93 Q45 Engine Noise (see video/audio link)

[mwaters]

Newbie here. Bought this car a couple weeks ago with 182K miles. Don't have much to go on with it's history. I found this video on youtube...mine's making the same tapping/knocking sound:

http://www.youtube.com/watch?v...lated



Thanks for your time and input!

[Infinitiguy19]

Welcome To NICO

When does it make the noise, All the time or in the cold when its warming up?

Did you get a service history on the car? If not then contact your local Infiniti Dealer and give the service department manager the VIN.

Did you get a carfax before buying?

What recipts do you ahve from the previous owner?

How does the oil look?

How does the oil fill hole look? Is it very dark and dirty?

Is there any lack of power?

Have you reved it above 4000 RPM's?

And lastly How much money do you have set aside for this car?

[mwaters]

At first the noise seemed most prevalent when starting/cold. However, it is now making noise when accelerating and feels like it's misfiring and yes lacking power. I don't have the service history, but will take your suggestion to contact dealer's service department for records. No CARFAX report. I bought it very cheap and can spend a reasonable amount of money on it, but hoping for a relatively cheap fix. When I bought it the oil and fill hole were clean. I've since changed the oil (Valvoline MaxLife plus Marvel Mystery Oil) and filter.

[Infinitiguy19]

Whats the build date?

And yea that sounds like an injector?

Do you have a laptop?

You can can check which injector is bad your self or have a dealer do it.

[mwaters]

Not sure how to determine build date. I tested the resistance on the injectors when I first bought the car and they all were OK. I'll check them again tomorrow. No laptop...why? Thanks ppastos!

[Infinitiguy19]

If you had a lapt top you could use a program called OBD Scan Tech or Nissan Data Scan, With OBD Scan tech you can shut off each cylinder and preform a some what complete Power Balance test. But with Nissan Data Scan you can only shut off a cylinder.

If you notice a differnce with the cylinder off then its good.

If not then that cylinder (Spark Plug or Injector is bad).

The build date will be posted where the drivers door striker is.

And I am glad that the resitance is good so one of them may be clogged.

Does the car shake at idle?

[maxnix]

Don't have much to go on with it's history.

Did you not avail yourself of the Infiniti dealer performed service history? How about the senior Infiniti technician pre-purchase inspection?

Very difficult to diagnose from the video some other car's engine.

MM oil is very light weight and will take some varnish and lsudge into suspension if changed within an hour or so of running after installation. Try some BG Quick Clean 15 minutes immediately beofre that change, draining immediately after shutting engine down.

[mwaters]

If you had a lapt top you could use a program called OBD Scan Tech or Nissan Data Scan, With OBD Scan tech you can shut off each cylinder and preform a some what complete Power Balance test. But with Nissan Data Scan you can only shut off a cylinder.

I'll work on borrowing a laptop. In the meantime, is there any other way to determine which cylinder?

The build date will be posted where the drivers door striker is.

Build date is 12/92

And I am glad that the resitance is good so one of them may be clogged.

Tested resistance again today. All are good. If clogged, how would I unclog?

Does the car shake at idle?

Yes, just a little bit.

[mwaters]

Did you not avail yourself of the Infiniti dealer performed service history? How about the senior Infiniti technician pre-purchase inspection?

I paid so little for the car...the wheels and tires are worth more than I paid so it was kind of a no brainer. I figured it would be a bit of a project which is OK....I enjoy the challenge. If it were serious money I certainly would have checked off with Infinity service.

Very difficult to diagnose from the video some other car's engine.

Yes, I understand. I made a video of my car, but can't find my video connectors to upload....I have kids that love to get in to my stuff.

MM oil is very light weight and will take some varnish and lsudge into suspension if changed within an hour or so of running after installation. Try some BG Quick Clean 15 minutes immediately beofre that change, draining immediately after shutting engine down.

I read some threads recommending Quick Clean, but the dealer didn't have it and sold me BG 109, saying it did would accomplish the same thing.

Thank you maxnix!
Modified by mwaters at 11:02 AM 12/6/2008

[Q45tech]

Not really but dealers are not chemical engineers. Varnish is the most difficult thing to remove and takes some exotic and powerful chemicals and must be watched carefully or they will destroy seals and rubber components in minutes.

BG Quick Clean for transmissions can be substituted but only allow this in warmed up fresh oil and keep rpms at idle for 15 minutes then shut of and drain immediately and add new oil and filter.

