Knocking at Start up....Oil weight recommended???

[big_yosh]

For all you Tahoe experts........I recently bought a 1999 Chevy Tahoe LS 4x4 with 86,000 miles on it..........it's the newest car I have ever owned, I'm used to old Chevy cars and trucks so when I pop the hood everything is all new to me......but it is still a 350. Anyways I got it from a dealer and everything was fine until recently, when I start the engine it has a knocking noise coming from the drivers side of the engine and as it warms up it goes away....somebody recommended changing the oil and the gas that I use......so I did an oil change to 5W-30 as read on the oil cap and added some Lucas oil stabilizer and went from regular to premium........the knocking went away and it was good for a month.........I took a trip from L.A. to S.F. and back, and now the hoe started to knock again at start up. My question is What is the recommended oil weight for a truck with this mileage and what type of gas should I be putting in it, and does any of this have to do with the knocking or am I looking at an abnormal piston and cylinder wear?......... I had never had any problems like this with any of my old schools, an I have had my fair share. Has anyone had this problem? Other than that the bitch has heat:crazy:

 

[t.ebentheuer]

Is it a heavy knocking sound or more like a loud tap? might be a lifter sticking

 

[supergas5959]

one of the lifters is sticking.if it was rod bearings it would be constant.

 

[big_yosh]

Is it a heavy knocking sound or more like a loud tap? might be a lifter sticking

It's more like a loud tap, but as soon as the engine starts warming up it starts going away..........then it dissapears

 

[Rick90467]

It's more like a loud tap, but as soon as the engine starts warming up it starts going away..........then it dissapears

I'd go with the lifter as well at this point, it wouldnt hurt to take the cover off and compare them when its cold as one of them could be bleeding down. But, technology kind of left me behind in the mid 80's and I wouldn't be able to fix anything without the help of some of the great folks here on the forum

 

[95TwinTT]

For all you Tahoe experts........I recently bought a 1999 Chevy Tahoe LS 4x4 with 86,000 miles on it..........it's the newest car I have ever owned, I'm used to old Chevy cars and trucks so when I pop the hood everything is all new to me......but it is still a 350. Anyways I got it from a dealer and everything was fine until recently, when I start the engine it has a knocking noise coming from the drivers side of the engine and as it warms up it goes away....somebody recommended changing the oil and the gas that I use......so I did an oil change to 5W-30 as read on the oil cap and added some Lucas oil stabilizer and went from regular to premium........the knocking went away and it was good for a month.........I took a trip from L.A. to S.F. and back, and now the hoe started to knock again at start up. My question is What is the recommended oil weight for a truck with this mileage and what type of gas should I be putting in it, and does any of this have to do with the knocking or am I looking at an abnormal piston and cylinder wear?......... I had never had any problems like this with any of my old schools, an I have had my fair share. Has anyone had this problem? Other than that the bitch has heat:crazy:

I know General Motors suggests 5W-30 for these engines, but it does not make any sense unless you are in Siberia. The knocking when cold that lasts for about the first 1/4 mile as you drive away, is very common, with 5W-30.

I'm sure if you change to 10W-30 you will find the knock goes away. The new corvettes come with Mobile One 5W-30 to hide the knocking. That little bit of information was passed on to me from a general manager of a chevrolet dealership.

I'm not convinced that the multi viscosities work that well. I run straight weight 30w in the summer and 10W in the coldest part of the winter. That winter being in Minnesota, where minus 30 degrees is possible.

Synthetic oils both engine oil and transmission oil hold the viscosity more accurately. I use synthetic tranny fluid for better performance when hot.

These trucks are also set up for regular unleaded, 87 octane. Anythig higher that that is wasting $.

 

[96ProCompTahoe]

i have the knocking when it gets cooler outside, like below 50 degrees, that goes away when it warms up. running 5w30.

i've talked to several other people locally and they all seem to have the "knock" when its cooler outside.


I've been told a few times i have a rocker knocking, but wouldn't it do it all the time?

 

[big_yosh]

I want to thank all of you who posted back..........I guess that I'll stick to 10w 30 like I have with all my other rides, I just so want to pamper my hoe so much.....You all know what I'm talking about?!........when I have some free time I'll take a look under the valve covers to see whats going on under there..........This was the first time I posted on a forum and I loved the feedback, Thanks a lot guys!!!!!!!!!!:thumbsup:

 

[deputy184]

knocking

Mine knocks to sometimes. I add about a cup or 2 of marvelous mystery oil to my oil and it helps a lot. about 3 months. usually by that time it is time for an oil change any way. It doesnt hurt it and the tapping goes away.