Thank you and I am supposed to get my Blackstone report tomorrow which will confirm our thoughts. The little puddle of clear fluid above the bald spot is pure coolant so it is pretty certain at this stage but I can wait one more day for the oil analysis. Thanks I will keep posting here for the person who is in need.
2003 Tahoe coolant system leak or head gasket leak?
- Thread starter tomloans
- Start date
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PLEASE NOTE I STARTED A NEW THREAD TO ADDRESS THIS QUESTION TO EVERYONE HERE...
www.tahoeyukonforum.com
I thought starting a new thread would be good for those who are having similar issues.
But here is the notes ( bad news ) from Blackstone...
"There is coolant in this first sample. Potassium and sodium are markers for antifreeze in testing, and
both are high. Sodium could be oil additive depending on the brand of 5W/30 being run, but potassium has
few other sources than coolant. Bearing wear (seen at copper and lead) is high too. Note the levels of each
that the universal averages show as typical for the 5.3L Vortec after ~5,400 miles of oil use. Stick to short
oil change intervals (like this) and be alert for coolant loses and symptoms of a bearing problem like
knocking and low oil pressure. Proceed carefully."
Copper is 132 should be about 19 ( after 5400 miles and my oil only had 900 )
Lead is 81... should be about 5 ( after 5400 miles and my oil only had 900 )
Sooo... Do I replace the engine or replace the heads and hope bearing wear will stop and live happily ever after with this engine...?
I have no idea if the bearings will stop wearing out once I get the coolant out of the system. This is my question, will bearing wear stop once it has started? Anybody have any experience with this please...?
Rod bearing wear question
This is a new off topic thread started based on cracked Castech 706 head and coolant in the oil. That great discussion about 706 heads is noted here... https://www.tahoeyukonforum.com/threads/2003-tahoe-coolant-system-leak-or-head-gasket-leak.132246/ Here is the notes from Blackstone...
www.tahoeyukonforum.com
I thought starting a new thread would be good for those who are having similar issues.
But here is the notes ( bad news ) from Blackstone...
"There is coolant in this first sample. Potassium and sodium are markers for antifreeze in testing, and
both are high. Sodium could be oil additive depending on the brand of 5W/30 being run, but potassium has
few other sources than coolant. Bearing wear (seen at copper and lead) is high too. Note the levels of each
that the universal averages show as typical for the 5.3L Vortec after ~5,400 miles of oil use. Stick to short
oil change intervals (like this) and be alert for coolant loses and symptoms of a bearing problem like
knocking and low oil pressure. Proceed carefully."
Copper is 132 should be about 19 ( after 5400 miles and my oil only had 900 )
Lead is 81... should be about 5 ( after 5400 miles and my oil only had 900 )
Sooo... Do I replace the engine or replace the heads and hope bearing wear will stop and live happily ever after with this engine...?
I have no idea if the bearings will stop wearing out once I get the coolant out of the system. This is my question, will bearing wear stop once it has started? Anybody have any experience with this please...?
iamdub
Full Access Member
PLEASE NOTE I STARTED A NEW THREAD TO ADDRESS THIS QUESTION TO EVERYONE HERE...
Rod bearing wear question
This is a new off topic thread started based on cracked Castech 706 head and coolant in the oil. That great discussion about 706 heads is noted here... https://www.tahoeyukonforum.com/threads/2003-tahoe-coolant-system-leak-or-head-gasket-leak.132246/ Here is the notes from Blackstone...
I thought starting a new thread would be good for those who are having similar issues.
But here is the notes ( bad news ) from Blackstone...
"There is coolant in this first sample. Potassium and sodium are markers for antifreeze in testing, and
both are high. Sodium could be oil additive depending on the brand of 5W/30 being run, but potassium has
few other sources than coolant. Bearing wear (seen at copper and lead) is high too. Note the levels of each
that the universal averages show as typical for the 5.3L Vortec after ~5,400 miles of oil use. Stick to short
oil change intervals (like this) and be alert for coolant loses and symptoms of a bearing problem like
knocking and low oil pressure. Proceed carefully."
Copper is 132 should be about 19 ( after 5400 miles and my oil only had 900 )
Lead is 81... should be about 5 ( after 5400 miles and my oil only had 900 )
Sooo... Do I replace the engine or replace the heads and hope bearing wear will stop and live happily ever after with this engine...?
I have no idea if the bearings will stop wearing out once I get the coolant out of the system. This is my question, will bearing wear stop once it has started? Anybody have any experience with this please...?
