Go Back   VetteMOD.com > VetteMOD Technical Discussion > Other Cars

Reply
 
Thread Tools
  #1  
Old 11-25-2015, 04:17 PM
VegasJen VegasJen is offline
United States | Formerly Known as Clutchdust
 
Join Date: Mar 2014
Location: In transition
Posts: 179
My Photos: (2)
Default Suburban burns oil. Rings or valves?

My 1994 burns oil and fouls plugs. There's 204k on the clock but the real mileage is anyone's guess. I got it for cheap because the PO overheated it and cracked both heads. I bought a pair of used junkyard heads and all I did to them was put new seals on. I freshened up the bottom end, put in new rings (cylinders were pretty clean), bearings, timing chain and oil pump but otherwise it's still pretty much stock.
The thing is I know it's burning oil, around a quart every 1000-1500 miles. It runs pretty well but when I idle for any length of time, like at a long traffic light, it runs pretty rough for the first 10-15 seconds of acceleration. After that, it runs as smooth as you would expect a 20 year old, 200k plus mile engine is going to run.
My guess is the valve guides/stems are worn and it's pulling oil past at high vacuum. Is there a way to check this theory? Any other suggestions?
Reply With Quote
  #2  
Old 11-25-2015, 11:39 PM
BBShark's Avatar
BBShark BBShark is offline
United States | Garage Monkey
 
Join Date: Mar 2008
Location: Right here
Posts: 4,308
My Photos: (257)
Default

wouldn't a leakdown test where you put a little oil in each cylinder tell you this?
__________________
Reply With Quote
  #3  
Old 11-27-2015, 01:09 AM
VegasJen VegasJen is offline
United States | Formerly Known as Clutchdust
 
Join Date: Mar 2014
Location: In transition
Posts: 179
My Photos: (2)
Default

I don't know. Would it? What do I need to do to test?
Reply With Quote
  #4  
Old 11-27-2015, 01:35 PM
BBShark's Avatar
BBShark BBShark is offline
United States | Garage Monkey
 
Join Date: Mar 2008
Location: Right here
Posts: 4,308
My Photos: (257)
Default

Here is a description where you listen to determine air leak. The oil in the cylinder test is supposed to "seal" the rings and if the cylinder does not leak down, you know it's the valves (sort of).

[Only registered and activated users can see links. Click Here To Register...]
Reply With Quote
Reply


Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT. The time now is 03:57 AM.
 


Design by: vBulletin Skins Zone
Powered by vBulletin® Version 3.8.5
Copyright ©2000 - 2018, Jelsoft Enterprises Ltd.