Newbie here and need advice based on mileage

[Scott Patrick]

I have an 05 tahoe 5.3l that my wife drives our kids around in. It's using about 3 quarts of coolant per month. I suspect it's the cracked head issue. It's got 180k+ on it and she drives about 30k miles a year. Should I replace engine or just heads? Vehicle is in pretty decent condition for the age. I would be doing the work with a buddy who has a lift thank God! Just wondering what would be the best option. I am a bit nervous with original trans to do an engine swap and bit nervous doing a head swap with possible bottom end damage from leak. It's been leaking into heads at least since we purchased in July. I'm sure you guys have some good advice and I'm ready to take it. Want to resolve the issue. ohh and she also has the heat cut in and out but I think that's just when fluid gets low. Usually is ok when I top it off.
Thanks all.
Scott

 

[Scottydoggs]

id just do the heads, and if the tranny feels ok and its fluid is still red ish, do a pan drop and new filter and top it off. like 4 qts or so depending on what trans pan you have.

sadly you'll need a milk crate to stand on more so then a lift on a head job. be nice for draining the oil and coolant and the trans service tho. might want to do all fluids while your under there, both rears and the t case.

 

[adriver]

You're not going to know until you pull the covers off.

What other steps have you taken to make sure its not something else?
What heads do you have?
180K is not HIGH mileage for engine or trans.

 

[Doubeleive]

3 QUARTS a month is a lot your oil would look like a milkshake, pull the oil fill cap off and look under the cap if it there is no milky residue there then your likely loosing coolant somewhere else.

 

[Scott Patrick]

I have the 706 castech heads. I have seen a white residue. Almost like a thin layer of jelly in a few spots around oil spout but truck doesn’t make oil or is it milky. Oil isn’t slushy either but It’s definitely no leaking that I can tell. I alsoa small oil leak started that appears to be rear main or oil pan. Can’t really tell where it’s leaking but that just started.

 

[Doubeleive]

I have the 706 castech heads. I have seen a white residue. Almost like a thin layer of jelly in a few spots around oil spout but truck doesn’t make oil or is it milky. Oil isn’t slushy either but It’s definitely no leaking that I can tell. I alsoa small oil leak started that appears to be rear main or oil pan. Can’t really tell where it’s leaking but that just started.

you can take it by a shop and have them do a test, I forget what it is called but they can take a sample of the coolant and see if it has carbon monoxide in it, you can probably just buy the kit and do it yourself as well, that will verify if the coolant and oil are mixing.

 

[dougo]

Scott
you are in sticky situation you don`t want this thing to die and leave the wife and kids stranded , Start by Pulling valve cover off if its white replace the engine, Then a pressure test followed by and exhaust gas leak test , Advance auto had tool loaner program , 05 and 06 engines are good but at 180 you may want to consider a replacement , Transmissions can be evaluated by a transmission shop to determine condition. I guess the question is the truck over all worth it or replace to My thought is if their are no other issues I would do the engine possible use search craigs list or just order a a new one the newer models are riddled with issues

 

[isp5190]

I have an 05 tahoe 5.3l that my wife drives our kids around in. It's using about 3 quarts of coolant per month. I suspect it's the cracked head issue. It's got 180k+ on it and she drives about 30k miles a year. Should I replace engine or just heads? Vehicle is in pretty decent condition for the age. I would be doing the work with a buddy who has a lift thank God! Just wondering what would be the best option. I am a bit nervous with original trans to do an engine swap and bit nervous doing a head swap with possible bottom end damage from leak. It's been leaking into heads at least since we purchased in July. I'm sure you guys have some good advice and I'm ready to take it. Want to resolve the issue. ohh and she also has the heat cut in and out but I think that's just when fluid gets low. Usually is ok when I top it off.
Thanks all.
Scott

My brother had the same problem with his 04 Tahoe. There is a service bulletin about if you change the coolant, water pump, t-stat, ect… to put some type of tablet in the coolant system. He got the tablets from the Chevy dealer and it took care of his problem.

 

[iamdub]

I have the 706 castech heads. I have seen a white residue. Almost like a thin layer of jelly in a few spots around oil spout but truck doesn’t make oil or is it milky. Oil isn’t slushy either but It’s definitely no leaking that I can tell. I alsoa small oil leak started that appears to be rear main or oil pan. Can’t really tell where it’s leaking but that just started.

If you have the Castech heads and it's losing coolant internally but doesn't appear to be in your oil, then it's probably leaking into the combustion chamber and burning off. Three quarts of coolant over 2,500 miles doesn't seem like enough to flood the engine and cause bearing damage, but it's still a serious issue and it will likely get worse. Replacing the heads is relatively cheap and easy and I'd do that just to eliminate that as a failure point, if it hasn't already failed. If this thing has been well-cared-for over that 180K, then it should still have plenty of life left in it. It'd be a shame to waste it over a few hundred bucks in heads and a Saturday in the garage.

 

[Doubeleive]

My brother had the same problem with his 04 Tahoe. There is a service bulletin about if you change the coolant, water pump, t-stat, ect… to put some type of tablet in the coolant system. He got the tablets from the Chevy dealer and it took care of his problem.

those tablets were made to seal up the systems on the Cadillacs but they use them whenever they can for anything else, you can just ask one of the service advisers for the cadillac tablets.