1998 Achieva Head Gaskets

[SteveG]

I am a newby here. My daughter is letting me change the head gaskets on her 1998 Olds Achieva 3100, and I have some quick questions.

1) Do you coat the head gaskets with sealant or put them in dry?
2) Should the head bolts always be replaced?
3) Do I need to put sealant, locktight, anit-seize on the head bolts?

Thank you in advance
Steve

[Carlspike]

No sealant is required on the head gaskets. I'm not sure if the bolts are required to be replaced but I definently would, it's cheap insurance. I believe just clean engine oil should be fine for the head bolts. Good luck and remember to keep the pushrods in order.

[IsaacHayes]

Why did the headgaskets go bad?

If you found leaky coolant in the oil/outside the motor, it's probably the Lower intake manifold gasket and not headgaskets.

LOTS of people mistake the headgaskets on these motors as being bad when it's really just the lower intake gasket. I don't know of any one who has found a bad headgasket yet.

[SteveG]

Here's the whole story:
- My daughter told me her car had been going thru anti-freeze like crazy and now would not start. She also said that when the car had run, the exhaust had been white.
- I found that the crankcase was WAY overfilled with a brown chocolate milk liquid
- This brown liquid was also coming out of the hose between the upper intake manifold and air filter.
- This brown liquid was everywhere!

When I got the lower intake manifold off, I noticed that the seal for the water passage to the head had failed, and that this was the real problem.

The reason I took the heads off were:
a) I had heard these engines were prone to head gasket failure between 150K and 175K miles. This car has 148K
b) This would give me a chance to clean this brown goo out of the combustion chanbers
c) I'm a glutton for punishment

[IsaacHayes]

Oh wow! Well yeah I'd say it's defiantly a headgasket!!! Holy cow!! White exhaust, and it oozing out of the throttle body into the air box is extreme!! haha

And the motor's bearings are probably seized up or at least shot with all that coolant in the engine oil. It's probably not worth it to mess with this motor. Best to get a new low mileage 3100/3400 and drop it in there. A 3400 would be a nice upgrade over the small port 3100 thats in there now too.

[SteveG]

Isaac - The engine isn't seized, but I also think the bearings are toast. I just hope we're wrong. I'm sending all the positive waves I can muster at it. I'll know in a day or so.

[Carlspike]

Might be a little late to ask since it sounds like you already started the job but was the engine knocking or making any funny noises the last time it ran?

[SteveG]

Carl - I don't know for sure, but I don't think so. It's my daughters car and she lives in another town, so I don't see her as often as I'd like.

I just finished putting the engine back together after changing the head gaskets. I took Carls advice on the head bolts. Thanks, Carl. It doesn't seem to have any main or rod bearing noise (yay), but it isn't running very well. Lifters clatter, engine won't idle, the power brakes have no assist.

I'm thinking the engine vacuum is very low.

I'm going to double check the rocker arm torque tomorrow. I'm hoping I messed that up and the valve adjustment is too loose.

Thanks
Steve

[CNCguy]

I just finished putting the engine back together after changing the head gaskets. I took Carls advice on the head bolts. Thanks, Carl. It doesn't seem to have any main or rod bearing noise (yay), but it isn't running very well. Lifters clatter, engine won't idle, the power brakes have no assist.

I'm thinking the engine vacuum is very low.

Thanks
Steve

I may be wrong but that sounds like it could be the symptoms of a bent intake valve. Hopefully, none of the pushrods got mixed up since the intake and exhaust pushrods are different lengths. If you don't find your problem soon, try doing a compression check on each cylinder. If one is extremely low, it could be a problem with the valves.

Keep us updated on your progress.

[Bowtie70SS]

You didn't leave off a vacuum line did you? If you have lifter noise that could also be a symptom of low oil pressure. When I installed the engine in my Monte Carlo I had to let it run for at least 10 minutes before everything was all quiet and good. When you rev it does it pop? Like someone said in the beginning DON"T MIX UP THE PUSHRODS.

Dave

[SteveG]

I'm pretty sure I put the push rods in correctly. When I took the engine apart, I used two egg cartons, one for each bank. I put the rocker arms where the eggs would go, and stuck the push rod thru the carton cover above the rocker. I put the push rod thru the egg carton cover so that the upper end of the push rod (the part that contacted the rocker arm) was sticking out of the cover above the rocker) I wanted to make sure I kept the rocker arms with the push rods, and the push rods installed right way up.

However, that being said, it will not hurt for me to double check. I obviously did something wrong, and I greatly appreciate the advice I am getting here.

I looked thru the 3100 Specifications but could not find the length for the push rods.

Do any of you happen to know what the lengths are?

Thank You
Steve

[bszopi]

Well, I can't find the actual lengths right off the bat, but I know the exhaust ones are longer. And I know at least the intake ones are less than 6" long.

[SteveG]

Thanks Brad. That helps. I will check that and make sure I didn't leave any vacuum lines off tonight.

I'm also working on a contingency plan, in case the engine is toast. I have a line on 3100 engines from a '92 and '96 Chevy.

Is there a place I can find out what engines will bolt right in? I would like to stay with the 3100 engine to minimize any fabrication.

Thank You
Steve

[Carlspike]

My book says pushrod lengths are 6 3/8" for exhaust and 6" for intake. However when I did my 96's heads I remember the exhausts being just barely over 6" and the intakes about 5 5/8". Whatever your lengths turn out to be the exhaust pushrods are the longer ones. A compression check would be a quick and easy way to see if you've misplaced a pushrod and bent a valve.

The rocker arms on a 98 should be the one piece kind that you just torque to spec, there is no adjusting. As long as there tight they should be fine.


As for the bad running, double check your vacuum lines again, especially the brake booster since you have no assist. If you don't have a diagram then try and get one. I do have one that is for a 96 I could e-mail you but it might not be exactly the same. Make sure all of your plug wires are on and all the connectors are plugged in, do you have a SES light? Also remember that if you disconnect the battery and don't do the idle re-learn procedure the car might not idle perfect for a while. Have you driven the car since the job has been done, if so how does it drive?

Hopefully it will turn out to be something simple. After a major job some lifter clatter can happen while they pump back up and oil circulates through the top end. But if the noise continues it could be a sign of bad bearings letting the top end starve of oil. Good luck.

[SteveG]

Just wanted to provide an update. I had the push rods in correctly, but a couple of the rocker arms were loose. I torqued them and the engine ran much better.

However, there is a bad engine knock and I fear the lower end is gone. I don't know yet what I'm going to do with it- crank kit, another used engine, or bag it all together and get another car.

I would like to thank everyone here for their help. This was my first journey into the 60 degree V6 realm and it was nice to have you here. I do alot of work on the old air cooled VW engines, and contribute to a forum devoted to them. Sometimes, after working on something for a long time, like I have with VW's, things can become second nature. Then I got this project and I suddenly realized that I knew NOTHING about these V6 engines. It was quite a wake up call.

Thanks again
Steve