Is there any theory as to why every time I try a conventional oil in my Nissan Z32 the engine becomes very loud valve train wise vs when I use synthetic and it seems smoother? My only guess is that conventional oil has a harder time filling up my hydraulic lifters compared to synthetics. I have used Pennzoil and Valvoline and both make my engine develop a constant knocking.
Noisier engine with conventional vs synthetic
- Thread starter ChattZX
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Unless you measured the underhood decibel levels comparing the two oil types, I think there's a placebo effect going on.
With today's API standards on most brands and oil weights, the line between synthetic (especially Group III synthetic) and conventional is being blurred.
The Valvoline and Pennzoil you used are excellent oils and they are good to 5k in most conditions, as long as you don't have a fuel dilution problem.
With today's API standards on most brands and oil weights, the line between synthetic (especially Group III synthetic) and conventional is being blurred.
The Valvoline and Pennzoil you used are excellent oils and they are good to 5k in most conditions, as long as you don't have a fuel dilution problem.
Lol, no it seriously sounds like the motor is about to throw a rod on conventional oils. As soon as I put in Mobil 1 or Shell rotella T6 it runs beautifully. It's a constant knocking and I mean very noticeable knocking at idle. It won't run any different its just loud.
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Originally Posted By: ChattZX
Isn't valve train noise a sign to increase the weight of the oil viscosity? Maybe in conventional it needs a heavier weight.
No.
You need to consult your oil pressure gauge if you have doubts about your oil viscosity. If it's holding minimum pressure requirements at hot idle, there is no need to increase viscosity. Blindly switching to a more viscous oil will sacrifice cold start protection.
If it makes you feel better, you can try a ZDDP additive such as STP oil treatment.
Isn't valve train noise a sign to increase the weight of the oil viscosity? Maybe in conventional it needs a heavier weight.
No.
You need to consult your oil pressure gauge if you have doubts about your oil viscosity. If it's holding minimum pressure requirements at hot idle, there is no need to increase viscosity. Blindly switching to a more viscous oil will sacrifice cold start protection.
If it makes you feel better, you can try a ZDDP additive such as STP oil treatment.
Originally Posted By: Highline9
Are you sure that engine has hydralic lifters?
Lol yes, I know just about everything about 300ZX's. I just cant narrow down what this dang noise is. Its not loud enough to be rod knock, maybe a bit of piston slap?
Are you sure that engine has hydralic lifters?
Lol yes, I know just about everything about 300ZX's. I just cant narrow down what this dang noise is. Its not loud enough to be rod knock, maybe a bit of piston slap?
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That engine sounds messed up. I don't know why it would be insensitive to viscosity but sensitive to synthetic or not.
usually people say their engines are louder on synthetic especially the older gm slappers.. I notice when i use syn on my sons 91 3.1 its much worse with syn
The engine is fine and pulls like a train. Its just sensitive to conventional oils, idk why. It could also be the variable timing gears. Also that noise goes away completely after a hard drive for about 20 minutes. I was just wondering if anyone else has experienced this issue with conventional oils.
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Originally Posted By: ChattZX
Here is a video of the engine at idle.
That knocking/tapping sound are the VTC (vaiable valve timing) gears (all 1990-1995 Z32s had them. The 1996 doesn`t). Don`t worry Chatt,nothing`s wrong with your engine. You`re just going to have to replace the VTC gears.
As to the oil,I find that 50 weights definitely run smoother. Alot of TT.NET guys run 20W50. I want a good oil somewhere between a 10W40 and 20W50,hence why 5W50 will be my next to see how she likes it. I have a case of PP 5W50 and I`m going to buy some Syntec 5W50 tomorrow while it`s on sale at Oreilly. I`m going to do a search on Quaker State 5W50 tomorrow sometime too. My friend here who has a built of twin turbo uses Quaker State conventional 10w40 and it runds smooth as silk! He had cold start-up lifter tick on Mobil 1 10W30 and *none* whatsoever on the Quaker State dino. He says it pulls harder and smoother on the QS too. I just think all engines are different and "prefer" different oils :^)
Here is a video of the engine at idle.
