I have a 2000 blazer. I noticed it would get low on coolant every two weeks or so. I just changed the oil to see if it was leaking inside the engine. It was; there was a milky substance on the oil cap and the oil that came out was very discolored. I'm not sure how to tell which gasket is leaking. I've heard the head gasket is pretty much not worth the trouble to replace. How do I tell which is leaking?

 

If its in the oil its probably but not always a head gasket. The easiest way to tell is to do a compression test on each cylinder use the results to decipher where you issue is likely located. Whether or not it is worth replacing is a matter of what kind of condition the rest of the vehicle is in. I just did head gaskets in my son's 98 a month or two ago and including all the gaskets (Upgraded Felpro only) and buying new(refurbished ready to bolt on) heads and all the misc things needed I only spent around $400 if I remember correctly and spent about 8-10 hours total here and there to complete the entire job. I spent time teaching my son how to do a little wrenching so I would say I could do it in less time but even taking your time and doing it yourself you will save a ton of money and get to learn something new while your doing it.

 

Thanks. I like to do the work myself. I've just never done this before. If it turns out to be the head gaskets is it true you need to get the heads ground down first?

 

Honestly if your going that deep you would be crazy not to have them refurbished and have peace of mind. I found it much cheaper not to mention quicker to buy a pair of heads online and I'd be happy to share a link if your interested. For $239 to my door for fully rebuilt heads with all new valve seals and everything it was a no brainer for me. I was worried about the risk of having a crack or something that would have cost me $90 to have the machine shop find only to have to buy a new head or two anyway.

 

Yes I would like that link, thanks

 

Aren't the intake gaskets what is prone to failure on these 1996-2004 Vortec V6s, leaking coolant into the oil? I would certainly investigate that first before tearing the heads off the vehicle. Head gaskets are not a trivial job, especially with the engine in vehicle. If you do decide to change head gaskets/heads with engine in place, start by making sure you can get both exhaust manifolds completely off the engine. That has to happen before you can unbolt the heads. Good luck.

 

Here is a link to the heads I bought and I can't say anything bad about them at all 4.3 GM CHEVY 140 / 772 CYLINDER HEADS V-6 VORTEC 1996 - 2001 - 262CI | eBay. They showed up in 3 days and work as they should!

Lesmyer is correct you should make sure you can get the exhaust off but for me I didn't care if the bolts came out or snapped off knowing I had new heads and fresh bolts and gaskets took that concern away for me. Luckily every bolt came right out without issue for me though.

 

I'd be a bit worried about the bearings already being toast . How long have you been adding coolant every couple of weeks?

 

Maybe around a month or so. It hasn't been a real long time.

 

Doesn't take long to wash out a set of bearings...... personally if u have been driving the trk for a month I wouldn't do more than change the intake gaskets....even that's debatable, seeing how it doesn't take long for those bearings to be ruined by antifreeze.......if it's a head gasket issue I wouldn't even bother making an attempt at fixing that motor, I would swap in a low mileage motor.....good luck