Engine Knocking

mikeacetate

When my oil temp gets over 90C and if have given it a bit for a little while, I notice the engine has a loud roll over/ knocking noise but only at idle.

I have taken it to Nissan and they reckon it's normal. Once it cools down a bit the sound seems to go away. I think it might be the lifters??

Does anyone else have this problem or sound?

nogoodname

please take a video. engine knock requires ester oil or an ecu reset, which i did and the horrible knock is gone and i didnt switch to ester oil yet..


another noise that takes place when the car is warm is the cats, it a ticking sound. can be heard when car is on and when its off, but cooling off only....

ryanboy

is this still happening on your car?

i think i have the same issue... my roll over / knocking noise doesnt seem that loud but i do notice it. during idle... i put my hand on top of my engine and i can feel the knock that hits the top every 3-4 seconds.

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Slut RED Nismo Z34 2009 #60

ryanboy

ok i did a video with sound using my phone... i can hear it when you listen near the front tire and on top of the engine. i dont know if this is normal or loud enough but check it out and let me know what you think.

its only 38 seconds and its dark in my garage but what i did was put the phone near the front tire then moved the phone to the engine.

Nismo :: Nismo knocking video by ryanboy20 - Photobucket

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Slut RED Nismo Z34 2009 #60

ryanboy

just getting back to this post since i kinda have an idea now...

since i got my car in 2009, i have been researching this issue all over the planet because the noise really bugs me sometimes. its the LIFTERS by the way. here is the best answer that makes sense an expert told me:

""This is not normal, but it does happen. It's the lifters, 100 % positive on that one. You will distinctively tell the difference between a rod knock and a lifter. A rod knock will most definitely cause your car to run like sh*t as well.

Anyhow, let's go about ways to solve the issue if you want the noise to go away.

A: Run the car at 2000 rpm's for 10 minutes. This acts as a "bleeding" method to the lifters to get the air out of them. This should have been done right when the engine was started the first time.

B: Most of the time, in your case, people who run the car for as long as it has without bleeding them will have to literally take the lifters out of the car, take them apart and soak it in fresh oil. Putting them back together and making sure they don't flip upside-down to let air in and reinstall them will ensure the noise to go away after they are bled using method A once the engine is first started up after re-installation.

Again, this is NOT normal, it just so happens the fallacy of people countlessly repeating it's normal has stuck. I'm not saying you have to do this or your engine will fail from a valve seizing from a failed lifter, because lifters ticking like yours is not a big deal.

Sometimes you just can't do anything about it as they will always tick no matter what you do, but most of the time this is solvable using the above methods, but people are lazy/don't want to take the engine apart (or know how to).

So if it bugs you enough, it's time to take those rocker covers off. Good luck.""

ps... im not going to take my engine apart just for this bull crap noise! ill just deal with it since it doesnt mess with the performance! i wonder if the GT-R has the same problem...

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Slut RED Nismo Z34 2009 #60

DJ370

There is a product you can buy called Lifter Free. It is an oil adittive and can be placed in your oil filler along with your oil. This will improve the knock from the lifters but wont fix the issue. I have had cars with Lifter noise and used the adittive and they were fine and it took alot of the knock away. The adittive allows them to move with less effort. Hope this helps. I wouldnt worry though noisey lifters wont hurt your engine try owning an LS1 ! lol its been knocking since day 1 ! and its still making great power and runs fine and i punish that thing.

Also, dont leave the adittive in there for to long. do an oil change after 5,000 Kms. Cheers.

37Z

Add a pre-oiler (check out Amsoil) along with an oil cooler. This may reduce the valve train wear-related issues over the long run. but will not eliminate the valve noise. The GR-R block is different than the run-of-the-mill 370Z block. I am not sure if the the valve train is similar or different that in the Z.