Different oil brand & different idle

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Charlotte, NC
I've been running 5w-20 PU in my car since I've bought it. It was normally available at the local Walmarts, but it became unavailable. (I can do site to store now, but at the time that option wasn't available on their site for PU.) Anyway, I figured I could run Supertech 5w-20 synthetic for one interval until I could get a hold of PU again and not miss a beat. Also, I figured it might be an opportunity to find a hidden gem. Well, since I've put the stuff in my car, I notice that sometimes my car idles a bit "hard" and the idle will fluctuate. It has settled down some as I've driven it more, but it's still not like it was prior to the fill. Also, I noticed that the engine isn't as quiet as it was with the PU. Moving forward, I'll be going with QSUD or PP when I can't find PU since it was factory filled with Quaker State. I figured I'd experiment this one time. My question here is has anyone ever experienced something like this? I read reviews on Walmart's website for the ST synthetic oils and I saw another review that mentioned the same characteristics. I've always had a great deal of appreciation for the conventional and high mileage ST motor oils, but I'm feeling like I need to dump this stuff out as soon as possible since I'm not totally satisfied with it. I wish I could get my money back for this oil and get reimbursed for my OEM filter, but I don't think there's a way that can happen. Anyway, what are your thoughts?
 
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Clovis, CA
Originally Posted By: qdeezie
Also, I noticed that the engine isn't as quiet as it was with the PU.
That's a dead giveaway right there that the oil is too thin.
Originally Posted By: qdeezie
My question here is has anyone ever experienced something like this?
Yes, but I've had the opposite experience - my engine has never been smoother and quieter since switching to SuperTech full synthetic.
 
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I suppose the only way to confirm is to switch back to the oil you used before and see if it still happens. My guess is that it's always happened and you never noticed, or that it is a new phenomenon that won't go away with different oil. I just can't imagine that the oil brand (of reasonably quality) could make such a difference.
 
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Oil and filters are cheap; sanity is not. If you can hear it and will be thinking about it every time you drive the car, just change them. The filter is less expensive; start with that. It sounds like you moved from an OEM filter? I seem to recall that Hyundai engines seem to "prefer" the OEM filter. If you installed an aftermarket filter, try an OEM one first. If it's still not what you like, just drain the oil and pour in what you like. Sure, you'd save 30 bucks by keeping what you have in it now in for the whole oil change interval. To me, not enjoying your vehicle for another 5,000 or 7,500 miles or whatever your change interval is isn't worth 30 bucks.
 

qdeezie

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Originally Posted By: Merkava_4
That's a dead giveaway right there that the oil is too thin.
Based on this feedback alone, I'm going to drain it immediately.
Originally Posted By: Merkava_4
Yes, but I've had the opposite experience - my engine has never been smoother and quieter since switching to SuperTech full synthetic.
I was hoping for the same thing because I've always had great luck with SuperTech and I am a bit disappointed in this case. I'll still continue to use their conventional and high mileage where I see fit, though.
 
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qdeezie

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Originally Posted By: EdwardC
I suppose the only way to confirm is to switch back to the oil you used before and see if it still happens. My guess is that it's always happened and you never noticed, or that it is a new phenomenon that won't go away with different oil. I just can't imagine that the oil brand (of reasonably quality) could make such a difference.
I wish this was the case, but it is a drastic enough difference to notice. When the idle fluctuates at a stoplight, it feels like the car is going to "lurch ahead" at times. It wasn't doing that prior to the oil change.
 

qdeezie

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Originally Posted By: Hokiefyd
The filter is less expensive; start with that. It sounds like you moved from an OEM filter? I seem to recall that Hyundai engines seem to "prefer" the OEM filter. If you installed an aftermarket filter, try an OEM one first. If it's still not what you like, just drain the oil and pour in what you like.
I'm using an OEM filter based on that service bulletin. I bought a sleeve of 10 filters from the dealer when I first bought the car so I wouldn't have to run to the dealer each time I changed the oil.
Originally Posted By: Hokiefyd
Sure, you'd save 30 bucks by keeping what you have in it now in for the whole oil change interval. To me, not enjoying your vehicle for another 5,000 or 7,500 miles or whatever your change interval is isn't worth 30 bucks.
I agree. I'm going to go ahead and drain it out because as you mentioned, I am definitely not enjoying what I'm experiencing at this point.
 
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I have had no issues running ST-S.How an oil can effect the efi/timing of an engine to make it run rough is beyond me....
 
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Originally Posted By: qdeezie
Originally Posted By: Merkava_4
That's a dead giveaway right there that the oil is too thin.
Based on this feedback alone, I'm going to drain it immediately.
Really? Ok it is your call, but in your case I would double check things under the hood, vacuum, electrical connections, etc. No way does an oil change alone change your idle.
 
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quebec canada
I feel similar!i had mobil (whatever nissan dealer fill it when they recieve a new car!then i baught my self a mobil ep 5w20 synth .instead of a 5w30 conventional.since the change?at idle (less then 1000 rpm,i hear gravel sound (best description i can think of)like once every 5 to 15 second but its always there ,like something is chewing at my engine innard(gnome or dwarf miner maybe)joke aside,you can be sure i ll move to valvoline premium conventional 5w30 or synpower 0w30(if it exist)i dont like the taught of gold digger in my motor
 
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Ontario , Canada
Originally Posted By: qdeezie
Originally Posted By: EdwardC
I suppose the only way to confirm is to switch back to the oil you used before and see if it still happens. My guess is that it's always happened and you never noticed, or that it is a new phenomenon that won't go away with different oil. I just can't imagine that the oil brand (of reasonably quality) could make such a difference.
I wish this was the case, but it is a drastic enough difference to notice. When the idle fluctuates at a stoplight, it feels like the car is going to "lurch ahead" at times. It wasn't doing that prior to the oil change.
Sounds like something more then just a simple change of oil causing that ! Which car is it ? Could be as simple as a vacuum hose leaking that might have been touched during the oil change .
 
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28,123
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Regina, Saskatchewan, Canada
Originally Posted By: qdeezie
Originally Posted By: Merkava_4
That's a dead giveaway right there that the oil is too thin.
Based on this feedback alone, I'm going to drain it immediately.
He's using a watery, ILSAC rated 10w-30, the HTHS of which is perilously close to that of a 20 grade anyhow. wink
 

qdeezie

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I'm posting this months after the fact, but the end result was that I drained the Supertech Synthetic and went back with Pennzoil Ultra and the car ran and sounded the way it had been prior to the Supertech oil change, so the oil in fact, was the problem.
 
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Did you change the filter as well? I'd bet that any problem related to your ST experience was caused by a bum filter and not the oil.
 

qdeezie

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Originally Posted By: fdcg27
Did you change the filter as well? I'd bet that any problem related to your ST experience was caused by a bum filter and not the oil.
Yes, I changed the filter as well. It could have been a bum filter. In the interest of full disclosure, I do remember hearing a slight startup rattle at times, even though it was an OEM filter.
 
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