The varnish is almost transparent in brand new oil and used oil will negate the usefulness of a Quick Clean so think about the process of doing an oil change then add the QUICK CLEAN AND 15 MINUTES LATER CHANGING THE OIL AGAIN.

[Q45tech]

The solvents in a Quick Clean will evaporate around 200F so the ideal working temperature to free the varnish is 170-<200F. If you wait too long or the oil gets too hot the solvents just evaporate leaving the varnish to replate somewhere else in engine not drain out.

[Infinitiguy19]

I'll work on borrowing a laptop. In the meantime, is there any other way to determine which cylinder?

Build date is 12/92

Tested resistance again today. All are good. If clogged, how would I unclog?

Yes, just a little bit.

There is a way to determine which one is bad, But its not recomended.

it involves removing the plenum (the thing with the Infiniti logo) then removing the connector to each injector, Then start the car up to see how it runs, But that will take an entire day for sure.

You maybe lucky on the "Chain Guide" issue since its such a late build.

Try giving the injectors 12V of energy from the mulitimeter, Basically reverse the conector that you use to test the injectors.

That could mean a clogeed injector as well, But it could also be the MAF sensor, Search on Q45.org on how to clean it.

What does the car Idle at?

Does the car shake more when at idle you rev it between 1000 and 2000 RPM's?

[mwaters]

There is a way to determine which one is bad, But its not recomended. it involves removing the plenum (the thing with the Infiniti logo) then removing the connector to each injector, Then start the car up to see how it runs, But that will take an entire day for sure.

The laptop definitely sounds easier! Or, I can probably move a PC to the garage? Will this work? If so, what to do?

Try giving the injectors 12V of energy from the mulitimeter, Basically reverse the conector that you use to test the injectors.

OK, I did that and could hear each one "tick" but no change in noise and shaking.

That could mean a clogeed injector as well, But it could also be the MAF sensor, Search on Q45.org on how to clean it.

Already cleaned the MAF sensor a couple weeks ago.

What does the car Idle at?

Starts cold at 1250-1500, then drops to about 750-800 warm.

Does the car shake more when at idle you rev it between 1000 and 2000 RPM's?

Shakes most at idle, then no shake from about 1000 - 1500, shakes again 1500-2000 (but less than idle).

Also, checked the ECU codes. Getting 21 and 34 with engine off, then two short blinks...pause...then 4 short blinks with engine on.

Thanks again ppastos!
Modified by mwaters at 11:38 AM 12/6/2008

[Q45tech]

"Try giving the injectors 12V of energy from the mulitimeter" ?? Most multimeters only have a 1.5 or 9 volt battery.

All injectors constantly see +12 volts from battery. The ecu completes the ground circuit.

Solving a mechanical wear or blockage problem cannot be accomplished with electricity.

[mwaters]

The solvents in a Quick Clean will evaporate around 200F so the ideal working temperature to free the varnish is 170-<200F. If you wait too long or the oil gets too hot the solvents just evaporate leaving the varnish to replate somewhere else in engine not drain out.

I'll bet I waitied too long and it got too hot. Will try again as you suggest.

Thanks Q45tech!

[Infinitiguy19]

List of Codes

Pre-OBDII

11 Crank Angle Sensor

12 Mass Air Flow Sensor

13 ECT Sensor

14 Vehicle Speed Sensor

16 TCS Signal

21 Ignition Signal Circuit

25 Idle Air Control Valve

22 Fuel Pump Control

31 ECM

32 EGR Function

33 Heated Oxygen Sensor

34 Knock Sensor

35 EGR Temperature Sensor (RH)

41 Intake Air Temperature Sensor

42 Fuel Pump Sensor

43 Throttle Position Sensor

45 Injector Leak

46 Secondary Throttle Sensor

51 Injector Analysis

53 Exhaust Gas Sensor (LH)

54 Signal Circuit From A/T Control Unit To ECM

55 System OK (1990-1995 Q45 only)

65-71 Single Cylinder Or Multiple Cylinder Misfire

72 Three Way catalyst Function

76 Fuel Injection System Function

77 Rear Heated Oxygen Sensor

82 Crankshaft Position Sensor

84 A/T Diagnosis Communication Line

91 Front Heated Oxygen Sensor Heater

103 Park/Neutral Position Switch

105 EGR & Canister Control Solenoid

No problem.

O yea Q45tech, Why does it say in the FSM that giving the injectors 12V is bad for them?