I wrote out a long answer in that thread, but I didn't really answer the "will bearing wear stop" part. At least, not directly.
Technically, no wear ever "stops". New bearings have a thin surface layer (called the "babbitt"). It's really thin and often wears to begin showing hints of copper within a few thousand miles. The cam and all should ride on a film of oil. So, once you get the watered-down oil out, I expect the wear to return to a more normal rate.
Thanks. You and I are on the same page. I just purchased two 799 heads and the gaskets and bolts to replace everything below. Everything is about $1300.00 out the door including new bolts and all gaskets. This includes shaving the heads 0.20 to get them closer to the 706 heads. Not too bad. My labor is going to cost me about $40,000.00 but I am going to do it pro bono this time. LOL
Going to start tearing it down this weekend in anticipation. I am hoping that the wear was a one time event because I noticed a marked difference in coolant loss and some start up noise the last time I started it before I stopped everything. Hopefully a few oil changes later, I will run another Blackstone analysis and will all be well again. I need another 100K out of this SUV.
You have been really helpful and awesome. Thank you for your confidence and knowledge. I will post results as I get them. This is going to take some time. LOL
mattbta
Full Access Member
I had to do it twice. One of my refurb 706 heads cracked in 500 miles. You should be immune with the 799's.
With the intake and heads off, you'll have the opportunity to replace maintenance items like knock sensors/harness, valley cover gasket, cam sensor (if leaky), oil pressure sensor, coolant temp sensor, steam port gaskets, exhaust mani gaskets, intake gaskets.
I pulled the oil pan just for desludging (new gasket and o-ring for pickup tube) also did lifters/trays/bolts since I was in there. I only had to remove the passenger manifold entirely - left the DS in place.
Be sure and grab the coolant drain plug off the passenger head to re-use.
And I bought the ARP head bolt thread chasers - worked well.
Good luck and hit us up if you have questions.
Yes I am going to change all of these out. Have a gasket kit from Victor Heinz coming. Not going to drop the pan but everything else I have ready to go. Had a knock sensor go out already about a year ago. Rewired the bad one to the good one to trick the Chevy Computer so I can keep going. I have new ones ready to go and have the GM note on the silicon half circle for the knock sensor as well.
iamdub
Full Access Member
Just happy to be relevant!
iamdub
Full Access Member
I never understood building up a dam versus using sealant on the underside of the flaps. Maybe it's so they're more easily removable for servicing? I don't know. Maybe do both and be covered for anything.
iamdub
Full Access Member
It's easier and safer to leave the brake booster hose attached to the manifold and disconnect it from the booster.
You're gonna have to lift up on the wire harness and work the manifold forward, set it down, move the harness up and back some, set it down, lift and move the manifold forward, etc. and repeat until it's out. Or, if you can get enough slack, you can bungee the harness up to the cowl or wiper arm.
We'll address them wire nuts later. lol
I can't tell you how thankful I am for your input.
Watch that heater hose going into the light colored tee up by the firewall. It looks like it's coming loose from the quick-connect.
Tonyrodz
Resident Resident
Also they get brittle, and don't like to be pushed on, leaned on or moved too much. Ask me how I know lol.
Tonyrodz
Resident Resident
Did you use oem connectors?
mattbta
Full Access Member
Decades ago on my 99 30th Anniversary Trans AM (LS1/5.7), a popular mod was to put an LS6 intake manifold on. Everyone said, buy an Oil Pressure Sending Unit - you're going to break yours putting the intake on. 21 year old me was like, nah, I got this. I broke it. LOL.
For whatever reason, I haven't broken it on the Tahoe despite having the intake off numerous times. Regardless, if the sensor is original, I recommend having an OEM unit on hand to install. So much easier with all the stuff off the top.
For whatever reason, I haven't broken it on the Tahoe despite having the intake off numerous times. Regardless, if the sensor is original, I recommend having an OEM unit on hand to install. So much easier with all the stuff off the top.
Another one to consider for replacement is the cam position sensor that's right next to the oil pressure sending unit at the rear of the intake manifold. Mostly that is to avoid the potential oil leak from the cam position sensor sealing O-ring.
It's unfortunate that GM does not offer the O-ring seal by itself for replacement on the cam sensor and crank sensor for that matter, since those sensors rarely fail. The O-ring is more likely to allow an oil leak before the sensor itself goes out.
It's unfortunate that GM does not offer the O-ring seal by itself for replacement on the cam sensor and crank sensor for that matter, since those sensors rarely fail. The O-ring is more likely to allow an oil leak before the sensor itself goes out.
