Should I be using thicker oil? Tick related.

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I have an '06 G35 that since around 90K has had pretty loud valvetrain tick/knock and general top end noise when hot. I attributed it to the abuse the car takes on a daily basis. I have run M1 0w-40 since new - except for some track days. The oil temps in the car cruising on the highway floats around 115-125C typically, higher if I am over ~4.5K for extended periods of time. during track days it was hitting 160 w/ M10-w40 and also M1 15w-50. It hasn't really gotten any worse in the last 70K. Oil temp (in this car) seems to be related more to engine speed than load.

Yesterday I got home and (because it was almost 100 degrees outside) I left the car running with the AC on while I detailed the interior. I realized after an hour or so that the engine was totally silent - like it is when cold. I hooked up my scan tool to see if anything was significantly different than normal. Other than excessively high air (70c) intake temp, the oil temp had dropped to 82C. I went out and got on the highway for a few miles (highway here is ~85mph typically), came back home, the tick/knock was back. Let the car idle for another hour while I washed the outside if it and detailed the exterior, leaving the scan tool connected. The noise subsided around the time the oil temp dropped below 90c. At 90c it was just audible, by the time it dropped to 85 it was totally silent again.

So. I've been ignoring the noise that makes my car sound like a broken tractor for 70K miles. If I were to go to a thicker oil, potentially quieting the top end noise, is it likely that something in the bottom end would be unhappy?

When I used to do a lot of track days I used M1 15w-50 and still had the tick/knock, but the oil temps were significantly higher.

The next model year increased HP and RPM and many people added a secondary oil cooler (I think Nissan sold one for them). The newer ECU would also limit RPM after the oil got to a certain temp. The newer motor also had variable valve lift which apparently really increased oil temps and noise in the valvetrain.

Should I just continue to ignore it or would it be worth trying something thicker? The lowest temp this year was around 40F. It will be 95+ for the next 4 months.
 
Maybe the clearances are getting wider. If it is a clean engine I'd try a thicker like 20w50 to get a better response for this issue an note at witch temperature it starts to knock/tick. If it helps, I'd go to a more expensive fully syn 10w60.
 
Originally Posted By: CBR.worm
If I were to go to a thicker oil, potentially quieting the top end noise, is it likely that something in the bottom end would be unhappy?


The way I understand it from reading here on this site,thicker oils are better for the bottom end. Anyone definitely correct me if I'm wrong on this,like I said,I'm just repeating what I've read here over the years.
 
It sounds like you're trying to solve an engineering or usage pattern issue by changing oil viscosity. Why not upgrade your oil cooler? You'll even gain some oil capacity that way, you won't be limited in oil selection by your chosen viscosity, and you won't have to worry about the bottom end. A bigger or secondary oil cooler is probably a good idea for a car that sees track time anyway, right?
 
Quick and easy would be going to a thicker oil. Present oil viscosity thinness is driven by MPG, not engine longevity. In north FL you can use 20w50 all yr. It is fine for lower ends. Better, IMHO
grin2.gif
 
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I would look into the oil cooler for sure. For giggles I would try some mos2 with your current oil.
 
Originally Posted By: CBR.worm
I have an '06 G35 that since around 90K has had pretty loud valvetrain tick/knock and general top end noise when hot. I attributed it to the abuse the car takes on a daily basis. I have run M1 0w-40 since new - except for some track days. The oil temps in the car cruising on the highway floats around 115-125C typically, higher if I am over ~4.5K for extended periods of time. during track days it was hitting 160 w/ M10-w40 and also M1 15w-50. It hasn't really gotten any worse in the last 70K. Oil temp (in this car) seems to be related more to engine speed than load.

Yesterday I got home and (because it was almost 100 degrees outside) I left the car running with the AC on while I detailed the interior. I realized after an hour or so that the engine was totally silent - like it is when cold. I hooked up my scan tool to see if anything was significantly different than normal. Other than excessively high air (70c) intake temp, the oil temp had dropped to 82C. I went out and got on the highway for a few miles (highway here is ~85mph typically), came back home, the tick/knock was back. Let the car idle for another hour while I washed the outside if it and detailed the exterior, leaving the scan tool connected. The noise subsided around the time the oil temp dropped below 90c. At 90c it was just audible, by the time it dropped to 85 it was totally silent again.

So. I've been ignoring the noise that makes my car sound like a broken tractor for 70K miles. If I were to go to a thicker oil, potentially quieting the top end noise, is it likely that something in the bottom end would be unhappy?

When I used to do a lot of track days I used M1 15w-50 and still had the tick/knock, but the oil temps were significantly higher.

The next model year increased HP and RPM and many people added a secondary oil cooler (I think Nissan sold one for them). The newer ECU would also limit RPM after the oil got to a certain temp. The newer motor also had variable valve lift which apparently really increased oil temps and noise in the valvetrain.

Should I just continue to ignore it or would it be worth trying something thicker? The lowest temp this year was around 40F. It will be 95+ for the next 4 months.


When you mention the M1 15W-50 (one of their finest oils along with 0W-40, creme de la creme,) you mention higher oil temps.. because it was a track day, or because the oil itself is thicker and actually helps produce higher oil temps as well?
 
Originally Posted By: NormanBuntz
Sounds like another oil cooler should be in your future.


Given the temperatures involved, this is the expedient route to take. Temps in the 90C range are about ideal, anyway.

Best guess for the source of the racket is a chain tensioner that has some leak by going on.
 
