Little bit of a knock when cold after adding VSOT?

[Blue_Goose]

My 1ZZFE has always ran a little louder and more chattery with synths in there whether with Mobil 1, GC or now Pennz Plat.

This OIC I added 4 oz of LC20...no diff in the noise factor. About 500 miles into the change I added 4 oz of VSOT. Well, not only has the engine not quieted down that much it seems to have developed a bit of a knock at startup when the engine is cold....I think these engines have always been a bit noisey but I don't remember this noise before.

I think I read on another post that someone else also developed a cold weather knock at startup but he also added the whole bottle.

Could the VSOT be contributing(or the cause) to the knock noise? Bit paranoid as the engine seemed to be pretty smooth and quiet(er) with the Chevron in there.

Thinking about dumping the oil this weekend(only about 1.2k on it

) Even with the change would the VSOT still be "gunked" up in the engine and leave lots of residue behind? I plan on putting the last of my SL Chevron back in with quart of Havoline SL.

Why would the VSOT cause a knock(if it is?)


Goose

 

[Triple_Se7en]

According to Valvoline, a full bottle of VSOT still IMPROVES cold flow. What temps are defined by Valvoline as cold flow temps.... I dunno!

I have been running a half-bottle of VSOT and 5 oz LC with 4-1/2 quarts of 5W-30 Pennzoil Platinum with no issues or noises.

 

[savvy]

Sometimes our ears and memory can play tricks on us....... especially when you get to be my age : )

I've had absolutely no negative issues that I can determine using VSOT @ 1/2 oz per qt with my T&SUV. I think your 1 oz per qt is fine. The LC would tend to also thin your oil and VSOT somewhat.

I don't know how VSOT would interact with your specific oil, but I wouldn't think VSOT has gunked up your engine. If it makes you feel better, by all means dump the oil and start over.

 

[m2200b]

I'd just thin what you brewed to get through winter and this OIC. You could just pull the filter and add 0-20, 0-30 or, 5-20 as add back. Or you could dump it and pull even a full gt / 2 gt of thinner and just put the rest of your first 1200 OIC with VSOT in.

 

[shavenstringer]

"Sounds" like its time for Auto-rx.

 

[qadsan]

One point I'd like to make about this car is that it seems to work the tranny fluid pretty hard by 30K miles. I've changed the tranny fluid on our Matrix at 28K and it was a bit grimey & smelly. I've also changed the tranny fluid on two other Matrix's and the one at 20K looked OK, but the other one I did at 30K was grimey and smelly like mine.

It's an easy process for the DIY'r, especially if you have a helper to start and stop the engine at the needed times. Even changing the motor oil on this car is a piece of cake and the brakes are also quite easy

It's a great little car, even for tall people

 

[Dr. T]

Noise from the VSOT? Could be. Different chemicals, different interactions, different lubricative properties may cause the parts to function/behave differently contributing to different audible operating properties. Don't dump the oil though after 1.2k (ouch)...just hang in there...there is no harm from the cold start noise and is not abnormal if it goes away once engine warms-up.