Last post on May 03, 2013 at 7:11 AM
You are in the Chevrolet Silverado & GMC Sierra
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GMC Sierra 1500, Truck
#40 of 79 (help) thermostat
Jan 31, 2008 (2:26 pm)
whats involved with the replacement of thermostat on 2000 gmc z\71 5.3 litter: maybe someone can help me with this.on regular days with outside temps 70 are above,I get average mileage,as average as you can get with a 4x4,but on the way to the lease with temps in the 30's and below,I pass everything but the gas station,I use twice the fuel there and back,but gauge is in the normal range,if i make a stop for any amount of time the gauge drops below normal range,,way below.thats while it has been idling ,I have 275 thousand on her and have never changed the stat,could that be the problem.THANKS
#41 of 79 coolant leak on backside on engine
Oct 27, 2008 (5:35 pm)
been awhile since i last posted..silverado 1500
5.3, 4wd just ovrheated..pulled over to check things out and added some water and it seems to be pouring out the backside of the engine..not dripping put a gallon in and its out in less then 30 seconds.....both sides,passenger and drivers side..tough to see but either its on the heads or just below on the block....havent done a freeze plug in 15 years..do they still have them on the back of the block ,,2 at once tho???
even if its a head gasket..both at once??
and my big question here is do blown head gaskets always leak into the oil to show that white filmy telltale sign...engine runs great..no skips or stalls..was only 2 miles from home so i filled it and drove away and the temp gauge went up then down and then blew warm heat then back to cold..
i'm an old timer and just like tinkering with 70's and pre 70's engines,would there be any other coolant lines on the backside of the engine that might cause the leak?
thanks for any help!!
#42 of 79 Re: coolant leak on backside on engine [kegabear]
Oct 28, 2008 (3:29 am)
#43 of 79 Re: coolant leak on backside on engine [obyone]
Oct 28, 2008 (5:07 pm)
doesnt seem to be leaking by the heater hoses that goes to the heater core if thats what you meant..got a better look today..seem to be coming in and all around the tranny bell housing..another post told me the block heater near the oil filter housing..dont have a block heater..are the freeze plugs on the block behind the bell housing? meaning the tranny has to come out?
#44 of 79 Re: coolant leak on backside on engine [kegabear]
Oct 29, 2008 (3:53 am)
There are two block drain plugs toward the left and right rear of the block that you could check. These are the plugs used when draining coolant from the block or to back flush.
#45 of 79 1999 GMC Yukon 5.7lt Intake Manifold Coolant Leak
Feb 11, 2009 (5:47 pm)
I have a 1999 Yukon 2WD with the 5.7 lt engine. There is cooloant leaking out of the intake manifold just behind the alternator. It is coming out of the gasket where the manifold mounts to the engine block. How hard of a project am I getting myself into? I am fairly competant and have worked on a lot of engines in the past when I used to buy/sell used cars. That was 15 years ago and now it looks very complicated. Could I be biting off more than i can chew? Are there any big "pit falls" I need to be aware of? I will not do it myslef if I have to disconnect A/C lines.
#46 of 79 Very Slow Coolant leak 2004 serria 5.3
Mar 16, 2009 (9:52 am)
I have no pressure at the expasion tank lid after driving till temp gauge reaches normal reading. I had to add about 3 quarts of Dex Coolant the other day. The level is still the same. I can't find any trace of a leak except slight smell at exhaust pipe. What are the pills someone mentioned sold by GM to stop leak? I don't want to pull intake gasket then both heads.
#47 of 79 1990 Silverado Radiator Oil Cooler Hose Fittings?
Mar 16, 2009 (5:34 pm)
The truck is a 5.7L 2WD with only 137K on it and I hope to keep it forever.
I recently disconnected and bypassed the oil cooler hoses from the radiator while troubleshooting a curious high oil pressure indication. When I went to reconnect the hoses I found the lower fitting on the radiator stripped (the radiator was replaced several years ago, too late to raise a warranty/installation issue).
The nut that threads into the radiator is fine.
My question is...is the female thread in the radiator an insert, sort of like a helicoil, or is the thread milled into the radiator body?
I'd really prefer to not have to put in another new radiator.
#48 of 79 Patching leakly heater core
Mar 27, 2009 (10:40 am)
I have a 1999 Sierra,small block v-8.
For several months,I have been smelling antifreeze,ever now and then seeing a small amount on the driveway.
Just the other day saw a leak from the heater core area by the hoses.
Not the hoses;but a small 90 ell shaped rubber hose.I think maybe a drain to release coolant mix if the heater core was leaking.
Has anyone seen this?Is there a way to stop a small leak?
Maybe some type of stop leak?
#49 of 79 '04 Silverado 5.3L "Invisible" Coolant Leak
Oct 11, 2009 (5:56 pm)
I have an '04 Silverado 5.3L with the same coolant leak mentioned in the forums. Pressure testing, both at cool and hot, revealed nothing. No visible leaks. Not a huge loss. The thought was a seeping head gasket. Coolant would just burn before showing up on the ground. Was going to try the GM pills referenced in the forums but cannot find anyplace to add them to the radiator. Any suggestions?