
Expert:  Gary replied 5 months ago.

if it was not doing this before the oil change get a dealer oil filter and change the oil filter out with the dealer brand and the oil if 5W30 should be just fine in this engine

if it still makes this noise have the dealer listen with a stethoscope to narrow down the noise area of a bottom end possible bearing causing this noise or a lifter or valve train issue

we have had oil filters cause this kind of issue so its worth a shot to try if the noise is still there then it is very bad timing of an internal engine failure of a bearing or valve train part or lifter

but in a nut shell you did not do anything wrong at all

you can always get me back for FREE for any follow up any time with this question even after you rate me here at Justanswer

if you have any questions please ask as i do not get credit for my work until you rate me here at Justanswer

Customer: replied 5 months ago.
Just don't want to think that I would have to replace the engine.
Expert:  Gary replied 5 months ago.

i agree with you

but if it was not doing it before and you are 100 % sure it was NOT doing this before then its the filter or real bad timing for any kind of engine failure

you can always get me back for FREE for any follow up any time with this question even after you rate me here at Justanswer

if you have any questions please ask as i do not get credit for my work until you rate me here at Justanswer

Customer: replied 5 months ago.
No. The service rep even mentioned that the car is still like new. They have serviced for 10 years. The valves always seemed a little noisy, but never nothing like this.
Expert:  Gary replied 5 months ago.

try the filter and if it still this noisy tow it to the dealer

you can always get me back for FREE for any follow up any time with this question even after you rate me here at Justanswer

if you have any questions please ask as i do not get credit for my work until you rate me here at Justanswer