Piston Slap or something else

[Deltona_Dave]

My Titan has developed a knock over the past 2-3k miles. It is only noticeable when engine is loaded against transmission in drive with foot on brake (idle is about 500). If I put trans in neutral or park, idle is about 600 and the knock is barely audible. The knock seems to come from the lower end and taps about 2 times per second. It is intermittent though, mostly happens when engine is cold, but will do it when fully warmed up.
I have about 3500 on Pennzoil Platinum 5w30, and before I was using Mobil 1 10w30. I am hoping it is just piston slap (block and heads are alum, with CI bore liners). It may be the trans pump and I am due for a flush. I will be changing oil with P.U. next weekend, maybe that will quiet it up.

Any ideas?
Thanks,
Dave

 

[ARCOgraphite]

How many miles on the engine? Are you running a different "high efficieny" filter like Bosch or Purolator Gold? Does the noise go away when the engine is fully warmed up? It could also be the exhaust hitting something or the engine loading and unloading the DS. Hopefully its not a rod big end or main. Absolutely no need to run winter 5w30 multigrade in FL.
- I thought I was the only one to have engine failure in North America running 5w30 GF4 .

 

[Deltona_Dave]

Originally Posted By: ARCOgraphite
How many miles on the engine? Are you running a different "high efficieny" filter like Bosch or Purolator Gold? Does the noise go away when the engine is fully warmed up? It could also be the exhaust hitting something or the engine loading and unloading the DS. Hopefully its not a rod big end or main. Absolutely no need to run winter 5w30 multigrade in FL.
- I thought I was the only one to have engine failure in North America running 5w30 GF4 .


Engine has 56000. Sometimes I get it after engine is warmed up, but it goes away within a minute. The 5w30 is what nissan recommends, but 10w30 or 40 are on the list for warmer climates. I have 5w30 P.U. on the shelf, but I think I will try 10w30 if they have P.U. in that viscosity. This weekend I will crawl under and check the transmission mount (when you mentioned the exhaust, I recall transmission mounts on the T will get loose or worn out. I have already checked the Exhaust Manifold for cracks (04's had it bad, not so much in 05/06 models).

Dave

 

[heypete]

Originally Posted By: ARCOgraphite
Absolutely no need to run winter 5w30 multigrade in FL.


Why not? It offers better flow at startup and the same, 30-weight protection at operating temperatures? I live in Arizona and use 5w30, though my mechanic has occasionally used 10w30 in the past. Using 5w30 in warm climates is perfectly suitable.

Would 0w30 be "super-winter weight" and only be suitable for the most cold of climates? Certainly not.

 

[Schmoe]

If everything mechanically checks out, I'd run a 10w30 to see if that changes anything. Why yes.....I am a believer that thicker is better!!!!

 

[mpvue]

Originally Posted By: Deltona_Dave
The knock seems to come from the lower end and taps about 2 times per second.

are you sure? is it possible it's valvetrain noise? every Japanese OHC engine I've had experience w/ develops valvtrain ticking; although 'ticking' is more like 'knocking' sometimes. nissans seem to be especially prone to this, as are mazdas.

 

[Deltona_Dave]

Well, I think it is lifter tick. Just had one of the shop guys use his stethoscope. Hard to hear with just the hood open, as the injector clatter and the radiator fan are a little noisy. I could only hear it when I had the driver door open or if I am next to a building.

Think I should run a thicker oil to quiet down the lifters?

Thanks,
Dave

 

[mechtech2]

Dave - A thicker oil would make things worse for noise on a cold start up, if it is due to lifters that leaked down.
The thicker oil would not flow and get back in there as quickly as a thinner oil.
If the noise goes away, it is not a stuck lifter, but one that drained down while sitting from the valve spring pressure. You want flow.

If the noise is present when hot, a thicker oil may help.

 

[Deltona_Dave]

Thanks. I will stay with 5w30. I did some looking at Titan boards and several people have the same noise. One of the culprits is the evap solenoid for the canister (there is a TSB for it that I am trying to get), and some of it is just the valve train noise when cold. Mostly I hear it when it is cold, but when the idle speed comes down after a few minutes of running.

Thanks again,
Dave

 

[ARCOgraphite]

Originally Posted By: heypete
Originally Posted By: ARCOgraphite
Absolutely no need to run winter 5w30 multigrade in FL.


Why not? It offers better flow at startup and the same, 30-weight protection at operating temperatures? I live in Arizona and use 5w30, though my mechanic has occasionally used 10w30 in the past. Using 5w30 in warm climates is perfectly suitable.

Would 0w30 be "super-winter weight" and only be suitable for the most cold of climates? Certainly not.
5w30 mineral is compromised with high VII adds it does NOT offer tha "same" High temperature protection as a SAE 30 or 10w30. VII are the leading cause of sludge and varnish from the oil itself and the leading cause for oils to shear out of grade. The old "innertube rubber" (EPDM) VII are not lubricants. Problem is most new 10w30 are just the 5w30 without pour depressors. 0w-xx oils are group IV/V synthetic and another issue altogether.

 

[ARCOgraphite]

Originally Posted By: Deltona_Dave


Think I should run a thicker oil to quiet down the lifters?

Thanks,
Dave
Avoid synthetic for now. Try Rotella T 10w30 CJ-4/SM and a wix filter. Quietest running stuff out there. Filter selection is critical - I'd avoid a high efficieny filter (pureone/M1/Bosch) for now until you get this sorted out. An Evap solenoid is not knock - though they can be noisy. Forget the 5w30.

 

[Deltona_Dave]

Well, On the way home yesterday, I stopped by my friend's shop and he heard the knock. Plugged into the computer and triggered the Evap solenoid and it knocks. Since the solenoid is bolted onto the intake manifold, the sound resonates. He said nothing to worry about, but there is a TSB to get it fixed under the emissions warranty. Looks like a couple of new bolts, a new bracket and a re-designed service port.
--- Below is part of the TSB ----
IF YOU CONFIRM:
A slight knock noise coming from the engine area at idle speed,
NOTE: This noise:
• May sound like engine "knock".
• Is heard only at idle speed.
• May be intermittent.
----------------------------------
I will schedule with the dealer to get it repaired in the next week or so.

Thanks for the help.
Dave

 

[ARCOgraphite]

That much better news than a rod knock! Here's to good continued luck on you Titan!

 

[Deltona_Dave]

I was relieved that it was simple, and not a major overhaul type repair.

Dave

 

[mechtech2]

Arco - You are right 'on paper', but do you really thing this is a problem nowadays?