Mechanic put 10W-30 in my engine instead of recommended 5W-30
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From: Broomall, PA
Car: 1992 Chevrolet Camaro RS; 1986 Oldsmobile Cutlass Ciera Brougham
Engine: LH0 3.1 Liter V6; YBN 2.8 Liter V6
Transmission: TH-700-R4; TH-440
Mechanic put 10W-30 in my engine instead of recommended 5W-30
Hey guys,
I noticed today that the mechanic put 10W-30 in my car last week when it went for an oil change. This is written on a little sticker on my rad support that they put everytime its serviced. My problem is, the cap says 5W-30. Guess he didn't read the cap, oh well.
I noticed today that the mechanic put 10W-30 in my car last week when it went for an oil change. This is written on a little sticker on my rad support that they put everytime its serviced. My problem is, the cap says 5W-30. Guess he didn't read the cap, oh well.
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From: USA
Car: yy wife, crazy.
Engine: 350, Vortecs, 650DP
Transmission: TH-350
Axle/Gears: 8.5", 3.42
It's OK.
The '5' in the '5W-30' is as thin as it'll get. Basically it'll thin to 5 weight when it's below 0* F IIRC. 10 weight is good until 0* and above.
So unless you suspect you'll see the low side of 0* often, it'll be fine.
AJ
The '5' in the '5W-30' is as thin as it'll get. Basically it'll thin to 5 weight when it's below 0* F IIRC. 10 weight is good until 0* and above.
So unless you suspect you'll see the low side of 0* often, it'll be fine.

AJ
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Joined: Jan 2002
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From: Broomall, PA
Car: 1992 Chevrolet Camaro RS; 1986 Oldsmobile Cutlass Ciera Brougham
Engine: LH0 3.1 Liter V6; YBN 2.8 Liter V6
Transmission: TH-700-R4; TH-440
So if he put it in my car (5W-30) do you think it would have more of a tendency to leak?
I dont think there is that much of a difference in weights. I dont think it would cause it not to leak. I always used 10w-30 in my 305 but with the brand new 350 I think I used 5w-30 valvoline synthetic and a k&n filter. Its getting synthetic only for now on since its brand new.
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Car: 99 Formula
Engine: LS1
Transmission: T56
Axle/Gears: 342
Yup, I put 10w-30 in my GF's Blazer and she bitched at me, "look it says 5w-30 only"
I'm like, it'll be fine, geesh.
I'm like, it'll be fine, geesh.
I wouldn't worry about it. The temp ranges for 5W-30 and 10W-30 have a large overlap. I run 10W-30 in CA in the summer and 5W-30 in the winter in CO. If the mechanic used conventional oil you shouldn't have to worry about leaks (sometimes a conventional to synthetic which can bring on leaks).
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From: Littleton, CO USA
Car: 82 Berlinetta/57 Bel Air
Engine: L92/LQ4 (both w/4" stroke)
Transmission: 4L80E/4L80E
Axle/Gears: 12B-3.73/9"-3.89
Although a 5W will be slightly thinner than a 10W (and there is some overlap, as mentioned above), the biggest difference is that 5W oils must have a pour point of no higher than -20 degrees F, whereas there is no such requirement for 10W oils. As long as you don't try to start the car when it is cold-soaked below -20 F, you shouldn't have a problem.
Most synthetic 10W oils have a pour point below -20 F, anyway, but I wouldn't guarentee all of them do (AMSOIL, Mobil 1, yes).
Most synthetic 10W oils have a pour point below -20 F, anyway, but I wouldn't guarentee all of them do (AMSOIL, Mobil 1, yes).
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From: Central NJ, USA
Car: 1986 Firebird
Engine: 2.8 V6
Transmission: 700R4
Before I knew about the distributor o-ring leak (o-ring dries up and you get an oil leak down the back of the engine block), I had a small/slow oil drip. My dad suggested I run 10w30 to minimize the oil leak while the car sat overnight... seemed to have worked. Since then, I've always used 10w30 instead of 5w30. Doesn't get quite that cold in NJ, anyway... cold, yeah, but not enough to require 5w30 (in my opinion)...