That knocking/tapping sound are the VTC (vaiable valve timing) gears (all 1990-1995 Z32s had them. The 1996 doesn`t). Don`t worry Chatt,nothing`s wrong with your engine. You`re just going to have to replace the VTC gears.
As to the oil,I find that 50 weights definitely run smoother. Alot of TT.NET guys run 20W50. I want a good oil somewhere between a 10W40 and 20W50,hence why 5W50 will be my next to see how she likes it. I have a case of PP 5W50 and I`m going to buy some Syntec 5W50 tomorrow while it`s on sale at Oreilly. I`m going to do a search on Quaker State 5W50 tomorrow sometime too. My friend here who has a built of twin turbo uses Quaker State conventional 10w40 and it runds smooth as silk! He had cold start-up lifter tick on Mobil 1 10W30 and *none* whatsoever on the Quaker State dino. He says it pulls harder and smoother on the QS too. I just think all engines are different and "prefer" different oils :^)
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Quote:
Noisier engine with conventional vs synthetic
Usually it's the other way around.
Noisier engine with conventional vs synthetic
Usually it's the other way around.
Originally Posted By: aquariuscsm
Originally Posted By: ChattZX
Here is a video of the engine at idle.
That knocking/tapping sound are the VTC (vaiable valve timing) gears (all 1990-1995 Z32s had them. The 1996 doesn`t). Don`t worry Chatt,nothing`s wrong with your engine. You`re just going to have to replace the VTC gears.
As to the oil,I find that 50 weights definitely run smoother. Alot of TT.NET guys run 20W50. I want a good oil somewhere between a 10W40 and 20W50,hence why 5W50 will be my next to see how she likes it. I have a case of PP 5W50 and I`m going to buy some Syntec 5W50 tomorrow while it`s on sale at Oreilly. I`m going to do a search on Quaker State 5W50 tomorrow sometime too. My friend here who has a built of twin turbo uses Quaker State conventional 10w40 and it runds smooth as silk! He had cold start-up lifter tick on Mobil 1 10W30 and *none* whatsoever on the Quaker State dino. He says it pulls harder and smoother on the QS too. I just think all engines are different and "prefer" different oils :^)
Okay good, I was just wondering why it changes the noise depending on the oil I run though. I knew my VTC gears needed replaced so I'm just glad its not actual engine related
and thanks for the new oil recommendation man!
I'll try out that next oil change.
Originally Posted By: ChattZX
Here is a video of the engine at idle.
That knocking/tapping sound are the VTC (vaiable valve timing) gears (all 1990-1995 Z32s had them. The 1996 doesn`t). Don`t worry Chatt,nothing`s wrong with your engine. You`re just going to have to replace the VTC gears.
As to the oil,I find that 50 weights definitely run smoother. Alot of TT.NET guys run 20W50. I want a good oil somewhere between a 10W40 and 20W50,hence why 5W50 will be my next to see how she likes it. I have a case of PP 5W50 and I`m going to buy some Syntec 5W50 tomorrow while it`s on sale at Oreilly. I`m going to do a search on Quaker State 5W50 tomorrow sometime too. My friend here who has a built of twin turbo uses Quaker State conventional 10w40 and it runds smooth as silk! He had cold start-up lifter tick on Mobil 1 10W30 and *none* whatsoever on the Quaker State dino. He says it pulls harder and smoother on the QS too. I just think all engines are different and "prefer" different oils :^)
Okay good, I was just wondering why it changes the noise depending on the oil I run though. I knew my VTC gears needed replaced so I'm just glad its not actual engine related
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Possibly after 22 yrs you might develop some sound like that. I think 22yrs more than the oil should be considered.
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