Loud Nissan engines?

[aquariuscsm]

If Nissan VQs are anything like VGs,they`ll love the thicker oils. I read on my350z.com that the VGs do in fact respond better to thicker oils vs thinner ones. 40 weights seem to be a popular choice (0W40,5W40,10W40,and 15W40).

 

[tig1]

Originally Posted By: G35_TX
I have learned to use a good oil and the car won't do it. They have timing chain slap a lot on the VQs. Mobil 1 really caused it to do it, but since I used PP on all my VQs and Amsoil, I never had the issue again.


It's my understanding that timing chains can wear or streach and cause chain slap. By changing oils I don't see how that stops chain slap.

 

[tig1]

Here is a slight explanition of why timing chains need to be replaced on some engines with high miles.

http://www.drivewire.com/part/engine-timing-belt-chain/timing-chain/

 

[hostile]

Fwiw, I just changed out the oil on my '95 Pathfinder I mentioned earlier in the thread.

The odometer is literally at 249,999 KMs and has only seen Mobil 5W30 and Napa Gold filters right from the day I got my hands on it in 2000.

It turned out the "sound of marbles" just after startup was the belt pulley. I replaced that, and the startup rattling is now gone. The passenger side valves were sounding a little "ticky" since my last oil change, but I just put in Rotella T 5W40 today and the engine is even smoother now. The ticking it had with the 5W30 is almost completely gone.

There is no measurable difference on my butt dyno, but my ears and intimate knowledge of how this engine runs tells me that this engine seems a little happier with the RTS 5W40 over the M1 5W30.

I know that is entirely subjective, but I just thought I would add to the thread a little bit.

 

[saberz]

Originally Posted By: aquariuscsm
If Nissan VQs are anything like VGs,they`ll love the thicker oils. I read on my350z.com that the VGs do in fact respond better to thicker oils vs thinner ones. 40 weights seem to be a popular choice (0W40,5W40,10W40,and 15W40).


To an extent, going back to Dino killed the slight ticking noise I would experience, the MC5k is a CST 10.6, the synthetics I used were lower. The X forums recommended Mobil 1 as this has corrected a lot of noises they experienced. Mobil 1's cst is 11.3.

I've tried PP, QS HP and Valv Synpower with the same results(noise). QS was fine until about 1-1.5k in to the OCI and the noise would come back. I'm now over 2.5k on MC5k and no noise.

Wife's Grand AM GT did not like QS HP. Car sounded different, and at first I thought it was a faulty filter so I swapped the Delco to a PPO and same noises. This OCI I put in 0w30 Mobil 1 AFE and you can barely hear the car running.

Thicker oils can help, but if you switch to a heavier weight of oil you just need to be cautious. Throwing in a 40w in a Versa engine may or may not have issues dependent on engine design. Secondly the heavier you go, the less fuel economy you get(albeit very minor, but in some cars its a noticeable difference).

I also believe the formulation of the oil(additives etc) determine the role they play in an engine. Certain oils work better in certain engines. Some play nice with all oils and others do not.

 

[Bigsyke]

Originally Posted By: tig1
How does oil stop timing chain slap?


the upper and lower chain tensioners are drivin by oil pressure.

This is why the KA24de's go best with a synthetic.

There is a TSB about removing the tensioners, which cause the said noises durring startup.

Also cleaning out the tensioners using PBblaster/deepcreep and a screwdriver.