Gain extra benefits by becoming a Supporting Member Click here find out how!
Classic Performance Products Classic Parts
American Auto Wire Classic Industries
Chevs of the 40sDanchuk Catalog
Hellwig Products IncPerformance Rod & CustomEcklers AutoMotive
Nu-Relics Power WindowsRain Gear Wiper Systems
Impala Bob's Bob's Chevy Trucks Bob's Chevelle Parts Bob's Classic Chevy



Username Post: Coolant in intake        (Topic#355563)
ah64 guy 
Poster
Posts: 61

Loc: Columbia , Mo
Reg: 01-01-10
03-10-19 06:49 PM - Post#2761777    

I have a 2000 Chevy Suburban with the 5.3L, It has 260K miles on it. At about 254K I was getting exhaust gas in the coolant system. I pulled the heads and had them planned and checked. Installed new head gaskets. Everything was good until about 1500 miles ago. It started loosing coolant and would not pressures the coolant system. I could not find any leaks and replaced the coolant cap with an OEM cap. I pulled the upper intake to check the crossover tubes where they connect to the rear of the heads and put better intake gaskets on. After getting it back together I noticed a small leak coming from the throttle body. I bypassed the throttle body coolant line. I had to remove the throttle body to get one of the lines off and found coolant in the intake. So I am at a point where I have no idea what to look for next. I appreciate all the help I can get.

95 GMC C1500 5.0L Long Bed (Was my Pappy's)
02 Ultra Classic
00 Chevy Suburban LT


 
ah64 guy 
Poster
Posts: 61

Loc: Columbia , Mo
Reg: 01-01-10
03-15-19 03:18 PM - Post#2762158    
    In response to ah64 guy

So after re-reading everything I posted I forgot to mention that I also rented a coolant pressure tester to check for leaks in the coolant system. I could not find any leaks but would loose about 1PSI every 5 minutes or so. Today I pulled the passenger side valve cover and it had a small amount of milky oil on the underside of the cover but the oil on the rocker assy was not milky. I talked to someone that suggested pulling the plugs to see if they were dry or looked like they had been wet with coolant. All of them were dry. This issue is driving me nuts. Would greatly appreciate any input.

95 GMC C1500 5.0L Long Bed (Was my Pappy's)
02 Ultra Classic
00 Chevy Suburban LT


 
someotherguy 
Senior Moderator
Posts: 28894
someotherguy
Age: 48
Loc: Texas
Reg: 08-01-03
03-16-19 06:13 AM - Post#2762215    
    In response to ah64 guy

Hope you don't have the porous head casting issue. There were some 5.3 heads that were known for it. Look up "Castech heads" as I'm not familiar enough with the problem to know what years it was a problem.

Richard

06 Silverado ISS / 06 Silverado SS / 06 300C SRT8


 
ah64 guy 
Poster
Posts: 61

Loc: Columbia , Mo
Reg: 01-01-10
03-17-19 04:19 PM - Post#2762317    
    In response to someotherguy

I have looked into it the TSB is for 2001-2006. When I had my heads machined I expressed this issue to the machinist and he said that he could pressure test them to check for this issue. I drove the suburban about 45 minutes yesterday and when I came back home it had pressure in the upper radiator hose, not hard pressure like it should have but was better than normal. It was up to temp on the gauge as well.

95 GMC C1500 5.0L Long Bed (Was my Pappy's)
02 Ultra Classic
00 Chevy Suburban LT


 
Icon Legend Permissions Topic Options
Report Post

Quote Post

Quick Reply

Print Topic

Email Topic

165 Views
FusionBB
FusionBB™ Version 2.1
©2003-2006 InteractivePHP, Inc.
Execution time: 0.114 seconds.   Total Queries: 17   Zlib Compression is on.
All times are (GMT -0800) Pacific. Current time is 10:23 PM
Top