3.1 Intake Gasket bad

Two recent oil analyses on my mom's '01 Century with the 3.1 show very high levels of potassium which is an indication of either a head gasket or intake gasket problem. How likely is it that the head gasket is going? The highest potassium level on my GP 3.8 was 29 and the level on this one has gone from 122 on the first sample to 184 in 4000 miles. The car only has 52,000 miles on it. I'm afraid one of the gaskets is deteriorating rapidly and a gasket job is needed very soon. From what I have gleaned here it is most likely the intake, correct?

The intake manifold gaskets on the 3.1 are junk. Change the lower intake manifold gaskets and the problem should go away. If you think there may be a problem with the head gaskets do a compression check on the engine and see what you get. A bad head gasket would show low compression on one or more cylinders. But I still think the intake gasket is your culprit.

Two recent oil analyses on my mom's '01 Century with the 3.1 show very high levels of potassium which is an indication of either a head gasket or intake gasket problem. How likely is it that the head gasket is going? The highest potassium level on my GP 3.8 was 29 and the level on this one has gone from 122 on the first sample to 184 in 4000 miles. The car only has 52,000 miles on it. I'm afraid one of the gaskets is deteriorating rapidly and a gasket job is needed very soon. From what I have gleaned here it is most likely the intake, correct?
Gotta watch these oil analysis deals, they can be misleading, if you have a problem with the high potassium, then coolant would be mysteriously disappearing, certainly the lim gaskets are an issue with this engine though.

The intake manifold gaskets on the 3.1 are junk. Change the lower intake manifold gaskets and the problem should go away. If you think there may be a problem with the head gaskets do a compression check on the engine and see what you get. A bad head gasket would show low compression on one or more cylinders. But I still think the intake gasket is your culprit.
Thanks Dad. (I always wanted to say that--although I'm probably older than you.) Is this more complicated than the 3.8's?

No pretty straight forward. If you can change a 3.8 the 3.1 will be no problem.

Gotta watch these oil analysis deals, they can be misleading, if you have a problem with the high potassium, then coolant would be mysteriously disappearing, certainly the lim gaskets are an issue with this engine though.

Since the gaskets on this model are considered junk I'd rather be safe than sorry. I figure if I do the labor it should be less than $100 job. If the engine was ruined I'm sure it would be extremely expensive. My poor mother just got this thing paid off about two months ago and I'd hate to see it go south.

I've been searching but can't find a very good detailed procedure on the gasket replacement procedure. Anyone have a good link?

I've been searching but can't find a very good detailed procedure on the gasket replacement procedure. Anyone have a good link?

You think it might help to post an issue on a Buick Century in the right forum. Who knows maybe someone there might be able to help or maybe that link or info you need might mysteriously show up.

The mysteries of AF, gotta love them. The 3.1 is not much more difficult than the 3.8, but does require the removal of the pushrods, as the intake gasket goes under them. I've done a few of them (and the 3.4's) and have it down to about 4-1/2 hours (expect it to be a weekend job your first time), including changing the oil pump drive o-ring and t-stat while it's down.

The mysteries of AF, gotta love them. The 3.1 is not much more difficult than the 3.8, but does require the removal of the pushrods, as the intake gasket goes under them. I've done a few of them (and the 3.4's) and have it down to about 4-1/2 hours (expect it to be a weekend job your first time), including changing the oil pump drive o-ring and t-stat while it's down.

From what I gathered Rich he was looking for a more detailed procedure which is a lot of work but I have one someplace like maybe the Buick Century forum (hint) to include the TSB with the new intake manifold torquing sequence and specs. However, I will not post it here because it does a disservice to other similar car owners that are looking for similar information at that respective forum.

You think it might help to post an issue on a Buick Century in the right forum. Who knows maybe someone there might be able to help or maybe that link or info you need might mysteriously show up.
I figured a 3.1 was a 3.1 whether a Pontiac or Buick. I have visited over there and don't see many responses to a lot of questions. I see answers from as many people on the GP forum so I figured I might as well ask here. Maybe I was wrong.

I figured a 3.1 was a 3.1 whether a Pontiac or Buick. I have visited over there and don't see many responses to a lot of questions. I see answers from as many people on the GP forum so I figured I might as well ask here. Maybe I was wrong.

Thats not the data I have. 99% of questions on late model Centurys (97 and up) are answered at that forum. As a matter of fact a lot of them are answered by me and GTP Dad. It just doesn't have the traffic of the GP forum but there is a wealth of knowledge there. For example the best info on the 4T65E tranny and PCS problems on AF is there in old posts.

BTW - Where you post is your perogative.