Originally Posted By: CBR.worm
I have an '06 G35 that since around 90K has had pretty loud valvetrain tick/knock and general top end noise when hot. The oil temps in the car cruising on the highway floats around 115-125C typically, higher if I am over ~4.5K for extended periods of time. during track days it was hitting 160 w/ M10-w40 and also M1 15w-50. It hasn't really gotten any worse in the last 70K. Oil temp (in this car) seems to be related more to engine speed than load.

The noise subsided around the time the oil temp dropped below 90c. At 90c it was just audible, by the time it dropped to 85 it was totally silent again.

When I used to do a lot of track days I used M1 15w-50 and still had the tick/knock, but the oil temps were significantly higher.

Oil temp is more related to engine speed than load in any vehicle.

My 2000 E430 was very quiet the first 70-80k miles with M1 0W40, it was very loud around 80-90k miles, the engine sound liked a diesel engine of the 80's.

I then tried Pennzoil Platinum 5W20, the engine was so quiet that I can hear the A/C fan running at lowest speed when the car was stop at red light, it used to be I could not hear the fan running until the speed was at 4th or 5th. Also, the engine(coolant) temperature was and is lower with thinner oil by about 5-8C.

The car doesn't have oil temp gauge and I don't have scan tool to measure oil temp so I don't know, but my guess is the oil temp is probably somewhat cooler at all engine speed.

You can display oil temp of your car, why not try xW20 to see if you will get lower oil temp and quieter engine ?
 
Originally Posted By: aquariuscsm
Originally Posted By: CBR.worm
If I were to go to a thicker oil, potentially quieting the top end noise, is it likely that something in the bottom end would be unhappy?


The way I understand it from reading here on this site,thicker oils are better for the bottom end. Anyone definitely correct me if I'm wrong on this,like I said,I'm just repeating what I've read here over the years.


Besides the Ferrari guy on the university 101 ... He uses 0w16 now, the car is approaching 5k miles and "run like new".

JK
 
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Originally Posted By: HTSS_TR

Oil temp is more related to engine speed than load in any vehicle.


its related to how much gas you are burning. Its incredibly easy to burn much more at 4000+rpm vs 2000rpm.

The more gas you burn=more heat=hotter oil.

Originally Posted By: HTSS_TR

The car doesn't have oil temp gauge and I don't have scan tool to measure oil temp so I don't know, but my guess is the oil temp is probably somewhat cooler at all engine speed.

You can display oil temp of your car, why not try xW20 to see if you will get lower oil temp and quieter engine ?



That is incredibly bad advice. You want him to run a tracked car that sees 300F oil temp on 20w? There would be no viscosity reserve and damage would result.

It might be ok for regular highway driving.
 
Going to a heavier oil favors the main bearings, "bottom end" and the lubed valve train in general.

However, heavier oil detracts a little or a lot from lubrication at cylinder walls, piston rings, etc. The issue is to get the full shot of oil into the cylinder walls and the scrapper ring to get off just the right amount.

Spiking aluminum levels in engine oil analysis usually point to excessive aluminum piston or cylinder wear.

If you didn't race the engine using a heavier oil can reduce noise. Really high piston speeds don't like thick oil.

In a 1980's 318 V8 I used 20W50 (!!) oil to slow crankseal leaks even in cold weather, but I never raced it. With 10W30 oil, it puked at least 1 quart a day easy!!
 
Originally Posted By: Rand
Originally Posted By: HTSS_TR

The car doesn't have oil temp gauge and I don't have scan tool to measure oil temp so I don't know, but my guess is the oil temp is probably somewhat cooler at all engine speed.

You can display oil temp of your car, why not try xW20 to see if you will get lower oil temp and quieter engine ?

That is incredibly bad advice. You want him to run a tracked car that sees 300F oil temp on 20w? There would be no viscosity reserve and damage would result.

It might be ok for regular highway driving.

The reason I posted my opinion was he said "When I used to do a lot of track days", I understand this means he doesn't track his car lately, only normal daily drive.
 
Originally Posted By: i_hate_autofraud
Going to a heavier oil favors the main bearings, "bottom end" and the lubed valve train in general.

However, heavier oil detracts a little or a lot from lubrication at cylinder walls, piston rings, etc. The issue is to get the full shot of oil into the cylinder walls and the scrapper ring to get off just the right amount.

Spiking aluminum levels in engine oil analysis usually point to excessive aluminum piston or cylinder wear.

If you didn't race the engine using a heavier oil can reduce noise. Really high piston speeds don't like thick oil.

In a 1980's 318 V8 I used 20W50 (!!) oil to slow crankseal leaks even in cold weather, but I never raced it. With 10W30 oil, it puked at least 1 quart a day easy!!


Not that simple.

Plenty of engines that spec a 30 or 20 for street, spec a 50 for racing. Seems the 50 is not only free from harm, but does a better job at protecting an engine when racing.
 
It is true, the car is no longer tracked, but does still see a lot of extended high RPM operation. I don't drive it much, but when I do I really enjoy it.

The noise isn't timing chain/guide noise (I'm familiar with that noise), it is basically lifter noise. If the car had a timing belt, I would pull the cams and adjust the valves. Since it has a timing chain, I'm not even remotely interested.

An oil cooler probably would be the best solution, but at this point, the car is well past its prime and I do not want to spend unneeded money modifying it. I have no doubt that if I did nothing aside from feeding it the same M1 0w40 that is has been receiving, the engine will last longer than I need it to. But - if I can make it happier by something as simple as changing the oil - I'm all for it.

I put <6K a year on it, so at my current rate, it will be 2023 by the time I hit 200K. I don't foresee having this car in 2023. Although it hardly seems like I have had it for more than 10 years already.
 
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