View Full Version : 5w 30 oil and valve train noise

06-17-2008, 05:35 PM
gents have any of you experienced valve train ratteling on deceleration when running 5w 30 weight oil?:mad:

06-17-2008, 08:30 PM
I dont know which motor you have, but in a USA summer 5w-30 is simply too thin an oil for most motors, no matter what the owners manual says..

The KA needs a bit thicker anyway due to bigger clearnaces and the SR, RB and CA are usually turbo and need thicker simply fo that reason.

try a 0w/5w/10w-40 or if turboed a Mobil11 15w-50.

If you have a turbo and go with M1 15w-50 it wont degrade on youa s quickly as some otehr oils either.

A good summer oil for the money and hard driving while staying at half price or less of Mobil 1 is Valvoline Durablend in 10w-40.


06-17-2008, 08:48 PM
I am currently using the syntec 10-40 and am very very happy with it!

06-17-2008, 08:50 PM
thats another good choice.:)

06-19-2008, 08:04 AM
I put 5w-30 in my SR S14 for about 3 days but I was worried by the noises so I dropped it out for some 10w-40. It did run pretty well though, just too thin for warm temps.

06-19-2008, 10:46 AM
I run VR1 50W Race oil.... I maintain higher oil pressure for longer since I changed from M1, and its only 2.79 qt not 6.99 qt .. sooo.. me likey!!

06-19-2008, 03:16 PM
Im headed out to buy some VR1 50w.. Where did you buy it? I assume valvoline makes that right?

06-19-2008, 04:06 PM
Its a valvoline race formulation in 20w-50

Definetly a summer only oil, if you get cold nights in your area I would consider not using it.. also true race formulations have little or no rust inhibitors or detergents..
Consider that.

M1 in 15w-50 will be superior in a daily driver.

if you have a weekend of auto Xing and will drain it afterward, yes then the VR1 will be a better choice.

06-19-2008, 09:12 PM
^^ good point too.... I do change my oil about every 500-800 miles. soo...

06-20-2008, 03:17 PM
You can always chose which brand you want to run and call them and tell them your clearances. They will tell you what they recommend. Going off oil temps and pressures I really think going any thicker than 10w-30 in most cases is too thick. Higher pressure does not mean better. If you have a decent idle pressure 11psi or greater when hot that is really about what you want. Its better to have an oil that can get into all the small spots rather than an oil that has higher pressure but is too thick to coat the bearings and other tight clearances. I test oil for a living and see way too many people always think high pressures are better. All that means if you oil system has to work harder to push the oil around and working your seals harder. And most likely on startup which is one of the hardest times on an engine that the oil is really thick and will cause premature bearing wear. I think 10-30 is a great summer oil and would run the thinest oil you can without too low of pressure.

Also remember that all oils are not the same and that some have linear viscosities and some do not. I always use Mobil 1 10W-30 and its a great oil. It can take very high temps before it breaks down. That being done in my lab not my car!

06-20-2008, 03:59 PM
Oil test I found a while back on another forum. My buddy had a problem in his H22 with the rocker pads and since switching to royal purple has no more problems. After seeing this test it really makes me wanna run royal purple in everything.



06-20-2008, 04:17 PM

Many oil test on bobistheoilguy seem to show that ticiker oils vs the more popular thin ones seem to do better with wear.

I think we have empriical data on this.

summer temps will also raise oil temps therefore lower viscosity of an oil. if you start out with a thicker oil you wll ahve much better HTHS values...

a turbo car in a USA summer needs an oil more than 5w-30..

Keep in mind many of those motors are recommended in other countries with thicker vicosities
There 10w-40 being a mid range oil and 15-w50 not particularily thick as even thickr is us.

thicker is not always better of course.

Its a balance between the needs of the bearings and the rings during running ( too thin and the oil wont protect, too thick and it wont get in there enough) and otehr parts like cams etc during start up ( need thin for startup).

Clearances modify these things often as well.

And while anectdotal evidence is just that a friends Evo always had issues on factory recmended weight but when he went wiht Mobil1 15w-50 ( he sometimes autoXes) he was fine.


06-22-2008, 10:42 AM
Oil test I found a while back on another forum. My buddy had a problem in his H22 with the rocker pads and since switching to royal purple has no more problems. After seeing this test it really makes me wanna run royal purple in everything.


MarcusIs it me or does every 0w- oil in the test faired poorly, while 10w-40 and up held up well? I'm sure that RP makes great oil, but they should have tested the 0 weight as well. Makes me wonder if their testing machine is more or less geared towards one specific parameter, and does not represent all the challenges that conventional oil has to deal with.

06-22-2008, 01:59 PM
And dont forget folks its not for nothing that mchaines like BMW M3 requires castrol TWS 10w-60 and Ferraris similiar exotic 60 weights

06-23-2008, 03:21 PM
I really don't have any problems with thicker oils at warm temps but from my testing, as well as real world experience from myself and other that build and race the cold temp viscosity is what really kills motors. Granted if you live somewhere really warm a 15W would be fine. But I don't think for a daily driver of any kind that going any thicker than a 10W is beneficial. If you have more of a race setup with larger clearances than a 15W or even a 20W would be fine. The only reason for my stating what I did above is too many people that don't understand oil think that having high pressure is a great thing. And so they run thick oil to achieve that, and end up adding to the stress on the oil system as well as the engine. If I get a chance one of these days I'll grab some of each of the major brands and do some viscosity curves and post them on here.

I get the opportunity to go to an engine lab in the next few weeks and they actually design and test motor oil. All they do is make new formulations, add it to an engine on the dyno and run them till they blow up or break down a few with a 1000 miles and check for wear. They claim that there is almost no way that even a cheap oil is not almost exactly the same performance wise because of the strict ASTM standards for motor oil. I can't wait to go play with it.

06-23-2008, 07:54 PM
I've used Mobil 1 5-15 in my s15 since 5,000 klms Oil changed at least every 2500klm's. It's done 40,000K mainly driven on the street and some circuit work which usually consists of 20 - 30 mins at a time. It's stock save for a 3 inch exhaust and dump pipe. I didn't run an oil cooler.

Mt tuner has just pulled the head off and stripped the head. To my surprise there is scuffing in the cam journals in the head. Blackened lines around circumference of the cam journals where the oil flows onto the journal. Black stains also in the timing chain cover. Pads on the rockers are fine as are the lobes on the cam. Bores are perfect and cross hatching still evident on the bores.

My tuner said wear in the head is all evident of oil overheating and breaking down - more than likely from the lengthy stints at the circuit. I think the head is also the last part of the engine to receive flow so oil will be at its hotest.

In summary, you can put decent oil in your car but if the oil overheats -protection against wear is compromised even in a stock engine.

Along with a host of other things I now have greddy sump and greddy oil cooler going in. Now using Motul 10 - 40 based on my tuners recommendation. FWIW he's never rated Mobil 1 that highly based on the engines he's torn down.

Also found "another one of those oil tests" for what its worth - where Mobil 1 doesn't fair too badly.


06-24-2008, 05:48 PM
There were some good posts about oil for SRs on this board in the past. With a decent oil cooler your oil temps will be pretty low, and I think an oil thinner than a 15W50 will be in order for cold starts. For track use you probably don't want to run without an oil cooler, but on the street it may be counterproductive as you'll be overcooling. Even the thermostat sandwich plates let some oil flow to the cooler below the activation temp.

06-24-2008, 07:31 PM
late edit: I used 5 - 50 Mobil 1 .......not 5 - 15 as previously posted.