Hi Everyone

Have 1999 tahoe 4x4 5.7 Liter, Can smell anti-freeze but cannot find source.I have 152,000 miles on it. Also sometimes when i start it it sounds like I have a lifter stuck. But goes away in about 2 minutes. Thanks

are you loosing coolant (antifreeze)? More detail better than less.

Sorry Ketch New to site. Yes I am losing coolant.

Has the intake manifold gasket ever been replaced?

Very common on this your engine.

//2000CAYukon

Not that I know of. It would almost have to be that due to the fact I can't find where I'm losing the coolant. Would it be in rear of intake. Thanks for Info.

If its the intake gasket, its quite possible that its at the rear of the engine. Thats where most of them leak. It could also be the heater hose fitting leaking(front of the manifold on the passenger side), thats a pretty common leak also, but you said you cant find where the leak is coming from and that would be pretty obvious if you gave the engine a good looking over. It could also be a leaking water pump. Maybe you should get under the truck and see if you can see where the coolant is coming off at. My bet is that its probably a leaky gasket. It's almost a fact of life with these model engines that the gasket is going to start leaking at some point.

Thanks for input. I changed water pump about a year ago, The more I think about it it smells like it's going on to exhaust or engine block you really smell it when you get out after driving. Must be burning off as it leaks. Thanks People.

Another possible loss point is the heater valve, if it is used on your model. My '97 Tahoe has a valve that controls the amount of water flowing to the heater core. It is under the air filter housing on the passenger side wheel well.

Checked but thanks

tfoneal, sounds like intake gasket. My '99 is doing the same thing at 142k. Go to the parts store and get the Fel-pro set MS98000T. Probably going to cost you $200-300 in labor depending on who you get to do it. While they are doing it have them drill out the bottom of your distributor housing (TSB on it). This will let the housing drain out. Common problem causing premature cap failure.
As far as the cold start noise...probably piston slap. Mine does it to. So do all the ones that have similar milage. Very common. Just make sure you use a 5w-30 oil to get the better pumpability and just drive the sucker. You'll know when it's time! It can do this for many, many miles more.

I just replaced mine.And also had to replace the intake which you don't want to have to buy $697.00.Mine was leaking at the front at the water ports and running to the back of the engine.The problem with these gaskets breaking is that it is such a dreadful job i think that most people prolong the job and over time the coolant is eating away at the metal on the intake.

Another possible loss point is the heater valve, if it is used on your model. My '97 Tahoe has a valve that controls the amount of water flowing to the heater core. It is under the air filter housing on the passenger side wheel well.

Hey, mine is leaking there, what do you do to fix it? what did you buy?

Hey, mine is leaking there, what do you do to fix it? what did you buy?
Normally all you have to do is replace the intake gasket.....But mine had been leaking for some time i'm guessing.I had to replace the whole intake,the corrossion was so bad on the front of the intake,i was amazed it wasn't pouring out of the intake.I found out if you have one leaking it is best to go ahead and correct the problem before it does too much damage.The intake at the dealership is $697.00..The coolant usually leaks from the intake and runs down to the back side of the engine.

The intake at the dealership is $697.00...

That is an absurd price. Dorman sells that for around $80 (part #615-181). You can get it at most part stores. Also pick up the Fel-pro gasket for around $80 as well (part #MS98000T). This has the updated gasket and all the misc. gaskets you need as well as the valve cover gaskets.
Also have the tech punch out the two breather holes in the bottom of the distributor housing. This will keep the condensation from building up inside and causing premature cap and rotor failure (a common problem).
Just did mine two months ago after 141,000 miles. That and a full tune up with AC Delco plugs did the trick. Runs like a champ and got 18 mpg recently on a 750 mile trip (lots of cruise control driving!).