The mechanic might just have a big drum of 10w30 oil with one of those sweet automatic pumps; every car you bring in might get 10w30. That setup's on my Christmas list but I doubt I'll get it
The mechanic might just have a big drum of 10w30 oil with one of those sweet automatic pumps; every car you bring in might get 10w30. That setup's on my Christmas list but I doubt I'll get it
Originally posted by TomP
Before I knew about the distributor o-ring leak (o-ring dries up and you get an oil leak down the back of the engine block), I had a small/slow oil drip. My dad suggested I run 10w30 to minimize the oil leak while the car sat overnight... seemed to have worked. Since then, I've always used 10w30 instead of 5w30. Doesn't get quite that cold in NJ, anyway... cold, yeah, but not enough to require 5w30 (in my opinion)...
The mechanic might just have a big drum of 10w30 oil with one of those sweet automatic pumps; every car you bring in might get 10w30. That setup's on my Christmas list but I doubt I'll get it
Before I knew about the distributor o-ring leak (o-ring dries up and you get an oil leak down the back of the engine block), I had a small/slow oil drip. My dad suggested I run 10w30 to minimize the oil leak while the car sat overnight... seemed to have worked. Since then, I've always used 10w30 instead of 5w30. Doesn't get quite that cold in NJ, anyway... cold, yeah, but not enough to require 5w30 (in my opinion)...
The mechanic might just have a big drum of 10w30 oil with one of those sweet automatic pumps; every car you bring in might get 10w30. That setup's on my Christmas list but I doubt I'll get it
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From: SE Michigan
Car: Bright Red 91 GTA
Engine: CARBED LT4
Transmission: MK6
25 years ago before i was born my dad had a jeep that had an oil leak...so he put in some 50weight...that winter he tried to crank it and it broke the timing chain
i thought that was funny when he told me that...
dude 1030 is cool
i thought that was funny when he told me that...
dude 1030 is cool
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From: WI,USA
Car: 89 FORMULA 350, 91 Z28 Convertible
Engine: ls1, LB9
Transmission: t56, Auto
Axle/Gears: S60/ 3.73
yep, just check your owners manual it will show a graph and basically repeat whats above
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From: Rock Hill, SC
Car: 1999 Pontiac T/A Firehawk
Engine: ***'s Engine
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I actually don't use 5w30 on anything. I much prefer 10w30... the less viscosity modifiers in the oil, the better, I always say. That and my LS1 has a nasty tendency to burn 5w30 synthetic....
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From: England UK
Car: 85 Z28
Engine: LG4 modified
Transmission: 700R4
If you think about it, the cap is the same age as the car. Therefore 5w30 would be ideal when the car was new, but after 15-20 years of wear and tear a thicker oil like 10w30 would in fact be better.
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From: Johnstown, Ohio
Car: 84 Z28
Engine: 355 (fastburn heads, LT4 HOT cam)
Transmission: 700R4
Axle/Gears: 9-bolt, 3.27
Am I the only one that runs 10-40 here? I have 10-30 in my S-10 right now and it really doesn't like it (I really don't like TBI 2.8's anyway). In the Camaro, I always run 10-40, primarily due to age and mileage, and the oil pressure stays right at about 30 (have to consider the accuracy of a stock gauge). As for the Intrepid, I'm being very careful, they have enough troubles with the bottom end on the 2.7 to scare me!
For an loder vehicle such as a thirdgen, I wouldn't be overly concerned, but some of the newer engines, primarily Imports (Ford 4 cyl is a MAzda, and therefore is Import) the wrong oil can be detrimental, and kill the engine. Not so much the weight of the oil, but more on the API ratings.
For an loder vehicle such as a thirdgen, I wouldn't be overly concerned, but some of the newer engines, primarily Imports (Ford 4 cyl is a MAzda, and therefore is Import) the wrong oil can be detrimental, and kill the engine. Not so much the weight of the oil, but more on the API ratings.
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