Lifter noise after replacement of fuel injector

[kevinpaigeking]

Codes read replacement of injector 6 and knock sensor. Initial new injector was deemed faulty because it stayed open. 2nd new injector was installed along with knock sensor. Car starts with a noticeable lifter-type noise that was not present before repair. Car does run and idle much better. After 45 min drives the check engine light comes back on, but car seems to run the same. Lifter noise is noticeable even after oil change and additives (seafoam). What should I do next to try and eliminate ticking sound.

[Infinitiguy19]

Codes read replacement of injector 6 and knock sensor. Initial new injector was deemed faulty because it stayed open. 2nd new injector was installed along with knock sensor. Car starts with a noticeable lifter-type noise that was not present before repair. Car does run and idle much better. After 45 min drives the check engine light comes back on, but car seems to run the same. Lifter noise is noticeable even after oil change and additives (seafoam). What should I do next to try and eliminate ticking sound.

Did you replace both Knock Sensors?

What are the codes on the ECU?

How to check ECU codes:http://www.nicoclub.com/articles.php?id=164376

Seafoam is totally useless and at best a temporary fix dealers or people selling there cars privately.

Where did you use the Seafoam on the car?

How did you come to notice the injectors was bad?

How to check injector ans Knock sensors: http://q45.org/ohminjectors.html

Welcome to NICO.

[kevinpaigeking]

No, we only replaced one knock sensor. I saw it was cracked but did not see the other, as it was not removed. Could a bad knock sensor cause this lifter noise when it was present before the replacement? Although the car's idle was rough, with the check engine light on, it did not have this noise until after the aforementioned replacements. I have read that the codes which led to the repair could have been mislead by O2 sensors or fuel pump malfunctions. Should I try starting my car with the fuel pump fuse removed? This repair has caused the removal of the intake 4 times and needs a logical diagnosis based on what? Help kevin

[Infinitiguy19]

Well there are some very intelligent Nico members where you live which is good news, just have to wait for them to chime in.

But a Knock sensor was bad the engine would retard the timing to prevent knock, which might be what your experiencing.

but if you can check the codes and check all the knock sensors and injectors that would really help narrow it down.

Can you go into more detail about the noise?

When does it start and stop, does it get loader or quieter after the car is warmed up?

[kevinpaigeking]

It is present at all times. At idle, it is overwhelmingly present. When rpm's go up, it is not as noticeable, but still present

[Infinitiguy19]

Yea like I said a video and more information from those tests you can perform would go a long way.

[silkysmoothyjud]

How long did it sit? Mine did the same thing, but it sat a while. I changed the oil to get the gas out, it was bad, but it went away. BG MOA and 500 miles later O-tay. switch to 10-w40 as well if you have over 90k. If you have any vibration with the knock, dont drive. The injectors may cause slight random vibration for 1-200 miles, but will go away.

Bad KS will cause the car to fall flat on its face at any speed over 80 mph at WOT and its ashame, but wont cause lifter tick.

Perhaps another injector is on the way out. I replaced 1-4 one right after the other. 20k later, yes you guessed it 4-8 started to fail slowly.

[kevinpaigeking]

Also, the check engine light comes on after 30 min of driving. Performance is the same, but ticking never goes away. I dont understand how injector replacement could fix the obvious timing problem, but could now create such an obvious ticking symptom. The car still will not pass smog inspection.

[maxnix]

Problem shouldn't be realted to injector replacement. Are you sure it failed open? Hydraulic locking may have done some damage.

Why KS and harness weren't all replaced raises some suspicions of competence.

[MinisterofDOOM]

Problem shouldn't be realted to injector replacement. Are you sure it failed open? Hydraulic locking may have done some damage.

That's exactly what I was thinking. Hopefully we're wrong.

[Q45tech]

Poor installation competence causing an injector oring leak [never seen a bad injector leak unlike orings which leak], then gasoline lock and stress on pistons, rods, wrist pins, bearings, caps, valves, lifters, cams.

When an engine hydrolocks [water or gasoline] and is saved there is always some damage it may still run, but not of the quality of before a hydrolock.

Years and years ago T3 had a trainee asian technican who was not the most accurate oring installer or crankshaft pulley torquer. We got lots of training in repairing his engines, bearings, rods, pistons. He loved Q [buy cheap and fix] many of his mistakes still hang on the wall of shame.

The point is there are places on a Q engine where EXTREME CARE is required.

