0-30 GC cause knock or low compression?

Messages
20
Location
Malvern, PA
Since i put 0-30 GC in my car i have had some knock and my compression was slightly lower. Can oil effect compression or knocking? Anyone have experience. This is on a 4 cyl with a turbo. Thanks.
 

vad

Messages
1,856
Location
So Cal
Coincidence. Sounds like your engine has developed a serious mechanical problem. It has nothing to do with oil.
 

pa-sale

Thread starter
Messages
20
Location
Malvern, PA
I believe there is no mechanical issue. I put new gas in lastnight and it fixed almost everything. i had a 1/4 tank left of the old stuff so that is what i think is the reason. just wanted to see if the oil had anything to do with it.
 
Messages
2,338
Location
Charlotte Metro area
Different fuel won't affect compression. Did you mean boost? A prematurely detonating condition should result in the car's ECU dumping boost pressure, so it would not boost as much as it does when the correct fuel is being burned.
 
Correct - Had a friend with a nice BMW 330ci put some 87 octane gas in his car by mistake. The thing ran like crap - first time I've really experienced knocking. I believe there is a sensor that retards the spark so that a lower octane can be used without harming the engine. (Results in loss of power &/or knocking in high compression engines).
 

pa-sale

Thread starter
Messages
20
Location
Malvern, PA
fuel effects knock not compression. i had bad fuel. but i did hear that too thin of oil can cause or aid to knock and make it more apparent. i have an EXTREMELY sensative knock sensor, way more sensative than my ecu, so when it thinks it will knock i let off.
 
pa-sale - With my searching I do recall something about how some Turbo engines don't like GC 0w30 (I think it was a VW). Every engine is different I think. My engine seemed to run really hard on Mobil 5w30. When I put GC 0w30 in, it sounded a lot smoother and my MPG has gone up (when I am not racing).
 
Messages
2,493
Location
MSP 'burbs, MN
quote:
Originally posted by OriginHacker21: pa-sale - With my searching I do recall something about how some Turbo engines don't like GC 0w30 (I think it was a VW)
I think if you do a bit more searching you'll discover that far more VW/Audi turbo owners like GC in their car, versus the few that have indicated that they didn't care for it. I'm another turbo owner ('05 Subaru Impreza WRX STi) who uses and likes GC.
 
Yeah AndyH - I've come to the conclusion that the MAJORITY of Turbo/supercharged engines need/should use/use a good synthetic (GC 0w30). But I've seen several postings how their turbo ran like crack or whatever. Because of the heat synthetic should be used otherwise you'll be changing your baked oil a lot.
 
Messages
258
Location
Ft. Morgan, CO
Bad gas sucks. My dads taurus has been running kinda crappy, I think it is because of the <b>85</b> octane fuel here instead of 87, as 87 is the "plus" and 89 is the premium.(at most of the stations here anyway) It's b.s.
 
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