What Would you do? Chevy 3.4

[azu]

Seems my 99 Olds Silhouette needs the intake manifold gaskets changed. Starting to see some moisture in the oil and losing a bit of coolant as well. Engine runs well with the usual piston slap. Engine is original with 172K and only work done was the very same gaskets changed at 50K. Van is still in good shape with no body rust but transmission is original and never worked on (except for fluid changes) but does have that occasional PCS problem. I won't be doing the repair, too many oddities that scare me. Is this engine worth saving or should I go with a junk yard one with lower miles?

[94SilverSSEi]

Well, you could have a shop do it. But doing it yourself will save a lot of money.

No harm in ripping it apart, yourself. I have heard they are more difficult than a 3800 intake but really it will be much EASIER and CHEAPER than replacing the whole engine.

Does that van have an oil pressure gauge? What does it read?

[azu]

Does that van have an oil pressure gauge?

No gauge, only a warning light. No indication of any pressure problems. I can see oil flowing through the oil fill.

[Saturn Simon]

I don't know how much you use the van, but are you certain the head gasket has gone?

I only ask because you say it is running well and there doesn't appear to be any oil pressure issues. You also say you are strating to see some moisture in the oil, which suggests it is only slight at this stage. I'd tentatively suggest that a small amount of moisture could just be condensation - especially if the van is infrequently used or mainly used for short journeys. A small amount of coolant loss could just be a small cooling system leak - a hose if you're lucky. Have you checked the cooling system thoroughly for leaks?

I would wait and see if it gets any worse first, then you can be certain it's the gasket. I'm no mechanic though, it's just a thought.

If it does get worse, and the gasket does need replacing. DIY if you can.

[allchargedup]

Something to consider. At least have someone do some troubleshooting so you can know for sure what you are up against. If it is the intake gasket going bad and you continue on without doing anything,
you run the risk of the moisture increasing and taking out the main and rod bearings and seizing the engine
completely. That takes away an option or two. Do some homework and fine out what the cost of each will be. I would base your decision on the expense aspect.

[MattStrike]

These engines will last if taken care of, our's made it to 400k miles with 3k oil changes (trans didn't, but that's another story) At this point, I would not suspect head gaskets given the LIM gaskets are a known issue. However, if you already have the aluminum framed gaskets then it's more likely that the head gaskets are a problem.
This can be done in vehicle, but I recommend removing the wiper assembly if you are having problems reaching around.

FYI, on a 3100 in a Grand Am, the best price I have seen for the LIM replacement is $900. In the minivan this jumps up to a premium because it takes longer and shops charge by the hour. This is a solid weekend job for a beginner, but the gaskets you need would be about $200, including head gaskets (last I checked anyway). The hardest part is getting the lower nut off the throttle body, but there's also a lot of stuff that's in the way.

The repair can be put off, but check the oil daily, until you start seeing the "milkshake" tan discoloration anywhere (look at the bottom of the oil cap...). Also check the coolant level daily because you don't want to overheat causing warped heads. If you can't go a full day without adding water/antifreeze, then the leak is significant enough to warrant repairs (before it leaves you stranded).

For the trans, I recommend installing a DIY shift kit. It should help with the PCS problems. I also recommend a trans cooler, the one in our Montana always seemed to run hot based on how long the fluid was(n't) lasting.

If you decide to replace the engine, do the trans at the same time. Everything has to come out either way, and if the van is in good shape it's worth a rebuild or two (or three).

[Jrs3800]

In all honesty if I had to deal with one again, I would unhook everything and roll the engine/sub frame out from under it and work on it that way... Do everything you can while its out too...lol

I would keep it and do the gaskets myself...

[azu]

These engines will last if taken care of, our's made it to 400k miles with 3k oil changes (trans didn't, but that's another story) At this point, I would not suspect head gaskets given the LIM gaskets are a known issue. However, if you already have the aluminum framed gaskets then it's more likely that the head gaskets are a problem.

Wow, 400K, awesome. I have a habit of checking the oil and filler cap weekly just because these are prone to the intake gasket issues. I know the ones the dealer did at 50K are not the new aluminum ones. Here is how this started.

One morning, single digits, I had to move the van from the street to my drive way as we had snow coming. Van made a lot of lifter noise/ piston slap which concerned me. I have had that piston slap at warm up for many many years and wasn't too loud but noticeabled until it warmed up in about 5 minutes. I checked the oil and it looks fine but had evidence of moisture because of film on the oil cap and PCV valve. Coolant in reservoir was low. I thought the worse but thought it might be low oil pressure even though light wasn't on. Van sits for or about 5 days. Then I unscrewed oil filter and emptied it and found nothing unusual. Placed it back on and cranked the engine over and ran for a few seconds. Still had that lifter noise. I took off oil filter and had oil in it which meant I had pressure. The oil however had an orange tinge to it, definitely not normal. I put a new oil filter on. I put a can of dry gas in tank and a gallon of premium gas in tank (tank was low). Started up the van and ran for a minute or so. Lifter noise slowly decreased in volume. I put a bottle of oil detergent (I believe it was made by Gunk) in. Restarted and ran for 10 minutes and lifter noise slowly went away. Checked oil and looks normal. The van has recently been used for a lot of short trips in the past 2 months since I changed the oil so that may be the cause. I have been checking the oil the day after each trip and everything looks ok. Big test will be Friday when I take it to work and put 100 miles on it. Thanks for all the tips everyone!

[allchargedup]

This is just my opinion and I may be way off, but I have only experienced problems using dry gas.
Maybe it was the type or brand. I have had much better results with using higher grade octane (93) and an ethanol specific treatment. I know this is slightly off your topic, but I do try to steer people away from using dry gas in the winter at all costs.

I hope you have a trouble free trip on Friday.