98 Lumina with 3.1 V6 losing coolant?

[mstrjon32]

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Oh yeah- and the bolts come loose... especially the short ones in the corners. New locktited bolts from GM are fine. I've always just cleaned the old bolts and put red locktite on them- works fine, too... and is much cheaper than $4 per bolt at the stealer.

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x2, when doing this job I've put blue loctite on the bolts and reused them. Last time I did this the diagonal bolts that I removed had no torque at all, and could be turned and removed with two fingers...

IMO, the GM 60*V6 is an *excellent* engine if you can get past this problem. They will take a beating and keep on cranking. It's definitely a job you can tackle yourself in a weekend, provided you've got all the tools and parts at hand. The biggest slow-down with jobs like this is making trips to the store to buy things you forgot.

Remember to change the oil pump drive o-ring seal while you're in there, it will only take an additional 5 minutes and will save you future pain. Get it from the dealer, there is a revised design made from a different material that won't leak. I also agree with the guys saying go for FelPro problem solvers, good gaskets.

Also, remember, those push rods are different lengths, keep them in order or you'll be (very) sorry!

 

[onion]

Lemme repeat that... as I've seen posts on other message boards WAY too many times- along the lines of "changed the LIM gaskets and now I got a miss!"

KEEP THEM PUSHRODS IN ORDER. DO NOT UNDER ANY CIRCUMSTANCES CRANK THAT ENGINE UNLESS YOU'RE ABSOLUTELY SURE THAT ALL THE PUSHRODS ARE IN THEIR PROPER PLACE.

Sorry 'bout the yelling... but I've seen this time and again... a shop ruined my Mom's '96 Corsica that way back in 2000. It's for yer engine's own good.

 

[pbm]

Unfortunately we didn't change the oil pump drive o-ring seal (because I forgot to read 'onions' older posts which advised it right before doing the job). My friend had spoken to a GM mechanic friend and also had a 28 page instruction guide (from one of the paid subscription services) and neither recommended it. I regret not changing it but maybe my 2002 already has the 'revised' seal. What do you think?
PS: We didn't have to remove the oil pump while doing the gasket replacement.

 

[mstrjon32]

It is not necessary to remove the LIM to do the oil pump drive o-ring, I only recommended it since if you've got the LIM off its really easy to get to. If it starts to leak down the road, you won't have to remove the LIM in order to replace it, it will just be a tighter squeeze to get at it.

I'm not sure when the revised seal came out but if you're not leaking oil, don't worry about it. I only recommended it since you were already taking everything apart, and its another common leak for the 60*'s.

 

[m2200b]

If we're adding what to change while yout in there
since many of these are 10 years old - I do all the bypass hoses in the mix.

 

[onion]

My wife's '01 Lumina had the new style o-ring... so you're probably good to go. I wouldn't lose any sleep over it.

 

[pgc]

I started working on replacing the intake manifold gasket. I took out the air intake duct and I am now at the point of removing the throttle body. I was wondering if I should remove the accelerator cable and cruise control cable from the throttle body or if I can let them attached to the throttle body and remove the throttle body with them attached.

Thank you,
Paul

 

[onion]

You don't really need to remove the throttle body from the upper intake. Just disconnect everything from the throttle body and upper intake- unbolt the upper intake and remove them as one piece.

 

[mechanicx]

Yeah you do not have to remove the throttle body. Just unhook the cables at the throttle. You will need to take the sheet metal throttle cable bracket off the throttle body though. At least that's how I always had to do it. You do not have to remove the thermostat housing either.

 

[pgc]

I unhooked the cables and removed the bracket of the throttle body - it worked beautifully!

Now I am fighting the coolant bypass hoses on the throttle body. I sharpened a chop stick in a pencil sharpener and I dipped it in (olive) oil and also used olive oil cooking spray (my wife declared the can "no longer welcome in the kitchen") in order to loosen these coolant bypass hoses on the throttle body. Is there a better approach to removing these hoses? Shall I try to remove the end that is connected to the throttle body or the end that is connected to the coolant pipe? Which one is easier?

I should also disconnect the two fuel lines - any suggestion for the fuel line disconnect tools? (in Haynes they show a 3/8 and 5/16 fuel line disconnect tools - which one shall I get?).