[tfvesquire]

Hi There:

From reading your post, you mentioned that you did a Seafoam treatment. Are you referring to through the brake line or in the fuel tank? If you ran a can (or two) through your brake line you will have to do another oil change or your oil will be too thin. Sort of the same situation as when you had one of your injectors stuck open. It floods the cylinder with gas, which washes the cylinder wall of oil and then it drains down into the oil pan and dilutes your oil.

Try doing another oil change and putting in a bottle of CD2 varnish and lifter treatment. At $4.00 a bottle, it may help clean out a clogged oil passage in your HLA and make it function properly again. You may also want to remove the valve cover on the head where the lifter is ticking and make sure your camshaft lobes are not damaged. My guess is you have a semi collapsed lifter (hydraulic lifters need to pumped full of fluid to operate properly) due to a clogged or semi-clogged oil passage. I see it all the time on these overhead valve engines.

Try that and post your results. Good luck!!

Ted

[Q45tech]

Almost never hear or see a clogged HLA on a Q45 engine with proper oil change intervals [90 days]..................nearly impossible to rehabilitate a clogged HLA with dozens of exotic treatments due to tiny orifice size without damaging the bearings.

Once hydrolocked forever crippled without major internal component replacements.

[Q451990]

Initial new injector was deemed faulty because it stayed open. 2nd new injector was installed along with knock sensor.

When you say it "stayed open" do you mean electrically or physically. A bad injector will read open electrically, but typically stays physically closed. My guess is that the tech. who installed your new o-ring failed to properly seat the injector's lower o-ring and that caused the fuel flow... not a faulty injector itself.

The knock sensor will not cause your symptoms, but it would be helpful to know what is triggering your "check engine" light.

Heath

[tfvesquire]

Almost never hear or see a clogged HLA on a Q45 engine with proper oil change intervals [90 days]..................nearly impossible to rehabilitate a clogged HLA with dozens of exotic treatments due to tiny orifice size without damaging the bearings.

Once hydrolocked forever crippled without major internal component replacements.

I agree totally, but this problem is usually the result of improper oil change intervals, too much in town driving and other lack of maintenance. Sometimes you get lucky and a $4.00 bottle of lifter cleaner helps and many times the damage is too far gone to do a quick fix and then stick to the proper maintenance schedule. That is why buying a used car even with a documented maintenance history is always a gamble.

I would like to think if his car was hydrolocked due to excessive fuel from a faulty injector that it wouldn't run worth a darn and would be obvious (ie: bent rod, excessive water or oil consumption, etc.), but maybe I'm mistaken and this would somehow affect one of the lifters. Hopefully for this member, he caught the problem early enough to fix it without having to resort to tearing the engine down. We can surmise all we want to, but until he discovers the root of the problem, all we as members can do is provide valid suggestions on what to look out for.

Ted

[maxnix]

Or until we can have what an "open injector" is explained to us!

[kevinpaigeking]

Thanks for your thoughts. I now think that the clicking sound might be the injector itself. The car is running smooth and accelerating just fine. The mechanic said that when he put the first new fuel injector in (#6) the car was running terrible, he took out spark plug 6 and gas was shooting out, because the injector was stuck open. Then he ordered a new injector, installed it, and car is running the best it has in a while. But when I went to pick it up, the clicking sound was obvious.He thought it was lifters, so I did an oil change and added seafoam to it. So far it has not made a difference. Someone said I should do a fuel rail flush. I do not understand how the 14 yr old injectors never made a sound, and now the presence of a new one could create such an unhealthy sound. After the car has been driven for about an hour, the check engine light comes back on. Before the repair , the check engine light was on constantly. I think some good was done by this repair but I want to eliminate this tapping. What should I do next?

[maxnix]

You should take it to an experienced Infiniti technician

http://www.jerrytucker.net

I think your guy missed an O ring he pinched on his injector installation and the fact he can't tell you jack about your CEL should speak volumes about his lack of competence on the G50.

[silkysmoothyjud]

Please read some of the posts on this sight. Pull CEL code, use bg engine clean and MOA per elwesso. That fixed my LOUD tick when I first got the car. My lifters are always loud before and after all injector changes and oil changes, but go away after driving for a minute. You should have changed both KS, KS harness, coolant hoses, all four injectors under the plenum (only left one screw in #7) and plenum gaskets and just had been done with it. I would not be suprised if that CEL is KS or injector related. Those injectors will fail one right after the other so save yourself some time. But for now, just drive it and driving it alone should quite it down for the most part.