dug through the forums for a thread about this, couldn't find anything. Is there a guide for reinstalling/ lashing the valves after doing head gaskets on the 3.4 Montes? I'm doing a really good job with this project so far and I'd hate to have to tear it back apart over some valve train noise, thanks guys.

 

Since you have a 2003 Monte, this must be the 3400 branded 3.4l engine.
Are you installing new valves or re-installing the old ones? If you are re-installing the old ones, there should be no magic to it. To my knowledge, just put them in, add a valve seal, compress the spring, reseat the spring with the cap/retainer and valve locks, decompress the spring and you are done.

One thing I will point out, in case you have not caught it, the push rods are different lengths for intake and exhaust valves. Be sure not to mix those up.

 

I mis-spoke a bit here, I meant to say that I am reinstalling the the rocker arms and pushrods. What I need to know is if the bolt that holds down the rocker has a torque spec, or if it is installed based on the gap between the rocker and the valve, I have not removed the valves from the head, thank you for the info though.

 

I checked the shop book and according that that, you just put the push rods in the correct positions (remember the length difference between intake and exhaust). Set the rocker down, bolt it up to 19 N·m (14 lb ft) plus an additional 30 degrees.

Now, see no mention on these bolts should be replaced due to torque to yield (which on the 3800, it is recommended). But I have re-used rocker bolts with no issues. Also, on the 3800 GM tells you to use a thread locker (aka LocTite), I don't see that recommendation on the 3400 (and with my experience with 3100 and 3400's, I don't recall ever using LocTite on the rocker bolts). They do recommend applying a special lubricant on certain parts (like tips of the push rods and the spots of the rockers that can have friction. I admit, I never bothered and the cars were fine, but it doesn't hurt anything if you decided you wanted to.

 

Awesome information thank you! One other question I've had, should I swap out for green or some other antifreeze? It seems like the dexcool had a big part to play in the demise of these head gaskets, as they were really rotten around the water jackets. These head gaskets lasted 19 years and 95k miles, with the last 55k accumulating over the last 4 years. My gasket set came with revised metal LIM gaskets, so those aren't a worry anymore.

 

I will tell you my opinion. Doesn't matter. The intake gaskets are horrible material regardless of coolant. My 1994 Grand Am with the 3100 (which is the same basic engine as your 3400, same block, just better air flow) never had Dex, usied green from the factory. I bought it used and personally had failed plastic intake gaskets twice (around 90k and then 180k, which I also did the head gaskets at 180k as they finally failed). Flip side, my friend owns a 1994 Formula Firebird since it was brand new, has less than 100k miles to this day, it came from the factory with Dex and Dex is all he has used, zero issues.

People CLING to the notion Dex is bad because GM lost a class action lawsuit in the late 90's. What people fail to notice, GM also reformulated Dex. Ask yourself this, if you lost a class action lawsuit and paid big money, would you honestly continue to follow a failed plan (running the risk of yet another class action lawsuit)? Now my black Monte Carlo with the 3800, which I bought from the original owner with over 200k miles. I changed the upper/lower intake gaskets on it. My friend (the original owner) states that he is pretty certain those were the original gaskets. I can tell you this, if they are, they were in way better shape AND no signs of coolant "sludge" compared to when I did the same work on my blue Monte when it had 60k miles. My friend that I got the black Monte from stated any time he had to re-fill coolant, he got the blue AC Delco DexCool and used distilled water if he had to dilute it. He claimed he read that the actual AC Delco dex differed from going to the store and buying Preston "with Dex". So this year, both my Montes got that treatment.

I also drive a 2004 Grand Am with the 3400 (so three cars that run dex, not including all my past vehicles and what they ran).

Personally, I believe it falls into maintenance. GM lures you in with the idea Dex cool is good for 10 years/100k miles. Personally, regardless if you use green or Dex, I would never run it that long. Drain it/flush the cooling system and refill from time to time. Maintenance is key.

Somewhere in this thread I shared pics of the gaskets and I believe comparison pics between my two Montes:
https://montecarloforum.com/forum/sh...k-monte-62826/

All this being said, I believe either option will suit you fine. If you switch to green and don't flush all the Dex out, your coolant will look an ugly brown color (but will still work just fine).

I hope that helps. And just know, you will run into others with different opinions. Take it as you wish.

 

Yours seems to be the most popular opinion on here, and I tend to agree with it, maintain your **** and it'll work well. At some point I'm probably due for a radiator swap because alot of sludge has probably built up in there. I've got the Peak brand flush system installed on my Monte so I'll take advantage of that more often. Is the blue dex from ac Delco compatible with the orange dex? I have a couple gallons of orange laying around that I got for free when my neighbor sold his cavi. Would be nice if I could mix the two.

 

When I said blue dex, I actually meant the bottle, sorry about that. This is what my friend used and I am now using:

In theory, I would think that can mix with any other manufacturer's version of dex. The key part is that there is a chance this AC Delco dex is formulated different from Prestone and other vendors. So that being said, if that is true, I am doubting you get the full benefit until most the system is all on the same formula. Just a guess. That being said, when I drained the coolant from my blue Monte this year, it was Prestone with Dex, I did not flush, just refilled with the AC Delco Dex (properly diluted with distilled water).

 

Great info! I'll probably just grab a couple bottles from the dealership and start fresh with that. If I flush the block, heater core/hoses, and radiator, how much water will be in the system, and how much water does it take to completely fill the system? It rarely goes below 10 degrees here, so I think I'm going to shoot for about 30% antifreeze, 70% water.

 

I'll second this having run multiple cars on dex and never having swapped a single one to a different coolant.

The thing that blows me away is how many people (even car people) just flat out ignore everything other fluid beyond engine oil. Even the generous 10/100k, they'll just blow right by that and never think about it until something goes wrong.