Coolant Leaking Into Engine

[dukbludvl]

My 2000 Yukon 5.3L with 203K miles is leaking coolant into the engine. I regularly have my oil tested and at first it was only about 0.25% antifreeze in the oil. About 6 months ago when this started, I had the engine pressure tested and there were no problems. They said they could tear down the engine and not find the problem, so they told me to keep an eye on it. Recently, I've had to start adding coolant more frequently, and my last oil test showed an increase to about 0.5%.

 

Any ideas on what the likely cause of this is... and ballpark on what it will cost to fix? Intake gaskets?

 

I'm keeping my oil change intervals at about 1,800 miles for now. The wear on the engine has been minimal to none, according to the oil tests. Please help!

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My 2000 Yukon 5.3L with 203K miles is leaking coolant into the engine. I regularly have my oil tested and at first it was only about 0.25% antifreeze in the oil. About 6 months ago when this started, I had the engine pressure tested and there were no problems. They said they could tear down the engine and not find the problem, so they told me to keep an eye on it. Recently, I've had to start adding coolant more frequently, and my last oil test showed an increase to about 0.5%.

 

Any ideas on what the likely cause of this is... and ballpark on what it will cost to fix? Intake gaskets?

 

I'm keeping my oil change intervals at about 1,800 miles for now. The wear on the engine has been minimal to none, according to the oil tests. Please help!

 

I'm pretty sure (certain) that the genIII lsx engine don't have anitfreeze running throught the intake, so intake won't help. I don't know where the leak would be, but if it was me, at .5% I wouldn't even worry about that amount of antifreeze in the oil. I would assume head gaskets as GM has many problems with Head gaskets and that red coolant they use. So, if you get it fixed, I recommend going to regular coolant and not that red junk.

[bossier62guy]

My 2000 Yukon 5.3L with 203K miles is leaking coolant into the engine. I regularly have my oil tested and at first it was only about 0.25% antifreeze in the oil. About 6 months ago when this started, I had the engine pressure tested and there were no problems. They said they could tear down the engine and not find the problem, so they told me to keep an eye on it. Recently, I've had to start adding coolant more frequently, and my last oil test showed an increase to about 0.5%.

 

Any ideas on what the likely cause of this is... and ballpark on what it will cost to fix? Intake gaskets?

 

I'm keeping my oil change intervals at about 1,800 miles for now. The wear on the engine has been minimal to none, according to the oil tests. Please help!

 

Do a search for "castech" heads.....that might be your problem but then again the TSB that I read on it says they weren't a problem until 01. If it were me I'd pull the valve covers and make sure you don't have them anyway.

[txab]

My 2000 Yukon 5.3L with 203K miles is leaking coolant into the engine. I regularly have my oil tested and at first it was only about 0.25% antifreeze in the oil. About 6 months ago when this started, I had the engine pressure tested and there were no problems. They said they could tear down the engine and not find the problem, so they told me to keep an eye on it. Recently, I've had to start adding coolant more frequently, and my last oil test showed an increase to about 0.5%.

 

Any ideas on what the likely cause of this is... and ballpark on what it will cost to fix? Intake gaskets?

 

I'm keeping my oil change intervals at about 1,800 miles for now. The wear on the engine has been minimal to none, according to the oil tests. Please help!

 

Do a search for "castech" heads.....that might be your problem but then again the TSB that I read on it says they weren't a problem until 01. If it were me I'd pull the valve covers and make sure you don't have them anyway.

 

 

Problem Castech heads or not. He could stll have a cracked head.

 

Sooner or later you're going to have to start pulling things apart to find/fix the problem.

[jro909]

My 2000 Yukon 5.3L with 203K miles is leaking coolant into the engine. I regularly have my oil tested and at first it was only about 0.25% antifreeze in the oil. About 6 months ago when this started, I had the engine pressure tested and there were no problems. They said they could tear down the engine and not find the problem, so they told me to keep an eye on it. Recently, I've had to start adding coolant more frequently, and my last oil test showed an increase to about 0.5%.

 

Any ideas on what the likely cause of this is... and ballpark on what it will cost to fix? Intake gaskets?

 

I'm keeping my oil change intervals at about 1,800 miles for now. The wear on the engine has been minimal to none, according to the oil tests. Please help!

 

I'm pretty sure (certain) that the genIII lsx engine don't have anitfreeze running throught the intake, so intake won't help. I don't know where the leak would be, but if it was me, at .5% I wouldn't even worry about that amount of antifreeze in the oil. I would assume head gaskets as GM has many problems with Head gaskets and that red coolant they use. So, if you get it fixed, I recommend going to regular coolant and not that red junk.

 

 

yes that red junk, your quite wrong... dex-cool is a great coolant, if you neglect to change it, it will bite you in the ass but if you maintain it and the system it flows through, it will not cause any problems....it got labeled as death cool because of the v6 intake gasket failures which if i remeber right were because the intake gasket design was shotty...if dex was so bad why would gm still be using it to this day? dex-cool type coolants are the way of the future, it has less of an impact on the enviroment to have a coolant last 150k then 70k like the green crap...people that run into problems will the coolant system are generally the guys that don't ever flush the system or change the fluid and it turns into hot fudge in the radiator or turns acidic....p.s not saying the OP neglected his system, i'm going with castech heads also

[gapost]

Might be a little early for the castech head problem, but still could be a bad head. You don't say if you have the dexcool or regular anti-freeze. You won't notice the dexcool in the oil like the regular. It generally turns into a black gunk and you can stick a screwdriver in your oilpan when you change your oil and see if there is black gunk in the bottom. (My 5.3 had so much gunk in the pan, it clogged up the drain hole). The best bet would be to pull the rocker covers and see if you see chocolate pudding in them.