Thank you,
Paul

 

[mechanicx]

Yeah those TB hoses are tough to get off. I don't know of any way that is easier, but the cvooking oil should help.

With the fuel line disconnects I'm thinking you will need a 3/8 but you might need both sizes, I'm not really sure. Usually I just unbolt the flare nuts from the fuel rail after taking the upper intake manifold off. They way the metal lines won't get tangled up. There is a nut on the engine holding the metal lines.

 

[Colt45ws]

You dont have to disconnect the fuel lines. I didnt when I just did the LIM on a 3400 in a Van. There was enough slack in the lines to just unbolt it and move it to the side.
I did remove it a couple months later when I redid it because it had blown a head gasket. They are two different sizes. The tool I used is one that has both sizes. Its made of metal and looks like an X if I open it up.

 

[mechanicx]

Yeah you don't have to disconnect the fuel lines. You can drape it off to the side. But then you have to remove the fuel injector rail from the manifold. You can actually change the lower IMG without removing the fuel rail from the manifold. It's not a bad idea to remove the fuel rail but it's not really necessary for the purposes to change the orings or because dirt might fall into the injectors while cleaning the manifold. It'll be OK if the car is low miles and you are careful.

There's all kinds of shortcuts you can take. There's the pushrod remover tool where you don't have to remove the alternator, coil packs and rear plug wires, and valve cover. That'd be a huge time saver but I haven't tried it.

 

[Colt45ws]

Originally Posted By: mechanicx
Yeah you don't have to disconnect the fuel lines. You can drape it off to the side. But then you have to remove the fuel injector rail from the manifold. You can actually change the lower IMG without removing the fuel rail from the manifold. It's not a bad idea to remove the fuel rail but it's not really necessary for the purposes to change the orings or because dirt might fall into the injectors while cleaning the manifold. It'll be OK if the car is low miles and you are careful.

There's all kinds of shortcuts you can take. There's the pushrod remover tool where you don't have to remove the alternator, coil packs and rear plug wires, and valve cover. That'd be a huge time saver but I haven't tried it.

I needed the room to work, so I removed it from the lower so I could get it out of the bay. I could see that working in car or something, however, yes..
Im assuming the tool is some sort of lever to open the valve enough to remove the pushrod? That would save a lot of time. On the van the alternator and bracket was probably one of the more time consuming parts of the job. Things right up against the firewall.

 

[mechanicx]

Yeah it's a lever tool that allows you to press the rockers up and remove the pushrods. Like you said it takes a lot of time removing the alternator and the mounting braket and all the assemblies related to removing the valve cover. Lisle has the tools and snap on has one too.

There are a couple tools to make the job much quicker.


pushrod remover

This tool makes removing and installing the lower intake bolts easier and faster than a crow's foot. Italso comes in 13mm so it should help with the pesky power steering pump mounting bolts.

swivel drive socket

 

[pgc]

I just removed all the 12 bolts of the upper intake manifold. The upper intake manifold is stuck to the engine. I used a rubber mallet to unstuck the manifold but it did not work. What else shall I try?

 

[pgc]

I removed all 12 bolts of the upper intake manifold. The manifold, however, would not move - it appears it is stuck. I used plastic mallet but it did not work. Any suggestions?

Thank you,
Paul

 

[Texan4Life]

gently use large flat screw drivers to pry a little. Thats what we did.

and yes some of the push rods have to come undone from the rocker. use the special tool or we used a 12 inch adjustable wrench to to grab them similar to the special tool and compress them. all you have to do is move the push rod to the side of the rocker and let it back down.

Of of curiosity were any of the LIM bolts loose?

Do you have a torque wrench and torque values? because the LIM only torque to 10 or 15 ft lbs. IIRC.

 

[pgc]

Thank you for your suggestion!

The bolts were not loose.

Yes, I have the a torque wrench and I also have the Service Manual for the car. So, I know the torque values.

Thank you, again.

Paul

 

[pgc]

I used a large flat screwdriver and pounded on it with a plastic mallet but the upper intake manifold did not move. Shall I keep pounding or shall I do something else?

Thank you,
Paul