What Oil To Quiet Me Down?

[Jakegday]

hello all. i just did the an oil change on my 81 fairmont. 113,000 miles. for the winter time it had MC5k 5w30 with a bottle of STP. now that i changed it to MC5k 10w30 with a bottle of STP, i have a start up knock. the knock starts after about 20-30 seconds and lasts a couple minutes. i thought maybe the warmer weather might have something to do with it, but this issue didnt exist last summer. i understand i have a 30 year old engine and some start up knock is probably "normal" at this point, however i would like to help it as much as possible. if that means spending $30 on a jug of a full synthetic, so be it.

so guys, what are your suggestions?

 

[DieselTech]

81 mont= HDEO such as rotella 15-40 or delvac

 

[Warstud]

Remove the STP..

 

[biodiesel]

Both those suggestions are spot on. Get that STP [censored] out of there and use a robust oil. The Shell Rotella 15-40 is perfect.

 

[Velo_Fello]

I have a shot engine that has horrible startup knock on conventional oil.

But it goes away with ester-based synthetic oil, such as Redline. It's expensive and hard to find, though.

Another possibility is Royal Purple or Mobil One; they both have a bit of Group V esters.

Of course, you could just go whole hog and use Motul motorcycle oil; easy to find at bike shops, but $15 a quart.

 

[Texan4Life]

I would try a 15w40 HDEO before anything else. I would also skip on the STP

 

[Steve S]

Synthetic won't buy you anything.

 

[DieselTech]

Im not familiar with RP or many M1 products that have quite a bit of ester in them.

 

[Garak]

Originally Posted By: Texan4Life
I would try a 15w40 HDEO before anything else. I would also skip on the STP


+1

15w-40 quieted up my old 4.9L before I got it rebuilt. As an added suggestion, considering you're in a place that gets cold enough winters, try Valvoline MaxLife 5w30 in the winter. It helped the motor run as quietly (and with as few leaks) as the HDEO did, and it did the trick when it was -40.

 

[fdcg27]

If you have a start-up knock now, and had none before, the oil filter should be your first suspect.
Change it and see what happens.
Use the same brand/type you used before.
If you are already doing that, you may simply have a bad one.
It happens.
If you think you need a thicker oil for summer, go with the guys above and use a 15w40 HDEO, not STP.
These oils are great values.
There is even a Motorcraft oil available in this grade, along with Rotella, Delo, Devac, Tection and a host of others.
Figure around $11.00/gallon.

 

[mechtech2]

If you have a start up knock [not a rattle] it sounds like a rod knock.
The crank and/or bearings are worn.
Thin oil won't help.
Baby it - no high revs or full throttle.

I wonder if using STP in the winter caused oil starvation and puked your bearing?

 

[Kiwi_ME]

Perhaps the oil pump intake screen is clogged?

 

[Triple_Se7en]

Originally Posted By: Jakegday
hello all. i just did the an oil change on my 81 fairmont. 113,000 miles. for the winter time it had MC5k 5w30 with a bottle of STP. now that i changed it to MC5k 10w30 with a bottle of STP, i have a start up knock. the knock starts after about 20-30 seconds and lasts a couple minutes. i thought maybe the warmer weather might have something to do with it, but this issue didnt exist last summer. i understand i have a 30 year old engine and some start up knock is probably "normal" at this point, however i would like to help it as much as possible. if that means spending $30 on a jug of a full synthetic, so be it.

so guys, what are your suggestions?


Change to a better oil filter -- one that has a silicone ADBV.

 

[Jakegday]

Originally Posted By: Triple_Se7en


Change to a better oil filter -- one that has a silicone ADBV.


it has a pureone on it right now. im going to try rotella T and see what happens

 

[fdcg27]

Change the filter before you change anything else.
Install a Motorcraft, and see what happens.
If what mechtech2 describes has actually happened, no oil will save you.

 

[Robenstein]

German Castrol quieted my motor down.